conduit, it shall be contained in the conduit with the ... - NFPA

conduit, i t shall be contained in the conduit with the circuit conductors. Fittings and boxes shall be bonded or grounded in accordance with Article 250. SUBSTANTIATION: There is a very pressing need for an NEC art icle to cover l iquidtight f lexible nonmetallic conduit for a growing number of present day applications. Such a product is being produced and has been used extensively in the machine tool industry and other related uses for the past eleven years. At the present time there is no NEC reference for this material.

I t may be agreed that the need for this article is such that i t might be adopted based on the known, widespread and successful use in industry of l iquidtight f lexible nonmetallic conduit. Once in the NEC, such a product would immediately come under the scrutiny of UL and would be required to meet the levels of safety now required for other metallic and nonmetallic raceways before being eligible for UL or equivalent l ist ing and for use wherever inspection under the NEC was required. 220-9 of NFPA #79 Electrical Standard for Met61working Machine Tools covers l iquidtight f lexible nonmetallic conduit and f i t t ings. E13.3.2 of EMP and EGP-I-1967 Joint Industrial Council Electrical Standard covers Nonmetallic Conduit¢

Attached* is literature on this material: (a) Anaconda Standard for Liquid Tight Flexible Nonmetallic

Electrical Conduit; latest revision 6/12/78. (b) Anaconda Bulletin S-550 (BED), pages $3 and $7. *Attachments have been supplied to ~MP members.

PANEL RECOMMENDATION: Accept as Revised:

ARTICLE XXX - Liquidtight Flexible Nonmetallic Conduit XXX-I. Scope. This article covers use and installation requirements for l iquidtight f lexible nonmetallic conduit for industrial application. XXX-2. Definition. Liquidtight f lexible nonmetallic conduit is a raceway of circular cross sectioh having a smooth seamless inner core and cover bonded together and having one or more reinforcement layers between the core and cover. This conduit is flame-resistant and with f i t t ings is approved for the installation of electrical conductors. XXX-3. Use.

(a) Liquidtight f lexible nonmetal)ic conduit shall be permitted to be used:

(1) i n exposed locations; (2) where f l e x i b i l i t y is required for installation,

operation or maintenance; (3) where protection of the contained conductors is

required from vapors, liquids or solids. (b) Liquidtight f lexible nonmetallic conduit shall not be

used: (1) where subject to ohysical damage; (2) where any combination of ambient and conductor

temperatures is In excess of that for which the l iquidtight f lexible nonmetallic conduit is approved;

(3) in lengths longer than 6 feet; Exception: where approved for special installations.

(4) where voltage of contained conductors is in excess of 600 volts, nominal. XXX-4. Size. The sizes of l iquidtight f lexible nonmetallic conduit shall be electrical trade sizes 1/2 inch to 1 1/2 inch inclusive. XXX-5. Nund}er of Conductors. The nuraber of conductors permitted in a single conduit shall be in accordance with the percentage f i l l specified in Table 1, Chapter 9. XXX-6. Fittings. Liquidtight f lexible nonmetallic conduit shall be used only with terminal f i t t ings identified for such use. XXX-7. Grounding. Where a grounding conductor is required for the circuits installed in l iquidtight f lexible nonmetallic conduit, i t shall be contained in the conduit with the circuit conductors. Fittings and boxes shall be bonded or grounded in accordance with Arti.cle 250. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

8RETING: We believe the use of this material has been limited for "connection to frequently moving parts" under the provisions of Section 210-5(e) of NFPA Standard No. 79. This possible additional use restriction needs further clari f ication.

ARTICLE 351 -- LIQUIDTIGHT FLEXIBLE METAL CONDUIT

351-7: Accept CMP 8 SUB)lITTER: TSC-Approved for the Purpose

137 See the Technical Subcommittee "Reco~ndations" un--n-d'e'r-~'~e definition of "Approved for the Purpose'" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOI~ENDATION: Accept as Revised:

Delete the words "approved for the purpose" and add "approved" !after the word "with." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

351-9: Accept C~ 8 SUBMII-FER: TSC-Approved for the Purpose

138 See the Technical Subcommittee "Recommendations" under the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definltion of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete the words "the purpose" and substitute "grounding." VOTE ON PANEL RECOF~4ENDATION: Unanimously Affirmative.

351-9, Exception: Accept ' CMP 8 SUBMITTER: TSC-Approved for the Purpose

139 See the Technical Subcommittee "Recnmmendations" un--n'de~-t'~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION/ See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOI~NIENDATION: Accept as Revised:

I Delete the words "the purpose ° and substitute "grounding." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

351-10: Accept CMP 8 SUBMITTER: Dan Leaf, Westlake Village, CA I)ITOIR~TAIZT. • 140 Delete words "in concealed work" from the t i t l e , an--n'B-t'F~e-word "concealed" from the text. SUBSTANTIATION: No restriction, per se, is placed on the maximum number of bends in exposed work. No limit on number of bends could result in de~nage to conductors, in a run with excessive number of bends, or could encourage instaliatlon of conductors prior to conduit installation, with conduit then installed as a cable system. A l imit on number of bends for exposed work would bring this section in conformity with the requirements for other raceway systems, such as 345-12, 346-11, 347-14, and 348-10. PANEL RECOI~ENDATION: Accept as Revised:

Delete "For concealed raceway" after the words "A run of conduit" and delete "in Concealed Work" from t i t l e . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 352 -- SURFACE RACEWAYS

352-I: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose ]~l~b-O-S'~-~. • 141 See the Technical Subcommittee "Recummendations" un--n-d'e-r-'t~e definition of "Approved for the Purpose u in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "unless approved for the purpose" and substitute "unless otherwise approved." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

352-1: Reject CMP 8 SUBMITTER: S. J. Casasant~, The Wiremold Co. ~ 1 4 2 Add the word "only" at the end .of the f i r s t

• ~ . Add new (1) as follows: (1) in damp locations; unless approved for the purpose. Renumber remainder of paragraph. SUBSTANTIATION: The present wording is being interpreted as permitting use of surface raceways in damp locations. The addition of the word only in the above proposal clari f ies that surface raceways are i~tended for use in dry locations only, unless approved for use in damp locations.

Panel 8 comment to Proposal No. 160, for the 1978 Code, "Product not considered suitable for damp locations," is offered as just i f icat ion for the above Woposal. PANEL RECO)~(ENDATION: Reject. PANEL C~ENT: No additional clari f ication would be achieved by this Proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

i

352-1: Reject CMP 8 SUBMITTER: O. E. Dillon, Border County Div. IAEI FR-O-~'O-~-L-~: 143 In the f i r s t sentence, add the word "only" after the word "permitted." In the second sentence (1), delete the word "severe." In the second sentence (2), add the words "there. are" after the word "where." SUBSTANTIATION: The language is permissive and does not restr ict the use of surface raceways. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COIC¢~ENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECO@~IENDATION: Unanimously Affirmative.

154

conduit, i t shall be contained in the conduit with the circuit conductors. Fittings and boxes shall be bonded or grounded in accordance with Article 250. SUBSTANTIATION: There is a very pressing need for an NEC art icle to cover l iquidtight f lexible nonmetallic conduit for a growing number of present day applications. Such a product is being produced and has been used extensively in the machine tool industry and other related uses for the past eleven years. At the present time there is no NEC reference for this material.

I t may be agreed that the need for this article is such that i t might be adopted based on the known, widespread and successful use in industry of l iquidtight f lexible nonmetallic conduit. Once in the NEC, such a product would immediately come under the scrutiny of UL and would be required to meet the levels of safety now required for other metallic and nonmetallic raceways before being eligible for UL or equivalent l ist ing and for use wherever inspection under the NEC was required. 220-9 of NFPA #79 Electrical Standard for Met61working Machine Tools covers l iquidtight f lexible nonmetallic conduit and f i t t ings. E13.3.2 of EMP and EGP-I-1967 Joint Industrial Council Electrical Standard covers Nonmetallic Conduit¢

Attached* is literature on this material: (a) Anaconda Standard for Liquid Tight Flexible Nonmetallic

Electrical Conduit; latest revision 6/12/78. (b) Anaconda Bulletin S-550 (BED), pages $3 and $7. *Attachments have been supplied to ~MP members.

PANEL RECOMMENDATION: Accept as Revised:

ARTICLE XXX - Liquidtight Flexible Nonmetallic Conduit XXX-I. Scope. This article covers use and installation requirements for l iquidtight f lexible nonmetallic conduit for industrial application. XXX-2. Definition. Liquidtight f lexible nonmetallic conduit is a raceway of circular cross sectioh having a smooth seamless inner core and cover bonded together and having one or more reinforcement layers between the core and cover. This conduit is flame-resistant and with f i t t ings is approved for the installation of electrical conductors. XXX-3. Use.

(a) Liquidtight f lexible nonmetal)ic conduit shall be permitted to be used:

(1) i n exposed locations; (2) where f l e x i b i l i t y is required for installation,

operation or maintenance; (3) where protection of the contained conductors is

required from vapors, liquids or solids. (b) Liquidtight f lexible nonmetallic conduit shall not be

used: (1) where subject to ohysical damage; (2) where any combination of ambient and conductor

temperatures is In excess of that for which the l iquidtight f lexible nonmetallic conduit is approved;

(3) in lengths longer than 6 feet; Exception: where approved for special installations.

(4) where voltage of contained conductors is in excess of 600 volts, nominal. XXX-4. Size. The sizes of l iquidtight f lexible nonmetallic conduit shall be electrical trade sizes 1/2 inch to 1 1/2 inch inclusive. XXX-5. Nund}er of Conductors. The nuraber of conductors permitted in a single conduit shall be in accordance with the percentage f i l l specified in Table 1, Chapter 9. XXX-6. Fittings. Liquidtight f lexible nonmetallic conduit shall be used only with terminal f i t t ings identified for such use. XXX-7. Grounding. Where a grounding conductor is required for the circuits installed in l iquidtight f lexible nonmetallic conduit, i t shall be contained in the conduit with the circuit conductors. Fittings and boxes shall be bonded or grounded in accordance with Arti.cle 250. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

8RETING: We believe the use of this material has been limited for "connection to frequently moving parts" under the provisions of Section 210-5(e) of NFPA Standard No. 79. This possible additional use restriction needs further clari f ication.

ARTICLE 351 -- LIQUIDTIGHT FLEXIBLE METAL CONDUIT

351-7: Accept CMP 8 SUB)lITTER: TSC-Approved for the Purpose

137 See the Technical Subcommittee "Reco~ndations" un--n-d'e'r-~'~e definition of "Approved for the Purpose'" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOI~ENDATION: Accept as Revised:

Delete the words "approved for the purpose" and add "approved" !after the word "with." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

351-9: Accept C~ 8 SUBMII-FER: TSC-Approved for the Purpose

138 See the Technical Subcommittee "Recommendations" under the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definltion of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete the words "the purpose" and substitute "grounding." VOTE ON PANEL RECOF~4ENDATION: Unanimously Affirmative.

351-9, Exception: Accept ' CMP 8 SUBMITTER: TSC-Approved for the Purpose

139 See the Technical Subcommittee "Recnmmendations" un--n'de~-t'~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION/ See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOI~NIENDATION: Accept as Revised:

I Delete the words "the purpose ° and substitute "grounding." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

351-10: Accept CMP 8 SUBMITTER: Dan Leaf, Westlake Village, CA I)ITOIR~TAIZT. • 140 Delete words "in concealed work" from the t i t l e , an--n'B-t'F~e-word "concealed" from the text. SUBSTANTIATION: No restriction, per se, is placed on the maximum number of bends in exposed work. No limit on number of bends could result in de~nage to conductors, in a run with excessive number of bends, or could encourage instaliatlon of conductors prior to conduit installation, with conduit then installed as a cable system. A l imit on number of bends for exposed work would bring this section in conformity with the requirements for other raceway systems, such as 345-12, 346-11, 347-14, and 348-10. PANEL RECOI~ENDATION: Accept as Revised:

Delete "For concealed raceway" after the words "A run of conduit" and delete "in Concealed Work" from t i t l e . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 352 -- SURFACE RACEWAYS

352-I: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose ]~l~b-O-S'~-~. • 141 See the Technical Subcommittee "Recummendations" un--n-d'e-r-'t~e definition of "Approved for the Purpose u in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "unless approved for the purpose" and substitute "unless otherwise approved." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

352-1: Reject CMP 8 SUBMITTER: S. J. Casasant~, The Wiremold Co. ~ 1 4 2 Add the word "only" at the end .of the f i r s t

• ~ . Add new (1) as follows: (1) in damp locations; unless approved for the purpose. Renumber remainder of paragraph. SUBSTANTIATION: The present wording is being interpreted as permitting use of surface raceways in damp locations. The addition of the word only in the above proposal clari f ies that surface raceways are i~tended for use in dry locations only, unless approved for use in damp locations.

Panel 8 comment to Proposal No. 160, for the 1978 Code, "Product not considered suitable for damp locations," is offered as just i f icat ion for the above Woposal. PANEL RECO)~(ENDATION: Reject. PANEL C~ENT: No additional clari f ication would be achieved by this Proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

i

352-1: Reject CMP 8 SUBMITTER: O. E. Dillon, Border County Div. IAEI FR-O-~'O-~-L-~: 143 In the f i r s t sentence, add the word "only" after the word "permitted." In the second sentence (1), delete the word "severe." In the second sentence (2), add the words "there. are" after the word "where." SUBSTANTIATION: The language is permissive and does not restr ict the use of surface raceways. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COIC¢~ENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECO@~IENDATION: Unanimously Affirmative.

154

352-1, Exception No. 1: Accept CMA ° 8 SUBMITTER: TSC-Approved for the Purpose

144 See the Technical Subcommittee "Recommendations" un-"6Be'r--t-f~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOI~ENDATION: ~ccept as Revised:

Delete the words "approved for the purpose" and add at the end of the exception: "where identified for such use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

352-8: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose

145 See the Technical Subcommittee "Recommendations" definition of "Approved for the Purpose" in Article

100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECO~ENDATION: Accept as Revised: • "Delete the words "approved for the purpose for'which they are used" and add the words "identified for such use." VOTE ON PANEL REC~NDATION: Unanimously Affirmative.

352-22: Accept OMP 8 SUBMITTER: TSC-Approved for the Purpose

146 See the Technical Subcommittee "Recommendations" ' uncler the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "flndlngs" under the definition of "Approved .for the Purpose" in Article 100. PANEL RECO~ENDATION: Accept as Revised:

Delete the words "unless approved for the purpose." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

352-22: Reject CMP 8 SUBMITTER: O. E. Dillon, Border County Div. IAEI PRUPUSAL: 147 In the f i r s t sentence, add the word "only" after

"permitted." In the second sentence (2), delete the word "severe." SUBSTANTIATION: The .language is permissive and does not restr ict the use of nonmetallic surface raceways. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for llO-16(a). PANEL RECO~g~ENDATION: Reject. PANEL COMMENT:' The present wording adequately reflects the Panel's Intent. VOTE ON PANEL RECO~iENDATION: Unanimously Affirmative.

restr ict the use of underfloor raceways. See the attached op lnion* of the San Diego City Attorney. • *See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECO~ENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the P'Enel's Intent. VOTE ON PANEL RECOMMENDATION: Unanimously Aff irmative.

354-15: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose PKUPOSAL: 151 See the Technical Subcommittee "Recommendations" un--n-d'e~-ElTe definitli)n of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. P.A.NEL RECOMMENDATION: Accept as Revised:

J Delete the words "approved for the purpose" and add "approved" before the word " f i t t ings." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

r

ARTICLE 356 -- CELLULAR METAL FLOOR RACEWAYS

356-1: Reject CMP 8 SUBMITTER: Charles T. Flachbarth, Walker Parkersburg Division ~ n c . PROPOSAL: 152 Add a second sentence as follows: "-"l~-6F'-Ehe purposes of this art icle, a cellular metal floor consists of the entire floor area being covered with cellular metal floor sections or a combination of cellular metal f loor raceway sections and corrugated metal deck sections." SUBSTANTIATION In some building designs, there is confusion '~egarding when a cellular metal floor raceway system as described in Article 356 can be used, compared with an underfloor raceway system as described in Article 354 can be used. This proposed change wil l eliminate confusion regarding when Article 356 applies or when Article 354 applies, without changing the intention of the Code regarding the use of cellular metal floor raceways or underfloor raceway systems. PANEL RECOI~MENDATION: Reject. FANEL COMMENT: No additional clari f ication would be achieved by th is Proposal. VOTE ON PANEL RECOMMENDATION: i .

AFFIRMATIVE: 14. 'NEGATIVE: Breting.

EXPLANATION OF VOTE: "'BREIIN6: Whlle Installation instructions are supplied by the manufacturer covering the intended floor construction, this proposal would provide clarif ication to those who may not have access to these instructions.

ARTICLE 353 -- MULTIOUTLET ASSEMBLY

353-2: Reject CMP 8 SUBMITTER: O. E. Dillon, Border County Div. IAEI

148 In the f i r s t sentence, add the word "only" after "permitted." In the second sentence (2), delete the

word "severe." SUBSTANTIATION: The language is permissive and does not restr ict the use of multloutlet assemblies. See the attached opinion* of the San Diego City Attorney. ,

*See Border County Div. IAEI substantiation for proposal for 110~16(a). PANEL RECOMMENDATION: Reject. PANEL CDMMENT:' The present wording adequately reflects the Fanel's Intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

353-2: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose I~TOPI~L-~.. 149 See the Technical Subco~ittee "Recommendations" un--6"d~-F-tT~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the wOrds "unless approved for the purpose.". VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

t ARTICLE 354 -- UNDERFLOOR RACEWAYS

354-2: Reject CMP 8 SUBMITTER: O. E. Dillon, Border County Div. IAE'I

150 In the f i r s t sentence, add the word "only" after "permitted." In the third sentence, delete the word

"severe." SUBSTANTIATION: The language is permissive and does not

356-11: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose PITOFOS'AL-T." 153 See the Technical Subcommittee "Recommendations" un--n'de'r-~-~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Arti~:le 100. PANEL RECO~ENDATION: Accept as Revised: .... Delete the words "approved for the purpose" and add the word "approved" before the word " f i t t ings." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

356-12-(New): Reject CMP 8 SUBMITTER: R. S. Pinkerton, Los Angeles, CA

154 Change the, present Section 356-12 to 356-13 and ~dd a new 356-12 (under Part A) as follows: 356-12. Aligning and Sealing. Cellular metal floor raceways shall be so Installed that all sections which are used as . raceways for conductors are aligoed and joined to p~ovide a smooth raceway free of sharp edges or foreign materials. Raceway Joints shall be sealed to prevent the entrance of water and concrete mix as soon as possible after the ducts are secured in place. SUBSTANTIATION: The ends of adjoining sections of cellular metal floor raceways must be lined up to prevent insulation damage during the wire pulling process.. The design of cellular metal floor'does not assure alignment and there are no specific Code requirements for such an alignment. Accordingly, this has caused problems in enforcement. Also, the joints must be taped or sealed to prevent the entrance of water or concrete which obviously can damage the conductor insulation when branch circuits are installed. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is prlmarily a design consideration. V'dTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 14. NEGATIVE: Young.

155
















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155
















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155
















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155

EXPLANATION OF VOTE: YOUNG: The Code is not considered to be a design standard but

in my opinion to require a product to be properly protected from damage through transit and installation is not a design requirement.

356-12-(New): Reject CMP 8 SUBMITTER: Southwestern Section IAEI I~ROP-O-S'AI~-~. • 155 Change the present Section 356-12 to 356-13 and ~ w 356-12 (under part A) to read: 356-12. Aligning and Sealing. Cellular metal floor raceways shall be so installed that all sections which are used as raceways for conductors are aligned and joined to provide a smooth raceway free of sharp edges or foreign materials. Raceway joints shall be sealed to prevent the entrance of water

,and concrete mix as soon as possible after the ducts are secured in place. SUBSTANTIATION: The ends of adjoining sections of, cellular metal floor raceways must be lined up to prevent insulation damage during the wire pulling process. The design of cellular metal floor does not assure alignment and there are no specific Code requirements for such an alignment. Accordingly, this has caused problems in enforcement. Also the Joints must be taped or sealed to prevent the entrance of water or concrete which obviously can damage the conductor insulation when branch circuits are installed. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primaril~ a design consideration. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: YOUNG: See comments for Proposal No. 154.

ARTICLE 358 -- CELLULAR CONCRETE FLOOR P, ACEWAYS

358-4: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose !sI~3~-AL-~. " 156 See the Technical Subcommittee "Recommendations" unOer the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" unde~ the definition of "Approved for the Purpose" in Article 100; PANEL RECOMMENDATION: Accept as Revised:

Delete the words "approved for the purpose" and add "approved" before the word "f i t t ings~". VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

358-12-(New): Reject CMP 8 SUBMII-rER: R. S. Pinkerton, Los Angeles, CA

157 Add a •new section as follows: ~'3~r~I-2"7-. Aligning and Sealing. Cellular concrete floor raceways shall be so installed that all sections used as raceways for conductors are aligned and joined to provide a smooth raceway free of sharp edges or foreign materials. Raceway Joints shall be sealed to prevent the entrance of water and concrete mix as soon as possible after the ducts are secured in place. SUBSTANTIATION: The ends of adjoining sections of cellular concrete floor raceway must be lined up to prevent insulation damage during the wire pulling process. The design of cellular concrete floor raceway does not assure alignment and there are no specific Code requirements for such'an alignment. Accordingly, this has caused problems in enforcement. Also, the joints must be taped or sealed to prevent the entrance of water or concrete which obviously can damage the conductor insulation when branch circuits are installed. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primarily a design consideration. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

358-12-(New): Reject CMP 8 SUBMITTER: Southwestern Section IAEI PROPOSAL: 158 ~rS"l~'1-'~T-.Aligning and Sealing. Cellular concrete floor raceways shall be so installed that all sections used as raceways for conductors are aligned and Joined to provide a smooth raceway free of sharp edges or foreign materials. Raceway Joints shall be sealed to prevent the entrance of water and concrete mix as soon as possible after the ducts are secured in place. SUBSTANTIATION: The ends of adjoining section of cellular concrete floor raceway must be lined up to prevent insulation damage during the wire pulling process. The design of cellular concrete floor raceways does not assure alignment and there are no specific Code requirements for such an alignment. Accordingly, this has caused problems in enforcement. Also, the joints must be taped or sealed to prevent the entrance ~f water or concrete which obviously can damage the conductor insulation when branch circuits are installed. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primarily a design consideration. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 362 -- WIREWAYS

362-5: Accept CMP 8 SUBMITTER: CMP 8 PROPOSAL: 158A Revise section to read as follows: Wireways ~ t contain more than 30 current-carrying conductors at any cross section. Conductors for signaling circuits or controller conductors between a motor and its starter and used only for starting duty shall not be considered as current- carrying conductors.

The sum~o~ the cross-sectional areas of all contained conductors at any cross section of the wireway shall not exceed 20 percent of the interior cross-sectional area of the wireway.

The derating factors specified in Note 8 to Tables 310-16 through 310-19 shall not be applicable to the 30 L current-carrying conductors at 20 percent f i l ] specified above.

Exception No. l: Where the derating factors specified in Note 8 of Table 3]0-]6 through 310-19 are applied, the number of current-carrying conductors shall not be limited but the sum of the cross-sectional area of all contained conductors at any cross section of the wireway shall not e~ceed 20 percent of the interior cross-sectlonal area of the wireway.

Exception No. 2: As provided in Section 520-5, the 30 conductor limitation does not apply for theaters and similar locations.

Exception No. 3: As provided in Section 620-32, the 20 percent f i l l limitation does not apply for elevators and dumbwaiters. SUBSTANTIATION: Clarificat!on. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

362-5: Reject CMP 8 S U B M I T ~ 8 PROPOSAL: 15BB Revise section to read as follows: The number ~ c t o r s permitted in a wireway shall be such that the sum of the cross-sectional area of the contained conductors shall not exceed 20 percent f i l l of the wireway. The deratihg factors specified in Note 8 of Tables 310-16 through 310-19 shall not be applicable to the current-carrying conductors in wireways.

Exception: As provided in Section 620-32, the 20 percent f i l l limitation does not apply for elevators and dumbwaiters. SUBSTANTIATION: Clarif ication. PANEL MECOMMEMDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 158A. VOlt UN PANEL RECOM~MENDATION: Unanimously Aff irmative./

362-10: Accept . CMP 8 SUBMITTER: H. F. van der Vonrt Cleveland, Ohio I~TOIIO'S'AL-~. • 15g Insert: "r igid nonmetallic conduit" after ~ d i a t e n~tal conduit." Then add new sentence at end of section to read: "Where rigid nonmetallic conduit is used, connection of equipment grounding conductors in the rigid nonmetalllc~condult to the wireway shall comply with Sections 250-113 and 250-118." SUBSTANTIATION: This use of rigid nonmetallic conduit is now acceptable under Article 347. The change in Article 362 wil l bring i t into conformity with other parts of the Code. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

362-11-(New): Reject CMP 8 SUBMII'TER: R. S. Pinkerton, Los Angeles, CA

160 Add a new section as follows: ~ . . Posltion. Wi~eways may be installed wlth the cover face in a downward position provided suitable supports for conductors are installed therein at points not more than 3 f e e t apart. SUBSTANTIATION: In the definition of a wireway In Section 362-1 appears the statement "In which conductors are laid in place after the wireway has beeh installed." Thls In~)lies and has been interpreted ~o n~an that wireways must be installed with the cover on the'side or top for conductors to be laid in place. But in many applications, this is an impracticle position. Where conductors have sultable Insulatlng supports, they can be positioned in a wireway with the cpver facing down without danger of damaging the conductor insulation. This provision has been permitted in the City of Los Angeles for many years with no reported failures. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Such practice is not prohibited by present Code. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

362-12-(New): Reject CMI ~ 8 SUBMITTER: R. S. Pinkerton, Los Angeles, CA PROPOSAL: 161 Add a new section as follows: ~'~-~T~-.Working Space. At least 12 inches of working space shall be provided between the cover of a wireway and walls, ceilings or similar obstructions. SUBSTANTIATION: The intent of this requirement is to provide a safe work environment for electricians who wil l be performing maintenance work or making additions to existing wireway

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156

installations. Maintenance electricians should have sufficient workspace in front of a wireway that they can look inside and examine the. condition of conductor insulation for splice Insulation before pulling wires out of a wireway. Experience has shown'that conductor's insulation does become damaged and the insulation on splices can open up Which can present a severe shock hazard to people who reach into the wiroway while working "blind". A 12 Inch minimum working space is a reasonable and practical dimension and wil l greatly enhance safe working conditions for maintenance electricians. PANEL RECOI~MENDATION: Reject. PANEL COMMENT: Already covered by Section llO-16. volt uN PANEL RECO~WIENDATION: Unanimously Affirmative.

362-12-(New): Reject CMP 8 SUBMIl-rER: Southwestern Section IAEI

162 Position. Wiroways may be installed with the cover

face in a downward position provided suitable supports for conductors are installed therein at points not more than three feet apart. SUBSTANTIATION: in the definition of a wlreway in Section 362-i appears the statement "inwhich conductors are laid in place after the wireway has been installed." This implies and has been interpreted to mean that wireways must be installed with the cover on the side or top for conductors to be laid in place. But in many applications, this is an impractical position. Where conductors have suitable insulating supports, they can be positioned in a wireway with the cover facing down without danger of ,damaging the conductor insulation. This provision has been permitted in the City of Los Angeles for many years with no reported failures. PANEL RECOf~4ENDATION: Reject. PANEL CO,WENT: Such practice is not prohibited by present Code. VOTE ON PANEL RECO~4ENDATION: Unanimously Affirmative.

362-13-(New): Reject CMP 8 SUBMITTER: Southwestern Section IAEI ]~TOI~O~TAI--~. • 163 ~3~"~[~-.Working Space. At least 12 inches of working space shall be provided between the cover of a wiroway and walls,, ceilings or similar obstructions. SUBSTANTIATION: The intent of this requirement is to provide a Safe work environment for electricians wi~o will be performing maintenance work or making additions to existing wireway installations. Maintenance electricians should have sufficient workspace in front of a wiroway that they can look inside and ekamine the condition of conductor Insulation for splice insulation before pulling wires out of a wireway. Experience has shown that conductor's insulatlon does become damaged and

-the insulation on splices can open up which can present a severe shock hazard to people who reach into the wireway while working 'bl ind'. A twelve inch minimum working space is a reasonable and practical dimension and will greatly enhance safe working conditions for maintenance electricians. PANEL RECO~ENDATION: Reject. PANEL COf~ENT: Already covered by Section llO-16. VOtE ON PANEL RECOMMENDATION: Unanimously Affirmative.

364-5, Exception No. 2: Reject CMP 8 SUBMII"rER: TSC-Approved for the Purpose PROPDSAL: 166 See the Technical Subcommittee "Recammendations" un--B-d-~-~--tITe definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the clefinitlon of "Approved for the Purpose" in Article 100. PANEL RECOf~IENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 165. VOTE ON PANEL RECO~ENDATION: Unanimously Affirmative.

364-8: Accept CMP 8 SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.

IPRUPO~AL: 167 Add a sentence as follows: ~ l e cord assembly connections may be made directly to the =load end terminals of a busway plug-ln device, providing the connection includes a suitable tension take-up device on the cord. SUBSTANTIATION: Section 364-8 l ists eight types of equipment permitted for connection to busway but contains no guidelines for the make-up of such connections. In the case of cord assembly connections to busway plug-in devices, seekers of guidance may be drawn to 400-7(b). This paragraph is aimed primarily at fixed location connections and requires a receptacle outlet on the power supply plus an attachment plug on the cord.

Minimizes the possibility of unnecessary components being incorporated in the connection. PANEL RECO~ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

364-8: Accept CMP SUBMITTER: H. F. van der Voort, Cleveland, Ohio ~KUPU3AL: 168 Add "rigid nonmetallic conduit" after ~ d i a t e , m e t a l conduit." Then add now sentence at end of section,to read: "Where rigid nonmetallic conduit is used, connection of equipment grounding conductors in the rigid nonmetallic conduit to the wireway shall comply with Sections 250-113 and 250-118." SUBSTANTIATION: This use of rigid nonmetallic conduit is' now acceptable under Article 347. The change in Article 364 wil l bring i t into conformity with other parts of the Code. PANEL RECO~V~4ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

364L12: Reject CMP 8 SUBMITTER: David J. Snitzer, City of Los Angeles Code Advisory

PROPOSAL: 169 Add note as follows: ~ O v e r c u r r e n t devices on busways shall be installed in accordancewith the requirements of Section 380-8. SUBSTANTIATION: Clarification. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The cross reference is redundant. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 364 -- BUSWAYS

364-4(b): Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose I}ITOI~-~. • 164 See the Technical Subcommittee "Reco~nendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete the words "unless specifically approved for the purpose" and add "unless identified for such use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

364-5, Exception No. 1: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose ?ITOI~S'AL-~: 165 See the Technical Subcommittee "Reco~vnendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC."findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Revise 364-5 of the NEC as follows: "Busways shall be securely supported at intervals not exceeding 5 feet unless otherwise designed and marked." Delete Exception Nos. I and 2. VOTE ON PANEL RECOMI~IENDATION:' Unanimously Affirmative.

364-12, FPN-(New): Reject SUBMII-fER: Southwestern Section IAEI HRUPU3AL: 170 Fine Print Note.

~ r r e n t devices on busways shall be installed in accordance,with the requirements of Section 3~-8. SUBSTANTIATION: Clarification. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel Action on Proposal No. 169. VOTE ON PANEL RECOF~IENDATION: Unanimously Affirmative.

CMP 8

ARTICLE 365 -- CABLEBUS

365-2: Accept CMP 8 SUBMITTER: TSC-Approved for the Purpose HRUPU~AL: 171 See the Technical Subcofm~Ittee "Recommendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "approved for the purpose" and substitute "identified for such use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

365-8: Accept CMP ,8 SUBMITTER: TSC-Approved for the Purpose ]~l~-OIIiS-S~i~l~-~. • 172 See the Technical Subcommittee "Recommendations" under the definition of "Approved for the Purpose" in Article 100.

157

ARTICLE 363 -- FLAT CABLE ASSEMBLIES

363-i: Accept ~ CMP 7 SUBMITTER: TSC-Approved for the Purpose !bl~rOl~'X~-T. • 117 See the Tecl~nical Subcommittee "Reco~endations"

definition of "Approved for the Purpose" in Article 100, SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete "approved for the purpose." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

/ 363:4: Accept CMP 7 SUBMITTER: TSC-Approved for the Purpose l}ITOl~'AIL-~. • 118 See the Technical Subcommittee "Recommendations" un--n-d~-r-[ITe definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the 'definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete "specifically approved for the purpose" in (1) and (4). Insert "suitable fo r the application" in (I) and "identified for use in wet locations" in (4). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-5: Accept CMP 7 SUBMI1-TER: TSC-Approved for the Purpose ]~TOP-O-~Z:-." 119 See the Technical Subcommittee "Recommendations" un--n-d~--E~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete "approved for the purpose" and insert "identified for the use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-9: Accept CMP 7 SUBMITTER: S.J. Casasanta, West Hartford, CT

120 Revise as follows: ~ s shall be made in approved Junction boxes using approved wiring methods. SUBSTANTIATION: Use of approved terminal blocks has proved tedious and time-consuming. Many installations have been made where standard approved wiring methods, such as wire nuts, were permitted by the local inspector.

Individual conductors of f la t cable have been identified with imprinted marking to assure that phases are properly connected. The imprint marking will substitute for the color code marking on the terminal block. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-10: Accept CMP 7 SUBMITTER: S.J. Casasanta, West Hartford, CT PROPOSAL: 121 Revise as follows: a - - ~ h a l l be made between any phase conductor and the neutral or any other phase conductor by means of devices and f i t t ings approved for the purpose. Tap devices shall be rated at not less than 15 amperes or more than 300 volts and they shall be color-coded in accordance with the requirements of Section

1 3 6 3 _ 2 o . . . ~UBSTANTIATION: Section 210-6. Permits branch circuits with voltages not exceeding 300 volts to ground per the following:

(a) Voltage to Ground . . . . Exception No. 1: The voltage shall not exceed 300 volts to

ground on branch circuits in industrial establishments where all of the following condi¢ions are met:

(a) The conditions of maintenance and supervision indicate that only qualified persons wil l service the lighting fixtures.

(b) The branch circuits supply only lighting fixtures that are equipped with mogul-base screw-shell lampholders or with l ampholders of other types approved for the purpose.

(c) The fixtures are mounted not less than 8 feet above the floor.

(d) Integral lighting switch, i f used, shall not be readily accessible.

Exception No. 2: The voltage shall not exceed 300 volts to ground on branch circuits in industrial establishments, stores, health care faci l i t ies, office buildings, schools, or public and commercial areas of other buildings such as hotels or transportation terminals where all of the following conditions are mot.

(a) The branch circuits supply only the ballasts for electric-discharge lamps mounted in permanently installed fixtures.

(b) The fixtures do not have manual swi,tch control, as an integral part of the fixture.

(c) Electric-discharge lampholders of' the screw-shell type are mounted not less than 8 feet above the floor.

When the above conditions are met, fluorescent, mercury-vapor, metal-halide, high-pressure sodium, low-pressure sodium and/or incandescent fixtures may be supplied by 480/277 volt, grounded wye circuit -- with loads connected phase-to-neutral and/or phase-to-phase. Such circuits operate at 277 volts to ground - that "is, not over 300 volts to ground -- even when 480 volt ballasts are connected phase-to-phase.

The present Code restricts the use of Flat Cable to Feeding Fixtures with 277 volt ballasts. With the increasing demand for 480 ballast fixtures fed from a 480/277 grounded wye system i t is sound engineering to revise the' Code as proposed to permit the wiring of 480 ballasts with Flat Cable. PANEL RECOMMENDATION: Accept. VOTE ON PANEL"RECOMMENDATION: Unanimously Affirmative.


122 See the Technical Subcommittee "Recommendations" un-G~-d~-~--t'ffe definition of "Approved for the P~rpose" in Article, 100. SUBSTANTIATION: See the TSC "findings'; under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete "approved for the purpose" and replace with "identified for the use. ° VOTE ONPANEL RECOMMENDATION: Unanimously Affirmative,


123 See the Technical Subcommittee "Recommendations" un--6-d-e~--t-~e definition of "Approved for the Purpose" In Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECO~MENDATION: Accept as Revised:

Delete "approved ~or the purpose" in both paragraphs and replace with "identified for the use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-12~ Accept CMP 7 SUBMITTER: CMP 7 $1R-OIIO-S'A-L-~. 123A Delete "approved for the purpose ~ and replace w-Tt'h--~T~entifled for the use." SUBSTANTCATION: To comply with TSC on Approved for the Purpose recommendatlons. PANEL RECOI~MENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-14: Accept CMP 7 SUBMITTER: S.J, Casasanta, West Hartford, CT

124 Revise as follows: All extensions from f la t cabl@ assemblies shall be made by

approved wiring methods, within the Junction boxes, installed at either end of the f la t cable assembly runs. SUBSTANTIATION: Use of terminal blocks has proved tedious and time-consuming. Standard approved wiring methods such as wire nuts have been used and permitted by the local inspector.

Individual conductors of f la t cable have.been 'identified with imprinted marking to assure that phases are properly connected. The imprint marking wll l substitute for the color code marking on the terminal block. • PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-14: Accept CMP 7 SUBMITTER: TSC-Approved for the Purpose PITOPO-~-~.'125 See the Technical Subcommittee "Recommendations" un-GB-d'e-~"~Te definition of "Approved for the Purpose" in Article i00. SUBSTANTIATION: See the TSC "findings" under the definition of =Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete second sentence. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-15: Accept CMP 7 SUBMITTER: C'MP 7

I PROPOSAL: 125A Insert a period after "raceways" and delete remalnder of the f i r s t sentence. SUBSTANTIATION: To comply.with TSC on Approved for the Purpose reco~ndations. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

1 3 2


126 See the Technical Subcommittee "Recommendations" un--fi-dE~--t'F~e definition of "Approved for the Purpose" in Article I00. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOYAMENDATION: Accept as Revised:

I Delete "approved for the purpose" and replace with "identified for the use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-20: Accept CMP 7 SUBMITTER: TSC-Approved for the Purpose I~ITOI~O~'AL-~. • 127 See the Technical Subcommittee "Recon~mendations" un--n'd-6~-tT~ definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete "approved for the purpose" and replace with "identified for the'use."

VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 366 -- ELECTRICAL FLOOR ASSEMBLIES

366-6: Accept CMP 7 SUBMIITTER: TSC-Nominal Voltage

l l~TOl~S'~-~. 128 Add "nominal" after "120 volts." ~I~%"FA]~TIATION: Change recommended for clarif ication and to 6btain conformance with present practice and uniformity within the Code. PANEL RECOI~MENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

366-20(b)(1): Reject CMP 7 SUBMITTER: TSC-Nominal Voltage !MTOI~TS'AL-T 129 Revise as follows:

rated voltage and current. SUBSTANTIATION: Change recommended for clarif ication and to obtain conformance with present practice and uniformity within the Code. PANEL RECOMMENDATION: Reject. PANEL UOMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 645 -- DATA PROCESSING SYSTEMS

645-I: Accept ~P 7 Secretary's Note: I t was the action of the Correlating

Committee that the Panel clar i fy the Panel Recommendation with regard to original Proposal. [ SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn. I~TOI}~5"AL-~. • 130 Delete the word "including" and replace with the ~ t h e r than." SUBSTANTIATION: There are misinterpretations of this section. I t is unrealistic and we do not believe i t was the intent of the Panel to include in the requirements under Section 645-i the remote telephone terminal units and cash registers in supermarkets and other similar small terminals. PANEL RECOMMENDATION: Accept as Revised!

Add the words "in a data p~ocessing, room" at the end of Section 645-1. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

645-2(c)(2):" "" - Accept CMP 7 SUBMITTER: D. C. Smith, Sperry Univac IMTOI~'IE~.- 131 Revise as follows: ~ e branch circuit supply conductors to receptacles are in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, metal wireway, metal surface raceway with metal cover, f lexible metal conduit, l iquidtight flexible metal conduit, copper-sheathed cable, mineral-insulated metal-sheathed cable, aluminum-sheathed cable, or metal clad cable. Wireway or metal surface raceway, when-used, shall be mounted with a minimum clearance of 1 1/2 inches between the structural (true) f loor and the bottom of the raceway.

Exception: Wireway or metal surface raceway, so long as wiring method is exposed. SUBSTANTIATION: Large electronic data processing systems often require 200 to 600 or occasionally more branch circuit conductors in a single room. Many such fac i l i t ies undergo frequent changes in EDP hardware with associated branch circuit

additions, deletions and moves. Even with raised floors two or more feet above structural (true) floors I t is d i f f icu l t to get enough pipe' In an installation to satisfy such needs. Use of multiple runs of unpunched metal wlreway with hinged metal covers and side mounted* metal outlet boxes has proved the most practical way of handling large numbers of branch circuit conductors in the relatively confined space under raised floors in fac i l i t ies ndt presently subject to the National Electrical Code. Supporting raceway off the floor minimizes problems related to dir t accumulation and accidental water spil ls.

Inclusion of intermediate metal conduit was made to cover this newly listed material while metal clad cable appears as useful as other metallic cable types. ~

*Note: Side mounting of boxes allows horizontal mounting of receptacles which eliminates dir t collecting in up-facing receptacles. PANEL RECOMMENDATION: Accept as Revised:

Delete "copper-sheathed cable," "aluminum-sheathed cable," the last sentence, and the exception. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

- \

o

645-2(c)(2): Accept CMP 7 SUBMITTER: R. Bezdegian, Shrewsbury, MA PRI]PI)~'A~-F: 132 Add "Type AC cable." ~'I]~'~'AI~rIATION: Type AC cable is suitable for this use and is more readlly obtainable then Type MC. I t is permitted by Section 300-22(c) above ceilings used for air-handling. Why not under raised floors. It'could withstand physical injury, much the same as Type MC, flexible metal conduit, l iqu id t igh t . f lexible metal conduit, or data processing equipment cables. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: g. NEGATIVE: Sappington, Bowen, Hart.

EXPLANATION OF VOTE: ~APPIRGIDN: I do not feel sufficient supporting comment has

been submitted. I feel there is a real Question relative to terminations and mechanical execution, therefore, in order to minimize potential f ires resulting from same, said proposal should not be accepted.

BOWEN: I am voting negative. ° I do not feel that under raised floors is as acceptable as above ceilings. Also the termination difference.

HART: I do not believe that there is sufficient supporting • comment to accept this Proposal. Even though there are some

similarities between Type AC cable and those listed in the "substantiation," there is a considerable difference in the terminations. I see no need to include Type AC cable in this section.

645-3: Accept CMP 7 SUBMITTER: Southwestern Section IAEI PKUPU~AL: 133 Change the word "electric" to "electronic data processing" in Subparagraph (a); SUBSTANTIATION: There are certain associated functions carried out in data processing rooms whic~ e~)loy electric typewriters, adding machines, calculators, etc., and this equipment Js not part of the data'processing system. Under this present Code wording, these appliances must be capable of being disconnected along with the computer equipment. Furthermore; the present phrase "electric equipment in the room" can include f i re. warning systems and f i re suppression systems. I t appears from the statements made in NFPA 75 dealing with protection of electronic computers and data processing equipment that the Intent is to disconnect the electronic equipment rather than other appliances or systems in the'room. The wording of the Code should reflect this intent. PANEL RECOMMENDATION: Accept as Revised:

Replace existing Section 645z3 with the following paragraph: 645-3. Disconnecting Means. A disconnecting means shall be provided to disconnect the power to all electronic equipment in the computer room. This disconnecting means shall be controlled from locations readily accessible to the operator at the principal exit doors. There shall also be a similar disconnecting means to disconnect the air-conditioning system serving this area. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

645-3(a): Reject CMP 7 SUBMITTER: R. S. Pinkerton, Los Angeles, CA I~TOI~S'AL-~. 134 Delete the word "electric" and replace with the wor--6-F-d-~EFectronic., SUBSTANTIATION: There are certain associated functions carried out in data processing rooms which employ electric typewriters, adding machines, calculators, etc., and this equipment is not part of the data processing system. Under this present Code wording, these appliances must be capable of being disconnected along with the computer equipment. Furthermore, the present phrase "electric equipment in the room" can include f i r e wa~ning systems and f i re suppression systems. I t appears from the statements made in NFPA 75 dealing with protection of electronic computers and data processing equipment that the intent is to

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CMP 8





157





















CMP 8





157

SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete the words "approved for the purpose" and add the word "Approved" at the the beginning of the sentence. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 374 -- AUXILIARY GUTTERS

374-9(f)-(New): Reject CMP 8 SUBMITTER: S. D. Mauney, Carolina Power & Light Company PHUPU~AL: 173 Add new (f) as follows: - ~ h e r e an auxiliary gutter is to contain bends or taps to an electric supplier's service conductors larger than No. i AWG, its width at the cover shall be at least 200 percent of that given in Table 373-6(a) and its minimum depth from cover to back shall be 100 percent of the width given in Table 373-6(a). Where the size of the supplier's service conductors is not readily available, the conductor size may be calculated as the equivalent size of the largest aluminum conductors with a 75°C ampacity rating equal to the sum of the service overcurrent devices tapped to the supplier's service conductors. In the table, "Wires per terminal" is to be used to indicate the number of the supply service conductors in parallel per phase. SUBSTANTIATION The required width of the auxiliary gutters used on surv~ces for taps to several or more meter or service equip(nent cabinets is inadequate dn many instances. No stated minmum depth is required. Due to the stiffness and size of the service conductors and to the large size of taped connectors, the connections are under pressure from adjacent conductors, connectors, and the gutter cover.

Even the best tapes are subject to abrasion due to expansion and contraction of the conductors with the load cycle. They also soften due to heat. Shorts occur when the tape is abraded away or softened abnormally. More space wil l help connections to be positioned away from each other and from the cover. The proposed size is minimum. Experience may indicate that larger sizes may be needed.

More space is also needed as/additional taps are made to the service conductors. This is ~specially true of commercial buildings with movable walls where the number, size, and loads of the occupancies is ever changing. Space is also needed when loads are checked with cllp-on ammeters, etc.

Increasing the size of service gutters is already often done by some electricians Who realize that the savings in installation labor and maintenance easily offset the additional material cost involved.

Safety is involved anytime a f i l led gutter is opened for inspection or to make changes as removing the cover allows the spring action of the cramped conductors to come into play. Closing the cover puts additional pressure on the connections. PANEL RECOI~4ENDATION: Reject. PANEL COMMENT: Already covered by Section 374-9(d). Training space is being studied by Panel 9. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

CHAPTER 9 -- TABLES AND EXAMPLES

Chapter 9, A. Tables, Note 2: Reject CMP 8 SUBMITTER: Peter Pollak, The Aluminum Association I~OFOSAL-~. 174 In the second sentence of Note 2, replace ~ - ~ t e d or bare)" with "(insulated, bare or compact)." SUBSTANTIATION: Question arises in the f ie ld regarding the selection of the proper conduit size for the application.

Makes clearer the fact that the actual dimensions of compact equipment grounding conductor shall be used in the calculation of conduit f i l l . PANEL RECOI~4ENDATION: Reject. PANEL COMMENT: Proposal is pcimarily a design consideration. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 14. NEGATIVE: Durham.

EXPLANATION OF VOTE: DURflAM: Panel action is not consistent with Proposal No. 175.

Chapter 9., A. Tables, Note 4: Accept CMP 8 SUBMITTER: Peter Po'llak, The Aluminum Association

I PRUPU~AL 175 In Note 4 insert "such as compact or i = ~ d u c t o r cables," after "Chapter 9. '

' SUBSTANTIATION: Question arises in the f ie ld regarding the selection of the proper conduit size for the application.

Makes clear the fact that actual dimensions of compact or f multlconductor cables shall be used in the calculation o

condu'i t f i l l . PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Chapter 9 Table l , Note 5: Accept CMP 8 SUBMITTER! CMP 8 !aITOPOS'7~-~. • 175A Add to Note 5 the word "maximum" before ~ e . " Add FPN after Note 5 to read:

Table l is based on common conditions of proper cabling and alignment of conductors where the length of the pull and the number of bends are within reasonable limits. I t should be recognized that for unusual conditions a larger size conduit or a lesser conduit f i l l should be considered. SUBSTANTIATION: Clarif ication. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table l , Chapter g: Reject CMP 8 SUBMITTER: CMP 8

175B In the 3 conductor column, delete 40 (percent ~ d insert 33 (percent f i l l ) for both lead covered and non-lead covered conductors. SUBSTANTIATION: There exists a l~t t le understood problem of "jam ratio" where only three conductors are installed in a conduit. This is ratio of the diameters of the conduit and the single conductor (D/d). This ratio is cr i t ica l between 2.5 and 3.0 where the conductors are not triplexed. At a ratio of 3.0 and greater, the conduit is wider than the sum of the 3' conductors which prevents Jamming.

At this ratio the area of the conductors is 3d2~

The area of the conduit is (3d)2 = 9d2~ L ~ - - - I - -

F i l l = 3/9 = 33 1/3 percent. At 40 percent f i l l the maximum allowable conductors are always in the cr i t ical Jam ratio. PANEL REC~NDATION: Reject. PANtL ~UMM~NI: UMP ~ would prefer to withdraw the Proposal and I t is rejected on that basis. VOTE ON PANEL RECOMMENDATION: Unanimously Aff i rmative..

Chapter 9, Table l , Note 6: Reject SUBMITTER: CMP 8 PROPOSAL: I75C Add a new Note 6 as follows: ~ i l l shall be permitted for triplexed conductors." SUBSTANTIATION: Clarif ication. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel Comment on Proposal No. 175B. VOTE ON PANEL RECOI¢MENDATION: Unanimously Affirmative.

CMP 8

Table 1, Chapter 9: Reject CMP 8 SUBMITTER: Joseph M. Ostrlhonsky, Sioux City, IA PROPOSAL: ,176 I suggest that the number of wires that is a-lT6~--d-in 1/2 inch and 3/4 inch pipe be reduced to half. The wire I'm talking about is TW, THHN, THWN, sizes #12, #14, and #10. As an alternate, they would change the 40 percent f i l l to 60 percent f i l l based on individual diameters. SUBSTANTIATION: I f you have had any experience at al l , you wil l know that is I t very d i f f l cu l t to pull, say 9-12 inch TW wires into a piece of 1/2 inch conduit. I t is almost impossible i f you havetwo go ° bends in the conduit. This Js why I think they should reduce the number of wires or else change the percent f i l l of the conduit. PANEL RECOMMENDATION: Reject. PANEL CL)f~ENI: ine "conduit f i l l tables are based on the concept that a safe practical.conduit f i l l percentage is one in which the diameter of a circle circumscribed around the assembled conductors would approximate 75 percent of the conduit diameter. The net area of the conductors within this theoretical circle approximates 40 percent f i l l .

The Code establishes a 40 percent maximum conduit f i l l . The Code also establishes a maximum of four quarter bends (360 degrees total) . The Code does not establish a maximum length of pull . The allowable length of a pull is contingent on a number of factors including but not limited to: I) maximum allowable conductor tension, 2) the plane of the bends (whether they are horizontal or vertical and whether any are reverse bends), 3) proper cabling of the conductors, 4) the weight of the cable, 5) the coefflcent of f r ic t ion between the conductors and the conduit, and 6) sidewall pressure.

Since the Code is not a design manual Judgement must be used in studying all of these "factors on whether.to use the maximum f i l l and the maximum number of bends to accommodate the maximum length of pull. Proper cabling of a large number of conductors is of extreme importance in such a Judge~nt. VOTE ON PANEL RECOI~ENDATION: Unanimously Affirmative.

158


126 See the Technical Subcommittee "Recommendations" un--fi-dE~--t'F~e definition of "Approved for the Purpose" in Article I00. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOYAMENDATION: Accept as Revised:

I Delete "approved for the purpose" and replace with "identified for the use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

363-20: Accept CMP 7 SUBMITTER: TSC-Approved for the Purpose I~ITOI~O~'AL-~. • 127 See the Technical Subcommittee "Recon~mendations" un--n'd-6~-tT~ definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete "approved for the purpose" and replace with "identified for the'use."


ARTICLE 366 -- ELECTRICAL FLOOR ASSEMBLIES

366-6: Accept CMP 7 SUBMIITTER: TSC-Nominal Voltage

l l~TOl~S'~-~. 128 Add "nominal" after "120 volts." ~I~%"FA]~TIATION: Change recommended for clarif ication and to 6btain conformance with present practice and uniformity within the Code. PANEL RECOI~MENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

366-20(b)(1): Reject CMP 7 SUBMITTER: TSC-Nominal Voltage !MTOI~TS'AL-T 129 Revise as follows:

rated voltage and current. SUBSTANTIATION: Change recommended for clarif ication and to obtain conformance with present practice and uniformity within the Code. PANEL RECOMMENDATION: Reject. PANEL UOMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 645 -- DATA PROCESSING SYSTEMS

645-I: Accept ~P 7 Secretary's Note: I t was the action of the Correlating

Committee that the Panel clar i fy the Panel Recommendation with regard to original Proposal. [ SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn. I~TOI}~5"AL-~. • 130 Delete the word "including" and replace with the ~ t h e r than." SUBSTANTIATION: There are misinterpretations of this section. I t is unrealistic and we do not believe i t was the intent of the Panel to include in the requirements under Section 645-i the remote telephone terminal units and cash registers in supermarkets and other similar small terminals. PANEL RECOMMENDATION: Accept as Revised!

Add the words "in a data p~ocessing, room" at the end of Section 645-1. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

645-2(c)(2):" "" - Accept CMP 7 SUBMITTER: D. C. Smith, Sperry Univac IMTOI~'IE~.- 131 Revise as follows: ~ e branch circuit supply conductors to receptacles are in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, metal wireway, metal surface raceway with metal cover, f lexible metal conduit, l iquidtight flexible metal conduit, copper-sheathed cable, mineral-insulated metal-sheathed cable, aluminum-sheathed cable, or metal clad cable. Wireway or metal surface raceway, when-used, shall be mounted with a minimum clearance of 1 1/2 inches between the structural (true) f loor and the bottom of the raceway.

Exception: Wireway or metal surface raceway, so long as wiring method is exposed. SUBSTANTIATION: Large electronic data processing systems often require 200 to 600 or occasionally more branch circuit conductors in a single room. Many such fac i l i t ies undergo frequent changes in EDP hardware with associated branch circuit

additions, deletions and moves. Even with raised floors two or more feet above structural (true) floors I t is d i f f icu l t to get enough pipe' In an installation to satisfy such needs. Use of multiple runs of unpunched metal wlreway with hinged metal covers and side mounted* metal outlet boxes has proved the most practical way of handling large numbers of branch circuit conductors in the relatively confined space under raised floors in fac i l i t ies ndt presently subject to the National Electrical Code. Supporting raceway off the floor minimizes problems related to dir t accumulation and accidental water spil ls.

Inclusion of intermediate metal conduit was made to cover this newly listed material while metal clad cable appears as useful as other metallic cable types. ~

*Note: Side mounting of boxes allows horizontal mounting of receptacles which eliminates dir t collecting in up-facing receptacles. PANEL RECOMMENDATION: Accept as Revised:

Delete "copper-sheathed cable," "aluminum-sheathed cable," the last sentence, and the exception. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

- \

o

645-2(c)(2): Accept CMP 7 SUBMITTER: R. Bezdegian, Shrewsbury, MA PRI]PI)~'A~-F: 132 Add "Type AC cable." ~'I]~'~'AI~rIATION: Type AC cable is suitable for this use and is more readlly obtainable then Type MC. I t is permitted by Section 300-22(c) above ceilings used for air-handling. Why not under raised floors. It'could withstand physical injury, much the same as Type MC, flexible metal conduit, l iqu id t igh t . f lexible metal conduit, or data processing equipment cables. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: g. NEGATIVE: Sappington, Bowen, Hart.

EXPLANATION OF VOTE: ~APPIRGIDN: I do not feel sufficient supporting comment has

been submitted. I feel there is a real Question relative to terminations and mechanical execution, therefore, in order to minimize potential f ires resulting from same, said proposal should not be accepted.

BOWEN: I am voting negative. ° I do not feel that under raised floors is as acceptable as above ceilings. Also the termination difference.

HART: I do not believe that there is sufficient supporting • comment to accept this Proposal. Even though there are some

similarities between Type AC cable and those listed in the "substantiation," there is a considerable difference in the terminations. I see no need to include Type AC cable in this section.

645-3: Accept CMP 7 SUBMITTER: Southwestern Section IAEI PKUPU~AL: 133 Change the word "electric" to "electronic data processing" in Subparagraph (a); SUBSTANTIATION: There are certain associated functions carried out in data processing rooms whic~ e~)loy electric typewriters, adding machines, calculators, etc., and this equipment Js not part of the data'processing system. Under this present Code wording, these appliances must be capable of being disconnected along with the computer equipment. Furthermore; the present phrase "electric equipment in the room" can include f i re. warning systems and f i re suppression systems. I t appears from the statements made in NFPA 75 dealing with protection of electronic computers and data processing equipment that the Intent is to disconnect the electronic equipment rather than other appliances or systems in the'room. The wording of the Code should reflect this intent. PANEL RECOMMENDATION: Accept as Revised:

Replace existing Section 645z3 with the following paragraph: 645-3. Disconnecting Means. A disconnecting means shall be provided to disconnect the power to all electronic equipment in the computer room. This disconnecting means shall be controlled from locations readily accessible to the operator at the principal exit doors. There shall also be a similar disconnecting means to disconnect the air-conditioning system serving this area. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

645-3(a): Reject CMP 7 SUBMITTER: R. S. Pinkerton, Los Angeles, CA I~TOI~S'AL-~. 134 Delete the word "electric" and replace with the wor--6-F-d-~EFectronic., SUBSTANTIATION: There are certain associated functions carried out in data processing rooms which employ electric typewriters, adding machines, calculators, etc., and this equipment is not part of the data processing system. Under this present Code wording, these appliances must be capable of being disconnected along with the computer equipment. Furthermore, the present phrase "electric equipment in the room" can include f i r e wa~ning systems and f i re suppression systems. I t appears from the statements made in NFPA 75 dealing with protection of electronic computers and data processing equipment that the intent is to

133

REPORT OF CODE-MAKING PANEL NO. 9

ARTICLE 370 -- OUTLET, SWITCH AND JUNCTION BOXES, AND FITTINGS

370-3: Reject ~ CMP 9 SUBMITTER: R. W. Eckardt, Underwriters Laboratories Inc.

I Revise as follows: ~ N o n m e t a l l i c Boxes. Nonmetallic boxes shall be permitted only with open wiring on insulators, concealedknob and tube wiring, nonmetallic-sheathed cable and with rigid nonmetallic conduit.

Exception: Nonmetallic boxes over lO0 cubic inches manufactured with bonding means between all raceway and cable entries shall be permitted to be used with metal raceways and metal-sheathed cable. SUBSTANTIATION: The wording adopted for the Ig78 Code inadvertently emitted covering nonmetallic boxes over I00 cu. in. with rigid nonmetallic conduit. This error can be corrected by omitting the phrase "not over lO0 cu. in." in the f i r s t sentence and making the second sentence an "Exception." PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 3. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-3: Reject CMP 9 SUBMITTER: R. C. Medley, Square D Co. PROPOSAL: 2 In the f i r s t paragraph, delete the words "not over I-O-O cubic inches."

In the second paragraph, delete the words "over 100 cubic inches." SUBSTANTIATION: The volumetric limitations impose unnecessary restrictions to the usage and applications of nonmetallic boxes. The f i r s t paragraph describes normal usage. I t is irrelevant to state volumetric limits. The second paragraph permits usage with metallic connections provided suitable bonding is included. Again, volumetric restriction is not significant to usage. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Nonmetallic boxes less than 100 cu. inches are not suitable for use with all wiring methods. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

CRAMER: In our Panel discussions, pushbutton devices in nonmetallic boxes (pushbutton stations) smaller than 100 cubic inches wece discussed. Pushbutton ~tations are not covered under Article 370 and consequently this Section does not preclude the use of such a nonmetallic station with metal raceways.

370-3: Accept CMP 9 SUBMII-TER: J.J. Kark, National Electrical Manufacturers

PROPOSAL: 3 Delete the words "not over 100 cubic inches" from ~ t paragraph of 370-3. Add the word "also" after "shall" in the second sentence.

The recommended text would read: 370-3. Nonmetallic Boxes. Nonmetallic boxes shall be permitted only with open wiring on insulators, concealed knob-and-tube wiring, nonmetallic-sheathed cable, and with rigid nonmetallic conduit.

Nonmetallic boxes over 100 cubic inches manufactured with bonding means between all raceways and cable entries shall also be permitted to be used with metal raceways and metal-sheathed cable. SUBSTANTIATION: Needed for clarif ication. The wording "not over 100 cubic inch volume" is unnecessarily restrict ive.

The word "also" would c lar i fy this as an additional permitted use .

PANEL RECOMMENDATION: Accept as Revised: Add the words "In addition thereto" before the word

"Nonmetallic" in the second sentence. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 11. NEGATIVE: Barker.

EXPLANATION OF VOTE: BARKER: All nonmetallic boxes over 100 cubic inches should

have bonding means to prevent misapplication in the f ield with metal conduit. The alternate would be to prohibit the use of metal conduit. Grounding is an essential safety requirement.

370~3: Reject CMP 9 SUBMITTER: Donald W. Cremer, St. Louis, MO

4 In the f i r s t paragraph, eliminate "not over 100 ~ c h e s . "

In the second paragraph, add "Exception" prior to the f i r s t word of the paragraph. SUBSTANTIATION: Wording is intended to c lar i fy only. Present wording does not cover nonmetallic boxes over I00 cubic inches that are not manufactured with bonding means. The f i r s t

paragraph as presently written covers only nonmetallic boxes less than 100 cubic inches. The second paragraph as presently written covers nonmetallic boxes over 100 cubic inches manufactured with bonding means, i

The proposed wording should add c lar i ty to this section. The word UException" is needed in the second paragraph because "only" is contained in the f i rs t , paragraph. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CI~ ° agrees with the intent of the Proposal see action on Proposal No. 3. VOTE ON PANEL RECOI~IENDATION: Unanimously Affirmative;

f

370-4: Reject CMP 9 SUBMITTER: Allen KnicKrehm, Los Angeles Chapter, NECA ]~)'I)O-S~L-~.'5 A means shall be provided in each metallic box, ~ i t is a pressed steel or a cast material type, for the connection of an equipment grounding Conductor. SUBSTANTIATION: Nonmetallic raceway and nonmetallic cable systems using equipment grounding conductors require the connection of such conductors to metallic boxes.

The connections of grounding conductors where a means is not provided for the connections usually results in a hole and a nut-and-bolt situation which may void the l isting of the box, destroy its concrete or l lquidtight integrity. Therefore i t is fe l t that a grounding lug connection should be provided for the equipment grounding conductors. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 5A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-20(d): Accept CMP 9 SUBMITTER: CI~ ° g ]}]TOIsO-~-A-C-~. " 5A Add a new section 370-20(d) as follows: ~ s shall be provided in each metallic box, designed for use with nonmetallic raceways and nonmetallic cable systems, for the connection of an equipment grounding conductor. SUBSTANTIATION: We agree with the intent of Propdsal No. 5, but think this wording is better. PANEL RECOMMENDATION: Accept as Revised:

Add t i t l e to section "(d) Grounding Provisions. N Change "metallic" to "metal" box to remain consistent with

remaining portions of Section 370-20. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-5: Accept . CMP 9 SUBMITTER: TSC-Approved for the Purpose I~TOI~)-S'AL-~. 6 See the Technical Subcommittee "Recommendations" ~ t h e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATIONI See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOIIMENDATION: Accept as Revised:

Delete the words "shall be approved for the purpose" and add the words "shall be listed for use in wet locations." VOTE ON PANEL RECOI~MENDATION:

AFFIRMATIVE: 11. NEGATIVE: Cramer.

EXPLANATION OF VOTE: CRAMER: "Listed" boxes in the size desired are not always

available. Field fabrication or modification is sometimes required. Consequently the box cannot be listed. Remove "approved for the purpose" and replace with "suitable for the environment."

370-6(a) & Table 370-6(a): Reject CMP 9 SUBMITTER: Paul DeMuth, Sheldon, IA I~IOFO3XZT 7 ~'~o--be added to Table 370-6(a) between line 18 and line 19:

4 I /8 x 2 3/8 x 2 1/8 Device 18.0 g 8 7 6 0 t.

B. To be added after Section 370-6(a) with the current Section 370-6(a)(2) to follow as 370-6(a) 3:

(2) Where used, with oversized devices (dimmers, photo-cells, etcL) freespace in addition to that required in Section 370-6(a)(1) shall be adequately provided for.

SUBSTANTIATION: A. The 4 1/8 x 2 3/8 x 2 1/8 de~ice box is often needed for surface work requiring 3/4 inch and larger conduit for Junction and outlet boxes. As such i t should be added to the l ist ing of metallic boxes in B. When applying standard box f i l l methods to the use of some larger devices, i t has been found that planned boxes are often too small to properly provide required free space. By the addition of a new section to point out potential problems in this cr i t ical area, errors in freespace planning may be avoided. PANEL RECOMMENDATION: Reject.

k ,

160

PANEL COMMENT: (a) The table does not preclude the use of this box. While we recognize this is a commonly used box, i t is not necessary to include i t in Table 370-6(a) as a standard box. (b) I t is unenforceable. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 370-6(a): Reject CMP g SUBMITTER: Norman B. Cooney, Parma, Ohio

8 Delete 3 x 2 x 1 I/2 device box. ~ I A T I O N : All of these boxes contain cable clamps and flush devices. Deducting two conductors or even one conductor makes i t impossible to use this slze box for wiring wlth 12/2 or 14/2 N.M. cable w/grnd. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is notpersuasive as to necessity. The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-6(a)(1): Accept CMP 9 SUBMITTER: William E. Slater, RACO Inc. PROPOSAL: 9 Revise last sentence and add new sentence as

The volume of a wiring enclosure (box) shall be the total volume of the assembled sections, and where used, the space provided by plaster rings, domed covers, etc., that are marked with th'eir volume in cubic inches, and extension rings. The volume of extension rings shall be considered equal to the volumes shown in Table 370-6(a), for its cemparable box dimensions, unless marked with a greater volume. SUBSTANTIATION: Extension rings are basic boxes with the major portion of the bottom removed and some means provided for attachment to a box. The basic boxes, that are .listed in Table 370-6(a) are-generally used in manufacturing extension rings, but volume is not significantly increased by merely renw)ving the bottom of a box, therefore, additional conductor space is not provided. PANEL RECOMMENDATION: Accept as Revised:

I Revise paragraph 370-6(a)(I) of the 1978 NEC as follows: add the words to the last sentence "inches, or are made from boxes the dimensions of which are listed in Table 370-6(a)." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-6(a)(1): Accept CMP 9 SUBMITTER: Kirk Jervik, Sheldon, IA

10 Revise the second sentence as follows: Where one or more of each of the following fixture studs,

cable clamps, or hickeys are contained In the box, the number of conductors shall be one less than shown on the tables. SUBSTANTIATION: The problem lies in that there seems to be some confusion, to myself and others I've been associated with, as to whether the intent and purpose of the article is to make one deduction and only one, whether the box contains Just cable clamps; Just f ixture studs; Just hickeys, or all three. I firmly believe that with my proposal i t will c lar i fy the fact that a deduction wil l be made when the box contains one of the above mentioned, a box containing two of the above mentioned wil l have two dedbctions, and a box with all three deductions. For example, a box containing two cable clamps and a f i x tu re

"stud wil l have two deductions. One wil l be made for the cable clan~)s and one for the f ixture stud. PANEL RECOMMENDATION: Accept as Revised:

Revise second sentence as follows: Where one or mere of these types of devices, such as f ixture studs, cable clamps, or hickeys are contained in the box, the number of conductors shown in the table shall be reduced by one for each type of device; an additional deduction of one conductor shall be made for each strap containing one or mere devices; and a further deduction of one conductor shall be made for one or mere grounding conductors entering the box. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-6(a)(1): Reject CMP 9 SUBMITTER: Norman B. Cooney, Parma, Ohio

11 In second sentence after "for", delete "one or more grounding conductors" and substitute "any." SUBSTANTIATION: I t is a physical impossibility to install 2 switches on a 2-gang N.M. box that is 45 cu. in. and contains 3-12/3 and 4-12/2 N.M. cables. Those 6 grounding conductors that are not counted s t i l l reduce the cubic inch capacity of the box and when the combinations are 1-12/3 and 7-12/2, the conductors stick out of the box 1/2 inch. Now instead of 6 grounding conductors we have 7.

These cables must come into the box from the top and bottem and all the knock-outs are used so the grounding conductors must traverse diagonally as well as horizontally and vertically.

The end result is not only unsafe, but i t is impossible to terminate flush devices in the box. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. I f a larger box is needed the Code permits its use. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-6(c), Exception-(New): Reject CMP 9 SUBMITTER: Roger C. Troupe, Fremont, NB FR'OIB~)-S-A-L-~. 12 Amend by adding exception to read: ---E'R'E'epCion: Conduit bodies having two entries shall be permitted to have wire to wire splices, for the connection of uti l ization equipment leads (Including switching devices) where thls equipment does not have connection space provided in i t or for the connections required to change from a conduit wiring method to a single cord method as allowed by Article 400, where the f i l l wil l not exceed 75 percent at any cross-sectlon. SUBSTANTIATION: NFPA No. 70-PR78'contained nine proposed revisions in regard to Section 370-6(c), the one being accepted that of CI~ ° g. Although some clarif ication was made, one of the main objectives sought In the other eight proposals (the allowability of splicing cords and leads of ut i l izat ion equipment where connection boxes are not provided in conduit bodies with two entries) was s t i l l not achieved. I f i t can be interpreted that splicing conductors in conduit bodies with only two entries is allowable under the provisions of section (b), (even though section (b) opens with its reference being to boxes 100 cu. in. or less, conduit bodies having provision for more than two conduit entries, and nonmetallic boxes) when section (b) is refer~ed to by section (c), then the necessary ~llowability for splices and taps in all conduit bodies has been provided for. However, i t is 's t i l l v ir tual ly impossible to use standard conduit bodies sized the same as the conduit, where the conduit is sized properly in accordance with the conductor size and s t i l l f i t within the scope of Section 370-6(b).

Where cords or the attachment leads of uti l ization equipment (including switching devices) are spliced in a condui t body, the danger of damage to the conductors due to lesser space than required in Section 370-6(b) is minimized 6ecause of the greater degree of f l ex ib i l i t y of the cord or equipment leads due t 9 either their being stranded, or being smaller in size, or both. (Note: Table 370-6(b) does not specify conductors smaller than No. 14.)

Because these connections can be faci l i tated safely i f cross-section f i l l is limited to 75 percent, and because space about equipment is not always adequate to install a box or conduit body of adequate size as required by Section 370-6(b), there is a very definite need for the provisions of this exception. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. The present wording, adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

CRAMER: I disagree with the need for an exception for a two entry conduit body but feel that the requirements for two or mere entry conduit bodies need clari ty.

Splicing is now allowable in two entry conduit bodies but sizing requirements imposed by Section 370-6(b) are d i f f icu l t to follow. I don't feel the subject is clearly covered. We should' relocate t o Section 370-6(c) all requirements pertaining to conduit bodies and therein locate requirements pertaining to splices, taps and wires passing through the conduit body.

370-7(c): Reject Cl~ D 9 SUBMITTER: Dale R. Deming, RACO, Inc.

13 Revise as follows: ~ o n m e t a l l i c Boxes. Where nonmetallic boxes are used with open wiring or concealed knob-and-tube wiring, the conductors shall enter the box through individual holes. Where flexible tubing is used to encase these conductors, the tubing shall extend from the last insulating support to no less than 1/4-inch inside the box.

(2) Where nonmetallic sheathed cable is used with boxes which accept only one strap, containing one or more devices, and with boxes mounted in ceilings that do not contain devices and where the cable is fastened within eight inches of these boxes~ measured along the sheath, and the sheath extends into the box no less than 1/4-inch, securing the cable assc~nbly to the box shall not be required. In all other instances, the cable assembly shall be secured to nonmetallic boxes. SUBSTANTIATION: Considerable confusion has resulted from the terminology used in the present Code. Reference to single gang boxes does not indicate which specific types of boxes shall require some means of securing the cable to the box. Also, in combining the requirements for nonmetallic sheathed cable with open wiring and concealed knob-and-tube wiring methods, present wording indicates that individual conductors and cables shall be secured when using nonmetallic sheathed cBble. This was not the intent of C~ No. 9 in accepting the proposal. The reference to individual conductors is to apply only to open wiring and concealed knob-and-tube wiring.

This proposal, while not changing intent, clearly defines those applications in which securing the cable to t~e box is required and i t more properly states the cable assembly, thus eliminating the confusion of individual conductors within a cable assembly. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 13A. Present requirement is necessary. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

161

370-7(c): Accept CMP 9 SUBMITTER:. C/iP 9 PROPOSAL: 13A Delete the last sentence and add the t'oTFow-i~ng: "In all other instances, (1) cables and (2) individual conductors of open wiring and concealed knob and tube wiring, including the f lexible tubing i f used, shall be secured to nonmetallic boxes. Metal raceways, nonmetallic conduit, or metal-sheathed cable shall be secured to nonmetallic boxes. SUBSTANTIATION: Clarification for f i r s t sentence. Second sentence was inadvertently lef t out of the 1978 NEC. PANEL RECOMMENDATION: Accept as Revised:

Revise last sentence of 370-7(c) to read: "In all other instances all permitted wiring methods shall be secured to the boxes." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-7(c): Reject CMP 9 SUBMITTER: R. C. Medley, Square D Co.

14 In the fourth sentence, delete the words "is used ~ g l e gang boxes and where the cable." SUBSTANTIATION: The paragraph limits usage.to single gang boxes for which there is no.definition. Entry of multiplecables may be accomplished by securing cables within eight inches independent of box style description. PANEL RECO/~iENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 13A. Present requirement is necessary. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

VOTE ON PANEL RECOMMENDATION: AFFIRMATIVE: 11. NEGATIVE: Leiman.

EXPLANATION OF VOTE: LEIMAN: . I agree with the supporting comment. In my personal

experience and discussions with other inspectors, I have found that the cable sheath has been pulled out of single gang boxes.

370-7(c): Reject CMP 9 SUBMITTER: Rudolph V. Jones, Virginia Chapter,. IAEI PI~O]~O-{JJ~-~. • 18 Delete the words "with single gang boxes" in the ~6u-r-t-h--sentence. SUBSTANTIATION: The requirement for the securing of nonmetallic-sheathed cables to other than single gang boxes is not warranted and results in an unnecessary additional expense. I f i t can be considered safe that nonmetallic-sheathed cable need not be secured to single gang boxes when fastened within 8 inches of the box measured along the sheath, the application of such to multi-gang boxes should also be just as safe. The last sentence specifically requires that cables be secured to the multi-gang box where the cables are not fastened within 8 inches of the box measured along the sheath. Unnecessary cl~mps result in a decrease in volume and work space in the box and increase the possibil i ty of damage to the cables. PANEL RECOI~MENDATION: Reject. PANEL COMMENT: Present require~lent is necessary. See Proposal No. 13A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-7(c)~ Reject CMP 9 SUBMITTER: J.a. Kark, National Electrical Manufacturers ~ o n PROPOSAL: 15 Revise fourth sentence to read:

~-er-e nonmetallic-sheathed cable is used with boxes which accept only one strap containing one or more devices and wlth boxes mounted in ceilings which ,are for the support of a f ixture, and where the cable is fastened within 8 inches of the box measured along the sheath and the sheath extends into the box no less than i/4 inch, securing the cable to the box shall not be required. SUBSTANTIATION: This sentence as written in the 1978 NEC has created considerable confusion. The sentence Is being rewritten to c lar i fy i ts original intent. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 13A. Present. requlroment is necessary. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-7(c): Reject CMP 9 SUBMITTER: H.F. van der Voort, Cleveland, OH ]~-O'P-O~FA-CT.. 16 Change sentences 4 and 5 to read: Clamping o f ' "i~'-dTv-J'dual conductors or cables to the box shall not be required where supported within 8 inches of the box. Where rigid nonmetallic conduit is installed with nonmetallic boxes or f i t t ings, the conduit shall be secured to such boxes and " f i t t ings in an approved manner. SUBSTANTIATION: The present Code wording lacks clar i ty. In addition, i t has not been demonstrated by f ie ld fai lures that nonmetallic boxes when installed as described above constitute a hazard, and until the 1978 Code revision, this was the accepted procedure. In fact, even when clamps are provided for they are often not used. When recemmended changes increase costs, their need should be clearly demonstrated. PANEL RECOMMENDATION: Reject. PANEL COM~iENT: Present requirement is necessary as i t applies to the fourth sentence. See Committee action on Proposal No. 13A for the intent of the f~fth sentence. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-7(c): Reject CMP 9 SUBMITTER: Idaho Chapter IAEI I~'OP-O-S~--~. • 17 Delete last two sentences.

end of the third sentence of 370-7(c), change the "period" to a "comma" and add "individual conductors and cables shall be secured to such boxes" to read:

Where nonmetallic-sheathed cable is used¢ the cable assembly, including the sheath, shall extend into theXbox no less than 1/4 inch through a nonmetalllc-sheathed cable knockout opening, individual conductors and cables shall be secured to such boxes. SUBSTANTIATION: There is no assurance that the sheath of nonmetallic sheathed cable wll l remain in the nonmetallic box when the device Is inserted into the box even though the cable is strapped within 8 inches as required. I t is Just as important that the cable sheath remains in a single gang box as any other type of box. PANEL RECOM&iENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. There Is no evidence the present Code is inadequate.

370-10 and 380-9: Reject CMP 9 SUBMITTER: Norman B. Cooney, Parma, Ohio

19 After last word in paragraph "therefrom" insert "but no more than 1/8 inch." SUBSTANTIATION:' Since no dimensions are given for the projection of the box, i t could conceivably be out one (1) inch or more. By limiting the projection to I /8 inch you would be able to comply wlth 380-9 (faceplates to seat against the wall surface). PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. No • significant contribution to safety would result. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-I0, E~ception-(New): Reject CMP 9 SUBMITTER: Ted Steppe, STEPP-ELEX Corp. ]~-OIR~{~]~-~.'\20 Add a new exception as follows: . l~-x-Eeption: The front edge of box need not be flush with wall surface I f an approved cover plate having a recessed center section which effectively seals the box front and the adjoining wall surface Is used. SUBSTANTIATION: The problem: The extra thickness of paneling when added to a wall means the electrical outlets and switches must be moved out to make them flush with the new wall surface. This is a project in i tse l f and can be very costly and time consuming. The alternative is to shlm out the electrical device which could create a potential f i re hazard for lack of proper sealing of the electric box. Most home owners use the alternate method.

The answer: The STEPP-PLATE has a recessed center area of sufficient slze to effectively seal the electrical box as well as any approved cover. The advantage we have over other covers Is that STEppoPLATE also has the thickness of a new wall covering bui l t into I t . This insures a tight f i t to both the electric box and the wall surface. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirenent is necessary. I f the faceplate is changed later to a standard type, the installation wil l be In violation of the Code. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Eckardt, Cramer.

COMMENT ON VOTE: DEMING: I would vote to accept this proposal i f i t were

reworded to limit the exception to apply only where paneling or some similar finished surface, not over 1/4 Inch thick is applied over an existing wall. EXPLANATION OF VOTE:

ECKARDT: I can agree with the submltter and also wlth his substantiation under Proposal No. 22 i f the use of the device is limited to rework. I suggest the proposal be prefixed "For remodeling work the front edge etc."

CRAMER: The proposal has merit. The reason for rejection is i f the faceplate is changed later to a standard t~qoe, a violation would occur. I f this change were made, outlets and switches would then have to be moved out to make them flush. There's no difference in the work. I t ' s Just that In the latter case, I f the proposed faceplate were never changed, that work would never be required.

162

370-11: Accept CMP g SUBMITTER: Norman B. Cooney, Parma, Ohio

21 After "Repairing Piaster" add "and drywall or ~ o a r d . " After'"Plaster" ( f i rs t word in sentence) add "drywall or plasterboard." SUBSTANTIATION: Plasterboard or Drywall is used in 95 percent of today's construction end the oversight in not having included I t in previous Code changes eludes me.

This paragraph, llke so many others ,in the Code, mentions a specific covering "plaster" and does not address i tsel f to other forms of wall and/or ceiling coverings.

The end result is an untenable position for the enforcing authority explaining why this also applies to other forms of plaster-content wall coverings when the Code mentions no other forms. When appeals by contractors are refused by City Building Board of Appeals, they then f i l e in Con~on Pleas Court and t h e Judge is usually not concerned wlth the intent of the CMP, but the explicit wording of the article or paragraph in dispute. Since drywall construction has been used extensively since the end of World War I I by builders, I believe i t is time to use contemporary wording in the Code to alleviate the problems caused by outmoded building standards. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECO~ENDATION: "

AFFIRMATIVE: g. NEGATIVE: Barker, Biermann, Cock.

EXPLANATION OF VOTE: BARKER: This is a necessary requirement to protect wood

constructed walls from arcs, sparks and molten metal coming in contact with combustible walls and framing. I t is just as enforceable as any other safety requirement. Any loss from this would surely be called an electrical f i re.

BIERMANN: Thls is a building code rule. Electricians cannot be responsible for the installation practices of other tradesmen.

COCK: I believe that Section 370-11 should be deleted from the Code or changed because the present wording is entirely too restrictive and compliance is impossible in most cases. I t should be changed to require that gaps o~ open spaces be held to the minimum for practical working conditions. I agree that Section 370-11 should be changed to apply to all materials i f this Section remains in the Code. However, I would like to see the Section reworded to reflect reality.

370-11, Exception-(New): Reject CMP 9 SUBMITTER: Ted Steppe, STEPP-ELEX Corp. PROPOSAL: 22 Add a new exception as follows:

-~-~ception: Wall Surface need not contact the edge of th e electrical box i f an approvedcover plate having a recessed center section which effectively seals the box front and the adjoining wall surface is used for the purpose of recessing a device into the wall. SUBSTANTIATION: The box could be set flush with the stud in new construction. Then the receptacle or switch would be recessed the thickness of the finished wall. This would prevent the switch or cord cap and receptacle from being damaged when heavy objects are pushed against the wail. This would also protect the cord caps and switches in high t ra f f ic areas frombeing hit and damaged. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 20. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ECKARDT: This change is not needed regardless of the outcome of Proposal No. 20.

DEMING: Allowing receptacles to be recessed the thickness of the finished wall will lead to the practice of Jerking or pulling directly on the cord to remove the plug from the receptacle.

370-13: Accept CMP g SUBMITTER: J.J. Kark, National Electrical Manufacturers ~ o n PROPOSAL: 23 In f i r s t paragraph, revise second sentence to

Where nails are used as a mounting means and pass through the interior of the box, they shall be located so that they do not interfere with the installation of the device and are within 1/4 inch of the back or ends of the box. SUBSTANTIATION: For boxes such as 3-1/2 inch deep switch boxes or boxes with in turned device mounting ears, through nails located within 1/4 inch of the ends of the box can give less interference and better structural support than nails within I/4 inch of the back of the box. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-13: Accept CMP 9 SUBMITTER: TSC.Approved for the Purpose PITOI~CI--T. • 24 See the Technical Subcommittee "Recommendations" under the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of

"Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Revise the second paragraph of 370-13 to read as follows: "Boxes installed in walls of previously occupied buildings or In walls In which there are no structural menfoers shall be supported by the use of devices, clan~s or anchors which wil l provide the secure and rigid installation required by this

ISection of the Code." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-13: Reject CMP 9 SUBMITTER: Dean Woelber, Hull, IA PROPO--S-A-C~." 25 Proposed wording of new paragraph to be added at t--F;-e-en-d'-of 370-13 is as follows: "Threaded boxes or f i t t ings not over 100 cubic inches in size shall be considered to be adequately supported i f at least one conduit is threaded into the box wrenchtight, and is securely fastened to the surface on which i t is carried as required by Articles 345-12, 136-12, and by this article. The box shall have no other means of support readily available. The conduit shall be supported at least twice, one of these supports being no further than 18 inches from the box." SUBSTANTIATION: Many times i t can be in,possible to securely fasten a box exactly where i t is needed or wanted, because the surface to which i t should be mounted is either an irregular shape, a material such as glass, or some type of b r i t t le plastic. In these situations, i t could be Just as good i f not better to support the box by the conduit threaded into the box. The conduit must be.supported at least twice, one with 18 inches of the box which will give the box a rigid support, and the second support would keep i t from twisting. PANEL RECOMMENDATION: Reject. P/~I~EL COMMENT: Present requirement is necessary. The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-14: Reject CMP g SUBMITTER: Norman B. Cooney, Parma, Ohio

26 After "not less than" in second sentence, delete "15/16 inches" and add "that specified in Table 370-6(a) and 370-6(b)". SUBSTANTIATION: All devices measure 7/8 inch to 1 1/8 inches. Obviously any device measuring 15/16 inches and more cannot be used in this box so I wil l address myself to those measuring 7/8 inch. Not wishing to fractionalize, I wil l use whole numbers. The box is. 6 cu. in. and using 14-2 w/grnd., the conductors equal 6 cu. in. which simply means you could not use a flush device in this box. With a device and cable clan~o in the box you could not comply with Table 370-6(a) and (b). I have not mentioned EMT because the l~cknut measures 1 I/8 inches and is physically impossible to install in this box. Mathematically speaking, thls box cannot be used for flush devices. PANEL RECOMMENDATION: Reject. P~NEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-17(b): Accept CMP 9 SUBMITTER: TSC-Approved for the Purpose PITOPO-S~Z-~. 27 See the Technical Subcommittee "Recommendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Revise paragraph 370-17(b) to read: "Boxes listed specifically for this application shall be used for receptacles located in the floor.

Exception: Boxes located in elevated floors, of show windows and similar locations where the (authority having Jurisdiction judges them to be free from physical damage, moisture, and d i r t . " VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-18(c): Accept CMP 9 SUBMITTER: TSC-Approved.for the Purpose PROPOSAL: 28 See the Technical Subcommittee "Recommendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete "approved for the purpose" and insert "compatible with the box or f i t t ing construction and suitable for the conditions of use." \


163

370-19: Reject CMP 9 SUBMITTER: R. S. Pinkerton, Los Angeles, CA

29 Add a paragraph, revise Exception No. 1, and add new Exception Nos. I and 2.

A work space at least 24 inches horizontally and 24 inches in height shall be provided in front of each junction, pull and outlet box. Access thereto shall be provided by a space not less than 24 inches in height and 20 inches in width. Crawl holes, scuttles or similar openings to such space shallbe not less than 18 inches by 18 inches in size.

Exception No. I : Boxes approved For the purpose shall be permitted where covered by a thin coating of plaster or covered by gravel-like aggregate or noncohesive granulated soil i f their location is effectively identified and accessible for excavation; or

Exception No. 2: Boxes that are listed for use as pull or Junction boxes and are an integral part of a recessed f ixture or approved appliances; or

Exception No. 3: Outlets supplying bui l t - in appliances such as gas ovens and the like where there are ho conductors in the outlet box except the supply conductors terminating therein and the appliance is connected to the outlet in an approved manner. SUBSTANTIATION: The present vague and general requirements for accessibility to Junction and outlet boxes are unenforceable in new construction conditions as i t is not possible to know the conditions of, access, especially in attic or undeP floor spaces, until the construction is complete. To be enforceable a specific clear area as proposed in this requirement must be stated. .The proposed requirement has been in effect for many years in the City of Los Angeles and has proven to be effective, reasonable and enforceable. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. No evidence to support the suggested change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-19: Reject . CMP 9 SUBMITTER: Southwestern Section IAEI P--R-O'P-O-S~A-L-~ 30 Ad~ a second paragraph to present Section 370-19

A work space at least 18 inches horizontally and 18 inches in height shall be provided in. front of each Junction, pull and o~tlet box. Access thereto shall be provided by a space not less than 18 inches in height and 20 inches in width. Crawl holes, scuttles or similar openings to .such space shall be not less than 18 inches by 18 inches in size.

Exception No. 1: Boxes approved for the purpose shall be permitted where covered by gravel-like aggregate or non-cohesive granulated soll i f their location is effectively identified and accessible for excavation; or

Exception No. 2: B6xes that are listed for use as pull or junction boxes and are an integral part of a recessed f ixture or approved appliances; or

Exception No. 3: Outlets supplying bui l t - in appliances such as gas ovens and the like where there are no conductors in the outlet box except the supply conductors terminating therein and the appliance is connected to the outlet in an approved manner.

'SUBSTANTIATION: The present vague and general requirements for accessibility to junction and outlet boxes are unenforceable in new construction conditions as i t is not possible to know the conditions of access, especially in attic or under floor spaces, until the construction is complete. To be enforceable, a specific, clear area as proposed in this requirement must be stated. The proposed requirement has been in effect for many years in the City of Los Angeles and has proven to beeffective, reasonable~and enforceable. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. No evidence to support the suggested change. VOTE ON PANEL REC~ENDATION: Unanimously Affirmative.

370-20(b): Reject CMP 9 SUBMITTER: Harry Silver, Silvine, Inc. PROPOSAL: 32 Revise as follows:

~-~ Thickness of Metal. Sheet steel boxes or die cast aluminum boxes and f i t t ings not over 100 cubic inches in size shall be made from metal not less than .0625 inches thick. The wall of a malleable iron box, permanent-mold cast aluminum box permanent-mold brass or bronze box shall not be less than 2/32-inch thick. Other cast metal boxes shall have a wail thickness of not less than 1/8-inch. SUBSTANTIATION: The reason for the request for change is because the integrity of the die cast aluminum box wil l easily endure any of the impact, compression, and other mechanical strength tests that plastic boxes are now being subjected to for similar uses and exceed requirements at the upper and lower temperature levels. Aluminum has the advantage of not needing a protective finish to provide the l i fe tests presently required from steel boxes. The die cast box has the added advantage that we can design for added wall thickness at various points of possible stress to assure the integrity of the boxes under the necessary tests. At the areas of load such as the threaded holes, the thickness can be increased to provide any mechanical strength that may be required.

The connectors may be designed into the box at time of manufacture, eliminating possible build up of tolerance errors in assembly, and mistakes and misuse of parts. The thinner die cast boxes will be of great advantage to the industry and public in general by reducing the energy costs needed to produce the product. I t wil l be possible to save a good quantity of material by lowering the wall thickness. Benefits are four fold - saving of energy, material, ease of use, and reduction of freight costs to Job site.

Present variety of'die cast boxes with .093 inch wall thickness have more than required mechanical strength. This lighter product is more handy at the time of installation and at the same time has all benefits of boxes with thicker walls. PANEL RECOMMENDATION: Reject. PANEL COMMENT: We believe the present thickness is necessary. Thickness is necessary to contain arcing faults. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-20(b): Reject CMP g SUBMITTER: R. C. Medley, Squire D Co.

33 Revise as fol]ows: ~-T Thickness of Metal. Sheet steel boxes and f i t t ings not

over 100 cubic inches in size shall be made of a sheet thickness not less than 0.0625 inches. The wails of a malleable iron box and a die-cast or permanent-mold, case aluminum, zinc, brass or bronze box shall not be less than 3/32-inch thick unless suitably reinforced by ribs. Other cast metal boxes shall have a wall thickness not less than 1/8-inch unless/suitably reinforced by ribs. /

SUBSTANTIATION: Clarification of sheet steel thickness is necessary to identify the starting thickness of ~ drawn or bent steel box where the thickness is reduced sl ightly by the metal forming operation with no significant loss of strength or longevity.

The omission of die-cast zinc of comparable thickness has restricted the use of an available material as corrosion resistant as aluminum.

The reduction of minimum wall thickness for castings is now feasible by modern technology. I t is no longer necessary or economical torequire thickness where strehgth and r ig id i ty is achievable by suitable design. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary. The Panel does not agree with the supporting comment. Thickness is needed to contain arcing faults. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

370-19; Exception: Accept (~ CMP 9 SUBMITTER: TSC-Approved for the Purpose

31 See the Technical Subcommittee "Recommendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "approved for the purpose ''' and add the word "Listed" at the beginning of the exception. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Cramer, Deming.

EXPLANATION OF VOTE: CRAMER: Listed boxes in the size desired are not always

available. Field fabrication or modification is sometimes required. Consequently, the box cannot be listed. Remove "approved for the purpose" and replace with "suitable for the env irooment."

DEMING: I am opposed to the word " l isted." Listed as defined in Article 100 (definitions) woul~ prohibit the use of custom made boxes. In instances where a one-of-a-kind box is r~quired, " l is t ing" is not practical. Designed is a more appropriate word.

370-21: Reject CMP 9 SUBMITTER: R. C, Medley, Square D Co. ~ 3 4 Revise as follows: ~ C o v e r s . Sheet steel covers shall be made of a sheet thicknessnot less than .0625 inches or be suitably reinforced by ribs. Die-cast or permanent-mold cast metal covers shall be not less than 3/32-inch unless suitably reinforced by ribs. Other cast metal covers shall be not less than 1/B-inch unless suitably reinforced by ribs. Covers of porcelain or Other insulating material shall be permitted i f of such-form and thickness as to afford the required protection and strength. SUBSTANTIATION: Editorial changes requested to c lar i fy construction details. Present wording intended~to correlate . with Sections 370-20 and 373-10 but is ambiguous and confusing. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary. The Panel does not agree with the supporting comment. Thickness is needed to contain arcing faults. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

164

ARTICLE 372 -- ENCLOSURE TYPES

Article 372-(New): Reject CMP g SUBMITTER: Francis A. Marta, Circle A W Products Co.

35 Add a new article as follows: Article 372 -- ENCLOSURE TYPES

372-1. Scope. This article covers the general requirements for various types of enclosures for electrical equipment rated 600 volts nominal or less, installed in nonhazardous locations.

Exception to Scope: The enclosures described herein are not intended to: .protect the enclosed equipment against conditions such as condensation, icing, corrosion or contamination which occur within the'enclosure or enters via the conduit or unsealed openings; cover enclosures for rotating apparatus; or cover means to prevent attempted entry or operation by unauthorized personnel. This article does not cover requirements for wire and cable.

Enclosures for use in hazardous locations shall conform to Articles 500 through 517. 372-2. Purpose of Enclosures. Enclosures are constructed to provide a degree of protection, when completely and properly installed, against incidental contact with the enclosed equipment and to provide a degree of protection to the enclosed equipn~nt agalnstspecified environmental conditions. 372-3. Enclosure Type Descriptions. Enclosures shall be identified with one or more types for the following environmental conditions:

(a) Type 1-1ntended for indoor use primarily to provide a degree of protectio n against contact with the enclosed equipment.

(b) Type 2-1ntended for indoor use primarily to provide a degree of protection against limited amounts of fall ing water and dir t .

(c) Type. 3-1ntended for outdoor use primarily~to provide a degree of protection against windblown dust, rain, sleet and external ice formation.

(d) Type 3R-Intended for outdoor use primarily to provide degree of protection against fal l ing rain, sleet and external ice formation.

(e) Type 3S-Intended for outdoor use primarily to provide a degree of protection against windblown dust, rain and sleet, and to provide for operation of external mechanism when ice laden.

(f) Type 4-1ntended for indoor or outdoor use primarily to provide a degree of protection against windblown dust and rain, splashing water and hose-directed water.

(g) Type 4X-Intended for indoor or outdoor use primarily to provide a degree of protection against corrosion, windblown dust and rain, splashing water and hose-directed water.

(h) Type 5-Intended for indoor use primarily to provide a degree of protection against dust and fall ing dirt .

( i) Type 6-Intended for indoor or outdoor use primarily to provide a degree of protection against the entry of water during occasional temporary submersion at a limited depth.

(J) Type 6P-Intended for indoor or outdoor use primarily to provide a degree of protection against the entry of water during prolonged submersion at a limited depth.

(k) Type 11-1ntended for indoor use primarily to provide, by oil immersion, a degree of protection to enclosed.equipment against the corrosive effects of liquids and gases.

(1) Type 12-Intended for indoor use primarily to provide a degree of protection against dust, fal l ing dir t and dripping water.

(m) Type 12K-Enclosures with knockouts intended for indoor use primarily to provide a degree of protection against dust, fal l ing dir t and dripping water other than at knockouts.

(n) Type 13-1ntended for indoor use primarily to provide a degree'of protection against dust, spraying of water,'oil and noncorrosive coolant. 372-4. Applications. Tables 372-4A and 372-4B are comparisons of specific applications of indoor and outdoor enclosures.

Table 372-4A Comparison of Specific Applications of

Enclosures for Indoor Nonhazardous Locations

.,Prqvides a Degree of Protection Against the Type of Enclosure Following Environmental Conditions 1 2 4 4X'5 6 6P 11 12 12K 13 Incidental contact with

the enclosed equipment X X X X X X X X X X X Falling Dirt X X X X X X X X X X X Falling l!quids and

light splashing X X X X X X X X X Dust, l in t , fibers and

flyings X X X X X X X X X Hosedown and splashing

water X X X X Oil and coolant seepage X. X Oil or coolant spraying

and splashing X Corrosive agents X X Occasional temporary

submersion X X Occasional prolonged

submersion X

Table 372-4B Comparison of Specific Applications of

Enclosures for Outdoor Nonhazardous Locations

Provides a Degree of Protection Against the T~pe of Enclosure Following Enyironmental Conditions 3 3R 3S 4 4X 6 6P Incidental contact with

the enclosed equipment X X X X X X X Rain, snow and sleet* X X X X X X X Sleet** X Windblown dust X X , X X X X Hosedown X X X X Corrosive agents X Occasional temporary

submersion X X Occasional prolonged

submersion X

*External operating mechanisms are not required to be operable when the enclosure is ice covered.

**External operating mechanisms are operable when the enclosure is ice covered.

372-6. Operating Mechanisms. Externally operated mechanisms such as circuit breakers or disconnect operating levers ahd other mechanisms including pushbuttons and pi lot lights when installed through the enclosure wall shall provide the same

• degree of environmental protection as the enclosure. SUBSTANTIATION: Type numbers have been associated with various enclosures for many years but with a somewhat lack of standardization except for a few types, and these have not been too well publicized.

Electrical contractors, electrical inspectors and users have fe l t a need for having a basis for selecting and accepting the proper enclosures for the various applications with proper markings to meet the requirements of Sections 110-3 and 110-11 of the National Electrical Code. PANEL RECOMMENDATION: Reject. PANEL COGENT: The C~ believes that extending the requirements as intended by this Proposal isnot appropriate at this time. VOTE ON PANEL RECOt~iENDATION:


EXPLANATION OF VOTE: BARKER: The NEMA type numbers and classifications are used

throughout the industry wherever enclosures are used, specified on plans, liste~d by manufacturers or suppliers. The time is long past due for the Code to be consistent with the industry and give guidance on this subject. The reasoning that industry may revise this type of numbers is unacceptable because the entire Code is always being updated and any changes in these types, etc., could be accepted as any other Code change. The time to act is new.

[ Article 372-(New): Reject SUBMITTER: James M. Rice, Allen-Bradley Co. PROPOSAL: 36 Add new article as follows:

CMP

ARTICLE 372°ENCLOSED APPARATUS

372-i. This article covers the general requirements for surface mounted enclosures for the following equipment rated nominally 600 volts or less installed in nonhazardous locations: Circuit Breakers, Industrial Controls, Motor Controllers, Motor Control Centers, Panelboards, Switchboards, Switches, Transformers. 372-2. Application to other articles. Equipment for use in hazardous locations shall conform to Articles 500 through 517. 372-3. Purpose of Enclosures. Enclosures shall be constructed to provide a degree of protection against accidental contact with enclosed equipment and to provide ~ degree of protection for the enclosed equipment against specified enviFonmental conditions.

(f.p.n.) I t is recognized that enclosures do not protect the enclosed equipment against conditions such as condensation, icing, corrosion or contamination which occur within the enclosure or enter via the conduit or unsealed openings. 372-5. Enclosure Types. Apparatus within the scope of this article shall be marked with one or more of the following enclosure type designations:

(a) Type I , where the enclosure is intended for only indoor use, to provide protection against contact with enclosed equipment.

(b) Type 2, where the enclosure is intended for only indoor use, primarily to provide a degree of protection against limited • nounts of fall ing water and dir t .

(c) Type 3, where the enclosure is intended for outdoor use, primarily to provide a degree of protection against windblown dust, rain and sleet and from external ice formation.

(d) Type 3R, where the enclosure is intended for outdoor use, primarily to provide a degree of protection against fal l ing rain and sleet and against external ice formation.

(e) T)qoe 3S, where the enclosure is intended for outdoor use, primarily to provide a degree of protection against windblown

165

dust, rain and sleet and provides for operation of external' mechanisms when ice laden.

(f) Type 4, where the enclosure is intended for indoor 'or outdoor use, primarily to provide a degree of protection against windblown dust and rain, splashing water and hose directed water under specified conditions.

(g) Type 4X, where the enclosure is intended for indoor or outdoor use, primarily to provide a degree of protection against corrosion, windblown dust and rain, splashing water and hose directed water under specified conditions.

(h) Type 5, where the enclosure is intended for only indoor use, primarily.to provide a degree of protection against dust and fall ing dirt .

( i) Type 6, ~here the enclosure is intended for indoor or outdoor use, primarily to provide a degree Of protection against the entry of water during occasional, temporary submersion at a limited depth.

(J) Type 6P, where the enclosure is intended for indoor or outdoor use, primarily to provide a degree of protection against the entry of water during prolonged submersion at a limited depth.

(k) Type 11, where the enclosure is intended for only indoor use, primarily to provide a degree of protection for the enclosed equipment against corrosive liquids and gases, by immersion in oi l .

(I) Type 12, where the enclosure is intended for only indoor use, primarily to provide a degree of protection against dust, fall ing dir t and dripping water.

(m) Type 12K, where the enclosure includes knockouts that are utilized by the installer to result in an installation equivalent to Type 12.

(n) Type 13, wfiere the enclosure is intended for only indoor use, primarily to provide a degree of protection against dust, spraying of water, oil and noncorrosive liquids. 372-7. Indoor Aoplcations. Enclosure types appropriate for the anticipated indoor environmental conditions shall be used. Enclosures shall be selected in accordance with Table 372-7.

TABLE 372-7-Enc.losures for Indoor Nonhazardous Locations

ENVIRONMENTAL CONDITIONS Provides a Degree of Protection Against 1 2 4

Incidental contact with enclosed equipmt.X X X

Falling dir t . . . . . . . . . . . X X X Falling liquids and / l ight splashing . . . . . . . X X

Dust, l in t , fibers and flyings . . . . . . . . . . . X

Hosedown and splashing water . . . . . . . . . . . . . . . . . X

Oil andcoolant seepage . . . . . . . . . . . . . . .

Oil or coolant spraying and

splashing . . . . . . . . . . . . . . Occasional temporary submersion . . . . . . . . . . . .

Occasional prolonged submersion . . . . . . . . . . . .

Type of Enclosure

4 X 5 6 6 P 1 1 12 13

X X X X X X X X X X X X X X

X X X X X X

X X X X X X

X X X

X X

X

X X

372-9. Outdoor Applications. Enclosure types appropriate for the anticipated outdoor environmental conditions shall be used. Enclosures shall be selected in accordance with Table 372-9.

TABLE 372-g-Enclosures for Outdoor Nonhazardous Locations

ENVIRONMENTAL CONDITIONS Type of Enclosure

Provides a Degree of Protection Against Ty3 Ty3R Ty3S Ty4 Ty4X Ty5 Ty6P

Incidental contact with enclosed equipment . . . . . . . . . . . . . X

Rain, snow and sleet* . . . . . . . X

Sleet** . . . . . . . . . . . Windblown dust . . . . X Hosedown Occasional te~iporary submersion . . . . . . .

bccasional prolonged submersion . . . . . . . .

i

X X X X X X

X X X X X X X X X X X X

X X X X

X ,X I

* External operating mechanisms are not required to be operable when the enclosure is ice covered. ** External operating mechanlsms are operable when the enclosure Is Ice covered. ".

372-11. Materials. All enclosures shall be contructed of base materfals that will not support combustion in air. 372-13. Conductor Entry. When installed, conductor entry f i t t ings shall provide the some degree of environmental protection as the enclosure. 372-15. Operating Mechanisms. Externally operating mechanisms such as those for circuit breakers or disconnect switches, and other mechanisms including push-buttons and pi lot lights when installed through the enclosure wall shall provide the some degree of environmental protection as the enclosure. •

SUBSTANTIATION: This addition to the National Electrical Code wil l promote safety by assisting users and inspectors in determining the proper enclosure for electrical equipment for the environment. The enclosure type numbers in this article have been used in the trade and in industry for many years. Despite this fact, there is confusion as to the characteristics of the various type designations. Improper enclosures are the source of many accidents involving injury to workers and the large property losses. Examples of improper enclosures can be cited from numerous product l iab i l i t y l i t igations.

Electrical inspectors will find this new section particularly useful because of the clear and concise descriptions Of the types of enclosures. PANEL RECOMMENDATION: Reject. PANEL C~MMENT: 'The CMP believes that extending the requirements as intended by thls Proposal is not appropriate at this time. VOTE ON PANEL RECO~ENDATION:'


EXPLANATION OF VOTE: BARKER: Same comment as Proposal No. 35.

ARTICLE 373 -- CABINETS AND CUTOUT BOXES

373: Reject . CMP 9 SUBMITTER: Eldon Hemsey, Wilmington, DE PROPOSAL: 37 All exterior or interior switch cabinets, having expos-oseB-uninsulated electrical (current carrying) components which are accessible when the cabinet door is open, shall be provided with a lock or other device to prevent children from opening them. SUBSTANTIATION: Many existing disconnect switches, particularly on exterior air conditioning condensing units, mounted on pads on the ground, are within easy reach of curious small children. I f these boxes can be easily opened, a child could touch the current carrying elements inside the cabinet and be electrocuted.

There are millions (or at least thousands).of these switch cabinets, mounted on air conditioning condensing units outside houses and garden apartment buildings all over the country, which are not locked, so as to protect children from injury or death.

Perhaps local inspecting off ic ials should be alerted to the danger, and switch cabinet manufacturers required to provide a child-proof door catch, In addition to the padlock hasp they

ready provide. PANEL RECOMMENDATION: Reject. PANEL COMMENT: This equipment is already provided with means for locking. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

373-6, 380-18 and 384-25: Accept CMP 9 SUBMITTER: a.J. Kark, National Electrical Manufacturers Assn.

38 Revise as follows: ~Tr3~--CNo change).

(a) (No change). Revise t i t l e of table as follows: Table 373-6(a) - Minimum Width of Wiring Gutters and Minimum

Wire Bending Space for 373-6(b)(I). Revise present (b) as follows: (b) Wlre Bending Space at Terminals. Wire bending space at a

terminal shall be provided in accordance with (1) or (2) below:. (1) Table 373-6(a) shall apply where the conductor is

substantially deflected, but not more than 90 degrees and not more than once as i t leaves the terminal and .enters the gutter. Table 373-6(a) shall also apply where an individual connector of the removable or lay-in type for each conductor is furnished wlth the equipment or designated as suitable by marking on the equipment.

166

dust, rain and sleet and provides for operation of external' mechanisms when ice laden.

(f) Type 4, where the enclosure is intended for indoor 'or outdoor use, primarily to provide a degree of protection against windblown dust and rain, splashing water and hose directed water under specified conditions.

(g) Type 4X, where the enclosure is intended for indoor or outdoor use, primarily to provide a degree of protection against corrosion, windblown dust and rain, splashing water and hose directed water under specified conditions.

(h) Type 5, where the enclosure is intended for only indoor use, primarily.to provide a degree of protection against dust and fall ing dirt .

( i) Type 6, ~here the enclosure is intended for indoor or outdoor use, primarily to provide a degree Of protection against the entry of water during occasional, temporary submersion at a limited depth.

(J) Type 6P, where the enclosure is intended for indoor or outdoor use, primarily to provide a degree of protection against the entry of water during prolonged submersion at a limited depth.

(k) Type 11, where the enclosure is intended for only indoor use, primarily to provide a degree of protection for the enclosed equipment against corrosive liquids and gases, by immersion in oi l .

(I) Type 12, where the enclosure is intended for only indoor use, primarily to provide a degree of protection against dust, fall ing dir t and dripping water.

(m) Type 12K, where the enclosure includes knockouts that are utilized by the installer to result in an installation equivalent to Type 12.

(n) Type 13, wfiere the enclosure is intended for only indoor use, primarily to provide a degree of protection against dust, spraying of water, oil and noncorrosive liquids. 372-7. Indoor Aoplcations. Enclosure types appropriate for the anticipated indoor environmental conditions shall be used. Enclosures shall be selected in accordance with Table 372-7.

TABLE 372-7-Enc.losures for Indoor Nonhazardous Locations

ENVIRONMENTAL CONDITIONS Provides a Degree of Protection Against 1 2 4

Incidental contact with enclosed equipmt.X X X

Falling dir t . . . . . . . . . . . X X X Falling liquids and / l ight splashing . . . . . . . X X

Dust, l in t , fibers and flyings . . . . . . . . . . . X

Hosedown and splashing water . . . . . . . . . . . . . . . . . X

Oil andcoolant seepage . . . . . . . . . . . . . . .

Oil or coolant spraying and

splashing . . . . . . . . . . . . . . Occasional temporary submersion . . . . . . . . . . . .

Occasional prolonged submersion . . . . . . . . . . . .

Type of Enclosure

4 X 5 6 6 P 1 1 12 13

X X X X X X X X X X X X X X

X X X X X X

X X X X X X

X X X

X X

X

X X

372-9. Outdoor Applications. Enclosure types appropriate for the anticipated outdoor environmental conditions shall be used. Enclosures shall be selected in accordance with Table 372-9.

TABLE 372-g-Enclosures for Outdoor Nonhazardous Locations

ENVIRONMENTAL CONDITIONS Type of Enclosure

Provides a Degree of Protection Against Ty3 Ty3R Ty3S Ty4 Ty4X Ty5 Ty6P

Incidental contact with enclosed equipment . . . . . . . . . . . . . X

Rain, snow and sleet* . . . . . . . X

Sleet** . . . . . . . . . . . Windblown dust . . . . X Hosedown Occasional te~iporary submersion . . . . . . .

bccasional prolonged submersion . . . . . . . .

i

X X X X X X

X X X X X X X X X X X X

X X X X

X ,X I

* External operating mechanisms are not required to be operable when the enclosure is ice covered. ** External operating mechanlsms are operable when the enclosure Is Ice covered. ".

372-11. Materials. All enclosures shall be contructed of base materfals that will not support combustion in air. 372-13. Conductor Entry. When installed, conductor entry f i t t ings shall provide the some degree of environmental protection as the enclosure. 372-15. Operating Mechanisms. Externally operating mechanisms such as those for circuit breakers or disconnect switches, and other mechanisms including push-buttons and pi lot lights when installed through the enclosure wall shall provide the some degree of environmental protection as the enclosure. •

SUBSTANTIATION: This addition to the National Electrical Code wil l promote safety by assisting users and inspectors in determining the proper enclosure for electrical equipment for the environment. The enclosure type numbers in this article have been used in the trade and in industry for many years. Despite this fact, there is confusion as to the characteristics of the various type designations. Improper enclosures are the source of many accidents involving injury to workers and the large property losses. Examples of improper enclosures can be cited from numerous product l iab i l i t y l i t igations.

Electrical inspectors will find this new section particularly useful because of the clear and concise descriptions Of the types of enclosures. PANEL RECOMMENDATION: Reject. PANEL C~MMENT: 'The CMP believes that extending the requirements as intended by thls Proposal is not appropriate at this time. VOTE ON PANEL RECO~ENDATION:'


EXPLANATION OF VOTE: BARKER: Same comment as Proposal No. 35.

ARTICLE 373 -- CABINETS AND CUTOUT BOXES

373: Reject . CMP 9 SUBMITTER: Eldon Hemsey, Wilmington, DE PROPOSAL: 37 All exterior or interior switch cabinets, having expos-oseB-uninsulated electrical (current carrying) components which are accessible when the cabinet door is open, shall be provided with a lock or other device to prevent children from opening them. SUBSTANTIATION: Many existing disconnect switches, particularly on exterior air conditioning condensing units, mounted on pads on the ground, are within easy reach of curious small children. I f these boxes can be easily opened, a child could touch the current carrying elements inside the cabinet and be electrocuted.

There are millions (or at least thousands).of these switch cabinets, mounted on air conditioning condensing units outside houses and garden apartment buildings all over the country, which are not locked, so as to protect children from injury or death.

Perhaps local inspecting off ic ials should be alerted to the danger, and switch cabinet manufacturers required to provide a child-proof door catch, In addition to the padlock hasp they

ready provide. PANEL RECOMMENDATION: Reject. PANEL COMMENT: This equipment is already provided with means for locking. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

373-6, 380-18 and 384-25: Accept CMP 9 SUBMITTER: a.J. Kark, National Electrical Manufacturers Assn.

38 Revise as follows: ~Tr3~--CNo change).

(a) (No change). Revise t i t l e of table as follows: Table 373-6(a) - Minimum Width of Wiring Gutters and Minimum

Wire Bending Space for 373-6(b)(I). Revise present (b) as follows: (b) Wlre Bending Space at Terminals. Wire bending space at a

terminal shall be provided in accordance with (1) or (2) below:. (1) Table 373-6(a) shall apply where the conductor is

substantially deflected, but not more than 90 degrees and not more than once as i t leaves the terminal and .enters the gutter. Table 373-6(a) shall also apply where an individual connector of the removable or lay-in type for each conductor is furnished wlth the equipment or designated as suitable by marking on the equipment.

166

(2) In all other cases, Table 373-6(b) shall apply. Add new table as follows:

Table 373-6(b) - Minimum Wire Bending Space at Terminals forX373-6(b)(2) in Inches

AWG or Wires per Terminal Circular-Mil Size of Wire I 2 3 4

14-10 Not Spec. 8-6 1 1/2 4-3 .2 1/2 2 3 I/2 1 4 I/2 -

0 5 5 7 O0 6 6 7 1/2 000-0000 6 1/2 6 I/2 8 250 MCM 8 8 9 300 MCM 10 10 11 350 MCM 12 12 13 400-500 MCM 12 12 14 600-700 MCM 14 16 17 750 MCM 16 19 21 800-900 MCM 18 1000-1250 MCM 21 1500-2000 MCM 24

10 12 14 16 18 18 20 23 25

Bending space at terminals shall be'measured in a straight line from the end of the lug or wire connector (in the direction that the wire leaves the terminal) to the wall or barrier.

(c) (No change). SUBSTANTIATION: Several proposals were made for the 1978 Code to increase wire bending space to make offset or double bends at terminal points. These proposals were based on the application of a multiplier to the existing Table 373-6(a). NEMA has sponsored a Fact-Findlng study which Underwriters' Laboratories has conducted under guidance of a steering committee composed of electrical inspectors, industrial users and manufacturers. The purpose of the study was to establish factual data for the space necessary to make wire bends and to install wire into connectors.

TheFact-Finding Report wil l be provided tO CI~ ~ g members. Based on the result of this study, NEMA proposes the above text for 373-6 and the additional Table 373-6(b).

The attached tabulation* cross references values in proposed Table 373-6(b) with the Fact-Finding Study Project number for which test results show successful installation.

* Attachments have been supplied to CHP members. Table 373-6(b) establishes increased bending space

requirements f o r : (1) al l factory-installed connectors which are not of the

lay-in or removable type; (2) field-installed connectors which are not designated by

the manufacturer as part of the equipment marking. No changes are proposed in Table 373-6(a) except to clar i fy

its t i t l e . This existing table has been adequate for single bends up to 90 degrees.

The values in Table 373-6(a) also apply for lay-in or removable-type connectors where each connector accommodates only a single conductor. This wil l fac i l i ta te the use of f ield-installed connectors which may be dimensionally different from the connectors Furnished with the equipment. This also would require manufacturers to provide adequate bending space, electrical clearances and markings for specific types of f ield-installed connectors.

Tests 2C, 4G, 7H, lOB, I3F, 13J and 22B demonstrate that single conductors can be installed using removable or lay-ln lugs when gutter space is equal to the minimu~n amount required by existing Table 373-6(a). These tests cover wire sizes from #2 AWI; to 750 MCM. Additional supporting tests are in process for conductor sizes No. 3, 1,and 2/0 AWG. PANEL RECOMMENDATION: Accept as Revised:

373-6 No change. 373-6(a) No change. Table 373-6(a) No change. Reword the end of footnote to

read: "to the wall, barrier or obstruction." Revise 373-6(b) of the 1978 NEC to read as follows: (b) Wire Bending Space at Terminals. Wire bending space at

each terminal shall be provided in accordance with (I) or (2) below:

(I) Table 373-6(a) shall apply where the conductor does not enter nor leave the enclosure through the wall opposite the terminal.

Exception: Conductors which enter a second wire bending space conforming to Table 373-6(b) for that conductor.

(2) Table 373-6(b) shall apply where the conductor enters or leaves the enclosure through the wall opposite the terminal.

For removable (single barrel) compression (crimp) type terminals, bending space may be reduced'2 inches for 3/0 AWG to 250 MCM and 3 inches for 300 to 750 MCM."

Table 373-6(b). Minimum Wire Bending Space at Terminals for 373-6{b){2) in Inches.

Wires Per Terminal

Wire Size 1 2 3 4 or More

14-10 Not Specified

8 I 1/2 6 2

4 3 3 3 2 3 1/2

4 I/2 0 5 1/2 2/0 6

3/0' 6 1/2 4/0 7 250 8 1/2

300 I0 350 12 400 13

500 14 600 15 700 16

750 17 800 18 900 19

I000 20 1250 22 1500 24

1750 24 2000 24

5 I/2 7 6 7 1/2

6 1/2 8 7 1/2 8 1/2 8 I/2 9 lO

10 l l ~ 12 12 13 14 13 14 15

14 15 16 16 18 19 18 20 22

19 22 24 20 22 24 22 24 24

Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector (in the direction that the wire leaves the terminal) to the wall~ barrier or obstruction.

373-6(c) No change. Add a new 380-18 as follows:

"380-18 Wire Bending Space..The wire bending space required by Section 380-3 shall meet Table 373-6(b) spacings to the enclosure wall opposite the llne and load terminals."

Add a new 384-25 as follows: "384-25 Wire Bending Space in Panelboards. The enclosure for a )anelboard shall have the top and bottom wire bending space sized in accordance with Table 373-6(b) for the largest conductor entering or leaving the enclosure. Side wire bending space shall be in accordance with Table 373-6(a) for the largest conductor to be terminated in that space.

Exception: Either the top or bottom wire bending space shall be permitted to be sized in accordance with Table 373-6(a) where at least one side wire bending space is sized in accordance with Table 373-6(b) for the largest conductor to be terminated in that space." VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 11. NEGATIVE: Burniston.

COMMENT ON VOTE: HOGAN: I have not voted negatively on this proposal, however,

I would like to call the attention of the general public some of the provisions of this new proposal that may cause serious problems in the f ield.

This proposal wil l permit some substantial reductions in required bending provided a particular type of lug is utilized. I t would seem to me that i t will be necessary for manufacturers who intend that these special lugs be used with their equipment and therefore provide the smaller space permitted by this proposal wil l have to install the special lugs permanently in such equipment so that the contractors, mechanics and inspectors wil l know that only those lugs may be used in those enclosures. There should be some public comment from all facets of the industry so that this part of the proposal can be given further consideration at the November meeting of C~P 9.

BARKER: Voting affirmative is for "something better than nothing." The fact finding study proved that more bending space is a n~ust at terminations. There is no way that the manufacturer can control how a panel or switch is used in the f ield as to the point of entry or exit of any conductor or raceway. Therefore, the bending space should be opposite of all terminals. Time wil l prove that another change and retooling will be mandated by contractors, users and safety enforcement off ic ials. The needs for safety is there and proven and what is available for use cannot continue to be mandated by the manufacturers of this equipment in light of the proven facts.

LIEMAN: I haven't voted negatively on this proposal but would like to be on record to discuss this at our next meeting in December. I t is nly view that we wil l get a broader reaction at our Eastern Section meeting in September as to whether this

" 1 6 7

proposal wil l cause any problems. EXPLANATION OF VOTE:

BURNISTON: While NEMA accepts the proposed change in Section 373-6(a) and the associated Section 373-6(b) there is no substantiation for the addition of new Sections 380-18 and 384-25. Section 373-6 as revised adequately covers the requirements for enclosed switches, circuit breakers and panelboards, and Sections 380-3 and 384-3(g) presently refer back to Section 373-6.

Proposed Section 384-25 requires two (2) gutters large enough for the main conductors where in practically all cases this is not required to adequately wire the panelboard.

Table 373-6(a)and 373-6(b): Reject CMP 9 SUBMI1-FER: A. C. Clark, Manufacturing Chemists Association PROPOSAL: 39 Add new Table 373-6(a). Note that the ~ s e s and nunW)ers contained in the parentheses are the only changes.

After the one sentence note to Table 373-6(a), add the following. "Numbers in parentheses apply to conductors bent or deflbcted more than once. Nund)ers not in parentheses appIy to conductors bent or deflected once."

In Section 373-6(b) add the following at the end of the f i r s t sentenc e. " I f a compression type pressure connector is used, numbers in parentheses may be reduced to the.extent that i f the compression type pressure connector were replaced with an approved set- screw pressure connector, the requirements in the parentheses would be met." SUBSTANTIATION: The need. for increased wiring space for conductors bent or deflected more than once wasestablished three years ago by proposals for the 1978 National Electrical Code. Disagreement on the amount of increased space led to the appointment of a steering committee to agree upon and oversee a series of tests. Such tests to determine an adequate amount of bending space are nearing completion.

Based on the results of these tests, the proposed additions to Table 373-6(a) cover conductors which'are bent or deflected more than once. Included for background is summary (pages I to 5) of such tests along with comments. Tests were not run on alI bending spaces proposed. However, in view of results obtained, these numbers are though~ to be reasonable. The intent of the proposed addition to Section 373-6(b) is to not penalize those wishing to use compression type pressure connectors. These connectors are often longer than set-screw pressure connectors. In many instances, purchased equipment comes equipped with set-screw pressure connectors and replacement of these with compression type is sometimes impossible because of inadequate space per Table 373-6(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 38. VOTE ON PANEL RECO~MENDATION: Unanimously Affirmative.

Table 373-6(a) -- Minimum Wire Bending Space at Terminals and Minimum Width of Wiring Gutters in Inches

C

AWG Circular-Mil Wires per Terminal Size of Wire 1 2 3 4 5

14-10 Not Specified . . . . . . . . 8-6 1½ (2) . . . . . . . . 43 2 . . . . . . . .

2 2~ . . . . . . . . 1 3 ( 4 ~ ) . . . . . . 0-00 3~i (6) 5 - (6 , ) 7 (8) . . . . ooo-oooo 4 (7,) 6 (8) 8 l~I -" 250 MCM 4~ (9) 6 (9) 8~ 10 (10) - -

l ol !iil I :l 400-s00 '.CM 6 10 12 ~; 600-700 MCM 8 (16) 10 12 (19) 14 (20) 16 750-900 MCM 8 (20) 12 (22) 14 (24) 16 (26) 18 (26) 1000-1250 MCM 10 (22) . . . . . . . . 1500-2000 MCM 12 (24) . . . . . . . .

Table 373-6(a), 373-6(b), CMP g New Table 373-6(b): Reject SUBMITTER: Idaho Chapter IAEI

40 Revise t i t l e of Table 373-6(a) as follows: ~ m Width of Wiring Gutters in Inches.

Revise (b) and add new Table 373-6(b) as follows: (b) Wire Bending Space at Terminals. Conductors shall not be

deflected at a terminal unless bending space within a cabinet or cutout box is provided In accordance with Table 373-6(b). Conductors in parallel in accordance with Section 310-4 shall be Judged on the basis of the number of conductors in parallel.

Table 373-6(b) - Minimum Wire Bending Space in Inches in Enclosures Containin 9 Terminals

AWG or Wires per Terminal Circular Mil

Wire Size 1 and 2 3 4 5

14-10 Not Spec. 2 - 8-6 2 3 - 4-3 3 4 2 4 5 1 5 8 0-00 8 10 OOO-OOOO 9 I0 250 MCM 9 12 15 300-350 MCM 12 16 18 400-500 MCM 14 15 20 24 600-700 MCM' 16 18 22 28 750-900 MCM 20 21 26 32 1000-1250 MCM 22 24 1500-2000 MCM 24 27

Delete fine print note from Table 373-6(a) and relocate as FPN to Table 373-6(b). SUBSTANTIATION: Supporting comments for Proposal No. 40 and 43 Page 195 of the Preprint for the 1978 National Electrical Code determines that we are not mainly concerned wlth insulation damage when bending conductors, but with misaligument of the lay of the conductor strands which in turn cause excessive heating. Consequently causing further insulation damage, even f i re .

Field experience has, for years, been cr i t ical of the crowded bending spaces provided in enclosures containing terminals. This continual arbitration with industry f inal ly came to the point of a Fact Finding Committee compiling the data that actually substantiates the long sought extra bending spaces required to correct these f ield problems which have caused more trouble than was actually anticipated by the industry. These statistics were used for basis of the proposed new,Table 373-6(b).

The installation problems were found not only to exist In the conductor requiring bends or offsets, but, more consideration was required for the ones that are directed straight into the terminals, thus, more bending space for al ) the conductors in the enclosures is needed. PANEL RECOI~ENDATION: Reject. PANEL COI~ENT: See Panel action on Proposal No. 38. VOTE ON PANEL RECO~ENDATION: Unanimously Affirmative.

373-6(b) and (c): Reject Cl@ 9 SUBMITTER: Ralph H. Lee, Lee ElectrAcal Engineering, Inc. ~ 4 1 Revise as follows: ~ p a c e for single bend at terminals. Conductors required to be bent in one bend not exceeding 90 ° shall require bending space in accordance with Table 373-6(a). Change(c) to (d)and add new (c) as follows:

(c) Space for additional bends at terminals. Conductors required to be bent in more than one bend, such as an S-bend condition, shall be accorded bending space of two times 'that shown In Table 373-6(a). SUBSTANTIATION: Table 373-6(a) is properly based on conductors leaving a terminal, making one 90 a bend along the side gutter of a panelboard cabinet, and exiting from top or bottom of the cabinet. As such, I t properly specifies the allowance of space for this bend in accordance with the permitted bending radii of the varlous-sized wires and conductors as set forth by IPCEA, that body most knowledgeable about the susceptibility of wires and cables to the various installation problems.

In the absence of any other table in NEC regarding termlnal-to-side-wall spacing, this table has been applied without modification to all terminal sldewall/spacings, ~egardless of the need for additional bends. The great majority of uses in switches, circuit breakers and similar gear, requires that two of the three wires be formed into S-bends to accomodate the separation of terminals and the exit of the conductors, through a single conduit or bushing. In these many cases, the double bend must be cramped into the space which is properly specified for only a single bend. Over-sharp bending of cables at terminals, and In pressure against wlre insulation are major results. Both of these are serious sources of failures which can be responsible for f ires. C

Sln~)le short-time tests of over-sharp bending Just to show " i t can be done" can never be condoned as reason for retaining this monstrosity in the Code, any more than short-term testing could Justify the use of EC aluminum wiring in'residences. Any Journeyman electrician knows that the biggest problem in electrical installation Is the crowded termination space, requiring excessively sharp conductor bending; this is shown from a questionnaire published a few years ago. So why, i f Table 373-6(a) spacings are required for their real intent, single bends, does the Code not require double these values for double bends? PANEL RECOI~ENDATION: Reject. PANEL COGENT: See Panel action on Proposal No. 38. VOTE ON PANEL RECO~ENDATION: Unanimously Affirmative.

1 6 8

I

373-6(c)-(New)(HOD 1978 NEC): Reject CMP 9 SUBMITTER: CMP 9 PROPOSAL: 42 Amend Section 373-6 by adding thereto a new su--Gb-T~ETon (c) as fol lows:

(c) The provisions of subsections (a) and (b) of th is section apply to conductors bent or deflected no more than once. For conductor bending space at terminals and width of gut ter space fo r conductors that are bent or deflected more than once, the gutter or bending space required shall be one and one hal f times the value l is ted In Table 373-6(a). Present subsection " (c ) " w111 become "(d)." SUBSTANTIATION: We were convinced by the supportlng comment supplied wlth Proposal No. 39 in the 1978 Preprlnt. PANEL RECOMMENDATION: Reject. PANEL COGENT: See Panel action on Proposal No. 38. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

373-10(a): Accept CMP 9 SUBMITTER: TSC-Approved for the Purpose PR'O-~(5~_-T." 43 See the Technical Subcommittee "Recommendations" un--6-de-~'-t~f~e definition of "Approved for the Purpose" in Artlcle 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" In Article 100. PANEL RECOMMENDATION: Accept as Revised: i Delete the words "and shall be approved for the purpose." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

373-10(c): Reject CMP 9 SUBMITTER: Patrick J. Fox, St. Louis, MO PIIIS]IO'S'~-~. • 44 Change paragraph to read:

~-~ Nonmetallic Cabinets and Cutout Boxes. Nonmetallic cabinets and cutout boxes shall be approved for the purpose. SUBSTANTIATION: This is intended to make the statement consistent with the statement for metal cabinets and cutout

• boxes and with Section 370-3. To require submittal for approval of every nonmetallic cabinet and box appears unnecessary i f they are approved for the purpose. • This was previously submitted for the 1975 National Electrical Code and a Task Group was to have studied this proposal change. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present Code wording is necessary until standards are written. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: CRAMER: The existing Section required approval prior to

installation. Approval after installation should suffice. Sentence should read: "Norm~tallic cabinets shall be suitable for the environment."

373-11(a)(3); Accept CMP g SUBMITTER: TSC-Neminal Voltage P]TOlIO-~lZ~.'45 Change "600" in last line to "635." ~ I A T I O N : To conform to the method to express maximum voltage as per, guldellnes developed by the TSC on nominal voltage. PANEL RECOMMENDATION: Accept as Revised:

Leave 600 as is, but insert the word "nominal" after "600." VOTE ON PANEL RECOMMENDATION: Unanlmously Affirmative.

373-12-{New): Reject CMP 9 SUBMITTER: R. S. Pinkerton, Los Angeles, CA ]~ffO-P'O~-~ 46 Add a new section as follows: ~7"c[zT'ZT - . Equipment on Cabinet Door. No device or other equipment uti l izing electric wiring shall be mounted on or be supported by any cabinet or panelboard trim, cover or door - except where hinged doors designed for the purpose are employed. SUBSTANTIATION: Switches, pushbuttons, pi lot lights and similar control circuit equipment which might be mounted on a removable cabinet cover can offer a severe shock hazard to maintenance personnel. Usually the screWs holding the cover in place provide the equipment grounding, which means that a man removing the cover has an ungrounded piece of equipment in his hand. Furthermore, switches for disconnecting the control circuits are often within the cabinet, making i t d i f f icu l t to de-energize She circuit. I f the cover slips during the process of ren~)val, a live exposed terminal can be grounded to the side of the enclosure. PANEL RECOf~ENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

373-1?-(New): Reject CMP g SUBMITTER: Southwestern Section IAEI PROPOSAL: 47 Add new section as follows: ~TrJTI'2T-. Equipment On Cabinet Door. No device or other equipment uti l izing electric wiring shall be mounted on or be supported by any cabinet or panelboard trim, cover or door - except where hinged doors designed for the purpose are employed. SUBSTANTIATION: Switches, pushbuttons, pi lot lights and similar

• control circuit equipment which might be mounted on a reFnovable cabinet cover can offer a severe shock hazard to maintenance personnel. Usually the screws holding the cover in place provide the equipn~nt grounding, which means that a man removing the cover has an ungrounded piece of equipment in hls hand. Furthermore, switches for disconnecting the control circuits are often within the cabinet, making i t d i f f icu l t to de-energize the circuit. I f the cover slips during the process of removal, a live exposed terminal can be grounded to the side of the enclosure. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanlmously Affirmative.

)

373-X:. Reject CMP 9 SUBMITTER: Ralston W. Calvert, Dept. Bldg. & Safety, City of

P-al~--O'es-ert PROPOSAL: 48 Add a new paragraph to Article 373 (Installation) ~h-TcTi--s~all say "Cabinets or cut boxes located in wall or other places, shall not be installed less than two feet nor more than 6 I/2 feet vertically from the ground floor, concrete slab or roof).

Exception: Cabinets and cut out boxes located in vaults or other approved locations." SUBSTANTIATION:

I . An overcurrent protective device being used to protect an air conditioning unit. The OPD enclosure was located one inch above the ground, the cover of the enclosure hinged on top. When the cover was opened, the manufacturer's specifications and the directory could not be read. I had to l ie on my stomach to inspect the equipment and on my back to read the manufacturer's specifications and directory...(and that's when the sprinkling system came on).

2. A sub-panel located three inches above a patio concrete slab. To inspect the installation, I had to l ie on the slab as the cover was hinged on top. I t was also d i f f i cu l t for the owner to see the circuit breakers, as the cover part ial ly blocked his view. Whenever the patio was hosed off, which was often, the enclosure was drenched with water.

3. An overcurrent protective device and its enclosure was located on a f la t roof. The enclosure was two inches above the roof. To inspect the job or to work on the equipment, a most d i f f i cu l t and t ir ing position must be maintained. A man wearing glasses would be in a dangerous position, due to the required t i l t of his head, leading to poor vision, thereby contributing to a possible accident. PANEL RECOMMENDATION: Reject. PJ~NE[ COMMENT: Supporting comment is not consistent with the Proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COGENT ON VOTE:

CRAMER: I agree with the reject but feel.~hat the reason is that this is getting into design considerations and away from safety. To attempt to set limits that universally apply to every installation is very d i f f icu l t . The inspecting authority can judge the equipment in accordance with Section 110-3 and has the power to reject.

ARTICLE 380 -- SWITCHES

380-2(b): Reject ~ CMP 9 SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI PITOIR)'S'A-L-~." 49 Revise as follows: ~ r switches nor circuit breakers shall disconnect the grounded conductor of a circuit. SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without the correlation of 'ei ther. ' In many instances, this usage is not only gra~matically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Reject. PANEL CO~g4ENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOV~ENDATION: Unanimously Affirmative.

380-2(b), Exception No. 1: Reject CMP g SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI PROPOSAL: 50 Revise as follows: ~ e i t h e r the switch or the circuit breaker etc. SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without the correlation of 'ei ther. ' In many instances, this usage is not only grammatically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

169

SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete the words "approved for the purpose" and add the word "Approved" at the the beginning of the sentence. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 374 -- AUXILIARY GUTTERS

374-9(f)-(New): Reject CMP 8 SUBMITTER: S. D. Mauney, Carolina Power & Light Company PHUPU~AL: 173 Add new (f) as follows: - ~ h e r e an auxiliary gutter is to contain bends or taps to an electric supplier's service conductors larger than No. i AWG, its width at the cover shall be at least 200 percent of that given in Table 373-6(a) and its minimum depth from cover to back shall be 100 percent of the width given in Table 373-6(a). Where the size of the supplier's service conductors is not readily available, the conductor size may be calculated as the equivalent size of the largest aluminum conductors with a 75°C ampacity rating equal to the sum of the service overcurrent devices tapped to the supplier's service conductors. In the table, "Wires per terminal" is to be used to indicate the number of the supply service conductors in parallel per phase. SUBSTANTIATION The required width of the auxiliary gutters used on surv~ces for taps to several or more meter or service equip(nent cabinets is inadequate dn many instances. No stated minmum depth is required. Due to the stiffness and size of the service conductors and to the large size of taped connectors, the connections are under pressure from adjacent conductors, connectors, and the gutter cover.

Even the best tapes are subject to abrasion due to expansion and contraction of the conductors with the load cycle. They also soften due to heat. Shorts occur when the tape is abraded away or softened abnormally. More space wil l help connections to be positioned away from each other and from the cover. The proposed size is minimum. Experience may indicate that larger sizes may be needed.

More space is also needed as/additional taps are made to the service conductors. This is ~specially true of commercial buildings with movable walls where the number, size, and loads of the occupancies is ever changing. Space is also needed when loads are checked with cllp-on ammeters, etc.

Increasing the size of service gutters is already often done by some electricians Who realize that the savings in installation labor and maintenance easily offset the additional material cost involved.

Safety is involved anytime a f i l led gutter is opened for inspection or to make changes as removing the cover allows the spring action of the cramped conductors to come into play. Closing the cover puts additional pressure on the connections. PANEL RECOI~4ENDATION: Reject. PANEL COMMENT: Already covered by Section 374-9(d). Training space is being studied by Panel 9. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


Chapter 9, A. Tables, Note 2: Reject CMP 8 SUBMITTER: Peter Pollak, The Aluminum Association I~OFOSAL-~. 174 In the second sentence of Note 2, replace ~ - ~ t e d or bare)" with "(insulated, bare or compact)." SUBSTANTIATION: Question arises in the f ie ld regarding the selection of the proper conduit size for the application.

Makes clearer the fact that the actual dimensions of compact equipment grounding conductor shall be used in the calculation of conduit f i l l . PANEL RECOI~4ENDATION: Reject. PANEL COMMENT: Proposal is pcimarily a design consideration. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 14. NEGATIVE: Durham.

EXPLANATION OF VOTE: DURflAM: Panel action is not consistent with Proposal No. 175.

Chapter 9., A. Tables, Note 4: Accept CMP 8 SUBMITTER: Peter Po'llak, The Aluminum Association

I PRUPU~AL 175 In Note 4 insert "such as compact or i = ~ d u c t o r cables," after "Chapter 9. '

' SUBSTANTIATION: Question arises in the f ie ld regarding the selection of the proper conduit size for the application.

Makes clear the fact that actual dimensions of compact or f multlconductor cables shall be used in the calculation o

condu'i t f i l l . PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Chapter 9 Table l , Note 5: Accept CMP 8 SUBMITTER! CMP 8 !aITOPOS'7~-~. • 175A Add to Note 5 the word "maximum" before ~ e . " Add FPN after Note 5 to read:

Table l is based on common conditions of proper cabling and alignment of conductors where the length of the pull and the number of bends are within reasonable limits. I t should be recognized that for unusual conditions a larger size conduit or a lesser conduit f i l l should be considered. SUBSTANTIATION: Clarif ication. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table l , Chapter g: Reject CMP 8 SUBMITTER: CMP 8

175B In the 3 conductor column, delete 40 (percent ~ d insert 33 (percent f i l l ) for both lead covered and non-lead covered conductors. SUBSTANTIATION: There exists a l~t t le understood problem of "jam ratio" where only three conductors are installed in a conduit. This is ratio of the diameters of the conduit and the single conductor (D/d). This ratio is cr i t ica l between 2.5 and 3.0 where the conductors are not triplexed. At a ratio of 3.0 and greater, the conduit is wider than the sum of the 3' conductors which prevents Jamming.

At this ratio the area of the conductors is 3d2~

The area of the conduit is (3d)2 = 9d2~ L ~ - - - I - -

F i l l = 3/9 = 33 1/3 percent. At 40 percent f i l l the maximum allowable conductors are always in the cr i t ical Jam ratio. PANEL REC~NDATION: Reject. PANtL ~UMM~NI: UMP ~ would prefer to withdraw the Proposal and I t is rejected on that basis. VOTE ON PANEL RECOMMENDATION: Unanimously Aff i rmative..

Chapter 9, Table l , Note 6: Reject SUBMITTER: CMP 8 PROPOSAL: I75C Add a new Note 6 as follows: ~ i l l shall be permitted for triplexed conductors." SUBSTANTIATION: Clarif ication. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel Comment on Proposal No. 175B. VOTE ON PANEL RECOI¢MENDATION: Unanimously Affirmative.

CMP 8

Table 1, Chapter 9: Reject CMP 8 SUBMITTER: Joseph M. Ostrlhonsky, Sioux City, IA PROPOSAL: ,176 I suggest that the number of wires that is a-lT6~--d-in 1/2 inch and 3/4 inch pipe be reduced to half. The wire I'm talking about is TW, THHN, THWN, sizes #12, #14, and #10. As an alternate, they would change the 40 percent f i l l to 60 percent f i l l based on individual diameters. SUBSTANTIATION: I f you have had any experience at al l , you wil l know that is I t very d i f f l cu l t to pull, say 9-12 inch TW wires into a piece of 1/2 inch conduit. I t is almost impossible i f you havetwo go ° bends in the conduit. This Js why I think they should reduce the number of wires or else change the percent f i l l of the conduit. PANEL RECOMMENDATION: Reject. PANEL CL)f~ENI: ine "conduit f i l l tables are based on the concept that a safe practical.conduit f i l l percentage is one in which the diameter of a circle circumscribed around the assembled conductors would approximate 75 percent of the conduit diameter. The net area of the conductors within this theoretical circle approximates 40 percent f i l l .

The Code establishes a 40 percent maximum conduit f i l l . The Code also establishes a maximum of four quarter bends (360 degrees total) . The Code does not establish a maximum length of pull . The allowable length of a pull is contingent on a number of factors including but not limited to: I) maximum allowable conductor tension, 2) the plane of the bends (whether they are horizontal or vertical and whether any are reverse bends), 3) proper cabling of the conductors, 4) the weight of the cable, 5) the coefflcent of f r ic t ion between the conductors and the conduit, and 6) sidewall pressure.

Since the Code is not a design manual Judgement must be used in studying all of these "factors on whether.to use the maximum f i l l and the maximum number of bends to accommodate the maximum length of pull. Proper cabling of a large number of conductors is of extreme importance in such a Judge~nt. VOTE ON PANEL RECOI~ENDATION: Unanimously Affirmative.

158

I

373-6(c)-(New)(HOD 1978 NEC): Reject CMP 9 SUBMITTER: CMP 9 PROPOSAL: 42 Amend Section 373-6 by adding thereto a new su--Gb-T~ETon (c) as fol lows:

(c) The provisions of subsections (a) and (b) of th is section apply to conductors bent or deflected no more than once. For conductor bending space at terminals and width of gut ter space fo r conductors that are bent or deflected more than once, the gutter or bending space required shall be one and one hal f times the value l is ted In Table 373-6(a). Present subsection " (c ) " w111 become "(d)." SUBSTANTIATION: We were convinced by the supportlng comment supplied wlth Proposal No. 39 in the 1978 Preprlnt. PANEL RECOMMENDATION: Reject. PANEL COGENT: See Panel action on Proposal No. 38. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

373-10(a): Accept CMP 9 SUBMITTER: TSC-Approved for the Purpose PR'O-~(5~_-T." 43 See the Technical Subcommittee "Recommendations" un--6-de-~'-t~f~e definition of "Approved for the Purpose" in Artlcle 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" In Article 100. PANEL RECOMMENDATION: Accept as Revised: i Delete the words "and shall be approved for the purpose." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

373-10(c): Reject CMP 9 SUBMITTER: Patrick J. Fox, St. Louis, MO PIIIS]IO'S'~-~. • 44 Change paragraph to read:

~-~ Nonmetallic Cabinets and Cutout Boxes. Nonmetallic cabinets and cutout boxes shall be approved for the purpose. SUBSTANTIATION: This is intended to make the statement consistent with the statement for metal cabinets and cutout

• boxes and with Section 370-3. To require submittal for approval of every nonmetallic cabinet and box appears unnecessary i f they are approved for the purpose. • This was previously submitted for the 1975 National Electrical Code and a Task Group was to have studied this proposal change. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present Code wording is necessary until standards are written. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: CRAMER: The existing Section required approval prior to

installation. Approval after installation should suffice. Sentence should read: "Norm~tallic cabinets shall be suitable for the environment."

373-11(a)(3); Accept CMP g SUBMITTER: TSC-Neminal Voltage P]TOlIO-~lZ~.'45 Change "600" in last line to "635." ~ I A T I O N : To conform to the method to express maximum voltage as per, guldellnes developed by the TSC on nominal voltage. PANEL RECOMMENDATION: Accept as Revised:

Leave 600 as is, but insert the word "nominal" after "600." VOTE ON PANEL RECOMMENDATION: Unanlmously Affirmative.

373-12-{New): Reject CMP 9 SUBMITTER: R. S. Pinkerton, Los Angeles, CA ]~ffO-P'O~-~ 46 Add a new section as follows: ~7"c[zT'ZT - . Equipment on Cabinet Door. No device or other equipment uti l izing electric wiring shall be mounted on or be supported by any cabinet or panelboard trim, cover or door - except where hinged doors designed for the purpose are employed. SUBSTANTIATION: Switches, pushbuttons, pi lot lights and similar control circuit equipment which might be mounted on a removable cabinet cover can offer a severe shock hazard to maintenance personnel. Usually the screWs holding the cover in place provide the equipment grounding, which means that a man removing the cover has an ungrounded piece of equipment in his hand. Furthermore, switches for disconnecting the control circuits are often within the cabinet, making i t d i f f icu l t to de-energize She circuit. I f the cover slips during the process of ren~)val, a live exposed terminal can be grounded to the side of the enclosure. PANEL RECOf~ENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

373-1?-(New): Reject CMP g SUBMITTER: Southwestern Section IAEI PROPOSAL: 47 Add new section as follows: ~TrJTI'2T-. Equipment On Cabinet Door. No device or other equipment uti l izing electric wiring shall be mounted on or be supported by any cabinet or panelboard trim, cover or door - except where hinged doors designed for the purpose are employed. SUBSTANTIATION: Switches, pushbuttons, pi lot lights and similar

• control circuit equipment which might be mounted on a reFnovable cabinet cover can offer a severe shock hazard to maintenance personnel. Usually the screws holding the cover in place provide the equipn~nt grounding, which means that a man removing the cover has an ungrounded piece of equipment in hls hand. Furthermore, switches for disconnecting the control circuits are often within the cabinet, making i t d i f f icu l t to de-energize the circuit. I f the cover slips during the process of removal, a live exposed terminal can be grounded to the side of the enclosure. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanlmously Affirmative.

)

373-X:. Reject CMP 9 SUBMITTER: Ralston W. Calvert, Dept. Bldg. & Safety, City of

P-al~--O'es-ert PROPOSAL: 48 Add a new paragraph to Article 373 (Installation) ~h-TcTi--s~all say "Cabinets or cut boxes located in wall or other places, shall not be installed less than two feet nor more than 6 I/2 feet vertically from the ground floor, concrete slab or roof).

Exception: Cabinets and cut out boxes located in vaults or other approved locations." SUBSTANTIATION:

I . An overcurrent protective device being used to protect an air conditioning unit. The OPD enclosure was located one inch above the ground, the cover of the enclosure hinged on top. When the cover was opened, the manufacturer's specifications and the directory could not be read. I had to l ie on my stomach to inspect the equipment and on my back to read the manufacturer's specifications and directory...(and that's when the sprinkling system came on).

2. A sub-panel located three inches above a patio concrete slab. To inspect the installation, I had to l ie on the slab as the cover was hinged on top. I t was also d i f f i cu l t for the owner to see the circuit breakers, as the cover part ial ly blocked his view. Whenever the patio was hosed off, which was often, the enclosure was drenched with water.

3. An overcurrent protective device and its enclosure was located on a f la t roof. The enclosure was two inches above the roof. To inspect the job or to work on the equipment, a most d i f f i cu l t and t ir ing position must be maintained. A man wearing glasses would be in a dangerous position, due to the required t i l t of his head, leading to poor vision, thereby contributing to a possible accident. PANEL RECOMMENDATION: Reject. PJ~NE[ COMMENT: Supporting comment is not consistent with the Proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COGENT ON VOTE:

CRAMER: I agree with the reject but feel.~hat the reason is that this is getting into design considerations and away from safety. To attempt to set limits that universally apply to every installation is very d i f f icu l t . The inspecting authority can judge the equipment in accordance with Section 110-3 and has the power to reject.

ARTICLE 380 -- SWITCHES

380-2(b): Reject ~ CMP 9 SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI PITOIR)'S'A-L-~." 49 Revise as follows: ~ r switches nor circuit breakers shall disconnect the grounded conductor of a circuit. SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without the correlation of 'ei ther. ' In many instances, this usage is not only gra~matically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Reject. PANEL CO~g4ENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOV~ENDATION: Unanimously Affirmative.

380-2(b), Exception No. 1: Reject CMP g SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI PROPOSAL: 50 Revise as follows: ~ e i t h e r the switch or the circuit breaker etc. SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without the correlation of 'ei ther. ' In many instances, this usage is not only grammatically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

169

380-2(b), Exception No. 2: Reject CMP 9 SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI ]~TO-FO-S~A[~-. • 51 Revise as follows:

~here either the switch or the circuit breaker etc. SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without the correlation of 'either. In many instances, this usage is not only grammatically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


52 See the Technical Subcommittee "Recommendations" un-~-d-e~"the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Revise the f i r s t sentence of 380-3 to read: "Switches and circuit breakers shall be of the externally operable type mounted in an enclosure listed for the intended use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COf~ENT ON VOTE:

BARKER: For l isting, who determines the intended use?

380-4: Reject CMP 9 SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI

53 Revise as follows: ~rO'Zir~-~et Locations. Where elther a switch or j a circuit breaker (or both) is installe~ in a wet location shall be enclosed in a weather proof enclosure which complies with Section 373-2.

Note: Wet Iocation-definitioo includes outside buildings and exposed to the weather. Section 373-2 includes both cabinets and enclosures. SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without the correlation of 'either. ' In many instances, this usage is not only grammatically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

380-6(b): Accept CMP 9 SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI

54 Revise the last sentence as follows: ~ t h e throw is vertical, a locking device shall be provided to hold the blades in the open pos i t i on when sO set.

'SUBSTANTIATION: NFPA 70-1978 uses the word 'or" loosely without the correlation of 'either. ' In many instances, this usage is not only grammatically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Accept. PANEL COMMENT: We agree with the proposal, although his substantiation is not clear. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

380-6(b): Accept CMP 9 SUBMITTER: Southwestern Section IAEI

55 Revise the last sentence to read: ~ t h e throw is vertical, a locking device shall be provided to hold the blades in the open position when so set. SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without correlation of 'either. ' In many instances, this usage is not only gramatically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Accept. PANEL COMMENT: Same as Proposal No. 54.. We agree with the proposal, although his substantiation is not clear. VOTE ON PANEL RECOMMENDATION: Unanlmously Affirmative.

380-8(a): Accept CMP g SUBMITTER: Ernest E. Cannon, Arizona Chapter IAEI . ~ 56 Revise the f i r s t sentence by adding "so" between T~--aITl)e" and "located." SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without the correlation of 'either. ' In many instances, this usage is not only grammatically incorrect, but the meaning is not clear. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

CRAMER: I agree because he's grammatically correct although his substantiation is no good.

3BO-B(a): Accept CMP 9 SUBMITTER: Southwestern Section IAEI

I . ~ 57 Revise the f i r s t sentence by adding "so" between • ~ and located. J

SUBSTANTIATION: NFPA 70-1978 uses the word 'or' loosely without the correlation of 'ei ther. ' In many instances, this usage is not only grammatically incorrect, but the meaning is not clear. PANEL RECOI~4ENDATION: Accept. ' PANEL COMMENT: Sane as Proposal No. 56. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

CRAMER: Same comment as Proposal No. 56.

380-11: Reject CMP 9 SUBMITTER: R. S. Pinkerton, Los Angeles, CA PITOPO'S'~[L-T." 58 Add a sentence as follows:

The supply conductors of single circuit breakers in non-bussed enclosures shall be connected to the terminals nearest the on position of the operating handle. SUBSTANTIATION: The proposed connection configuration for circuit breakers in enclosures has been an industry standard for EXO switches for many years. Accordingly, electricians assume that the load conductors are connected nearest the off position. The purpose of this requirement has nothing to do with the operation of a circuit breaker as i t will function properly connected either way. Workmen have been injured when they attempted to remove what they thought was a de-energlzed load conductor because i t was connected to the load side, (near the off side), and i t turned gu t to be a line conductor. This requirmentprovldes a necessary safety precaution for maintenance personnel and equipment installers. PANEL RECOMMENDATION: Reject. PANEL CO~4ENT: No significant contribution to safety would result. This Proposal would lend i tse l f to a false sense of security. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

3BO-13(a) and (b): Accept CMP g SUBMITTER: TSC-Nominal Voltage ~ 5 9 In the second lines of (a) and (b) change "600" to ~ " SUBSTANTIATION: To conform to the method to express maximum voltage as per guidelines developed by the TSC on nominal voltage. PANEL RECOMMENDATION: Accept as Revised: 380-13(a) No change. Insert the word "nominal" after 250 volts and after 600 volts in Section (b). PANEL COMMENT: The voltages expressed are rated voltages. ° ~ R E C O M M E N D A T I O N : Unanimously Affirmative. COMMENT ON VOTE:

CRAMER: I agree with the action. The reason for the action is that the voltage expressed in (a) are rated voltages whereas in (b) voltages are nominal.

380-13(b): Accept CMP g SUBMITTER: TSC-Approved for the Purpose Pl~-OIR~-~.'60 See the Technical Subcemmittee "Recon~nendations" un-n-d~-~-t-~e definition of "Approved for the Purpose" in A r t i c l e I00. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Substitute the word "listed" for "approved." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

380-14ia)(2): Reject CMP g SUBMITTER: J.J. Kark, National Electrical Manufacturers ~ o n PROPOSAL: 61 Revise to read: --'-T~Tungsten-filament lamp loads not exceeding the ampere rating of the switch at 120 volts "for single-pole, double-pole, 3-way, and 4-way switches." SUBSTANTIATION: The present wording does not recognize that AC type switches are designed for other than lighting loads. Examples of switch actions not requiring tungsten test include: 3 position switches, momentary contact switches and maintained contact switches. These are used in Start-Stop circuits, Ralse-Lower circuits, etc. where the tungsten requirements are not applicable. The des!gn parameters of these type switches dif fer greatly from those used for tungsten loads.

Underwriters Laboratories interprets the present code wording to require tungsten tests on all AC switches regardless of end use. The requested change would allow manufacturers to design switch mechanisms to optimum performance as required by the end use. PANEL RECOI~dENDATION: Reject.

: e anel does not agree with the supporting comment. The switches mentioned in the substantiation could be used for tungsten loads. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Burniston, Demlng.

EXPLANATION OF VOTE: BURNISTON: As the proposal indicates, the concern Is with

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other than standard single pole, double pole, 3-way and 4-way switches used in l ight ing control c i r cu i t s . The speci f ic switches covered by th is proposal are a var ie ty of e i ther maintained or momentary contact switches of one, two or three posi t ion single or double pole. The loads being control led are e i ther resistance or inductive loads, but not tungsten loads. (The Panel was supplied the more typical diagrams.)

The Code has been interpreted as requir ing a l l genera] switches to be tungsten rated, which inh ib i ts design. C la r t f l ca t ton is required to exempt these special use AC switches to a l low the use of designs which maximize the performance on the intended loads.

DEMING: The switches mentioned in the substantiat ion could be marked'"Not sui table fo r tungsten loads."

There are many instances within the Code where a product misused or used for the wrong purpose could create a hazardous condition.

380-14(a)(4): Accept CMP 9 SUBMITTER: TSC-Approved for the Purpose

62 See the technical Subcommittee "Recommehdations" un--n-d'e'r't~Te definition of ~Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Change 380-14(a)(4) to 380-14(c) and revise to read as follows: "(c) CO/ALR Snap Switches. Snap switches rated 20 amperes or less directly connected to aluminum conductors shall be listed and marked CO/ALR." VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 11. NEGATIVE: Burnlston.

EXPLANATION OF VOTE: BURNISTO~I: ~MA has no objection to the Panel Recemmendatlon

to revise the text of Section 380-14(a)(4), but feels that relocating this Section to now Section 380-14(c) goes beyond the Panel's intent.

The Pane] did not intend to imply that CO/ALR snap switches are suitable for use on other than AC circuits wfien connected to aluminum conductors, nor that their suitabi l i ty should go beyond those uses covered under Section 380-14(a). The location of the 'recommended text should remain as Section 380-14(a)(4).

380-16: Accept CMP 9 SUBMITTER: TSC-Nominal Voltage ~ 6 3 ' Revise the end of the second llne and beginning o--'f'-TF~rF-d line to read "knife switch rated600 volts, etc." SUBSTANTIATION: To conform to the method to express rated voltage of equipment as per the guideline developed by the TSC on nominal voltage. PANEL RECOMMENDATION: Accept as Revised:

I Change the word "switch" to "switches." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

380-17, Exceptlon-(New): Reject CMP 9 SUBMITTER: W. Crelghton Schwan, Hayward, CA

64 Add a new exception as follows: - - ~ l o n : Fuses factory assembled in parallel, as permitted in the Exception to Section.240-8. SUBSTANTIATION: The proposed revision wil l remove a conflict from.the Code. High voltage fuses have long been recognized in parallel when assembled in a common mounting means designed for the purpose (see Section 710-21(b)(1)).

Section 240-8 was revised in the 1978 NEC to recognize fuses factory assembled in parallel. I f fuses in parallel are recognized by the Code, the same Code must a11ow a switch to accemodate them. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 65. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

380-17-FPN (NEW): Accept CMP 9 SUBMITTER: Idaho Chapter IAEI ~ 6 5 Add a FPN to 380-17 to read: See 240-8, ~ ' ~ n . SUBSTANTIATION: For the purpose of better correlation in the f ield. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative;

Article 384: Reject CMP 9 SUBMITTER: J.J. Kark, National Electrical Manufacturers Assn. ~ 6 6 Revise Article 384 to also specify LV switchgear ~ n c l o s e d low-voltage power circuit breaker switchgear).

Revise Article Title: SWITCHBOARDS, PANELBOARDS, AND LV SWITCHGEAR.

Revise 384-1:

384-1. Scope. This A r t i c l e covers (1) a l l switchboards, panelboards, d is t r ibu t ion boards, and LV swttchgear (metal-enclosed low-voltage power c i r cu i t breaker switchgear) insta l led fo r the control of - - - power c i r cu i t s .

Exception: (No change). Add (now) 384-X:

384-X. LV Switchgear (Metal-Encased Low-Voltage Power Ci rcu i t Breaker Switchgear). An assembly of one or more. individual enclosures containing the follOwing equipment as required: Low-voltage po~cer c i r cu i t breakers (fused or unfused); .bare bus and connections; instrument and control power transformers, instruments, meters, and relays, control wir ing and accessory devices.

The low-voltnge power c i r cu i t breakers a r e contained in individual grounded metal con~artments and control led e i ther ramotely or from the f ront of the enclosure. The c i r cu i t breakers may be stat ionary or removable type; when of removable type, mechanical Inter locks are provided to ensure a proper and safe operating sequence.

LV swttchgear assemblies are t o t a l l y enclosed with no exposed l ive parts.

Revise 384-2: 384-2. Other Ar t i c les . Switches, c i r c u i t breakers, and overcurrent de, ices used on switchboards, panelboards, d is t r ibu t ion boards, or LV swltchgear, and the i r enclosures, shall comply . . . . . . . that apply. Switchboards . . . . . . through 517.

Revise 384-3(a): (a) Conductors and busbars on a power switchboard, panelboard,

contro l board, or LV swttchgear shall be so located . . . . . . place. Other than the required . . . . . . in a ver t ica l section of a power switchboard or LV switchgear shall be located In that section. Barr iers shall be placed in a11 service power switchboards and LV swttchgear that w i l l iso late . . . . remainder of the equtp~nt .

Revise 384-3(c): ( c ) Each power switchboard, LV swttchgear, power switchboard

or LV swttchgear section, or panelboard, t f used . . . . . . to the equipment frame; All sections of a power switchboard or LV switchgear shall be bonded . . . . . . Table 250-95.

Revise 384-3(d): (d) Load terminals in power switchboards, panelboards, and LV

switchgear shall be . . . . . . connections. Revise 384-3(e): (el On a power switchboard, panelboard, or LV switchgear

supplied from a . . . . . . marked. Revise 383-3(f): (f) The phase arrangement --z--- the front of the power

switchboard, panelboard, or LV switchgear.' The B phase . . . . . . . . . . . ground. Other busbar . . . . . . marked.

Revise Part A Title: A. Switchboards and LV switchgear

Revlse384-7: 384-7. Clearance from Cei l ing. A space -~ . . . . of any switchboard or LV switchgear . . . . . . ce i l ing .

Exception No. 1: Where a . . . . . the switchboard or LV swltchgear and the ce i l ing .

Excepttoh No. 2: Tota l ly enclosed switchboards and LV swltchgear.

Revise 384-8: 384-8. Clearances Around Switchboards and LV Switchgear. Clearances around switchboards and LV switchgear shall . . . . . Section 110-16.

Revise 384-10: 384-10. Clearances for Conductors Entering Bus Enclosures. Where conduits or other raceways enter a power switchboard, or LV switchgear, floor standing panelboard, . . . . . . enclosure. The wiring . . . . . . obstructions. The conduit . . . . . . enclosure.

(Table) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Revise 384-11: 384-11. Grounding Power Switchboards and LV Switchgear Frames. Power switchboard or LV switchgear frames and . . . . . . grounded. •

Exception: Frames of direct-current single-polarity power switchboards and LV switchgear shall not . . . . . . insulated.

Revise 384,12: 384-12. Grounding of Instruments, Relays, Meters, and Instrument transformers onSwltchboards and LV Switchgear. Instruments, . . . . . . located on switchboards or LV swltchgear shall be . . . . . . through 250-125. SUBSTANTIATION: Article 384 does not presently include reference to LV switchgear which is also a product designed for the control of light and power circuits. This omission causes confusion and misunderstandlngabout the requirements for the installatlon of LV switchgear for this purpose. The proposed addition of 384-X and reference to LV switchgear in the other sectlons of Article 384 wil l c lar i fy these requirements. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The panel feels the scope covers switchgear. VOTE ON PANEL RECOMMENDATION:


COMMENT ON VOTE: ECKARDT: TO ellmninate the confusion a sentence could be

added, to Section 384-I namely "Where switchboards are mentioned

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other than standard single pole, double pole, 3-way and 4-way switches used in l ight ing control c i r cu i t s . The speci f ic switches covered by th is proposal are a var ie ty of e i ther maintained or momentary contact switches of one, two or three posi t ion single or double pole. The loads being control led are e i ther resistance or inductive loads, but not tungsten loads. (The Panel was supplied the more typical diagrams.)

The Code has been interpreted as requir ing a l l genera] switches to be tungsten rated, which inh ib i ts design. C la r t f l ca t ton is required to exempt these special use AC switches to a l low the use of designs which maximize the performance on the intended loads.

DEMING: The switches mentioned in the substantiat ion could be marked'"Not sui table fo r tungsten loads."

There are many instances within the Code where a product misused or used for the wrong purpose could create a hazardous condition.

380-14(a)(4): Accept CMP 9 SUBMITTER: TSC-Approved for the Purpose

62 See the technical Subcommittee "Recommehdations" un--n-d'e'r't~Te definition of ~Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Change 380-14(a)(4) to 380-14(c) and revise to read as follows: "(c) CO/ALR Snap Switches. Snap switches rated 20 amperes or less directly connected to aluminum conductors shall be listed and marked CO/ALR." VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 11. NEGATIVE: Burnlston.

EXPLANATION OF VOTE: BURNISTO~I: ~MA has no objection to the Panel Recemmendatlon

to revise the text of Section 380-14(a)(4), but feels that relocating this Section to now Section 380-14(c) goes beyond the Panel's intent.

The Pane] did not intend to imply that CO/ALR snap switches are suitable for use on other than AC circuits wfien connected to aluminum conductors, nor that their suitabi l i ty should go beyond those uses covered under Section 380-14(a). The location of the 'recommended text should remain as Section 380-14(a)(4).

380-16: Accept CMP 9 SUBMITTER: TSC-Nominal Voltage ~ 6 3 ' Revise the end of the second llne and beginning o--'f'-TF~rF-d line to read "knife switch rated600 volts, etc." SUBSTANTIATION: To conform to the method to express rated voltage of equipment as per the guideline developed by the TSC on nominal voltage. PANEL RECOMMENDATION: Accept as Revised:

I Change the word "switch" to "switches." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

380-17, Exceptlon-(New): Reject CMP 9 SUBMITTER: W. Crelghton Schwan, Hayward, CA

64 Add a new exception as follows: - - ~ l o n : Fuses factory assembled in parallel, as permitted in the Exception to Section.240-8. SUBSTANTIATION: The proposed revision wil l remove a conflict from.the Code. High voltage fuses have long been recognized in parallel when assembled in a common mounting means designed for the purpose (see Section 710-21(b)(1)).

Section 240-8 was revised in the 1978 NEC to recognize fuses factory assembled in parallel. I f fuses in parallel are recognized by the Code, the same Code must a11ow a switch to accemodate them. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 65. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

380-17-FPN (NEW): Accept CMP 9 SUBMITTER: Idaho Chapter IAEI ~ 6 5 Add a FPN to 380-17 to read: See 240-8, ~ ' ~ n . SUBSTANTIATION: For the purpose of better correlation in the f ield. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative;

Article 384: Reject CMP 9 SUBMITTER: J.J. Kark, National Electrical Manufacturers Assn. ~ 6 6 Revise Article 384 to also specify LV switchgear ~ n c l o s e d low-voltage power circuit breaker switchgear).

Revise Article Title: SWITCHBOARDS, PANELBOARDS, AND LV SWITCHGEAR.

Revise 384-1:

384-1. Scope. This A r t i c l e covers (1) a l l switchboards, panelboards, d is t r ibu t ion boards, and LV swttchgear (metal-enclosed low-voltage power c i r cu i t breaker switchgear) insta l led fo r the control of - - - power c i r cu i t s .

Exception: (No change). Add (now) 384-X:

384-X. LV Switchgear (Metal-Encased Low-Voltage Power Ci rcu i t Breaker Switchgear). An assembly of one or more. individual enclosures containing the follOwing equipment as required: Low-voltage po~cer c i r cu i t breakers (fused or unfused); .bare bus and connections; instrument and control power transformers, instruments, meters, and relays, control wir ing and accessory devices.

The low-voltnge power c i r cu i t breakers a r e contained in individual grounded metal con~artments and control led e i ther ramotely or from the f ront of the enclosure. The c i r cu i t breakers may be stat ionary or removable type; when of removable type, mechanical Inter locks are provided to ensure a proper and safe operating sequence.

LV swttchgear assemblies are t o t a l l y enclosed with no exposed l ive parts.

Revise 384-2: 384-2. Other Ar t i c les . Switches, c i r c u i t breakers, and overcurrent de, ices used on switchboards, panelboards, d is t r ibu t ion boards, or LV swltchgear, and the i r enclosures, shall comply . . . . . . . that apply. Switchboards . . . . . . through 517.

Revise 384-3(a): (a) Conductors and busbars on a power switchboard, panelboard,

contro l board, or LV swttchgear shall be so located . . . . . . place. Other than the required . . . . . . in a ver t ica l section of a power switchboard or LV switchgear shall be located In that section. Barr iers shall be placed in a11 service power switchboards and LV swttchgear that w i l l iso late . . . . remainder of the equtp~nt .

Revise 384-3(c): ( c ) Each power switchboard, LV swttchgear, power switchboard

or LV swttchgear section, or panelboard, t f used . . . . . . to the equipment frame; All sections of a power switchboard or LV switchgear shall be bonded . . . . . . Table 250-95.

Revise 384-3(d): (d) Load terminals in power switchboards, panelboards, and LV

switchgear shall be . . . . . . connections. Revise 384-3(e): (el On a power switchboard, panelboard, or LV switchgear

supplied from a . . . . . . marked. Revise 383-3(f): (f) The phase arrangement --z--- the front of the power

switchboard, panelboard, or LV switchgear.' The B phase . . . . . . . . . . . ground. Other busbar . . . . . . marked.

Revise Part A Title: A. Switchboards and LV switchgear

Revlse384-7: 384-7. Clearance from Cei l ing. A space -~ . . . . of any switchboard or LV switchgear . . . . . . ce i l ing .

Exception No. 1: Where a . . . . . the switchboard or LV swltchgear and the ce i l ing .

Excepttoh No. 2: Tota l ly enclosed switchboards and LV swltchgear.

Revise 384-8: 384-8. Clearances Around Switchboards and LV Switchgear. Clearances around switchboards and LV switchgear shall . . . . . Section 110-16.

Revise 384-10: 384-10. Clearances for Conductors Entering Bus Enclosures. Where conduits or other raceways enter a power switchboard, or LV switchgear, floor standing panelboard, . . . . . . enclosure. The wiring . . . . . . obstructions. The conduit . . . . . . enclosure.

(Table) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Revise 384-11: 384-11. Grounding Power Switchboards and LV Switchgear Frames. Power switchboard or LV switchgear frames and . . . . . . grounded. •

Exception: Frames of direct-current single-polarity power switchboards and LV switchgear shall not . . . . . . insulated.

Revise 384,12: 384-12. Grounding of Instruments, Relays, Meters, and Instrument transformers onSwltchboards and LV Switchgear. Instruments, . . . . . . located on switchboards or LV swltchgear shall be . . . . . . through 250-125. SUBSTANTIATION: Article 384 does not presently include reference to LV switchgear which is also a product designed for the control of light and power circuits. This omission causes confusion and misunderstandlngabout the requirements for the installatlon of LV switchgear for this purpose. The proposed addition of 384-X and reference to LV switchgear in the other sectlons of Article 384 wil l c lar i fy these requirements. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The panel feels the scope covers switchgear. VOTE ON PANEL RECOMMENDATION:


COMMENT ON VOTE: ECKARDT: TO ellmninate the confusion a sentence could be

added, to Section 384-I namely "Where switchboards are mentioned

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low voltage switchgear is also included." • EXPLANATION OF VOTE:

BURNISTON: NEMA believes that the Panel's conclusion is incorrect since LV switchgear is a specific product not already covered by theproducts defined as switchboards or panelboards.

384-3(a): Reject CMP 9 SUBMITTER: G. G. Biskupek, Federal Pacific Electric Co. ~ 6 7 To the last sentence, add the words, "in order to prevent accidental contact with any conductor which remains energized after the main devices in a service switchboard are turned off ." SUBSTANTIATION: Need for clarif ication is demonstrated by Field questions: isolate to prevent fault commutation, isolate to prevent access, etc.? PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Code does not and cannot provide an explanation or a reason for each requirement. I t would be foolhardy to start now. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

384-3(a): Accept CMP g SUBMITTER: Charles J. Hart, National Electrical Contractors

PROPOSAL: 68 Delete the second sentence of Section 384-3(a) ~ I A T I O N : Compliance with this requirement is next to impossible. In multi-section switchboard installations, i t is often unknown to the installer in what section a particular overcurrent device is located.

Moreover, decisions to relocate circuit entrances Into the switchboard section are often made in the f ield, particularly when there are obstructions or conflicts with other equipment. This requirementnecessitates.extenslve switchboard modification in these instances.

Most switchboards have large open spaces without barriers between adjacent sections. Fires can communicate between sections even i f there are no conductors common to adjacent sections. The interconnectlons between switchboards are often made with insulated conductors capable of transmitting f i re to the adjacent section. This requirement does not add a responsible degree of safety for these conditions. PANEL RECOMMENDATION: Accept as Revised:

Revise .as in Proposal No. 69. VOTE ON PANEL RECOI~4ENDATION:

AFFIRMATIVE: g. NEGATIVE: Hogan, Leiman, Wadhwa.

EXPLANATION OF VOTE: HOGAN: Once again we have indicated on t'his proposal that we

are accepting what the proponent has desired. I t is my op~nlon that we have f la t l y rejected the proposal and then formed one of o~r own. In any event I am voting negatively. Quite possibly, i f we had utilized the word raceway or something similar to that in lieu of the word barrier, I would have a different opinion about the proposal we have formulated. I am completely, opposed to the original proposal.

LEIMAN: The New York City code has had this requirement for the last 12 years without causing any problems to any installer. The Panel Recommendation wlll cause switchboards to be loaded wlth metal barriers. This wil l lead to hazardous conditions. Since the 1978 Code became effective, I have never received any negative comments from the f ield or at any of the IAEI meetings.

WADHWA: I agree'with the concept of the proposal, but the substantiation offered is not correct. The shop drawings generally are submitted by the manufacturers for approval of the switchboard and approved by the Engineer' before the SWBD is fabricated. The installer should be familiar with the location and arrangement of protective devices.

• 384-3(a}(HOD 1978 NEC): Accept CMP 9 SUBMITTER: NEMA PROPOSAL: 69 Delete the second sentence of this Section. ~:I]I~"FAlg'rIATION: Cempliance with this requirement is next to impossible. In multi-section switchboard installations, i t is often unknown to the installer in what section a particular oyercurrent device is located.

Moreover, decisions to relocate circuit entrances into the switchboard section are ~ften made in the f ield, particularly when there are obstructions or conflicts with other equipment. This requirement necessitates extensive switchboard modification in these instances.

Most switchboards have large open spaces without barriers between adjacent sections. Fires can c.emmunicate between sections even i f there are no conductors common to adjacent sections. The interconnectlons between switchboards are often made with insulated conductors capable of transmitting f i re to the adjacent section. This requirement does not add a responsible degree of safety for these conditions. PANEL RECOMMENDATION: Accept as Revised:

Add an exception as follows: 384-3(a). Exception: "Conductors shall be permitted to travel horizontally through

Ivertlcal sections of swltchboards where such conductors are

isolated from busbars by a metal barrier." VOTE ON PANEL RECO~ENDATION:

AFFIRMATIVE: g . NEGATIVE: Hogan, Lelman, Wadhwa.

EXPLANATION OF VOTE: HOr~N: Same as Proposal No. 68. LEIMAN: Same as Proposal No. 68. WADHWA: Same as Proposal No. 68.

384-3(c): Reject CMP g SUBMITTER: Robert W. Gilmore, Northwest Iowa Technical College

70 Add a second paragraph as follows: provisions shall be provided for the installation of an

equipment grounding terminal bar approved for the purpose, and i f used as service equipment, an equipment grounding terminal bar approved for the purpose shall be provided and secured inside of cabinet or panelboard for the attachment of all the feeder and branch-circuit equipment grounding conductors, where the panelboar~ is used with nonmetallic raceway or cable, or where separate equipment grounding conductors are provided. The terminal bar shall be bonded to the cabinet or panelboard frame and shall not be connected to the neutral bar In other than service equipment. SUBSTANTIATION: Most electricians and inspectors do not realize that when a panelboard approved for the purpose is used for service equipment, is s t i l l a panelboard. Most inspectors and electricians recognize the need for terminating the equipment grounds on a separate bar when used in a panelboard on the load slde of the service equipment, but don't see the need when a panelboard is being used a service equipment.

NOTE: The intent of this Is not to require the manufacturer to provide an equipment terminal bar with each panelboard but to provide the provlsidns for one; some disconnect switches approved for use as service equipment do not have these provisions and cause a real problem for the electrician or inspector. When thls equipment is used with an equipment grounding conductor, there is no place to terminate properly, forcing one ~o violate the NEC. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECO~MENDATION: Unanimously Affirmative.

384-3(f): Reject CMP 9 SUBHITTER: A.G. Aschenbeck, Wayzata, MN ~ 7 1 Revise, as follows: ~ e arrangement on three phase buses shall be A,B,C frem front to back, top to bottom, or le f t to right, as viewed from the front of the switchboard or panelboard. The C phase shall be that phase having the higher voltage to ground. Other busbar arrangements shall be permitted for additions to existing installations and shall be marked. . SUBSTANTIATION: There is too much confusion between the Hi-leg being assigned to the "B" phase (center) as Is presently done and the meter industry requirement of the Hi-leg on the right side of their fac i l i t ies. The "B u phase location serves no purpose other than locating the Hi-leg in the center. PANEL RECOMMENDATION: Reject. PANEL COI4a4ENT: The Panel does not agree with the supporting comment. No evidence to support the suggested change. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 11. NEGATIVE: Cock.

EXPLANATION OF VOTE: COCK: Section 384-3(f) should be clarif ied for 3-wlre delta

systems by adding the words: "on 3-phase, 4-wlre delta systems" after the word "ground, ~ in the second sentence. The second sentence wil l then read: "The B phase shall be that phase having the higher voltage to ground on 3-phase, 4-wire delta systems. ~

This action will c lar i fy the system" addressed in this requirement. A 3-phase, 3-wire corner (B-phase) grounded system cannot meet a requirement that B-phase be the highest voltage to ground.

384-3(h)-(New): Accept CMP 9 Secretary's Note: I t was the action of the Correlat ing

Committeethat th is Proposal be reported as a " r e j e c t , " because less than two-th i rds of the members e l i g i b l e to vote have not voted in the affirmative. SUBMITTER: Robert J. Freund, Chicago, IL P]TOPO-S'TTL-~. 72 Add new (h) as follows: ~ l l busbars in equipment that operates at voltages over 250 volts between phases or between any phase and ground and designed to carry currents of 1000 amperes or greater shall be insulated. The insulation shall be solid, mechanically secure, and suitable for the operating voltage. SUBSTANTIATION: Busbars that are not insulated are a hazard to personnel who install and maintain electrical equipment.

Busbars that are not insulated increase the likelihood of power interruptions of vital electrical systems that affect the public safety.

172

Ground fault protection only covers certain limited faults and increases the possibility of interruptions.

Insulated busbars provide personnel safety and continuity of service at a low cost. PANEL RECOMMENDATION: Accept as Revised:

"All busbars in solidly grounded ws, e switchboards that operate at voltages over 250 volts to ground but not exceeding 600 volts phase to phase and rated 1000 an~oeres or greater shall be insulated except at bolted Joints and connections. M VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 7. NEGATIVE: Hogan, Burniston, Cock, Cramer, LaMorte.

COMMENT ON VOTE: BARKER: I have voted affirmative as the Panel Recemmendation

is better than nothing. In time i t will again require another change to comply with the original proposal. Insulated busbars would greatly reduce the magnitude and resulting hazards of burndowns from arcing faults when failures occur.

LEIMAN: I haven't voted negatively on this proposal but would like to be on record to discuss this at our next meeting in Dece~foer. I t wil l give us more of an input when I attend our IAEI Sectional meetings. EXPLANATION OF VOTE:

HOGAN: I have voted negatively on this proposal for two reasons: (I) to call as much attentlon,to the proposal as is possible and (2) to give the Panel another opportunity to discuss the Proposal. I am not satisfied that we have actually accomplished what we intended~

BURNISTON: This proposal imposes a design requirement on equipment presently covered by A~erican National Standards and Underwriters Laboratories Inc. standards which deliberately do not include this requirement.

This type of equipment is not intended to be installed or maintained while energized.

Incomplete insulation as specified in this proposal wil l lead to a false sense of security on the part of personnel and wil l encourage the unsafe practice of working on energized equipment.

Addition of insulation to busbars in this equipment wil l lead to voltage stress concentrations on the insulation and result in failure of the insulation which maY cause equipment failure instead of preventing i t .

These products as presently buil t , have not experienced history of power interruptions and personnel safety hazard sufficient to just i fy this requirement.

COCK: I f busbars are to be insulated within this voltage range there should be an exception in Section 230-95 which would not require ground fault protection of equipment for insulated busbars.

The Panel has recognized that bolted joints and connections cannot be insulated. I submit that the condition of "insulated busbars" and "uninsulated Joints and connections" tends to give the workman a false sense of security since he tends to assume he is working on an "insulated system."

CRAMER: I disagree with the supporting comment that busbars that are not insulated are a hazard to personnel who install and maintain electrical equipment. Good safety practices can accomplish much more than any form of insulation.

Bare busbars are allowable even when located outside of enclosures provided they are suitably guarded. (See Section 110-17(a).) Here in a switchboard which already meets requirements of Section 110-17(a), we're requiring additional guarding in the form of insulation. This is not necessary. Furthermore, there's no real substantiating data to indicate that this will significantly add to safety. The only certain thing i t will do is increase costs.

LA MORTE: Submltter alleges that unlnsulated busbars are a hazard to personnel who instal] and maintaln.electrical equipment. I f personnel safety is the issue, this requirement would accomplish nothing, in that busbar Joints and cable connections would s t i l l be exposed; and these are the areas where problems and failures requiring attention occur. Also good safety practice dictates that you do not rely on electrical insulation; consequently, when working on electrical equipment, treat i t as i f bare. Such reliance can lead to carelessness and a false sense of security.

I t is a widely known fact that covering a bus with a thin coating does not make i t safe to touch. See NFPA No. 70-B, page 48 - "Electrical Equipment Maintenance," quoted following: "Although the bus and connections are insulated in metal clad switchgear, THE INSULATION IS NOT DESIGNED TO PROTECT AGAINST ELECIRICAL SHOCK. CONTACT WITH THIS BUS OR ITS CONNECTIONS SHOULD BE AVOIDED WHEN THE SWITCHGEAR IS ENERGIZED." (The capit'als are as in the NFPA No. 70-B text.)

Submitter alleges that busbars that are not insulated increase the likelihood of power interruptions of vital electrical systems that affect the public safety. No evidence has been submitted to substantiate this claim - merely hearsay. In fact, i f low-voltage buses were required to be insulated, manufacturers would begin to reduce or eliminate phase:to-phase and phase-to-ground air clearances and depend solely on insulation barriers. I t is expected that bus failures due to insulation breakdown would increase, resulting in more power interruptions.

Submitter a11eges that implementation of this proposal can be accomplished at low cost. This statement is not backed up with any cost analysis; consequently, i t is unfounded. I t is expected that the cost of switchgear and power distribution equipment would increase dramatically. Existing switchgear

designs, in general, would not be modifiable to incorporate bus insulation; consequently, major redesign programs would need to be initiated by the various equipment manufacturers. All NEMA, ANSI and UL standards would need to be revised. I t is estimated that a five to ten year timetable would be involved. Atte~)tlng to incorporate insulated bus systems on existing designs will involve design modifications and de-rat(ng factors and result in equipment designs which would not be in compliance with NEMA, ANSI and UL standards.

In conclusion, experience in the f ield does not warrant or Justify the need for insulated busbars in metal-enclosed, low-voltage electrical equipment. In fact, this requirement would not only increase costs substantially but would reduce re l iab i l i ty and complicate maintenance. I t is expected that f i re and smoke damage would increase as a result of, Insulatlon burning associated with bus faults. Ionized gases resulting from insulation burning would tend to propagate the fault arc, causing major equipment damage and power interrup~lons.

Plant safety records and maintenance experience do not indicate that unlnsulated buses in enclosed equipment are a hazard to maintenance personnel. One of the problems with insulated buses, for example, in high-voltnge equipment is that i t becomes d i f f icu l t to t ie grounds to these buses for safety during maintenance. This would also apply to low-voltage equipment that was completely insulated.

384-3(h)-(New): Reject CMP g SUBMITTER: Donald C. Smith, Texas Chapter IAEI ~ 7 3 Add (h) as follows: .---T~T)--A-ny multi-section service switchboard incorporating multiple main overcurrent devices feeding subsections within the same switchboard shall indicate by use of permanent mimic bus on the face of the switchboard the bussing schematic of that switchboard. SUBSTANTIATION: For many years design engineers have recognized the need for mimic bus on the front of switchboards for the safety of personnel and ease of identification. In modern design of switchboards installed on large industrial type installations, mimic bus is being util ized more and more. Some of the reasons for using the mimic bus are: When viewing the bus assembly from the rear o f the switchboard, line and load busses often are not easily distinguishable. Also, often time the rear of the switchboard is not accessible thereby making i t hard to determine which main device feeds which group of sub-devicos. Some switchboards with insulated buses make i t hard to identify line and load connections. Lack of identification presents an obvious hazard to workmen. PANEL RECOMMENDATION: Reject; PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 11. NEGATIVE: Leiman.

EXPLANATION OF VOTE: LEIMAN: I agree with the supporting comment.

384-6-(New): Accept CMP 9 Secretary's Note: I t was the action of the Correlating

Committee that the Panel shall delete reference to new and existing installations. The application of installation rules is the function of the authority enforcing the Code. SUBMITTER: Samuel S. Levinrad, VA, Wash., DC PITOITO-S'AI_-~. • 74 Renumber existing Sections and add new 384-6 as

384-6. Water Pipes and Accessories. Any pipe or duct system, foreign to the electrical installation, shall not be located in the vicinity of switchboards and service equipment, nor enter or pass through rooms specifically designed to house this type of equipment. No piping or air conditioning duct system, other than those systems which serve the electrica~ equipment space, shall be located in the vicinity of any switchgear or service equipment nor shall they pass through rooms or architectural space specifically provided for the housing of such equipment. SUBSTANTIATION: Sections 450-47 and 710-9 are the only areas within NEC prohibiting foreign piping (water pipes) in areas containing electrical equipment. With the advent of the large office and apartment house complexes, i t has become more economical to purchase primary voltage power, feed through the switchgear, stepdown to uti l ization voltage and distribute throughout the complex. We have seen hospitals and building complexes wherein chilled water pipes, steam pipes, cold water pipes, sanitary cleanouts and other piping pass directly over the building's secondary or primary switchgear. In addition, some a~chitects s t i l l ut i l ize the electrical closets as a chase for other than electrical conduit. The addition of a paragraph such as recommended wil l aid the inspection authority having Jurisdiction in performing its function and assure a safer installation. PANEL RECOMMENDATION: Accept as Revised:

Change 384-1 to "General." Change the "Scope" to paragraph (a) and "384-2. Other Articles" to paragraph (b). Number the following 384-2: 384-2 Installation. (a) New Buildings. In every new building hereinafter

173

designed, constructed or erected, an electrical service, distribution, transformation or control equipment shall be located in rooms or spaces dedicated exclusively to such equipment. No foreign piping, ducts or other mechanical or architectural equipment or appurtenances shall be permitted to be installed in, enter or pass through such spaces or rooms. (b) Existing Buildings. Previously approved electrical

installations shall be permitted to remain. (c) Existing Buildings Being Remodeled. An existing building

which is being remodeled more than 50 percent or in which a new electrl~al service and distribution system is being installed shall conform to the provisions of paragraph (a) of this section.

Exception No. 1: Control equipment which by its very nature or because of other rules of this Code must be adjacent to or within sight off its operating machinery.

Exception No. 2: Ventilating, heating or cooling equipment that serves the electrical rooms or spaces.

Exception No. 3: Transformers,, controllers, switches and distribution equipment located throughout industrial plants which are isolated from foreign equipment by height or physical enclosures which will afford adequate mechanical protection from vehicular t ra f f ic , accidental contact by unauthorized personnel or accidental spillage or leakage from piping systems.

Exception No. 4: Outdoor electrical equipment located in weatherproof enclosures protected from accidental contact by unauthorized personnel or vehicular t ra f f ic or accidental spillage or leakage from piping systems. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE:. 9. NEGATIVE: Biermann, Cremer, LaMorte.

COMMENT ON VOTE: ECKARDT: While the concept can be supported terms such as

"Every new building" and "Existing buildings" would seem to include residences. I do not believe this is the Panel's intent.

COCK: An "Exception No. 5" should be added for one and two family dwellings.

DEMING: I am in agreement with'the proposal) but believe we have exceeded our authority in Section 384-2(b) making the rule that previously approved electrical installations shall be permitted to remain. The Judgement of whether or not previously approved electrical installations are currently safe should be lef t to the inspection authority having Jurisdiction.

In Section 384-2(c) we should insert the word "structurally" before the word remodeled, which appears In the t i t l e and f i r s t sentence. The word "structurally" clarif ies our intent with regard to the type of remodeling. EXPLANATION OF VOTE:

BIERMANN: The precept of a double standard of rules for existing buildings and new buildings is a bad code. Moreover, retroactive rules are worse. The declaration that previously approved electrical installations shall be permitted toremain would clearly disfranchise the application of the code rules no matter how hazardous the condition.

CRAMER: When this ~unen&nent to this proposal was originally considered, i t appeared desirable. Later reflection on i t has uncovered some deficiencies.

( I) Interpretation of what constitutes a space can vary from person to person. Some industry users place switchgear or motor control centers in one portion of a machinery room. Some might consider this a violation because of machinery and piping in the same room with electrical; others might not consider this a vlolatlon because of the electrical gear in its own space. Similarly in a home, the mount of space required for a service entrance panelboard is vague.

(2) Industrial control rooms with operator attended control panels would fa l l under this section. Desks, f i l e cabinets, drinking fountains and other accessory items are included In these roo~s and would be In violation of the proposal.

(3) The exceptions themselves appear incorrectly located afterafter paragraphParagraph l~I~ They appear to be more logically located

LaMDRTE: At a glance i t appeared that this proposal, with some modifications, would be a good one. The revised proposal taking i t part by part was a disappointment, and I have voted negative for the following reasons:

I . There seems to be a lack of definition to "Spaces or Rooms." Is space, working space as defined in Article 1107 Are rooms total ly enclosed or merely a screened area?

2. Section 450-47 on Transformers does not consider piping for f i re protection foreign to the electrical installation. Would the proposed Section 384-2 permit sprinkler piping for a unit substation line-up consisting of primary switches, transformer and low voltage section?

3. In Part (c) who could determine i f a building is being remodeled more than 50 percent? I f a building Is required to be remodeled greater than 50 percent, one way of getting around the NEC would be to complete the installation In several different phases.

4. The objection I have about the 4 exceptions is that i t expands beyond the scope of the Article which should be on Switchboards and Panelboards.

384-7: Reject CMP g SUBMITTER:" H. K. Glenn, Pacific Coast Electrlcal Assn.

75 In 384-7, delete the word "nonfireproof" and ~ w i t h the words "nonfire-reslstant." In Exception No. 1,

delete the word "fireproof" and replace with the words "f lre-resistant." SUBSTANTIATION: In its present form, because of the word "fireproof" for which there appears to be no standard or definition, the section has l i t t l e value either to the building designer or to the constructor.

I f in fact, the intent is to establish a specific level of f i re resistant integrity, then the proposal could be expanded to include 1 hour, 2 hour, 3 hour, etc., based on, as example, ASTM-E119, etc. PANEL RECOMMENDATION: Reject. PANEL COMMENT: We do not intend to establish fire-reslstant ratings for ceiHngs above switchboards. VOTE ON PANEL RECO~MENDATION: Unanimously Affirmative.

384-9 (HOD 1978 NEC): Accept CMP 9 SUBMITTER: C~ g ili~-O'FO-~-~.76 Revise Section 384-9 so as to read as follows: ~ o n d u c t o r Covering. All insulated conductors used inside of switchboards shall be flame retardant and shall be rated not less than 600 volts. SUBSTANTIATION: The panel feels that i t is unnecessary to continue to add every new wire type that is brought on the market. The simple sentence above is all that is necessary to assure,that the proper wire wil l be used in switchboards. PANEL RECOMMENDATION: Accept as Revised:

Change 384-9 to read: "Conductor Insulation. An insulated conductor used within a switchboard shall be listed, flame retardant and shall be rated not less than the voltage applied to i t and not less than the voltage applied to other conductors or busbars with which i t may come in contact. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. ,

384-9: Accept CMP 9 SUBMITTER: TSC-Approved for the Purpose I~TOl~)~)~. • 77 See the Technical Subcommittee "Recommendations" un--n-d'e'~--t-Fe definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC °findings" under the definition of "Approved for the Purpose" In Article 100. PANEL RECOI~ENDATION: Accept as Revised:

As Proposal No. 76. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

384-15: Reject C~ 9 SUBMITTER: Mike Brendle, Mt. Vernon, WA -

78 Add the following paragraph after the presen t t e x t :

"Not more than 90 percent of the total spaces in any lighting and appliance branch-circuit panelboard in a one-family chwelling shall be occupied after in i t ia l installation." SUBSTANTIATION: The building and electrical construction industry, being very competitive, often causes electrical installation to meet only the minimum NEC requlren~nts. The owner of a new one-family dwelling often encounters a panelboard that has no available space for overcurrent devices. The only course of action for the electrician is to install tandem circuit breakers. These are approved for this application, but they increase current density and heating within the panelboard. I t is the intent of this amendment to provide a one-family dwelling with an electrical service which wil l accomodate the diverse electrical needs of the future. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primarily a design consideration. VOTE ON PANEL RECOI&M[NDATION: Unanimously Affirmative.

384-16(a): Reject CMP 9 SUBMITTER: Ralelgh W. Rheuby, Jr., Hueytown, AL ~ 7 9 Add the words "one and" after the words "on the su~-'u'~'Ty-side by." Revise Exception No. 2 as follows:

Exception No. 2: Individual protection for lighting and appliance branch-circuit panel boards Is not required where such panelboards are used as service equipment in supplying service t o signs, pumps and equipment separate from buildings of occupancy. SUBSTANTIATION: Since the words from the 1975 NEC Section 384-16(a), Exception No. 2 - and .where any bus supplying 15- or 20-an~)eres circuits is protected on the supply side by an overcurrent service, have been deleted from the 1978 NEC Section 384-16(a), Exception No. 2. The Code does not require a main disconnect or overcurrent service for service equipment of residential housing. This constitutes a conflict and confusion between Section 384-16(a), Exception No. 2 and Section 230-79(a) through (d) besides the need for the protection of equipment and safety of persons.

This proposal and any improvements are for con~ideratloo to

1 7 4 '

cause the Code to require a main disconnect current protection for residential occupancy panel and to be in accord with Section 230-79(a) through (d). PANEL RECO~MENDATION: Reject. PANEL COMMENT: See Panel•actlon on Proposal No. 80. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

384-16(a), Exception No. 2: Accept CMP 9 SUBMII-TER: Idaho Chapter IAEI IM~roI~FO-S'-A~-T.'80 Delete 384-16(a), Exception No. 2. 3u~I~NItATION: This is a subject that has come up in every Code for a number of years and has been rejected or blocked every time. I t is not quite clear as to the reason why except that the supporting comment of the "con" nature seems to reiterate the thought that no one has been electrocuted, injured, or there are not any f i re records showing contributory factors to this exception. I t seems that some pressures are applied in areas beyond the Code Making Panels' jurisdiction because Proposal No. 83 in the Preprint for the 1978 Code was submitted ~d accepted by Code Making Panel 9.

This seems to be indicating that polit ics has a greater bearing on Code making than the desire for having compatible Code especially when the negative pressures come from the segments of the industry not regulated by the NEC requirements. In other words, why is a residential service permitted to have equipment that is not only less restr ict ive than the other occupancies but can be mere easily tampered with by inexperienced persons Just because they feel they can do as they please w!th what they own even though i t may endanger their next door neighbor.

Proposal No. 83 page 204 of the 1978 NEC Preprint is evidence that i t is prime time that this exception be retired from the NEC. PANEL RECOMMENDATION: Accept as Revised:

I Add to Exception No. 2 at beginning of sentence: "For existing instal lat ions,." VOTE ON PANEL RECOMMENDATION:,

AFFIRMATIVE: 11. NEGATIVE: Biermann.

EXPLANATION OF VOTE: BIERMANN: I am in favor of ~he proposal. I am not in favor

of establishing one standard for existing dwellings and another for new dwellings. ~

384-16(c): Reject CMP g SUBMITTER: O. E. Dillon, Border County Div. IAEI ~ 8 1 Revise as follows: ~ h e total load of appliances or equipment fastened in place and connected to any overcurrent device located in a panelboard shall not exceed 80 percent of the overcurrent device rating where in normal operation and load wil l continue for three hours or mere.

"SUBSTANTIATION: This section is practicably unenforceable unless the jurisdiction has the man power to make periodic checks of all occupancies (commercial and residential) to determine i f the portable appliances are overloading any overcurrent devices. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for ' llO-16(a).

PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

384-16(d), Exception No.' 2-(New): Reject CMP 9 SUBMI1-FER: D. H. Mclntosh, E. I. du Pont de Nemours & Co. I~TOlbI~S';~-T.'82 Add exceptionas follows: ~ i o n No. 2: Individual protection for lighting and appliance branch-circuit panelboards is not required in . industrial establishments where conditions of maintenance and supervision indicate that only qualified persons wil l service the installation; the transformer primary (supply) is protected by overcurrent protection in accordance with Section • 450-3(b)(1); and, the conductors tapped to the transf6rmer secondary meet all of the following conditions: (1) the length ' of the tap conductors does not exceed 10 feet; (2) the ampacity of the tap conductors is not less than the ampacity of the panelboard; (3) the tap conductors are enclosed in a raceway approved for the purpose. SUBSTANTIATION: The following table of unitized transformer-panelboards il lustrates the application of 3 typical sizes of 480-208/120-volt transformers supplying lighting and appliance branch-circuit panelboards. A transformer secondary main circuit breaker requires an unjustified increased cost f o r the electrical installation without a commensurate increase in safety.

Typical Transformer I sec. Ratings (kVA)

15 30 83.4 45 125.0

Panelboard Ma in Panelboard Main Bus (amps) Circuit Breaker (amps)

IUU IUU

i00 . i00 225 225

The overcurrent protection of a 15 kVA unit substation with a fu l l load current of 41.7 amperes, 15 ampere branch-circuit breaker, and 100 amp standard panelboard bus, is not enhanced with the standard 100 amp transformer secondary main breaker rated at over twice fu l l load (calibrated to t r ip in 6 minutes at 200 amperes--UL489).

A branch-circuit fault close to the panelboard is seen by the instantaneous elements in both the main and the corresponding branch-circuit breaker. This can drop all the substation load possibly creating an unsafe condition due to a con~lete loss of power to cr i t ical process instruments or to the area lighting being served.

The identification and marking of each branch circuit is already a requirement of NEC 110;22 and assists in monitoring the load connected to each phase.

I believe that the restrictions of this proposal exceed those allowed under 384-16(a) Exception No. 2 for a safe installation. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

384-17-(New): Accept CMP 9 Secretary's Note: I t was the action of the Correlating

Committee that the Panel shall delete reference to new and existing installations. The application of installation rules is the function of the authority enforcing the Code. SUBMITTER: Samuel S. Levinrad, VA, Wash., DC ]~TO]~TS'A-L-~." 83 Renumber existing Sections and add new 384-17 as

384-17. Water pipes and accessories. No piping or duct system foreign to the electrical installation, shall be located in the v ic in i ty of panelboards and service equipment, or pass through rooms specifically designed to house this type of equipment. No piping or air conditioning duct system, other than those systems which serve the electrical equipment space, shall be located in the v ic in i ty of any switchgear, panelboards or service equipment and shall not pass through rooms or architectural space specifically provided for the housing of such equipment. SUBSTANTIATION: Sections 450-47 and 710*g are the only areas within the NEC prohibiting foreign piping (water pipes) in areas containing electrical equipment. With the advent of the large office and apartment house complexes, i t has become mere economical to purchase primary voltage power, feed through the switchgear, stepdowo to ut i l izat ion voltage and distribute throughout the complex. We have seen hospitals, office buildings and apartment houses wherein chilled water pipes, steam pipes, cold water pipes, sanitary cleanouts, pass directly over the building's secondary or primary switchgear. In addition, some architects s t i l l u t i l ize the electrical closets as a chase for other than electrical conduit. The addition of a paragraph such as recommended wil l aid the inspection authority having jurisdiction in •performing its function and assure a safer installation. PANEL RECOMMENDATION: Accept as Revised.

I ~ee Panel action on Proposal No. 74. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Biermann, LaMorte.

COMMENT ON VOTE: ECKARDT: See my comment under Proposal No. 74. COCK: An "Exception No. 5" should be added for one and two

family dwellings. EXPLANATION OF VOTE:

BIERMANNi See my comments on Proposal No. 74. LaMORTE: See comments on Proposal No. 74.

384-18: Accept ' CMP 9 SUBMITTER: TSC-Approved for the Purpose

84 See the Technical Subcommittee "Recommendations" un--6-de~--t'~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I ~hange the word "approved" to "designed." VOTE ON PANEL RECOMMENDATION: "'AFFIRMATIVE: 9.

NEGATIVE: Hogan, Barker, Cramer.

1 7 5 t

EXPLANATION OF VOTE: HOGAN: I don't find the word "designed" any more palatable

than the word "identif ied" in this section of the Code. I would much prefer the word, " l isted." At least we have a definition in the code book for i t . The word "designed" really doesn't t ie

t h i s down to anything. BARKER: The use of the word "designed" would result in

confusion and lack of uniformity. These enclosures should be listed.

CRAMER: See comments on Proposal No. 74.

384-21: Reject CMP 9 SUBMITTER: J.A. Fehr, General Electric Co lsITOlsO-S'Al--~. • 85 Revise as follows: ~ B u s b a r s . B~sbars may be copper or aluminum. I f r ig id ly mounted, they may be bare. SUBSTANTIATION: Section 110-5 states "Conductors normally used to carry current shall be of copper unless otherwise provided in this Code."

Since no such provision is contained in Article 384, this could be interpreted to mean all conductors in switchboards and panelboards must be copper. For manyyears the industry has manufactured these products with aluminum conductors and in large volume. The proposed change will bring this Arbicle into accordance with the intent of the proposed change to Section 110~5 in the 1978.NEC (Proposal No. 76). PANEL RECOMMENDATION: Reject. PANEL COMMENT: Such practice is not prohibited by present Code. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Cramer, Doming.

EXPLANATION OF VOTE: CRAMER: I believe the submitter is correct. To avoid

misunderstanding we should add statement, "Busbars may be copper or aluminum" as a fine print note.

DEMING: I agree with the submitter. All he is asking for is additional c lar i ty.

384-21: Accept ~ CMP 9 SUBMITTER: CMP 9 ~ 8 5 A Revise 384-21 to read: "Busbars shall be ~ m o u n t e d . " SUBSTANTIATION: See Proposal No., 72. FANEL RECOMMENDATION: Accept as Revised:

"Insulated or bare busbars shall be r ig idly mounted." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 384-26: Accept SUBMITTER: TSC-Nominal Voltage l~TOIsl~S'Al--~.'86 The voltage designation' in Column i should be ~ t o read:

Not over 127 volts; Not over 254 volts; Not over 635 volts;

SUBSTANTIATION: To conform to the method to express maximum voltage as per guidelines developed by the TSC on nominal voltage. PANEL RECOMMENDATION:' Accept as Revised:

Add the word "nominal" after "125 volts, .... 250 volts," and "600 volts" in Table 384-26. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

CMP 9

384-27: Reject CMP 9 SUBMITTER: Robert W. Gilmore, Northwest Iowa Technical College ~ 8 7 Revise as follows: ~ o a r d cabinets or panelboard when used as service equipment shall be grounded in'the manner specified in Article 250 or Section 384-3(c). An equipment grounding terminal bar approved for the purpose shall be provided and secured inside of cabinet or panelboard for the attachment of all the feeder and branch-circuit equipment grounding conductors, where the panelboard is used with nonmetallic raceway or cable, or where separate equipment grounding conductors are provided. The terminal bar shall be bonded to the cabinet or panelboard frame and shall not be connected to the neutral bar in other than service equipment. SUBSTANTIATION: Most electricians and inspectors do not realize that when a panelboard' approved for the purpose is used for service equipment I t is s t i l l a panelboard. Most inspectors and electricians recognize the need for terminating the equipment grounds .on a separate bar when used in a panelboard on the load side of the service equipment, but don't see the need when a panelboard is being used as service equipment.

Adding the words "when' used as service equipment" should help to enforce the meaning of the article.

Also, there is a need for the change from "approved" to "approved for the purpose" otherwise an inspector can approve any type of f i t t i ng for-equipment ground termination other than the equipment grounding terminal bar provided by the manufacturer.

NOTE: The intent of this is not to require the manufacturer to provide an equipment terminal bar with each panelboard but to provide the provisions for one; some disconnect switches approved for use as service equipment do not have these provisions and cause a real .problem for the electrician or inspector. When using equipment without these provisions and an equipment grounding conductor or conductors are present there is no place to terminate them properly, forcing one to violate the NEC. PANEL RECOMMENDATION: Reject. HANbL COMMENT: We do not agree with the supporting comment and do not believe that the Proposal accomplishes what the submitter intended. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

i

384-27, Exception No. 2-(New): 'Accept CMP 9 SUBMITTER: Robert B. West, St. Louis, MO P]TOIsO-S'A'L-~88 Add a new exception as follows: ~ i o n No. 2: The terminal bar for equipment grounding conductors shall be permitted to be connected to the neutral.bar at separate buildings in accordance with the provisions of Section 250-24, Exception No. 2. SUBSTANTIATION: This is to correct a conflict. Where the grounded circuit conductor is grounded at a separate building in accordance with Section 250-24, the terminal bar for equipment grounding conductors must be bonded to the neutral bar in order to complete the ground-Sault current path to the service.

• The reference to Section 250-24, Exception No. 2 correlates with my proposal to amend Section 250-24. I f Section 250-24 is not amended, the reference in this proposal should be Section 250-24(a). PANEL RECOMMENDATION: Accept as'Revised:

I Delete the words "Exception No. 2" at the end of sentence. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: BARKER: In accord with Articles 230 and 250, when the

conductors enter the second building they are service conductors to that building except for the exceptions. To add this to this section would be confusing and could result in improperly grounded installation with resultant hazards. We should leave services and grounding to the appropriate Panel, with only a cross-reference in this Section.

384-XX-(New): Accept CMP 9 Secretary's Note: I t was the action of the Correlating

Committee that the Panel shall delete reference to new and existing installations. The application of installation rules is the function of the authority enforcing the Code. SUBMITTER: Southwestern Section IAEI ~ 8 9 Add section as follows: 3ITATX]~Z-. Electrical switchboards, electrical controls or control panels other than those related to the Mechanical Code shall not be located in any machinery room. SUBSTANTIATION: The following problems have arisen due to the electrical requirements included in other uniform codes. Too often this requirement can be overlooked from the standpoint of design and plan check, therefore, creating a situation that can result in enormous cost in order to satisfy all model code requirements after the installation has been made. I feel that the electrical requirements included in other codes should be cross-referenced back to this Code.

The 1976 edition of the Uniform Mechanical Code wil l allow the following equipment in a machinery room:

(1) Lights and receptacles (2) Machinery room exhaust fans and blowers (3) Any refrigerating condensing unit or portion

thereof (4) Circulating pumps for condensers, cooling

towers, or cooling coils (5) Air compressors serving only automatic controls

within the refrigerating or cooling system (6) Electrically operated valves for the control of

a refrigerant or for the control of the circulation of a cooling f luid

(7) Blowers and fans for cooling towers or for condensers

, (8) Any electric control or control panel for any of the above items.

A readily accessible single emergency refrigeration control switch shall be provided to shut off all electr ical ly operated machinery in any machinery room, except the exhaust ventilation system complying with UMC Section 1508. Such switch shall be controlled from a point outside of, and within ten feet of the required opening to the machinery room i t serves, and the switch shall be )abeled to comply with UMC Section 1519. Except as modified by this article, wiring and equipment shall comply with the applicable requirements of Chapter I through 4. PANEL RECOMMENDATION: Accept as Revised:

I See Panel actlon on Proposal No. 74. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 9. NEGATIVE: Biermann, Cramer, LaMorte.

176

COMMENT ON VOTE: ~UCK: An "Exception No. 5" should be added for one and two

family dwellings. EXPLANATION OF VOTE:

BIERMANN: See my comments on Proposal No. 74. CRAMER: See comments on Proposal No. 74'. LaMORTE: See comment for Proposal No. 74.

384-XX-(New): Accept CMP 9 Secretary's Note: I t was the action of the Correlating

Committee that the Panel shall delete reference to new and existing installations. The application of installation rules is the function of the authority enforcing the Code. SUBMITTER: George Alexander, Fresno, CA ~ 9 0 Electrical switchboards, electrical controls or controTpanels other than those related to the Mechanical Code shall not be located in any machinery room. SUBSTANTIATION: The.following. problems have arisen due to the electrical requirements included in other uniform codes. Too often this requirement can be overlooked from the standpoint of design and plan check, therefore, creating a situation that can result in' enormous cost in order to satisfy all model code

'requirements after the installation has been made. I feel that the electrical requirements included in other codes should be cross-referenced back to this Code.

The 1976 edition of the Uniform Mechanical Code wil l allow the following equipment in a machinery room:

I ) Lights and receptacles 2) Machinery room exhaust fans and blowers 3) Any refrigerating condensing.unit or'portion

thereof 4) Circulating pumps for condensers, cooling towers,

or cooling coils 5) Air compressors serving only automatic controls

within the refrigerating or cooling system. 6) Electrically operated valves for the control of a

refrigerant or for the control of the circulation of a cooling f luid

7) Blowers and fans for cooling towers or for condensers

8) Any electric control or control panel for any of the above items

A readily accessible single L;mergency refrigeration control switch shall be provided to shut off all electrically operated machinery in any machinery room, except the exhaust ventilation system complying with UMC Section 1508. Such switch shall be controlled from a point outside of, and within ten .feet of, the required opening to the machinery room i t serves, and the switch shall be labeled to 'comply with UMC Section 1519.- Except as modified by this art icle, wiring and equipment shall comply with the applicable requirements of Chapter I through 4. PANEL RECOMMENDATION: ACcept as Revised: i See Panel action on Proposal No. 74. "VOTE ON PANEL RECOMMENDATION:

PJ-PIRMAIIVE: 9. NEGATIVE: Biermann, Cramer, LaMorte.

COMMENT ON VOTE: COCK: An "Exception No. 5" should be added for one and two

family dwellings. EXPLANATION OF.VOTE:

: ee my comments on Proposal No. 74. CRAMER: See comments on Proposal No. 74. LaMORTE: See comment for Proposal No. 74."

177

be permitted to be used at the ampacities shown in the tables of this article with any of the equipment or devices specified in Articles 210, 220, 230, 240, 250, 380, 384, 410, 430, 440, 517.

This section shall become effective January 1( 1985. SUBSTANTIATION: Problem: Terminal restrictions imposed upon conductors do not recognize improved insulation technology.

These restrictions cause under-utillzatlon of conductors and raceway systems. This under-utillzation causes excess costs for both material and labor, wasting both natural resources and energy. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:

AI-~IRMAIIVt: 6. NEGATIVE: Coffey, Conley, Durham, Hogan, Jannot.

EXPLANATION OF VOTE: COFFEY: T oppose the panel rec~mendation to accept th is

proposal because the ampacity and operating temperature are adequately covered in Sections 310-15 and 310-9 respectively of the 1978 NEC. This proposal does nothing to alleviate the problom described in the substantiation for the proposal, namely, that restrictions on the terminal presently control the load current through the insulated wire. The intent of the proposal is good but I t should appear in'the appropriate sections of the Code, that cover the use of wire and cable terminations. \

CONLEY: The Panel Comment on Proposal No. 54 is that terminations do not determine conductor ampacitles. Neither should conductor ampacities dictate the ratings of terminals on connected equipment. I t is desirable that all readily available conductors, equipment and devices be thermally compatible - that appears to be the intent of the proposal. See also my Co~ent on Proposal No. I .

DURHAM: This proposal is in conflict with 410-11 and 110-11 in that i t would permit conductors to be used in equipment with higher temperatures than that for which the conductor is rated.

HOGAN: I find it, impossible to understand how CMP 6 can make the statement made in your Panel Co¢mnent on Proposal No. 54 and then to accept the substantiating comments made by the proposer of the proposal. The Correlating Committee had better decide i f CMP 6 has the responsibility of tell ing how and where the conductors for which they are responsible may be used regardless of the provisions of all the other sections mentioned in this proposal. We may find that there are some panels that might not like to be told that information.

JANNOT: The panel should assign a section number.

ARTICLE 400 -- FLEXIBLE CORDS AND CABLES

Table 400-4: Reject CMP 6 SUBMITTER: R. Droste, National Elevator Industry, Inc. IqII~OS'AL-~63 Change the range of wire sizes for Hard Service ~ m 18-2 to 20-2 AWG. SUBSTANTIATION: More extensive use of electronics with corresponding lower required currents permits use of smaller wire.

Such a change was already made in 1978 Code on elevator cables, pages 236 and 237. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 400-4: Reject CMP 6 SUBMITTER: August Lukaslewicz, Cornish Wire Products ~ 6 4 , In the "Type Letter" column add SVR for vacuum cea--T'6-an'~-cords; add SJR for junior hard service cord; and, add SR for hard service cord. In the "Insulatlon" and "Outer Covering" columns for vacuum cleaner cord, junior hard service cord, and hard service cord add the words "Thermoplastic Elastomer." SUBSTANTIATION: Electrical wires insulated and jacketed with thermoplastic elastomers require a new class designation for the following reasons:

I . Chemistry: The chemical structure and characteristics of thermoplastic elastomers differ significantly as compared to other thermoplastic materials. Thermoplastic elastomers are chemically cross-linked yet remain thermoplastic. Thermoplastic elastomers represent a new class of block copolymers designed for wire and cable applications offering properties not previously available in a single polymer.

2. Performance: The performance of thermoplastic elastomers is generally superior to other thermoplastic materials, specifically in low and high temperature performance, abrasion resistance and in electrical performance. Thermoplastic elastomers are almost equivalent to rubber compounds in performance characteristics.

3. Aesthetics: Unlike other thermoplastic materials, thermoplastic elastomers have the feel and appearance of rubber. Thermoplastic elastomers can easily be mistaken for rubber, therefore, a separate class designation is in order. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 65, Table 400-4. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

107

Table 400-4: Accept CMP 6 SUBMITTER: William H. Korcz, Shell Development Co./Shell C'li;~-~-F~3T-Co.

I PROPOSAL: 65 Add the following new designation type letters to l'~Bl-~-~I;{IO-4 in the appropriate service cord (SP, SV, SJ, S; SDR) sections as shown in table and include a new Note 10 as follows: SUBSTANTIATION: The current NEC designation syste~ for service type flexlble cords (Article 400) does not provide for a broad group of acceptable cord insulations and outer coverings based upon thermoplastic rubber materials. What we propose is a revision to Table 400-4 as shown in the "Recommended Text" section which wil l provide the necessary differentiation of this group from currentqy designated "rubber" and "thermoplastic" insulation and outer covering classes of materials.

The substantiation for thls proposal has two aspects: (I) performance and fabrication considerations, and (2) the expressed need by cable producers and

users to develop this new type designation for thermoplastic rubber materials.

Detailing of arguments arising from these viewpoints is found in the accompanying appendices* to this proposalS:

Appendix 1: Sgmmary Appendix 2: Introduction, general background,

acceptance and performance, history, terminology and definitions associated with thermoplastic rubbers

Appendix 3: Performance considerations based upon UL fact finding programs and UL No. 62 listings

Appendix 4: New type designation survey of cable manufacturers and users.

*Appendices have been supplied to CMP members. PANEL RECOMMENDATION: Accept as Revised:

I Delete hyphens (1 places) in type letters preceeding "E" in proposed additions to Table. Delete proposed Note 10 and all references to Note lO. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 400-4: Accept - CMP 6 SUBMITTER: Peter Pol)ak, The Aluminum Association

J ~ 6 6 Insert "copper" in the second tabular heading under "Size AWG." SUBSTANTIATION This proposal is submitted to clar i fy the proper conductor tot the application. Makes clearer the fact that the conductor is to be copper. The panel is referred to the proposed revision in Section 110-5. PANEL RECOMMENDATION: Accept as Revised:

I Aoa "copper" to the third tablular column. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 400-4, Note No. 6: Accept CMP 6 SUBMITTER: R. Drgste, National Elevator Industry, Inc. FROPO~AC'~" 67 Reyise the f i r s t paragraph as follows:

~ o r traveling cables for operating control and signal circuits shall contain non-meta11~c f i l l e rs as necessary to maintain concentricity. Centrally located steel supporting members are supplied as needed for suspension methods described in Section 620-41. SUBSTANTIATION: The information on "Note 6" does not comply wlth the statements of 620-41 which permits three methods of traveling cable support.

The present.Note 6 states that a traveling cable shall have non-metallic f i l l e rs or a steel supporting f i l l e r . The non-metallic f i l l e rs are used by manufacturers with and without steel support. The standard steel is not a supporting f i l l e r . Fi l lers are used to round out (equalize) the conductor layup. PANEL RECOMMENDATION: Accept as Revised.

First sentence of proposal is to replace existing f i r s t sentence of Note 6. Second sentence of Proposal is. rejected. Also, delete the word " f i l le rs" and replace with "members" in the existing second and third sentences of Note 6. Revised f i r s t paragraph of Note 6 to read as follows:

6. Elevator traveling cables for operating control and signal circuits shall contain nonmetallic f i l l e rs as necessary to maintain concentricity. Cables exceeding 100 feet between supports shall have steel supporting members except in locations subject to excessive moisture or corrosive vapors or gases. Where steel supporting members are used, they shall run straight through the center of the cable assembly and shall not be cosied with the copper strands of any conductor. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 400-4, Note No. 6: Accept CMP 6 SUBMITTER: R. Droste, National Elevator IndUstry, Inc. PROPOSAL: 68 Delete the f i r s t three lines of the second

and substitute the following: "Type E, EO, EN, ET, ETP, ETLB, and ETT elevator cables shall

be permitted to contain No. 20 to No. 14 gage insulated conductors. In addition, they may have incorporated in the construction No. 20" . . . , etc. SUBSTANTIATION: ~rt icle 620-12(a)-(2) permits No. 20 gage conductors for operating control and signal circuits. The

subject article restricts this use to a shielded pair. PANEL RECOMMENDATION: Accept as Revised:

I Delete "gage" and replace with "AWG." Add "AWG" after "No. 20" in the second sentence. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 400-4, Note No. 7: Reject CMP 6 SUBMITTER: R. Droste, National Elevator Industry, Inc. I~ITO!~T~TTL-~. 69 Omit present wording of Note 7 and substitute the folIowlng:

"A separate conductor In these cables shall be available for grounding purposes only." SUBSTANTIATION: This note refers to "a third conductor in these (elevator) cables is for grounding purposes only." An elevator cable has a multitude of conductors. A "third conductor" has no meaning. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Note 7 is not applicable to elevator cables in Table 400-4. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Tables 400-4 and 400-5: Accept CMP 6 SUBMITTER: Austin D. Wetherell, Underwriters Laboratories Inc. ~ 7 0 Substitute the word "thermoset" for the word

ih Notes 6, 8 (line 4 only), and 9 to Table 400-4; Table 400-4 in its entirety; and Table 400-5 column headings.

Table 400-4, outer covering on Types SVO, SJO and SO, change "oil resistant compound" to "oil resistant thermoset."

Add new types to Table 400-4 as follows:

Trade Name T~pe Letter Insulation Vacuum Cleaner SV00 Oil Resistant Cord Thermoset.

Oil Resistant Thermoplastic or Thermoset

SVTO0

Junior Hard SJO0 Oil Resistant Service Cord Thermoset

Oil Resistant Thermoplastic or Thermoset

SJTO0

Hard Service SOD Oll Resistant Cord ' Thermoset

Oil Resistant Thermoplastic" or Thermoset

STO0

Comments All other columns identical to SVO All other columns identical to SVTO All other columns identical to SO0 All other columns identical to SJTO All "other columns identical to SO All other columns identical to STO

SUBSTANTIATION: 1. Based on test work and discussion with users, manufacturers, and inspection authorities, UL has declined to List "Rubber" cords employing elastometric (rubber) compounds which were not thermoset. Consequently, there are proposals to revise the 1978 NEC to recognize new types employing "thermoplastic elastomers." The above revisions are necessary in order to clearly differentiate the three types.

2. To make intent clearer. 3. UL has Listed these new types to give recognition to cords

with oil resistant insulations as well as Jackets. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

400-5: Accept CMP 6 SUBMITTER: Peter Pollak, The Aluminum Association !BIT(~B-O~L-~. 71 In the f i r s t sentence insert "copper" following

l ~ - c a r r y i n g . . . . " SUBSTANTIATION Thls proposal is submitted to c lar i fy the proper conductor for the application. Makes clearer the fact that the

~conductor is to be copper. The panel is referred to the proposed revision in Section 110-5. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOI~ENDATION: Unanimously Affirmative.

400-5: Reject CMP 6 SUBMITTER: Greg Batie, Seattle, WA

72 400-5. Ampacity of Flexible Cords and Cables. l'~BT~-~O-5 gives the allowable ampacity for not more than 3 current-carrylng conductors in a cord. I f the number of current-carrying conductors in a cord is from 4 to 6, the allowable ampacity of each conductor shall be reduced to 80 percent of the values for not more than 3 current-carrying conductors in the table (except in theaters and similar locations). A conductor used for equipment grounding and a neutral conductor which carries only the unbalanced current from other conductors. SUBSTANTIATION: In stage lighting systems there are usually more than 3 current-carrying conductors in multi-conductor cords between the grid terminal boxes and the lighting receptacles. The number of circuits are required to give the lighting designer additional F lex ib i l i ty in circuiting the lighting f ixtures, not because of greater loading.

I t does not make sense to require circuit derating in a stage lighting system, due to the fact that there is a large diversity factor in the number of fu l ly loaded circuits at any time. There is also a minimal probabllity:that enough circuits wil l be loaded long enough to cause an elevated temperature in the cord.

In most theatre projects the precedence has been not to derate the stage circuit conductors, in accordance~with Article 400-5. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

400-5: Accept CMP 6 SUBMITTER: R. Droste, National Elevator Industry, Inc,

73 Change the second sentence to the following: number of current carrying conductors in a. cord exceeds

3, the maximum allowable load current of each conductor shall be reduced as shown in the following table:

Number of Conductors Percent of Values in Table 400-5 4 through 6 -" 80

7 through 24 70 25 through 42 60 43 and above 50

In addition to the above, Table 400-5 should be revised to recognize size No. 20 wire. SUBSTANTIATION: Many Flexible Cords and/or cables are listed in Tables 400-4 as having 2 or more conductors. The ampacity rating described in Table 400-5 does not recognize cords/cables or more than 3 conductors. PANEL RECOM~IENDATION: Accept as Revised.

The CMP accepts the revision to change the second sentence and add the table as submitted.

In addition, revise Table 400-5 to include No, 20 AWG conductors and a tr ip le asterisk note as follows:

AWG At B+ 20 B*** 7***

*** Elevator cables only. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

400-5: Reject, CMP 6 Secretary's Note: I t was the action of the Correlating

Committee that action regarding the second paragraph of Section 400-5 wil l have to be correlated with proposals for Section 250-60. SUBMITTER:" Raymond Koster, Sheldon, IA IqTOI~OS'A~-~. • 74 Amend the second paragraph as follows: ~ a single conductor is used for both equipment 9r6und •and" to carry unbalanced current from other conductors, as provided for in Section 250-60 for electric clothes dryers and electric ranges, i t "shall" be considered as a current carrying conductor. SUBSTANTIATION: A grounded conductor in my opinion should be considered as a current carrying conductor in the art icle. Simply because i t does carry a current. I t carries the unbalanced current from the other conductors. I t is essential in the starting and running of electric ranges and electric clothes dryers. I t usually doesn't carry as much current as the phase conductors, but i t does carry a certain amount of current.

Referring to the Notes to Tables 310-16 through 310-19. Note lOB states that in a 3-wlre circuit consisting of 2-phase wires and a neutral of a 4-wire 3-phase system. The common (grounded) conductor carries approximately the same current as the other conductors and shall be counted in determining ampaclties.

Because of this, i t is my suggestion that the wording in Article 400-5 be changed from 'shall not' to 'shall be considered a current carrying conductor.' For the simple reason i t does carry a current. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting co(mnent is not persuasive as to necesslty. VOTE ON PANEL RECO~ENDATION: Unanimously Affirmative.

108

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Table 400-5: Reject CMP 6 SUBMIT~ER: Peter Pollak, The Aluminum Association l~TOl~O'S'~-~. • 75 Add the following note to Table 400-5: ~ The above ampacities are for copper conductors." SUBSTANTIATION This proposal is submitted to clar i fy the proper conductor for the application. Makes clearer the fact that the conductor is to be copper. The panel is referred to the proposed revision in Section 110-5. PANEL RECOMMENDATION: Reject.

: ee anel action on Proposal No. 71, Section 400-5. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 400-5: Reject CMP 6 SUBMITTER: R. Oroste, National Elevator Industry, Inc.

76 This table should be in line with Tables 310-16 ~6--3~!X~CT9 to show different ampacity ratings for conductors with rubber covered insulation cempared to thermoplastic insulation.

The table should also provide ampacity rating for size No. 20 AWG wire. SUBSTANTIATION: Section 340-7 states that ampacities of a Type TC tray cable (multiple conductors) should be determined from Table 400-5, etc.

In Table 400-5 the rubber insulated conductors (temp. rating 60°C) have the same ampacity rating as thermoplastic conductors (temperature rating gO°C).

Table 400-5 does not cover size No. 20 AWG conductor. Table 400-4 does. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel does not agree with the supporting ~ e n t . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

400-7(a)and(b): Reject CMP 6 SUBMITTER: Stephen D. Channer, Business and Institutional ~ M a n u f a c t u r e r ' s Assn., BIFMA PROPOSAL: 77 Add the following to (a):

. ~ 0 ) connection of office furnishings, appliances and lighting as permitted by Sections 410-100, 410-101, and 410-102."

Revise (b) as follows: Delete "and" after (a)(6) and add "and (a)(10)" after (a)(8).

SUBSTANTIATION: This proposal concerns i tsel f with wiring systems as provided by members of our industry with off ice furniture systems that are now being used extensively in offices throughput the United States. Although not exclusively, office furniture systems are primarily used in areas referred to as "open plan" or "landscape" office layouts.

Within our industry, office ,systems furniture has grown in popularity to a great extent over the past several years. Much of the popularity stems from the advantages of portablity and ease of rearrangement. Today the sales of this type of furniture are well over 300 million dollars annually and growing. Due to energy conservation requirements, users have demanded the inclusion of task and ambient lighting with this type of furniture. Current industry estimates show that approximately 80 percent of all office furniture systems sold contain electrical power. When such power is provided by manufacturers within our association, safety is foremost in their consideration and all wiring systems have. been or are in the process of being submitted to and listed by Underwriters Laboratories or other nationally recognized testing laboratories.

Our industry is very proud of its concern for product safety and performance and the good record that i t currently enjoys. Our purpose in submitting the enclosed proposal to the National Fire Protection 'Association is to establish a category within the National Electrical Code that deals specifically with products made within our industry that contain wiring systems and to provide in "writing the standard of quality that must be adhered to by those making such systems.

Your review and favorable consideration of this proposal wil l be very much appreciated by the business and institutional furniture industry. ( PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP feels proposal is not in consistence with 5ectlon 400-8. VOTE ON PANEL RECOMMENDATION:

AFFIR~t~IIVE: 9. NEGATIVE: Coffey, Segall.

EXPLANATION OF VOTE: COFFEY: I oppose the panels recommendation to reject this

proposal because I do no agree with the Panel Comment that the proposal is inconsistent with Secton 400-8. Section 400-8 talks about not using flexible cords as a substitute for fixed wiring, running in through walls, ceilings or floors, doorways, windows or similar openings, attached to building surfaces or where concealed behind building walls. A review of the proposed Section 410-100, 410-101 and 410-102 under consideration by Code Panel 21 indicates the use of f lexible cord would be limited to office furnishings, appliances and lighting which are free standing. In addition, the panels involved are also limited in height to approximately 7 feet and in no instance do they run from floor to ceiling and where more than one panel is involved, they are mechanically connected and not' Joined together by Just a length of flexible cord. After reviewing the proposed

l

/

revisions in Article 410, I am of the opinion that they describe satisfactory applications for f lexible cord.

SEGALL: I am voting to approve the proposal. Panel 21 who has the Jurisdiction for Article 410, has voted to affirm the proposals to Panel 21 in a revised form. Thls new form wil l recognize the use of cord and plug connections under a system of proper Identification by a recognized testing agency such as UL.

Again I wish to emphasize that all of the manufacturers of this equipment are getting wide acceptance of these open space office systems and they are being installed and widely accepted throughout the United States and Canada. Because of this acceptance and demand I feel that there should be some control through the NEC for the electrical components of the system.

Panel 6 wil l have to have some form of correlatin with Panel 21 and'for thls reason I feet that CMP 6 should reverse i tse l f on this Proposal and vote for the adoption of the proposal as written with the correction as to the Section references to conincide with the new numbers proposed by CMP 21.

0

400-7(a)(3) and (6) (HOD 1978 NEC): Reject CMP 6 SUBMITTER: Technical Subcommittee on Definitions of Stationary X~6TT~s PROPOSAL: 78 Delete Section 400-7(a)(3) and revise (6) to , rea--e-a-dT~m, connection of appliances to fac i l i ta te their frequent interchange." SUBSTANTIATION: The Technical Subcommittee found that some requirements for fixed appliances, portable appliances, and stationary appliances were based on different meanings of the terms. These differences arise from the intent of the authors of the requirements at the time the text is adopted. In some cases the requirements are based on the means of electrical connection of the appliance to the supply circuit. In other instances the requirements involve the physical location of the appliance. The TSC noted some requirements that appeared to involve both meanings and s t i l l others where I t was not clear from the wording what the concerned Code Making Panel intended.

The Technical Subcommittee suggests that the requirements 'pertaining to appliances differentiate between those that are necessitated by vlrtue of the method of the electrical connection and those that relate to the physical location of the appliance. With regards to the electrical connections, i t is" suggested that this be accomplished either by the use of a cord and plug or by a permanent connection, that is, without the use of a cord and plug. Requirements pertinent to appliance location involve physically fastening the appliance in place by means other than the e~ectrical connection or locating the appliance in dedicated space. These appliances may be moveable within the space. The result of either approach is to place the appliance on a specific circuit .

The Technical Subcommittee believes that i f these delineations were scrupulously observed and universally applied throughout the Code, both in the drafting of new requirements pertaining to appliances and revising current appliance requirements, the confusion surrounding the interpretation and application of the three terms under review would disappear. Moreover the TSC believes that adherence to this understanding would obviate the need for the three terms.

As an aid to clarifying the intent of the requirements, the, TSC suggests that as required, the following terms or phrases be employed: permanently connected; cord- and plug-connected; fastened in place; or located to be on a specific circuit.

There are requirements where in the opinion of the TSC the deletion of terms "fixed", "portable", or "stationary" wil l in no way affect the requirements. In such cases, i t is unnecessary to substitute any of the foregoing. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's Intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

400-7(c)-(New): Reject CMP 6 SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn. PlTOI~[-~.- 79 Add new (c) as follows: - - - ( -c~ lex ib le cord connections may be made directly to the load end terminals of busway plug-in devices,, providing such connections include a suitable tension take-up device on the cord to satisfy the requirements of Section 400-10. SUBSTANTIATION: The phrasing of paragraph 400-7(b) presumes that a f lexible cord with attachment plug wil l be plugged into a conveniently located receptacle outlet at a convenient fixed location. In actual practice, appliances may have to be moved from place to place in locations where the only available power supply might be from a run of plug-in busway.

For this application, s t r ic t interpretation of 400-7(b) requires the introduction of a costly but unnecessary intermediate connection between the flexible cord and the plug-in device.

1. Cord-to-busway connections are permitted per Section 364-8 but no guidelines are included for the make-up of such connections.

2. Proposed 400-7(c) satisfies the intent of 400-7(b); the busway plug-in device serves as the attachment plug--and the busway plug-in opening serves as the receptacle outlet.

3. Proposed 400-7(c) eliminates the unnecessary intermediate

109

connection in the sequence: flexible cord--to attachment plug--to receptacle outlet--to load terminals of busway plug-in device - to plug-in jaws--to bus bars of busway. PANEL RECOMMENDATION: Reject.' PANEL COM~iENT: Material is adequately covered in Section 364-8.

~l)InL'-OIl-l~Al~'~ RECOM~IENDATION: AhFIRMATIVE: 8. NEGATIVE: Conley, Oannot, Lipsey.

EXPLANATION OF VOTE: CONLEY: The proposal should be revised by changing "May

to "shall be permitted to" in the f i r s t line. Thls is a safe and suitable means of making connections to

busway plug-in devices as explained in the substantiation, but i t is not adequately covered in Section 364-8 as the Panel Comment claims.

JANNOT: I disagree with the Panel Comment that the materi~1 is adequately covered in Section 364-8. The submitter has stated that the NEC now requires the complex arrangement detailed in item 3 of his Substantiation. The consensus of the Panel was that this is not required and that cords can be -- and are now -- connected directly to the plug-in devices. Obviously, then, the NEC as i t is now written is subject to misinterpretation and, in my opinion, accepting this proposal would clari fy this point.

LINSEY: I do not agree with the Panel Comment that this mate~al is properly covered by Section 364-8. The submitter, NEMA, states that the present Code requires the arrangement outlined in paragraph 3 of his Substantiation. The Panel fe l t that this is not required and that cords can and are now being connected directly to the'plug-ln devices. I t appears that the Code, as now wHtten is being misunderstood. The acceptance of the proposal wou ld clarify this.

400-9: Reject CMP 6 SUBMITTER: Idaho Chapter, IAEI ~ 8 0 In Section 400-9 the third line down change the wor--o-f-d~-"ITard-service" to "hard-usage." SUBSTANTIATION: This will make the wording here in 400-9 compatible wTth the wording in the Table 400-4. There wil l be no question of the type flexible cords that are permitted to be repaired after in i t ia l installation. PANEL RECOI~MENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's Intent. The intent of Section 400-9 is to permit the splicing of hard-service cord only, such as Types S, SO, ST, and STO. VOTE ON PANEL RECOMMENDATION:

A~FIRMATIVE: 10. NEGATIVE: Hogan.

EXPLANATION OF VOTE: HOGAN: I would change my vote on the proposal i f the words

"hard service flexible cords" were revised to read as fol}ows: "flexible hard service cords." This would then pin down precisely what the panel says is intended and .would also answer the proposer's aim.

. 400-I0: Accept CMP 6 SUBMITTER: R. S. Pinkerton, Los Angeles, CA )ITOP1~']~-~.. 81 Add a sentence as follows: -'-l~TexT~le cords shall, where passing through holes in outlet boxes, covers or similar enclosures, be protected by approved bushings or f i t t ings especially designed for the purpose. SUBSTANTIATION: Flexible cords or cables should be protected from sharp ~ges where they pass through holes in sheet metal covers or boxes. UL standards require a bushing or protection where passing through a sheet metal hole and this same protection should be given to f ield installed cords. PANEL RECOMMENDATION: Accept as Revised:

Add a new section as follows: 400-14. Protection From Damage. Flexible cords and cables shall be protected by bushings or f i t t ings where passing through holes in covers, outlet boxes or similar enclosures, VOTE ON PANEL RECO~IENDATION: Unanimously Affirmative.

AOO-lO:ReJect CMP SUBMITTER: Southwestern Section IAEI PRuPOSAL: 82 Add the following sentence to Section 400-10:

Flexlble cords shall, where passing through holes in outlet boxes, covers or similar enclosures, be protected by approved bushings or f i t t ings especially designed for the purpose. SUBSTANTIATION: Flexible cords or cables should be protected fromsharp e~ges where they pass through holes in sheet metal covers or boxes. UL standards require a bushing or protection where passing through a sheet metal hole and this same protection should be given to f ield installed cords. PANEL RECOMMENDATION: Reject. PANEL ~Ui~MENT: See Panel action on Proposal No. Bl, Section 400-10. VOTE ON PANEL RECOte~ENOATION: Unanimously Affirmative.

400 Part C: Reject CMP SUBMITTER: TSC-Nominal Voltage

83 Delete the word "nominal" from heading. ~'I]I~'FA]qTIATION: Change recommended for clarif ication and to obtain conformance with present practice and uniformity within the Code. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

400-31(a): Reject CMP 6 SUBMITTER: Peter Pollak, The Aluminum Association

84 In the f i r s t sentence following "No~ 8" insert ~ o r No. 6 aluminum . . . . SUBSTANTIATION This proposal is submitted to clar i fy the proper slze equivalent of aluminum conductor for the application. The size limitation is based upon an ampacity requirement which can be met with an aluminum conductor sized to provide the required ampacity. The panel is referred to the proposed revision in Section 110-5. .,

PANEL RECOMMENDATION: Reject. : ee Panel action on Proposal No. 84A, Section

400-31(a). VOTE ON PANEL RECOHMENDATION: Unanimously Affirmative.

400-31(a): Accept CMP 6 SUBMITTER: CMP 6

84A Revise as follows: --'X'~T-C-Bnductors. The conductors shall be No. 8 AWG copper or larger and sha!l employ flexible stranding. SUBSTANTIATION: To clari fy the proper conductor type for the application. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unaniinously Affirmative.

• ARTICLE 402 -- FIXTURE WIRES

402-1: Accept CMP 6 Secretary's Note: I t was the action of the Correlating

C~m~nittee that the Panel review this Proposal for possible conflict withTable 402-3 which mentions other kinds of conductors, o SUBMITTER: Peter Poliak,'The Aluminum Association PIIOIIIIS'XL-T. • 85 Change the sentence to read as follows: This ~ c o v e r s general requirements and construction specifications for copper fixture wires." SUBSTANTIATION This proposal is submitted to clari fy the proper slze equivalent of aluminum conductor for the application. Makes clearer the fact that the conductor is to be copper. The panel is referred to the proposed revision In Section 110-5. PANEL RECOMMENDATION: Accept. vuIE DN PANEL RECOMMENDATION:

AFFIRMATIVE: g. NEGATIVE: Coffey, Hogan.

EXPLANATION OF VOTE: COFFEY: I oppose the Panel Recemmendation to accept this

proposal because I feel the introduction of the limitation copper fixture wires in the scope of this Article is not correct. This Article covers the installation of a11 fixture wires and.while at present,, f ixture wires are limited to copper conductors, this limitation is r ightful ly stated in Section 110-5 of the Code and i f the panel feels further clarif ication is necessary, i t could appear in another Section of Article 402, such as 402-5 or 402-6.

HOGAN: The heading for this Article is Fixture Wires. I t would seem to me that anyone using this book would take from that heading that any restrictions or provisions for f ixture wires would be found in this Article. By accepting this proposal you have limited the Scope of this Article to copper f ixture wires and have le f t the door open for any one to manufacture fixture wires of any material and there wll l be no regulations covering them. The Scope of this Article is not Just copper fixtures wires; i t is all f ixture wires now and forever.

402-3:Accept CMP 6 SUBMITTER: TSC-Nominal Voltage ~ 8 6 Revise second sentence as follows: ~ x t u r e wires listed In Table 402-3 are all suitable for service at 600 volts, nominal or less unless otherwise specified. SUBSTANTIATION: Change recommended for clarif ication and to obtain conformance with present practice and uniformity within the code. PANEL" RECO)eiENDATION: ACcept as Revised:

I "Delete the words "or less." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

B

110

connection in the sequence: flexible cord--to attachment plug--to receptacle outlet--to load terminals of busway plug-in device - to plug-in jaws--to bus bars of busway. PANEL RECOMMENDATION: Reject.' PANEL COM~iENT: Material is adequately covered in Section 364-8.

~l)InL'-OIl-l~Al~'~ RECOM~IENDATION: AhFIRMATIVE: 8. NEGATIVE: Conley, Oannot, Lipsey.

EXPLANATION OF VOTE: CONLEY: The proposal should be revised by changing "May

to "shall be permitted to" in the f i r s t line. Thls is a safe and suitable means of making connections to

busway plug-in devices as explained in the substantiation, but i t is not adequately covered in Section 364-8 as the Panel Comment claims.

JANNOT: I disagree with the Panel Comment that the materi~1 is adequately covered in Section 364-8. The submitter has stated that the NEC now requires the complex arrangement detailed in item 3 of his Substantiation. The consensus of the Panel was that this is not required and that cords can be -- and are now -- connected directly to the plug-in devices. Obviously, then, the NEC as i t is now written is subject to misinterpretation and, in my opinion, accepting this proposal would clari fy this point.

LINSEY: I do not agree with the Panel Comment that this mate~al is properly covered by Section 364-8. The submitter, NEMA, states that the present Code requires the arrangement outlined in paragraph 3 of his Substantiation. The Panel fe l t that this is not required and that cords can and are now being connected directly to the'plug-ln devices. I t appears that the Code, as now wHtten is being misunderstood. The acceptance of the proposal wou ld clarify this.

400-9: Reject CMP 6 SUBMITTER: Idaho Chapter, IAEI ~ 8 0 In Section 400-9 the third line down change the wor--o-f-d~-"ITard-service" to "hard-usage." SUBSTANTIATION: This will make the wording here in 400-9 compatible wTth the wording in the Table 400-4. There wil l be no question of the type flexible cords that are permitted to be repaired after in i t ia l installation. PANEL RECOI~MENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's Intent. The intent of Section 400-9 is to permit the splicing of hard-service cord only, such as Types S, SO, ST, and STO. VOTE ON PANEL RECOMMENDATION:

A~FIRMATIVE: 10. NEGATIVE: Hogan.

EXPLANATION OF VOTE: HOGAN: I would change my vote on the proposal i f the words

"hard service flexible cords" were revised to read as fol}ows: "flexible hard service cords." This would then pin down precisely what the panel says is intended and .would also answer the proposer's aim.

. 400-I0: Accept CMP 6 SUBMITTER: R. S. Pinkerton, Los Angeles, CA )ITOP1~']~-~.. 81 Add a sentence as follows: -'-l~TexT~le cords shall, where passing through holes in outlet boxes, covers or similar enclosures, be protected by approved bushings or f i t t ings especially designed for the purpose. SUBSTANTIATION: Flexible cords or cables should be protected from sharp ~ges where they pass through holes in sheet metal covers or boxes. UL standards require a bushing or protection where passing through a sheet metal hole and this same protection should be given to f ield installed cords. PANEL RECOMMENDATION: Accept as Revised:

Add a new section as follows: 400-14. Protection From Damage. Flexible cords and cables shall be protected by bushings or f i t t ings where passing through holes in covers, outlet boxes or similar enclosures, VOTE ON PANEL RECO~IENDATION: Unanimously Affirmative.

AOO-lO:ReJect CMP SUBMITTER: Southwestern Section IAEI PRuPOSAL: 82 Add the following sentence to Section 400-10:

Flexlble cords shall, where passing through holes in outlet boxes, covers or similar enclosures, be protected by approved bushings or f i t t ings especially designed for the purpose. SUBSTANTIATION: Flexible cords or cables should be protected fromsharp e~ges where they pass through holes in sheet metal covers or boxes. UL standards require a bushing or protection where passing through a sheet metal hole and this same protection should be given to f ield installed cords. PANEL RECOMMENDATION: Reject. PANEL ~Ui~MENT: See Panel action on Proposal No. Bl, Section 400-10. VOTE ON PANEL RECOte~ENOATION: Unanimously Affirmative.

400 Part C: Reject CMP SUBMITTER: TSC-Nominal Voltage

83 Delete the word "nominal" from heading. ~'I]I~'FA]qTIATION: Change recommended for clarif ication and to obtain conformance with present practice and uniformity within the Code. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

400-31(a): Reject CMP 6 SUBMITTER: Peter Pollak, The Aluminum Association

84 In the f i r s t sentence following "No~ 8" insert ~ o r No. 6 aluminum . . . . SUBSTANTIATION This proposal is submitted to clar i fy the proper slze equivalent of aluminum conductor for the application. The size limitation is based upon an ampacity requirement which can be met with an aluminum conductor sized to provide the required ampacity. The panel is referred to the proposed revision in Section 110-5. .,

PANEL RECOMMENDATION: Reject. : ee Panel action on Proposal No. 84A, Section

400-31(a). VOTE ON PANEL RECOHMENDATION: Unanimously Affirmative.

400-31(a): Accept CMP 6 SUBMITTER: CMP 6

84A Revise as follows: --'X'~T-C-Bnductors. The conductors shall be No. 8 AWG copper or larger and sha!l employ flexible stranding. SUBSTANTIATION: To clari fy the proper conductor type for the application. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unaniinously Affirmative.

• ARTICLE 402 -- FIXTURE WIRES


C~m~nittee that the Panel review this Proposal for possible conflict withTable 402-3 which mentions other kinds of conductors, o SUBMITTER: Peter Poliak,'The Aluminum Association PIIOIIIIS'XL-T. • 85 Change the sentence to read as follows: This ~ c o v e r s general requirements and construction specifications for copper fixture wires." SUBSTANTIATION This proposal is submitted to clari fy the proper slze equivalent of aluminum conductor for the application. Makes clearer the fact that the conductor is to be copper. The panel is referred to the proposed revision In Section 110-5. PANEL RECOMMENDATION: Accept. vuIE DN PANEL RECOMMENDATION:

AFFIRMATIVE: g. NEGATIVE: Coffey, Hogan.

EXPLANATION OF VOTE: COFFEY: I oppose the Panel Recemmendation to accept this

proposal because I feel the introduction of the limitation copper fixture wires in the scope of this Article is not correct. This Article covers the installation of a11 fixture wires and.while at present,, f ixture wires are limited to copper conductors, this limitation is r ightful ly stated in Section 110-5 of the Code and i f the panel feels further clarif ication is necessary, i t could appear in another Section of Article 402, such as 402-5 or 402-6.

HOGAN: The heading for this Article is Fixture Wires. I t would seem to me that anyone using this book would take from that heading that any restrictions or provisions for f ixture wires would be found in this Article. By accepting this proposal you have limited the Scope of this Article to copper f ixture wires and have le f t the door open for any one to manufacture fixture wires of any material and there wll l be no regulations covering them. The Scope of this Article is not Just copper fixtures wires; i t is all f ixture wires now and forever.

402-3:Accept CMP 6 SUBMITTER: TSC-Nominal Voltage ~ 8 6 Revise second sentence as follows: ~ x t u r e wires listed In Table 402-3 are all suitable for service at 600 volts, nominal or less unless otherwise specified. SUBSTANTIATION: Change recommended for clarif ication and to obtain conformance with present practice and uniformity within the code. PANEL" RECO)eiENDATION: ACcept as Revised:

I "Delete the words "or less." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

B

110

Table 402-3: Accept CMP 6 SUBMITTER: John E. Conley, General Electric Co.

~ 87 Under Type Letter "AF," revise third column'as

ImpreGnated 18-14 -- 30 Asbestos or . . . . 20 10

"SUBSTANTIATION: This proposal was accepted for inclusion in the 19/8 NEC but was Imbroperly:transcribed for printing; therefore the printed version of the 1978 NEC does not correctly reflect the action of the Cammittee. Refer: Proposal No. 4 page 213 of 1978 Preprint NEPA 70PR78. PANEL RECOMMENDATION: Accept. VUlt UN PANEL R~COMMENDATION: Unanimously Affirmative. CO~IENT ON VOTE:

COFFEY: I suggest that when presenting this proposal in the preprint for public comment, that the ent4~e third column of Table 402-3 for Type AF fixture wire be included.

Table 402-3: Accept CMP 6 SUBMITTER: Cutter D. Palmer, Wilmington, DE l}ITOl~--~. " 88 For wire types KF-1 and KFF-1, revise X~FTcal~ions Provisions column to read: "Fixture wire, and as permitted in Sections 725-16 and 760-16. Limited to 300 vo]ts."

For wire types KF-2 and KFF-2, revise Applications Provisions column to read: "Fixture wire, and as permitted in Sections 725-16 and 760-16." SUBSTANTIATION: Multiple conductor type KFF-2 cable has been tested by Underwriters Laboratories in Northbrook, I l l ino is , in both the modified Steiner Tunnel Test and the IEEE-383 vertical tray test. In both tests fu l l cable trays were subjects to the f lme. Flame spread and smoke values were the lowest of any cables previously tested. Enclosed is a copy of a letter f r ~ UL with these test results. Also enclosed is a copy of the UL Fact Finding Investigation which was the basis for l isting these wire types in the 1978 NEC.

Hundreds of mil]ions of feet of wire with the KFF-2 insulation system have been used' for approximately 10 years in con~ercial and military aircraft as well as the wiring for most space vehicles and missiles. For instance, each Lockheed L-lOll has approximately 650,000 feet of this wire installed as open, / unjacketed bundles, both in the fuselage and in the SWAMP (special wind and moisture problems) areas. The airlines report type KFF-2 wire to be essentially malntenance'free in spite of temperature extremes, high vibration, exposure to hydraulic, deicing, fuels, etc. I t also meets the FAA proposed \ requirements for extremely low smoke generation. PANEL RECOMMENDATION: Accept as Revised:

CMP 6 rejects f i r s t paragraph as Sections 725-16(b) and 760-16(b) do not permit conductors limited to 300 volts. CMP 6 accepts second paragraph to revise "Applications Provisions" column for Types KF-2 and KFF-2. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 402-3 (HOD 1978 NEC): Reject SUBMITTER: Paul J. Koch, Allied Chemical Corporation, ~ n , NJ PROPOSAL: 89 Amend Section 402--Table 402-3 to add:

Extruded 18-14--20 None 150°C Fixture Wire 302°F and as per-

mitted In Section 725-16

CMP 6

Poly-ethylene ECTFE Poly- chlorotrl- ethylene

fluoroethylene chlorotri- Fixture Wire fluoro- Flexible ethylene Stranding SUBSTANTIATION: HALAR ECTFE Fluoropolymer is a high temperature resln exceptionally suited for electrical wire insulation. Its dielectric strength in thin sections is as high as 2000 V/mil, volume resistivit% of 1015 ohm-cm, dielectric constant measures 2.5-2.6 over a wise temperature and frequency range, and dissipation factor lower than most dielectrics, varying from 0.0008 at 102 Hz to 0.13 at 106Hz.

In addition HALAR has high tensile strength on the order of 6-7000 psi, is moderately s t i f f and notched impact strength greater than 20 f t . ]bs. Its cut-through resistance and abrasion resistance are excellent, which allows i t to withstand considerable abuse during installation and service. HALAR insulation will not support combustion in air or in atmospheres up to 60 percent oxygen. I t chars rather than melts or drips. I t is inert to acids, bases, and strong oxidizing agents and does not dissolve or stress crack in any known solvent at temperatures up to 120°C.. HALAR insulation is capable of continuous service at 150°C and has a brittleness temperature less than -80°C.

In support of the above statement v~e offer the following items for consideration:

a. HALAR is recognized as a resin by Underwriters Laboratories for continuous service at 150°C and for Appliance Wiring Material, Style 1587, for service up to 125°C--no voltage specified.

b. HALAR passes the Naval Air Systems Command Mil-W-22759/24 (AS) for Wire, Electric, Fluoropolymer-insulated, Medium Weight,

111

Tin-coated Copper conductor for 150°C-600V service. c. HALAR insulated cable passes IEEE 383, "Standard for Type

Test of Class IE Electric Cables...for Nuclear Power Stations" when subjected to radiation aging and conditions designed to simulate a loss of coolant accident (LOCA).

d. HALAR insulated cable is approved for "Fluoropolymer insulation for use on Public Conveyance MR-73" for the Montreal Metro. The specification cal]s for oven aging for 96 hours at 200°C among its tests.

e. HALAR insulated cable manufactured by Revere Corporation of America passes a variety of tests required by IPCEA~19-81 and is qualified for insulation for nuclear power stations.

f . HALAR insulated cable, produced by BOFA, is recognized by Sweden's SEMIKO standards for 155°C and 600V service.

g. HALAR insulated wire is recognized by Canadian Standard for App]iance Wire at 105°C and 150V for a 5 mil wal].

h. HALAR insulated wire Is recognized by the Electrical Trust of South Australia for 150°C 250V service and is therefore reciprocally recognized for use throughout Australia.

In addition, the use of ECTFE as insulation fo r f ixture wire wil l be substantiated by a Fact Finding Report by the Underwriters Laboratories. The investigation is underway with a preliminary report on the short term and 30 day aging expected by December ist and the final report in ]ate January. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Pane] action on Proposal No. 89A, Table 402-3. Accept CMP 6 Proposal 89A and refer to CMP 16. VOTE ON PANEL RECOVJ~ENDATION: Unanimously Affirmative.

Table 402-3: Accept CMP 6 SUBMITTER: CMP 6

I I~T(~-O~-~.'89A Revise "Applications Provisions" column for and HFF to read: "Fixture wiring, and as permitted in

Section 725-16." SUBSTANTIATION: See Proposal No. 89. PANEL RECOMMENDATION: Accept contingent upon the concurrence of

16. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. CO~ENF DN VUIL:

HOGAN: Since Pane] 16 has rejected their proposal we should also indicate rejection of this proposal.

Table 402-3 (HOD 1978 NEC): Reject CMP 6 SUBMIITER: Cutter Palmer, E. I . duPont de Nemours & Co., Inc., ~TI-~F6~-6n, DE PROPOSAL: 90 Add fixture wife Types KF-1, KF-2, KFF-I, KFF-2

402-3.

Tape KF-1 Aromatic 18-10...5.5 None 200°C Fixture Wiring Insulated Polyimide 392°F Limited to Fixture Tape 300 Volts Wire

Solid or KF-2 Aromatic 18-10...8.4 None 200°C Fixture Wiring 7-Strand Polyimide 392°F and as per-

Tape mitted in : Section 725-16

Tape , KFF-1 Aromatic 18-10...5.5 None 200°C Fixture Wiring Insulated Polyimide 392°F Limited to Fixture Tape 300 Volts Wire

Flexible KFF-2 Stranding

Aromatic 18-I0...8.4 None 200°C Fixture Wiring Polyimide 392°F and as per- Tape mitted in

Section 725-16

SUBSTANTIATION: Kapton Tape insulated wire has been used for several years in aircraft such as the LI011 and other military and government applications. Kapton's excellent electrical and

mechanical properties, coupled with the abi l i ty to consistently apply the tape uniformly and concentrically over the conductor, results in reduced insulation thicknesses not possible with conventional extruded insulations. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 88, Table 402-3. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

402-10: Reject CMP 6 SUBMITTER: O. E. Dillon, Border County Div. IAEI P'R'O-FO-S~A'C-~. " 91 Add the word "only" after the word "permitted." ~U~IANIIATION: This language is permissive and does not restr ict the use of f ixture wires. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for CMP I Proposal No. 90 for 110-16(a). PANEL RECOf~MENDATION: Reject. PANbL ~UMMhNI: Panel feels subject is adequately covered. vu} t UN PAflhL RECOMMENDATION: Unanimously Affirmative.

402-11 Exception: Accept CMP 6 SUBMITTER: W. R. Hitchens, E. I . du Pont de Nemours & Co. I~ITO]~-O~TAL-~. 92 Revise as follows: ~ i o n : As permitted by Section 725-16 for Class 1 circuits and Section 760-16 for f i re protective signaling circuits. SUBSTANTIATION: Table 402-3 (right hand column) permits this for types of f ixture wires covered in 760-16(b). In correlating changes to the 1978 NEC, I believe the reference to 760-16 in the Exception to 402-11 was lef t out in error. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


Chapter 9, Tables 6, 7 and 8: Accept CMP 6 SUBMITTER: Alton R. Thompson, Durham, NC ~ROPOSAL: 93 Add to Tables 6, 7 and 8: "No. 8 stranded ~ r s . " SUBSTANTIATION: Since January 1973, No. 8 solid wire has been removed from the Nationa] Electrical Code book to be installed in conduit, except for Article 680. The properties of No. 8 stranded should be listed in Tables 6, 7 and 8. PANEL RECOMMENDATION: Accept as Revised. Table 6. Add "sol." after existing "8" and add No. 8 stranded din~nsions as follows: 8 str. .43 .145 .43x.75 .282 .86 .581

ReviSe Note as follows: Note - No. 14 to No. 10, solid conductors; No. 8, solid or stranded conductors; No. 6 and larger, stranded conductors.

Table 7. Add "sol." after existing "8" and add No. 8 stranded dimensions as follows: 8 str. .325 .083 .285 .064 .390 .119

Revise Note as follows: Note: No. 14 to No. 10, solid; No. 8, solid or. stranded; No. 6 and larger, stranded; except AVL where all. sizes are stranded.

Table 8. Add No. 8 stranded properties as follows: 8 16510 7 .0486 .1458 .0167 .653 .679 1.07

VOTE ON PANEL RECO~MENDATION: Unanimously Affirmative.

112

• REPORT OF CODE-MAKING PANEL NO. 21

ARTICLE 410 -- LIGHTING FIXTURES,. LAMPHOLDERS, LAMPS RECEPTACLES, AND ROSETTES

410-Editorial (HOD 1978 NEC): Accept CMP 21 • SUBMITTER: A. KnicKrehm, Los Angeles, CA

]~q~5-O'S'AL~. • I Amend Article 410 as follows: T1-~--2rro-65(a) Remove the words "constructed or." (2.) 410-65 Add new:

(c) Maximum Operating Temperature. Fixtures shall be, so installed thaU the maximum operating temperature of the component parts of the fixtures wil l not be exceeded. (3.) 410-36 Add new third sentence:

Fixtures shall be so designed that the component parts of the fixtures will not exceed their maximum operating temperature when the fixture is installed in compliance with this article. (4.) 410-68 Add new second sentence:

Fixtures shall be so constructed that-the maximum operating temperature of their component parts will not be exceeded. SUBSTANTIATION: To insure that the maximum temperatures of f ixture parts are not exceeded. Fixtures are sometimes boxed in by f i re resistant materials to comply with f i re and building codes. This causes excessive temperatures to fixture parts, such as "P" rated lamp ballasts. When i t is required to box-in fixtures suitable low heat equipment is available for fixture construction. PANEL RECOMMENDATION: Accept as Revised.

Accept the item (1.) portion of the proposal by deleting the words "constructed or" from Section 410-65(a). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Article 410: Accept CMP 21 SUBMITTER: "CMP 21 PROPOSAL: 1A Rev,ise Article 410 as follows: 410-14. Make existing f i r s t sentence of f i r s t paragraph (a); relocate balance of f i r s t paragraph; all of paragraph two and four to new 410-30(c); Relocate third paragraph to new 410-16(9). 410-23. Relocate text to (b) of 410-24. 410-24. Change heading to "Conductors"; make existing text (a) with t i t l e "Insulation." Delete present (b)l 410-26. Delete heading; relocate 410-26(a) to new 410-28(e) with t i t l e "Stranding"; relocate 410-26(b) to new 410-28(f) with t i t l e "Tension." 410-28. Relocate 410-28(c) to new 410-30(a). Change t i t l e to "Lampholders." 410-29. Relocate 410-29(e) to 410-57(b) and change 410-57(b) to (c); (c) to (d); (d) to (el. 410-30. Change heading to "Cord connected l ampholders and fixtures." Relocate 410-30(a) to new 410-16(b); Relocate 410-30(b) to new 410-28(c); Relocate 410-30(c) to new 410-28(d); Relocate 410-30(d) to new 410-14(b); Change 410-30(e)to (b).

410-32. Relocate to new 410-23. 410-40. Relocate to new 410-16(d). 410-41. Relocate to new 410-16(e). 410-77. Relocate to 4)0-77(b) to new 410-29(e) and revise to read: Where show cases are cord connected, the secondary circuit(s) of electric discharge lighting shall be limited to one show case. Change 410-77(c) to 410-77(b). SUBSTANTIATION: Arranged to place requirements of the same subject in the same sections. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-Editorial(HoD 1978 NEC): Reject CMP 21 SUBMITTER: A. KnicKrehm, Los Angeles, CA

2 Amend Article 410 as follows: Part K shall be moved to follow Part F. Part N shall be moved to follow relocated K. Parts Q and R shall be moved to follow relocated N. Part G shall be relocated to follow relocated R. Part H and J shall be relocated to follow relocated R~

All parts shall be reassigned letter designation. SUBSTANTIATION: To arrange the article so that general and Installation requirements precede construction requirements for each of the s6bJects covered by the article. Article 410 does not comply with the editorial style of the Code. The proposed reorganization is in keeping with the editorial policy set forth by the correlating committee. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 1A, Article 410. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-X: Reject CMP 21 SUBMITTER: C. E. Muhleman, Marion IN , PROPOSAL: 3 Add new sections to Article 410 Part A as follows: ~ c u r r e n t . Each fixture shall have overcurrent protection built into the fixture or its cord cap.. The overcurrent device shall not exceed 150 percent of the fixture load. 410-Overtemperature. Each recessed fixture shall have overtemperature protection built into the fixture. 410-Location. A permanent lighting f ixture shall be installed in each room or space into which a person can enter.

Exception: Residential living rooms. SUBSTANTIATION: Proposed "Overcurrent" should prevent small faults from not being detected by a large overcurrent device and thus wil l reduce fires.~

Proposed "Overtemperature" should prevent fires from overtemperatures such as may be caused from installing thermal insulation around the fixture.

Proposed "Location" wil l eliminate some of t~e need for extension cords, etc., which have attributed to many electrocutions. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment provided no evidence that small faults are resulting in fires and therefore the CMP rejects the proposed requiroment for overcurrent protection. In Proposal No. 42, CMP 21 has accepted a proposal addressing overtemperature. Section 210-26(a) already contains requirements concerning "required lighting fixtures" and this proposed addition to Article 410 is unnecessary. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-4(a): Accept CMP 21 SUBMITTER: TSC-Approved for the Purpose PI~-OPO-S'AZ-~." 4 See the Technical Subcommittee "Recommendations" under the definition of "Approved for the Purpose" inAr t ic le 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete the words "shall be approved for the purpose and." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-4(a): Reject CMP 21 SUBMITTER: CMP 21 ~ 4 A In the third paragraph, after the word "basements a add "some bathrooms." SUBSTANTIATION: CMP 21 considers that some bathrooms are damp locations, and that all bathrooms are damp locations at some times. PANEL RECOMMENDATION: Reject. PANEL COMMENT: In re-evaluating this proposal, the CMP cannot just i fy a damp location fixture to be required in all areas of a bathroom. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-4(c)(1): Reject CMP 21 SUBMITTER: Jim Fleshman, Boise, ID

5 Revise as'follows: ~ h e fixture and hood shall be an approved assembly and so 'installed that the temperature limits of the materials used are not exceeded. SUBSTANTIATION: We are having problems where lights are listed and labeled and are not properly installed as a complete assembly. The hood and lights should be tested and approved to meet Section 410-4 and Section 300-22(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 6, Section 410-4(c)(i). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. (

410-4(c)(1): Accept CMP 21 SUBMITTER: TSC-Approved for the Purpose ~ 6 See the Technical Subcommittee "Recommendations" under the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "approved for the purpose" and replace with "identified for use within commercial cooking hoods." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-4(c) (5) (New): Reject CMP 21 SUBMITTER: Idaho Chapter IAEI Boise, ID

7 (5) When f i re extinguishing equipment is required, the energy supply to the appliance shall be simultaneously interrupted upon actuation of the extinguishing system. SUBSTANTIATION: To coordinate with NFPA 17 4-4.1 the amended addition will reduce f i re hazards which would result from overheated appliances when extinguishing chemical is expended. PANEL RECOMMENDATION: Reject.

3 2 0

PANEL COMMENT: Proposal is not within the scope of Article 410. CMP 21conferred with CMP 10 and there was a lack of support for the Proposal. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 8. NEGATIVE: Wells.

EXPLANATION OF VOTE: WELLS: I concur with the fact that thls proposal, is not

within the scope of ~ 21 and Article 410. I disagree with the statement that there was a lack of support for the proposal from Panel. For the record, I cite the comments of Panel 10 members In their vote following the December, 1978 Panel meeting.

"Erickson: In i ts present form the proposal cannot be inserted in Article 422.' I believe the proposal has merit and would like to see i t reworked for Article 422."

"Mazzoni: In my view Code Making Panel 21 was correct in recognizing that the proposal did not belong in the referenced section of the Code. On the other hand, I strongly feel that thls proposal does not belong In Article 422 since i t is a requirement that affects the appliances when installed in a particular application. This is a very complex issue and in my vlew should be thoroughly discussed at the April meeting before being subject to a vote by CMP 10."

"Jordan: . . . . I would support a proposal that requires electric fat fryers located under ventilating equipment protected by a f i re extinguishing system to be automatically de-energized upon operation of f i re extinguishing system."

The vote in December of CMP 10 was 1 affirmative, 3 negative and, 5 not voting. I t appears to me there are many and varied concerns about the wording but that the proposal does have some support and I don't want to see i t lost between Panels.

410-4(d)-(New): Accept ~ CMP 21 SUBMITTER: Fred Mays, Albuquerque, NM

8 Add now (d) as follows: --C-d~I~ixtures in Bathrooms.

(I) A f ixture in a bathroom shall be on a c i rcu i t protected by a ground-fault circuit- interrupter.

(2) Hanging fixtures and pendants shall not be permitted directly above bathtubs, unless approved for damp or wet locations, and shall be marked, "Suitable for Damp Locations." SUBSTANTIATION: Article 410 is very careful in defining the proper methods for installing fixtures in closets. The same attention is required for fixtures in bathrooms. There is an increasing trend toward the Installation of f ixtures, chandeliers, swag lamps and pendants over bathtubs, thereby creating an extreme hazard. • We cannot legitimately object to the installatlon of fixtures over bathtubs, because i t is not specifically prohibited by NEC. We cannot say that a bathroom is a wet or damp location. PANEL RECOI~HENDATION: Accept as Revised:

(d) Pendants. Hanging fixtures and pendants shall be so installed that the f ixture is not 'less than 8 feet above the top of the bathtub. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-8: Reject CMP SUBMITTER: Allen KnicKrehm Los Angeles Chapter, NECA P R ~ L : g Move the material in Section 410-8 regarding

in clothes closets, to a new Section 210-27 t i t led: "Lighting outlets permitted but not required." SUBSTANTIATION: Article 210 new covers required outlets and receptacles. Section 410-8 more clearly follows the scope of Article 210 than Article 410. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel does not agree with the supporting co~ent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

21

410-8: Reject , CMP 21 SUBMITTER: S. B. Koontz, Chesapeake Chapter IAEI ~ 10 Revise t i t l e as follows: 410-8. Incandescent Fixtures in Clothes Closets. SUBSTANTIATION: The biggest f i re hazard seems to be the surface temperature of the incandescent bulb and hot particles of metal fal l ing onto clothes. Since incandescent buIbs have a surface temperature in the range of 500°F., and when broken will drop hot particles, then i t would seem that only these fixtures should be considered. By clarifying that i t is only incandescent, i t would allow fluorescent fixtures to be used, as they have always been classified as "cold" l ighting, and can even be touched after being on for long periods of time. This would help some areas of the country where the main concern of fixtures installed in closets is to provide lighting only and not to provide any drying effect, as in some areas of the country where incandescent fixtures are used. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 13, Section 410-8(a)(2). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative."

410-8: Reject CMP 21 SUBMITTER: Richard P. Kuchnicki, National Association of Home B-GTI-a-~-(NAHB) PROPOSAL: 11 Revise as follows: ~IIO-z~---.Fixtures in Clothes Closets.

(a) Location. A f ixture in a clothes closet shall be permitted to be installed: (1) on the wall above the closet door, provided the clearance between the f ixture and a storage area where combustible'material may be stored within the closet is not less than 18 inches or is protected in accordance with Section 410-5 and (2) on the ceiling over an area which is unobstructed to the floor maintaining an 18-inch clearance horizontally between the f ixture and a storage area where combustible material may be stored' within the closet. I f the f ixture is protected in accordance with Section 410-5, the 18-inch clearance is not necessary.

A flushed recessed f ixture equipped with a solid lens shall be considered outside the closet area. SUBSTANTIATION: The current Code requirement is in contradiction with Section 410-5. I f a f ixture is protected in accordance with 410-5, the 18-inch clearance should not be necessary. Many builders are forced to use recessed fixtures in closets because i t is impossible to attain the 18-inch clearance. Numerous fires have been reported due to recessed fixtures coming in contact with improperly manufactured cellulose insulation. Even though Section 410-66 regulates insulation around recessed fixtures, i t is impossible to enforce this regulation since insulation is added by the homeowner usually without a building permit. Homeowners are not familiar with the NEC. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 13, Section 4fO-8(a)(2). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

C

410-8(a), Exception-(New): Reject CMP 21 SUBMITTER: Ray H. Mil ler, Fond du Lac, WI

12 Add new exception as follows: Exception: Fluorescent fixtures shall be permitted to be

installed on the wall above the closet door. SUBSTANTIATION: Many new homeowners and builders wish to have closet lights and with the restrictions of thermal insulation near recessed fixtures, the Code makes i t almost impossible to install recessed closet lights in second floor bedroom closets. There would be no hazard involved i f the Code permitted a two-foot fluorescent strip l ight above the closet door where the surface temperature, of the tube is no danger and i t is in a normally protected area. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 13, Section 410-8(a)(2). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-8(a)(2): Accept CMP 21 SUBMITTER: Clyde H. Craig, Toledo Chapter NECA PlTOPO-S'Xt-~." 13 Change last sentence of paragraph i2) to read: ~ s enclosed surface f ixture, r~cessed f ixture with a solid lens or fluorescent strip may be used providing there is a 6-inch clearance horizontally between the f ixture and the storage area. SUBSTANTIATION: Most closets in homes are 24 inches deep, making i t impossible to install anything but recessed fixtures. Under today's insulation standards, i t ' s not practical to install recessed fixtures in second floor closets. The 18 inch requirement is too severe. PANEL RECOMMENDATION: Accept as Revised:

Change the second paragraph as follows: A flush recessed f ixture with a solid lens, or a ceiling-mounted fluorescent f ixture shall be permitted to be installed provided there is a 6-inch clearance~ horizontally, between the f ixture and the storage area. ' VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-11: Accept ~ CMP 21 SUBMITTER: TSC-Approved for the Purpose 151TOP-O-S'AL~-~: 14 See the Technical Subcommittee "Recommendations" under the definition ~f "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definit ion of "Approved fo r the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete "approved for the purpose" and replace with "identif ied ifor through wiring." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-11, Exception-(New): Reject CMP 21 SUBMITTER: Arnold W. Rodin, American Home Lighting Inst i tute ' PROPOSAL: 15 Add the following exception: ~ i o n : Branch circuit conductors having insulation suitable for at least gO°C (194°F) shall be used for wiring of

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all ceiling outlet boxes on which a lighting f ixture is, or may be, mounted. The ampacity of 90°C wire shall be limited to the ampacity of 60°C wire (140°F). SUBSTANTIATION: With the advent of energy conservation, thermal insulation is being used more and more to combat winter heat losses and summer heat gains in buildings. As a result, all new construction, especially home construction, is being f i t ted with greater amounts of thermal insulation.

In most instances, electrical outlet boxes to which surface ceiling incandescent fixtures are attached and junction boxes supplying power to recessed fixtures are engulfed in a heavy concentration of thermal insulation. This can lead to heat buildup in the outlet boxes which may exceed safe values. These higher temperatures are l ikely to destroy the insulation on wiring in the boxes, resulting in shock hazard, short circuits and f i re. The condition may be further compounded when the consumer chooses to ignore the fixture wattage marking and installs higher wattage lamps.

In order to reduce the hazards that can be created by higher temperatures in ceiling outlet boxes, we request that branch ' circuit conductors having insulation suitable for at least 90°C (lg4°F) be used for wiring of all ceiling outlet boxes on which a lighting f ixture is, or may be, mounted. The ampacity l imit (15 amperes) for 60°C (140°F) conductors should be included to retain the benefit of the higher temperature rating of gO°C (Ig4°F) insulation. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ON PANEL RECO~NDATION: Unanimously Affirmative. COMMENT ON VOTE:

KNICKREHM: This proposal referred to CMP 6; CMP 6 rejected the proposal.

410-14: Reject CMP 21 SUBMITTER: D. H. Mclntosh, E. I . du Pont de Nomours & Co. ~ L : 16 Revise the second sentence as follows:

I t shall be permissible to locate cord-connected fixtures directly below the outlet box i f (a) the flexible cord is Type S, SO, ST or STO; (b) the cord is not subject to strain or physical damage; and (c) the overall'length of fixture-attached-cord does not exceed 6 feet. SUBSTANTIATION: The word "suspend" cord-equipped fixtures directly below the outlet box is a poor word choice implying that the cord and outlet box support the weight of the fixture. The words " i f the cord is continuously visible for its entire length" has absolutely nothing to do with safety to either persons or property, unless someone wants to devote their lifetime to watching the cord. This section of Code has been frequently massaged in past Code revisions. This is an earnest attempt to resolve the issue.

UL has accepted and listed electric-discharge lighting f ixture connections for hung ceilings consisting of wiring in flexible meta'l tubing terminating in an approved grounding plug (cap). With over 1,500,000 fixture-years, of trouble free service, and with f ixture maintenance greatly enhanced by allowing the fixture to be readily removable, i t seems reasonable to recummendthis excellent system. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. Panel feels subject is adequately covered. No evidence to support the suggested change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

WELLS~ The words " i f the cord is continuously visible for its entire length" relates directly to safety. These words effectlvely prohibit using a cord and plug to connect fixtures in a lay in suspended ceiling where the ceiling panels would render the cord invisible. Since these spaces above such ceilings/are frequently air handling spaces i t is most undesirable to have exposed plugs and receptacles which, over time, would accumulate dust, grease and other potentially hazardous contaminants.

i

SUBSTANTIATION: The Uniform Building Code requires that suspended ceilings be adequately supported. This is usually in the form of an iron wire support attached to the structural ceiling members and the other end of the wire attached to the suspended ceiling frame me~ers. The lighting fixtures are then laid in the openings and secured only by light metal clips. There have been numerous accidents occur when these metal clips have been dis!odged causing fixtures to fa l l to the floor. There have been several instances, where fixtures are installed .in end-to-end rows, when one fixture becomes dislodged from construction vibration causing the entire row to also fa l l to the floor.

There is also the danger of fixtures being shaken loose by seismic disturbances-Los Angeles, Oroville and Santa Rosa areas, to mention a few~ locations.

Having these fixtures attached to the framing members also becomes a severe problem to firemen. When the ceiling area becomes involved in a f i re or enough heat generated from the f i re , the framing members distort and cause the fixtures to fa l l through the openings. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMA o agrees with the intent of the Proposal see action on Proposal No. 17A, Section 410-16(b). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-16(b): Accept CMP 21 SUBMITTER: CMP 21 ~ 17A Revise second sentence as follows: Fixtures so

shall be securely fastened by mechanical means, such as bolts, screws, or rivots to the ceiling framing member. SUBSTANTIATION: ~ 21 feels that f r ict ion alone is not an adequate means for fastening, hence the use of bolts, screws, or rivots. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: B. NEGATIVE: Wells.

COMMENT ON VOTE: DUFFY: Although I am voting affirmative I believe there are

methods other than the rivets, bolts or screws that are acceptable but can only be judged by the authority having jurisdiction at the time of installation. I believe this should be clarif ied.

KNICKREHM: The revised wording does not prohibit (he use of clan~s secured by the mechanical means mentioned in the proposal in my opinion. EXPLANATION OF VOTE:

WELLS: Since there are listed clips for this purpose i t seems to me they should be recognized. I suggest adding " . . . . screws, Clips identified for the purpose, and rivets."

410-16(c): Accept CMP 21 SUBMITTER: TSC-Approved for the Purpose P]TO'P-O-~FA-C~- 18 See the Technical Subcummittee "Recommendations" un-'n-dFe~-E~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

{c) Raceway Fittings. Raceway f i t t ings used to support l lighting fixtures shall be suitable to support the fixture(s). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

KIENER: I vote affirmative on this proposal; however, the wording of the proposal could be in~)roved. I suggest the following as an alternative:

"Raceway f i t t ings used to support light f ixtures shall be capable of supporting the total weight of the complete fixture ass~ ly . "

410-14: Accept CMP 21 SUBMITTER: CMP 21 : ~ 16A In the~second sentence delete the word "suspend" l~an--nd--~e-pTace with "locate." SUBSTANTIATION: The word "locate" better reflects the intent of the Panel. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-16(b}: Reject CMP 21 SUBMII-TER: Southwestern Section IAEI

17 Revise as follows: - - ~ s p e n d e d Ceilings. Framing members of suspended ceiling systems used to support fixtures shall be securely fastened to each other and shall be securely attached to the building structure at appropriate intervals. In addition, lighting fixtures shall be independently supported at each end of each fixture. The usual iron wire used for suspended ceiling supports shall be permitted for this purpose.

410-18 (a): Reject CMP 21 SUBMII-rER: G. A. Wintz Southern California IAEI

19 Add a second sentence as follows: ~ t and swag type incandescent lighting fixtures having exposed conductive parts and of types generally used in dwellings shall be conspicuously marked "This f ixture may be unsafe where not properly connected to an outlet that is equipped with a means for grounding." SUBSTANTIATION: Pendant and swag type fixtures are being found hung over bathtubs and the like. These fixtures are equipped with bare or green grounding conductors and are tested and listed for use when properly grounded.

However, millions of lighting outlets in existing dwellings are not equipped with a means for grounding fixtures. Furthermore the grounded circuit conductor is unidentified at many existing lighting outlets supplied by knob and tube wiring.

Most replacement lighting flx~Jres for dwellings are sold, hung and used by persons who are unaware of these serious hazards attendant to the use of ungrounded or otherwise impnoperly connected fixtures within reach o£ wet grounded surfaces. PANEL RECO~tENDATION: Reject.

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PANEL COMMENT: CMP bases its rejection on Section 90-1(c) "This Code is not intended as a design specification nor an instruction manual for untrained persons." VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 8. NEGATIVE: Licursi.

EXPLANATION OF VOTE: LICURSI: A negative vote was cast on the Panel Recommendation

because experience has proven that many pendant and chain-hung fixtures are installed in bathrooms on branch circuits not supplied with a grounding conductor.

I cannot conscientiously ignore the impact a warning label on the f ixture would have toward eliminating this very unsafe practice.

410-18(a): Reject CMP 21 SUBMITTER: International Association of Electrical Inspectors

20 Add a sentence to (a) as follows: Pendant and swag type incandescent lighting fixtures having

exposed conductive parts and of types generally used in dwellings shall be conspicuously marked "This f ixture may be unsafe where not properly connected to an outlet that is equipped with a means for grounding," or words to that effect. SUBSTANTIATION: Pendant and swag type fixtures are being found hung over bathtubs and the like. These fixtures are equipped with bare or green grounding conductors and are tested and listed for use when properly grounded.

However, millions of lighting outlets in existing dwellings are not equipped with a means for grounding fixtures. Furthermore, the grounded circuit conductor is unidentified at many existing lighting outlets supplied by knob and tube wiring.

Most replacement lighting fixtures for dwellings are sold, hung and used by persons who are unaware of the serious hazards attendent to the use of ungrounded or otherwise improperly connected fixtures within reach of wet grounded surfaces. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP bases its rejection on Section go-1(c) 'iThis Code is not intended as a design specification nor an instruction manual for untrained persons. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: LICURSI: See Comment on Proposal No. 19.

410-20(New): Accept CMP 21 SUBMITTER: Allen KnicKrehm, Los Angeles, CA

21 Add section as follows: Equipment Grounding Conductor Attachment. Fixtures

with exposed metal parts shall be provided with a means for connecting an equipment grounding conductor for such fixtures. SUBSTANTIATION: Wiring methods providing equipment ground conductors as a grounding means, such as nonmetallic raceway syste~1~ and nonmetallic cable systems, must have a method whereby the equipment ground connector can be connected to the exposed metal parts of the lighting fixtures.

I t has been brought to the writer's attention that dr i l l ing a hole or fastening a grounding conductor to a listed or labeled f ixture may void the l ist ing of the f ixture. Therefore i t is fe l t necessary for the Code to provide a means for connecting the equipment grounding conductor to the f ixture to assure compliance with the provisions of the Code. PANEL RECOMMENDATION: Accept. VOTEON PANEL RECOMMENDATION:

AFFIRMATIVE: 8. NEGATIVE: Short.

EXPLANATION OF VOTE: SHORT: the proposal would require a method of attaching a

grounding conductor on all f ixtures. This is unnecessary, when the f ixture is connected with conduit.

410-24(b): Accept CMP 21 SUBMITTER: TSC-Approved for the Purpose I~R-O-P-O-S~At-~. " 22 See the Technical Subcommittee "Recnmmendations" un--~-d-e~-~e definit ion of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept.

IPANEL COMMENT: See CMP Proposal No. 22A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

conductors wil l be subjected. (FPN) For ampacity of f ixture wire, see Table 402-5. (FPN) For maximu~ operating temperature and voltage limitation

l of f ixtures, wires, see Section 402-3. SUBSTANTIATION: The words "environmental conditions" better reflect the requirements of (b) and the overall proposal is in agreement with the recoaraendations of the technical subcommittee--Approved for the Purpose. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


23 See the Technical Subcommittee "Recommendations" un--6-d~-r--t-~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

r 410_41. Insulating Joints. Insulating joints that are not designed to be mounted with screws or bolts shall have an exterior metal casing, insulated from both screw connections. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-42(a): Accept CMP 21 SUBMITTER: TSC-Approved for the Purpose I~TO]~-S'A-C~ 24 See the Technical Subcommittee "RecommendationsZ' ~ e definition of "Approved for the Purpose" in Art icle 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

(a) General. Portable lamps shall be wired with f lexible cord recognized by Section 400-4 and an attachment plug of the polarized or grounding type.

Delete the exception. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-42(b)(2): Accept CMP 21 SUBMITTER: TSC-Approved fo~ the Purpose ~ 2 5 See the Technical Subcommittee "Recommendations" under the definition of MApproved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definit ion of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

(2) Handlamps shall be equipped.with a handle of molded composition or other insulating material. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

KIENER: I vote affirmative, but recommend the following change in wording:

"Handlamps shall be equipped with a handle of molded composition or other insulating mater,ial capable of withstanding the voltages involved."

410-49: Reject CMP 21 SUBMITTER: H. B. Love/B. L. Auger, Michigan Chapter IAEI

26 Revise to read: Lampholders.

(a) Lampholders installed in wet or damp locations shall be of the weather-proof type.

(b) Porcelain or metal shell sockets used as cord pendant lighting outlets shall not be permitted within reach of grounded portion of buildings. SUBSTANTIATION: Where such fixtures are used in areas containing high humidity, such as basements, they tend to collect moisture and become a shock hazard. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not Justify the proposed change. Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

WELLS: There is no definition or product category called "weather-proof" and to accept this proposal without such would be meaningless. There are "wet location" and "damp location" definitions and in view of the Panel's action on Proposal 4A the problems referred to in the substantiation supported the (b) portion of the proposal.

410-24: Accept CMP 21 SUBMITTER: CMP 21

I PROPOSAL: 22A Add the words "environmental conditions" after ~ s "suitable for the." Delete (b), and'(a) becomes text of 410-24. Fine print notes remain. To read as follows: 410-24. Conductor Insulation. Fixtures shall be wired with conductors having insulation suitable for the environmental conditions, current, voltage, and temperature to which the

t

410-52: Accept CMP 21 SUBMITTER: Clyde H. Craig, Toledo Chapter NECA Is-R-O-fs~-~L-~. • 27 Add additional sentence as follows:

~ o r d shall be nonflammable or chain shall extend a minimum of 10 inches frnm lamp holder. SUBSTANTIATION: There have been cases of large wattage lamps burning pull cord and causing smoldering cord to fa l l to fIoor

323

where flammable material may be present. PANEL RECOMMENDATION: Accept as Revised: J Pull cord shall be nonflammable, or chain portion shall extend a minimum of 7 inches from the lampholder. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: SHORT: There is no evidence of a problem. Not a single case

has been reported to the concerned manufacturers involving accidents of this type.

410-56(a)-(New): Reject CMP 21 SUBMITTER: R. C. Cressman, General Electric Co.

2B Add new (a) and existing (a) becomes (b), etc. - - - ~ e p t a c l e s , cord connectors, and attachment plugs rated 15 and 20 amperes and intended for use with connection to portable cords shall be approved for the use intended (not.hard usage, hard usage, extra hard usage). SUBSTANTIATION: The Code presently recognizes in Table 400-4 three types of usages for portable cords (not hard usage, hard usage, extra hard usage). The devices intended for use with these cords should be similarly recognized. The attachment plug, connector and receptacle receive abuse similar to that of cords. Plugs and connectors are subject to the same crushing forces as portable cords. Plugs, connectors, and receptacles can be damaged by abrupt removals, even more so than the cord.

The requirements 6or a receptacle, cord connector, and attachment plug for use in the home on AWG 18 SPT are quite different from those used in heavy industry on AWG 18 SO. Definitions of use difference have been made by NEMA (WD1-1974, Part 3-General Duty and Heavy Duty), the Federal Government (WC5996-E), the International Electrotechnical Commission (Household Use and Industrial Use), and by UL 498 (Regular and Hospital Grade). The recognition by the Code of two usage differences would give guidance to UL to develop requirements to meet the needs of the user as they have done in flexible cords. I t would also serve as a basis for a single standard eliminating the duplication now being done by the various agencies. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-56(b), Exception-(New): Reject CMP 21 SUBMITTER: Ted Steppe, Stepp-Elex Corp.

29 Add a new exception as follows: x - ' ~ l o n : A metallic faceplate of ferrous metals which is stamped in one piece and having a recessed center section of sufficient area to effectively seal a standard device box shall have a thickness not less than 0.020 inch. SUBSTANTIATION: A faceplate with a recessed center is by far many times more rigid than any f la t faceplate. We therefore feel that the thickness of the metal can be reduced from 0.030 to 0.020 inches without giving up a large amount of strength, because of the internal bends in the center of the faceplate. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION: UnanimouslyAffirmative.

receptacle. SUBSTANTIATION: TIA to the 1978 NEC. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-S6(f)-(New): Reject CMP 21 SUBMITTER: R. S. Pinkerton, Los Angeles, CA

32 Addnew i f ) as follows: ---(-~'--(~perating at Over 300 Volts. Attachment plugs or other connectors supplying equipment at over 300 volts shall be of the skirted type or otherwise designed that arcs will be confined within the case of the plug or receptacle. SUBSTANTIATION: The users of electrical equipment have been severely injured when they attempted to plug in or connect a piece of faulty equipment to a circuit operating at over 300 volts. At this higher voltage a fault will produce severe arcing and violent discharge of molten metal which requires a skirted type of receptacle to provide workman safety. ,, PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. Existing devices, rated in excess of 300 volts, are tested at 150 percent of rated current at rated voltage. In addition, the Chairman has appointed a Task Force, chaired by Walter Short, to obtain further information for consideration for the next Code cycle. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

/

410-56(f)-(Newi: Reject CMP 21 SUBMITTER: Southwestern Section IAEI

33 Add subsection i f ) to 410-56 to read: ~ p e r a t i n g At Over 300 Volts. Attachment plugs or other connectors supplying equipment at over 300 volts shall be of the skirted type or otherwise designed that arcs will be confined within the case of the plug or receptacle. SUBSTANTIATION: The users of electrical equipment have been severely injured when they attempted to plug In or connect a piece of faulty equipment to a circuit operating at over 300 volts. At this higher voltage a fault will produce severe arcing and violent discharge of molten metal which requires a skirted type of receptacle to provide workman safety. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 32, Section 410-56(f). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-56(g)-(New): Accept CMP 21 SUBMITTER: CMP 2 III~-O]~O~'A-L-~. • 29 (CMP 2) Revise as follows: -~{-~(~onductors. Receptacles rated 20 amperes or less directly connected to aluminum conductors shall be marked CO/ALR. SUBSTANTIATION: I t was the action of the Correlating Committee to advise CMP 2 that the Correlating Committee has referred Proposal No. 29 to CMP 21 for action. PANEL RECOMMENDATION: Accept. PANEL COMMENT: ThF'text of Section 210-7(g) (see Proposal No. 29-CMP 2) has been revised and relocated to new Section 410-56(g) as per action of the Correlating Co~nittee. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-56(c): Accept CMP 21 SUBMITTER: E. E. Carlton, Menlo Park CA

30 Revise the second sentence as follows: ~ a t e s shall be installed so as to completely cover the wall opening and seat against the wall surface. SUBSTANTIATION: To provide safety and prevent access to exposed live metal parts. This islan accepted practice and should be added to the Code. The same requirement presently is included in Section 380-9 for switches. Addition of this proposal to 410-56(c) wil l provide safety for receptacle outlet installations also. PANEL RECOMMENDATION: Accept as Revised:

Delete the word "wall" before the word "opening." Delete the word "wall" before the word "surface" and replace wlth "mounting." To read as follows:

Faceplates shall be installed so as to completely cover the opening and seat against the mounting surface. PANEL COMMENT: C~ 21 feels that there are times when covers are required to seat against surfaces other than "walls" such as gaskets or surface-mounted boxes. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-56(e)(TIA 1978 NEC): Accept CMP 21 SUBMITTER: TIA 2-70-1978

31 Add a new Section 410-56(e) and change present ~ h (e) to (f).

{el Attachment Plug Ejector Mechanisms. Attachment plug ejector mechanisms shall not adversely affect engagement of the blades of the attachment plug with the contacts of the

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410-57(b), Exception: Reject CMP 21 SUBMITTER: O. E. Oillon, Border County Div. IAEI )~rOl~O~'At-~.34 Delete exception. ~OI~S~F~J~rIATION: This section is legally unenforceable due to the use of the words "not likely" and "not usually." At the time of inspection, the inspector cannot determine the future use of the receptacle. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for C~ I Proposal No. 90 for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL CO~MENT: CM@'-agrees with the intent of the Proposal see action on Proposal No. 34A, Section 410-57(b). VOTE ON PANE~ RECOMMENDATION: Unanimously Affirmative.

410-57(b), Exception: Accept SUBMITTER: C~ 21

II)~IOP~)-S'-A-L-~: 34A Delete the words "likely" and "usually." ~'I)~rS'~'~N~rIATION: The words "likely" and "usually" are not definitive of the requirement. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

CMP 21

410-57(b), Exception: Reject CMP 21 SUBMITTER: R. C. Medley, Square D Co. ]~II)POS'XL-~.. 35 Delete the words "self-closing." ~'I]I~'rAI~FIATION: The reason for the request to remove "self-cl6sing" results from the interpretation by UL based upon these words that any cover which required user assistance wll l no longer be acceptable for such usage effective January I , 1979, as covered by UL S14-C dated November 3, 1977, Paragraph 10.6. I t states: UA cover with a detent or other feature designed to hold i t open Is not to be assisted in closing." Unfortunately, the UL interpretation prohibits" a feature which is of importance to the users of cover plates. Such p)ates are typlcally used for switches as well as temporarily connected receptacles. A hold-open feature permits the user to open the l id an.d then insert or remove a plug (or operate a switch) a11owing one hand operation. I t also permits one hand closure with equal ease.

Such covers have been successfully used for over 15 years without incident. A hold-open feature is also of necessity to the milllons of ar thr i t ical ly affected consumers, as well as others of physical incapacity who use these covers on their homes.

The removal of the term "self-closlng" wil l allow the use of weatherproof covers marked "Wet Location with Covers Closed" which wil l otherwise satisfy UL requirements. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Pane I ' s l n t e n t . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

WELLS: In my opinion, i t is the specific intent of the present wording to prohibit what the submitter wants to permit. While I t may be convenient for one-handed operation to have a cover stay open, I t is also convenient for a user to fa i l to close the cover thus defeating the very purpose of the cover in the f i r s t place. Further, covers with hold-open features expose the open covers to physical abuse which may prevent their future effective use.

410-68(a)(HOD 1978 NEC): Reject CMP 21 SUBMITTER: John M. Wall, Central Calif. Chapter, Fresno, CA !~TOPI~S'~-~.'36 Amend Section 410-SB(a) to read: ~ o u n d i n g type receptacles, cord connectors and attachment plugs shall be provided with one fixed grounding pole in addition to the circuit poles "and shall be polarized when of the 2 parallel slot and blade configuration." SUBSTANTIATION: There is a built- in safety feature in the grounding type receptacles in the form of a wider slot and associated terminal for the grounded circuit conductor and a narrower slot for the phase or hot circuit conductor and termination of the parallel slot 16 ampere 125 volt configuration. This feature provides safety whereby a 2 wire parallel polarized blade attachment plug and identified conductors and appliances may be used with a better degree of safety. PANEL RECOMMENDATION: Reject. PANEL COMI~ENT: No significant contribution to safety would result. VOTE ON PANEL RECOMMENDATION:


CO~IENT ON VOTE: WELLS: the present wording in 410-42 wil l require polarized

plugs on portable lamps January I , 1980. Nothing in the substantiation Justifies requiring polarized plugs on two wire clocks, appliances, double insulated tools, etc. EXPLANATION OF VOTE:

LICURSI: A negative vote was cast on the Panel Recommendation because with the requirement of 410-42(a) becoming effective January 1, 1980, there is no requirement in the Code that will provide a polarized receptacle for a two-wire polarized portable lamp.

410-58(a), Exception: Reject CMP 21 Secretary's Note: I t was the action of the Correlating

Committee that correlation may be necessary with Proposal Nos. 50 and 52 of Code-Making Panel 5. SUBMITTER: John L. Bennett, Power Tool Institute

37 Delete the exception. ~I]B-~'~]~IATION: Thi~ Exception anticipates the connection of a ~oo1 or appliance to either a receptacle with a grounding pole or to a two pole receptacle without a grounding pole. The availabil i ty of grounded receptacles has increased to the point that there is very l i t t l e advantage in the use of plugs with movable grounding poles. The installation of grounded receptacles or fixed adapters should be encouraged. There is no apparent need to condone the ungrounded use of a tool or appliance which is normally required to be grounded. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to ~ecesslty. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-58(b)(4): Reject OMP 21 SUBMITTER: F. K. Kltzantides, NEMA I~R-O-PO-S'A~-~..38 Revise as follows:

"(-4")-- I f the terminal for the equipment grounding conductor is not visible, or i f terminal screw is removable, the conductor entrance hole or the area adjacent to the terminal shall be marked with the word "green" or the symbol " ~--~-_" or otherwise identified by a distinctive green c o l o r . SUBSTANTIATION: The ground symbol " ~ " is an international means of Identifying ground. I t is used in electric drawings and schematic diagrams. A symbol is used to transmit a message in a clear understandable manner independent of any language. PANEL RECOMMENDATION: Reject. PANEL COI~4ENT: The proposal to use a ground symbol to identify a groundlng terminal would not, in the CMP's opinion, further the cause of electrical safety. The proposal to use a grounding symbol in lieu of the present green identification as required by the '78 NEC is unacceptable since i t would increase the probability of miswiring of the device. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 8. -

NEGATIVE: Knickrehm. COMMENT ON VOTE:

WELLS: The grounding symbol is unknown to millions of consumers who wire devices. Coloring the terminal provides color identification with the green wire. Using a technical symbol on a product which can be wired by a broad spectrum of non technical users is, in my opinion, wrong. EXPLANATION OF VOTE:

KNICKREHM: This use of graphics to overcome language and color barriers is internationally accepted. The NEC should also accept this fact.

410-58(c): Accept CMP 21 SUBMITTER: Nathaniel J. Addleman, Wichita, KS PROPOSAL: 39 Add a sentence as follows: Grounding type ~ n t plugs shall not be installed without a proper ground connection being made between the appliance and the grounding terminal of the plug. SUBSTANTIATION: At present there seems to be no explicit prohibition against installing a grounding type attachment plug on an electrical cord w~thout a grounding conductor. Such an installation could lead to the erroneous conclusion that the appliance that has a "two wire cord" connected to a "three prong plug" is grounded, since the wire connections on the backside to the plug are usually hidden from view, and since i t has become common knowledge that a "three pron 9 plug" means that the appliance to which i t is connected {via the power cord) is grounded.

Section 410-58(c) is not explicit enough to prohibit the above misleading use of a grounding type attachment plug. PANEL RECO~FF4ENDATION: Accept as Revised:

I Add a new {e] to 410-58 as follows: (e) Use. Grounding-type attachment plugs shall be used only

where an equipment ground is to be provided. VOTE ON PANEL RECOMMENDATION:' Unanimously Affirmative.

Article 410, Part M: Reject CMP'21 SUBMITTER: Warren Anderson, Mount Vernon, WA !°ITOPl~'~B~-~.'40 Delete 410 Part M. Rosettes ~]I~'AI~FIATION: The need to cover rosettes in the 1981 Code has disappeared with the dinosaur. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-64: Accept CMP 21 SUBMII'TER: TSC-Approved for the Purpose ~ 4 1 See the Technical Subcommittee "Recommendations" un--n-d-e-r-t~Te definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "of a type approved for the purpose and l i shall" and replace with 'identified for such instal lat ion. '


410-64(a)-(New): Accept CMP 21 SUBMITTER: R. E. Ward, Tenn. Chapter, IAEI I~TOTrO~K[~-.'42 Add new (a) as follows: - - - ~ e c e s s e d or surface mounted incandescent f ixtures' installed indoors adjacent or on co(nbustible materials shall have thermal protection integral with the lampholders.

Exception: Fixtures with miniature intermediate l ampholders. SUBSTANTIATION: Fires are being caused under present Code rules usually due to over-lamping or misuse of insulating materials.

This proposal, i f enacted, wil l give protection from this type hazard.

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PANEL RECOMMENDATION: Accept as Revised: Where recessed or surface-mounted incandescent fixtures are

installed indoors, the lampholders shall have thermal protection integral within the l ampholder or otherwise thermally protected and identified for such conditions of use. Replacements for these l ampholders shall also be integrally protected.

Exception No. 1: Fixtures with minature l ampholders. Exception No. 2: This requirement shall become effective

January 1, 1982. PANEL COMMENT: CMP 21 has accepted the revised text and indicated the material be relocated to proposed Section 410-40 as per CMP 21 Proposal 1A. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 7. NEGATIVE: Duffy, Short.

,COMMENT ON VOTE: WELLS: I vote affirmatively because I believe the magnitude

of the problem, in part demonstrated by the many proposals from manufacturers and distributors of such fixtures, mandates action. Subsequent to the Panel Meeting, I have been informed of a patent which might directly affect "integral protection of l ampholders" and I believe the Panel, in its next meeting must revise the wording so as to allow other equally effective means of protection. EXPLANATION OF VOTE:

DUFFY: I am voting negative on the proposal because i t includes surface mounted units. Surface mounted incandescent fixtures labeled by Underwriters Laboratories since August of 1978 have been tested and found acceptable for use on insulated ceilings. These fixtures are identified by the letters IC (Insulated Ceiling). Also I believe the technical complexity of having the thermal protection integral with the lampholder is impractical. I would support the proposal with the deletion of "or surface mounted" and I believe the requirement for integral l ampholder thermal protection and replacement of such lampholders should be deleted.

SHORT: The proposal should be altered to call for the f ixture i tse l f to have thermal protection rather than singling out the lampholder within the f ixture. This would permit UL, in their examination l ist ing, to determine the hottest point of the f ixture under an abnormal temperature test and that the thermal protection within the fixture would be such as to control the maximum temperature of that particular point of the f ixture.

/ 410-66: Reject CMP 21 SUBMITTER: Murray Feiss, American Home Lighting Institute I~RI)]~S'AlZ~.'43 Add new sentence as follows: Retrofit thermal l-6-s-~laTTon installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure cempliance with Section 410-66, the installation should be inspected.

The absence of the requirement for such inspection constitutes a potential f i re hazard. PANEL RECOMMENDATION: Reject. PANEL CO~V4ENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-66: Reject CMP 21 SUBMITTER: Arnold W. Rodin, American Home Lighting Institute !~R'(I!~'AL-~. • 44 Add new sentence as follows: Retrofit thermal l-6s'~-l-~-t-Ton installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This Is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.

The absence of the requirement for such inspection constitutes a potential f i re hazard. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-66: Reject CMP 21 SUBMITTER: Harry W. Rothenberg, Timely Lighting

45 Add new sentence as follows: Retrofit thermal Insu~-6-s-~l~-t-fon installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: The push for energy savings has resulted in thermal insulation being added after recessed fixtures have been installed and inspected, in too many cases, years after installation of recessed fixtures. The reference to re t ro f l t installation is as indicated above. To assure co~oliance with Section 410-66, the thermal installation should be inspected.

The lack of such a requirement to inspect creates a potential f i re hazard. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-66: Reject CMP" 21 SUBMITTER: Ronald C. Zaker, Halo Lighting I~q~O-S'A-L-T.'46 Add new sentence as follows: Thermal insulation ~ d in ceilings that contain recessed fixtures, shall be inspected, including re t ro f i t installations. SUBSTANTIATION: Thermal insulation is being added to ceilings after recessed f ixture installations have been inspected. This normally occurs at the termination of the building construction or at a later date after the building is occupied as a re t ro f i t installation. In order to assure compliance with Section 410-66, both installation types should be inspected.


410-66: Reject CMP 21 SUBMITTER: R. A. Wiedemer, Jr., Hinkle Lighting PROPOSAL: 47 Add new sentence as follows: Retrofit thermal l-n-sula-L~Fon installed in ceilings tha~ contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.


410-66: Reject CMP 21 SUBMITTER: Harold S. Minoff, L. D. Kichler Co. PROPOSAL: 48 Add a new sentence as follows: Retrofit thermal ~ o n installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ce111ngs after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.


410-66: Reject CMP 21 SUBMII-FER: Marvin Leichtung, Puritan Lighting Fixture Co. PROPOSAL: 49 Add a new sentence as follows: Retrofit thermal

' ~ o n installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances, thermal insulation is added to ce111ngs after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.


410-66: Reject CMP 21 SUBMITTER: Marc A. Katz, Fredrick Ramond, Inc. PROPOSAL: 50 Add a new sentence as follows: Retrofit thermal ~ o n installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ce~I1ngs after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.

The absence of the requirement for such inspection constitutes a potential f i re hazard. PANEL RECOMMENDATION: Reject. PANEL ~OMMENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION:. Unanimously Affirmative.

410-66: Reject CMP 21 SUBMITTER: A. Ebenstein, American Home Lighting Institute I~TOI~S'XL-~.'51 Add a new sentence as follows: Retrofit thermal insulation installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This

326

is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.

The absence of the requirement for such inspection constitutes a potential f i re hazard. PANEL RECOIC~ENDATION: Reject. PANEL COI~ENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-66: Reject CMP 21 SUBMITTER: ai~ Wiederhold, Corbett Lighting, Inc.

52 Add new sentence as follows: ~ i t thermal insulation installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.

The absence of the requirement for such inspection constitutes a potential f i re hazard. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative~

410-66: Reject CMP 21 SUBMITTER: Sidney Wolkin, Lightolier, Inc.

53 Add a sentence as follows: Retrofit thermal insulation installed in ceilings that contain

recessed fixtures, shall be inspected to assure that no insulation is within 3 inches nor on top of f ixture. SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.


410-66: Reject CMP 21 SUBMITTER: Irwin Goldberg, Coronet Chandelier Originals PROPOSAL: 54 Add a sentence as follows: ~ I t thermal insulation installed in ceilings that contain recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to cei|ings after recessed fixtures have been inspected. This is normally referred to as re t ro f i t installation. In order to assure cempliance with Section 410-66, the installation should be inspected.

The absence of the requirement for such inspection constitutes a potential f i re hazard. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECO~V~IENDATION: Unanimously Affirmative.

410-66: Reject CMP 21 SUBMIl-rER: O. E. Dillon, Border County Div. IAEI ~OSAL: 55 Revise second sentence as follows: ~ e d f ixture enclosures, wiring compartments or ballasts shall not be installed within" three inches of thermal insulation or in such a location so that heat is entrapped and free circulation of air is prevented except when the f ixture is listed for the use. SUBSTANTIATION: This section is practicably unenforceable as Che electrical inspector does not inspect or control the installation of thermal insulation. The use of the words "combustible material" without a definition of combustible material renders this section legally unenforceable. See the attached opinion* of.the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for" 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-66: Reject CMP 21 SUBMITTER: Julian Chacon, Lightcraft of California

56 Add new sentence as follows: Retrofit thermal insulation installed in ceilings that contain

recessed fixtures, shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with 410-66, the installation should be inspected.

The absence of the requirement for such inspection constitutes a potential f i re hazard. PANEL RECO~ENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-66: Reject C~ 21 SUBMITTER: Reynolds K. Ohal, Santa Fe Springs, CA ~ 5 7 The following additional sentence should be added to Section 410-66.

Retrofit thermal insulation installed in ceilings that contain recessed fixtures shall be inspected. SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected. The absence of the require~nts for such inspection constitutes a potential f i re hazard. PANEL RECOMMENDATION: Reject. PANEL COVa4ENT: See Panel action onProposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-66: Accept SUBMITTER: TSC-Approved for the Purpose PITOP-O-S'AI_-~: 58 See the Technical Subcommittee "Recommendations" under the def!nition of "Approved for the Purpose" in Art icle 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "approved for the purpose" and replace with ]"Identif ied for installation within thermal insulation." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

CMP 21

410-66: Reject CMP 21 SUBMITTER: Frederick W. Van Cott, Sea Gull Lighting Products~

PROPOSAL: 59 Add the following sentence: ~ i t thermal insulation installed in ceilings that contain recessed fixtures, shall be inspected, SUBSTANTIATION: In many instances thermal insulation is added to ceilings after recessed fixtures have been inspected. This is normally referred to as a re t ro f i t installation. In order to assure compliance with Section 410-66, the installation should be inspected.

The absence of the requirement for such inspection constitutes a potential ~ire hazard. PANEL RECOf~4ENDATION: Reject. PANEL COVd~ENT: See Panel action on Proposal No. 42. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-66: Reject CMP 21 SUBMITTER: K. V. Jester, Texas Chapter/IAEI P R O P ~ 60 Revise as follows:

Recessed portions of enclosure S , other .than points of support, shall be sp~ced at least 1/2 inch from combustible material andsuch fixtures shall incorporate thermal protection when located in an area where thermal insulatiun wil l be installed.

Fixtures which are so designed or installed to physically prevent thermal insulation from being installed within three inches of the ~ecessed f ixture enclosure, wiring compartment or ballast are not required to be thermally protected. SUBSTANTIATION: For several years the Code has attempted to deal with the problem of thermal insulation surrounding recessed lighting fixtures without a great deal of success. This is a growing problem due to the energy conservation efforts where more and more insulation is being installed, especially in homes. The present requirements in the Code of thermal insulation not being installed within three inches of recessed fixtures is practically unenforceable by electrical inspectors. When the fixtures are installed and inspected they co~iply with the Code but only until the insulation installers come on the job. This problem is real and needs to be corrected by the electrical industry and not by placing requirements on people (insulation installers) over whom we have l i t t l e control. The requirement for thermal protection for the fixtures themselves is not the complete solution to the problem but should relieve a situatiq~ which can only beceme worse with time. Therefore, the exception needs to be included to permit the installation of fixtures without thermal protection where other safeguards are provided or where in some cases thermal insulation wil l not be installed. PANEL RECOMMENDATION: Reject.

• PANEL COMMENT: See Panel action on Proposal Nos. 42 and 63A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

327


61 See the Technical Subcommittee "Recemmendations" ~ e r the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "approved for the'purpose" and replace with or other suitable insulating materials."

VOTE ON'PANEL RECOMMENDATION: Unanimously Affirmative.

410-73(b): Accept CMP 21 SUBMITTER: TSC-Nominal Voltage J~ROPOSAL: 62 Change "supply" to "circuit." SUBSTANTIATION: For the sake of uniformity in terminology consistent with recommendations being made by the TSC for usage throughdut the Code. PANEL RECOM~IENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-73(e), Exception: Reject CMP 21 SUBMITTER: O. E. Dillon, Border County Div. IAEI ~ 6 3 In the Exception to (e), add the phrase " i .e . ,

does not employ capacitors" to the end of the sentence. SUBSTANTIATION: The exception renders this section legally unenforceable as there is no definition of a simple reactance ballasts. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for C~ 1 Proposal No. 90 for 110-16(a). I PANEL RECOMMENDATION: Reject. PANEL COr~4ENT: The present wording adequately reflects the Panel's intent. The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

410-73(f)-(New): Accept CMP 21 • SUBMITTER: CMP 21

PROPOSAL: 63A Add (f) as follows: ~ e r e recessed high-intensity discharge fixtures with integral ballast are installed indoors, the ballasts shall have thermal protection integral within the ballast. Replacements for these ballasts shall also be integrally protected.

Exception: This requirement shall become effective January 1, 1982. SUBSTANTIATION: CMP 21 extends the same protection to provide for recessed high-intensity discharge fixtures that is now applied to fluorescent fixtures. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:


COMMENT ON VOTE: DUFFY: Although I am voting affirmative I believe further

consideraton of the effective date may be necessary to allow time for development and implementation of the,protection program.

WELLS: See Comment on Proposal No. 42. EXPLANATION OF VOTE:

SHORT: This requirement is unnecessary because HID ballasts fa i l in a low resistance mode which results in blowing of fuses or tripping of circuit breakers whereas fluorescent ballasts fa i l in a high resistance mode.

410-75(b): Reject CMP 23 SUBMITTER: Norman B. Cooney, Parma, OH

64 Revise Section 410-75(b) as follows: ~ n t exceeding 300V may be installed in dwelling occupancies i f the design prevents exposed live parts. SUBSTANTIATION: These sections are so confusing I don't believe an explanation is possible. Yo~ can, you can't, you can. Which is it? Can you or can't you?

I would think somewhere In this morass of perplexibility that someone would correlate the different CMP's and come up with a viable solution to this absurdity.

How can someone be expected to intell igently enforce provisions of theNEC when they are written in thls fashion?

Simplicity in articles and words should be the byword of the NEC, not the confusion that is usually expressed. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL, RECOMMENDATION: Unanimously Affirmative.

410-80 (b): Accept CMP 21" SUBMITTER: TSC-Nominal Voltage J ~ 65 Change "supply" to "circuit ." ~'~)I~7"~NI"IATION: For the sake of uniformity in terminology consistent with recommendations being made by the TSC for usage throughout the Code. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

"Article 410 Part S-(New): Accept CMP 21 SUBMITTER: Stephen D. Channer, Business and Institutional

Manufacturer's Assn. BIFMA PROPOSAL: 66 Add Part S at the end of Article 410 as follows:

S. Special Provisions for Office Furnishings 410-100. General. Wiring systems shall be listed and approved for the purpose of providing power for lighting and office appliances to office furnishings. 410-101. Other Articles. All articles of the Code shall apply where applicable. 410-102. Flexible Cords and Cables.

(a) Office furnishings shall be permitted to be connected by flexible cords or cables to outlets approved for the purpose.

(b) Flexible cords and cables shall be permitted for the wiring within office furnishings approved for the purpose. SUBSTANTIATION: Thls proposal concerns i tsel f with wiring systems as provided by members of our industry with office furniture'systems that are now being used extensively in offices throughout the United States. Although not exclusively, office furniture systems are primarily used In areas referred to as "open plan" or "landscape" office layouts.

Within our industry, office systems furniture has grown in popularity to a great extent over the past several years. Much of the popularity stems from the advantages of portabil i ty and ease of rearrangement. Today the sales of this type of furniture are well over $300 million dollars annually and growing. Due to energy conservation requirements users have demanded the inclusion of task and ambient lighting with this type of furniture. Current industry estimates show that approximately 80 percent of all office furniture systems sold contain electrical power. When such power is provided by manufacturers within our association, safety is foremost in their consideration and all wiring systems have been or are in the process of being submitted to and listed by Underwriters Laboratories or other nationally recognized testing laboratories.

Our industry is very proud of its concern for product safety and performance and the good record that i t currently enjoys. Our purpose in submitting the enclosed proposal to the National Fire Protection Association is to establish a category within the National Electrical Code that deals specifically with products made within our industry that contain wiring systems and to provide in writing the standard of quality that must be adhered to by those making such systems.

Your review and favorable consideration of this proposal wil l be very much appreciated by the business and institutional furniture industry. PANEL RECOMMENDATION: Accept as Revised.

S. SPECIAL PROVISIONS FOR LIGHTING ACCESSORIES AND WIRED PARTITIONS

410-100. General. Wiring systems shall be identified as suitable for providing power for lighting accessories and appliances in wired partitions. These partitions shall not extend from the floor to ceiling or exceed 7 feet in height.

410-103. Other Articles. Wherever the requirements of other articles of this Code ~nd Part S of Article 410 di f fer, the requirements of Part S, Article 410 shall apply.

410-106. Wireways. All conductors and connections shall be contained within wiring channels of metal or other material identified as suitable for the conditions of use. Wiring channels shall be free of projection or other conditions that may damage conductor insulation.

(FPN) Conductors as used in this section do not include flexible cord.

410-108. Partition Interconnections. The electrical connection :between partitions shall be a flexible assembly marked for use with wired partitions.

Exception: Flexible cord shall be permitted for the connection between partitions provided all of the following conditions are met.

' a. The cord is extra-hard usage type. b. The partitions are mechanically contiguous. c. The cord is not longer than necessar~ fo~ maximum

positioning of the partitions but, in no case to exceed 2 feet. d. The cord is terminated at an attachment plug and cord

connector with strain rel ief.

410-110. Lighting Accessories. Lighting equipment marked for use with wired partitions shall comply with all of the following:

(a) Support. A means for secure attachment or support shall be provided.

(b) Connection. Where cord and plug connection is provided,

328

the cord length shall not exceed 8 feet~ (c) Receptacle Outlet. Convenience receptacles shall not be

)ermitted in lighting accessories.

%10-112. Fixed Type. Wired partitions that are fixed (.secured to building surfaces) shall be permanently connected to the building electrical system by one of the wiring methods of Chapter 3.

410-115. Free-Standing Type. Partitions of the free-standing type (not fixed) shall be permitted to be permanently connected to the building electrical system by one of th~ wiring methods of Chapter 3.

Individual partitions of the free-standing type, or groups of not more than six individual partitions which are mechanically contiguous, shall be permitted to be connected to the building electrical system by a single f lexible cord and plug provided all of the following conditions are met.

(a) Cord Type. The flexible power-supply cord shall be extra-hard usage or hard usage type with No. 12 AWG or larger conductors with a green grounding conductor and not exceeding 18 inches in length, ,

(b) Supply Receptacle. The receptacle supplying power shall be located not more than 12 inches from the partition which is connected to i t . The receptacle supplying groups of partitions shall be on a separate circuit serving no other loads.

(c) Multiwire Circuits. Individual partitions, or groups of individual partitions where connected together, shall not contain multiwire circuits.

(d) Number of Receptacle Outlets. Individual partitions, or groups opf interconnected individual partitions, shall not contain more than thirteen 15-ampere 125-volt receptacle outlets. PANEL COMMENT: This Panel Proposal recognizes the existence of wired partitions for offices, schools and other applications and establishes rules concerning the construction and installation of the electrical system within and feeding these partitions. This type of equipment contains receptacles and lighting equipment and is, in the Panel's opinion similar to showcases which are within the scope of Article 410 and covered in Section 410-29. Section 410-29 served as a source for many of the proposed requirements. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: B. NEGATIVE: KNICKREHM.

COMMENT ON VOTE: WELLS: I suppo[t the Panel Recommendation and point out that

subsequent to the meeting, I have become aware of some Panels with no f lex ib i l i t y between panels. The Panel should review 410-108 in this context. EXPLANATION OF VOTE:

KNICKREHM: I t is my belief that this material does not fa l l within the scope of Article 410. The UL employee who listed this material before i t was recognized by the NEC is a me~)er of C~4P 21 and for that reason, I believe, the propbsal was assigned to CMP 21 for a fa i r appraisal, that i t has recieved, but the subject does not, in my opinion belong in the Article 410, chapter 4 "Equipment for General Use" i t should be in chapter 6 "Special Equipment." The Panel Recommendation is good and could be used with l i t t l e change in a new Article, which should also include fixture connections by cabIe assembies. The future effective date is required because a device "identified for this use" is not now available.

ARTICLE 600 -- ELECTRIC SIGNS AND OUTLINE LIGHTING

600-2(b): Accept CMP 21 SUBMITTER: TSC-Approved for the Purpose ]~-RI)-PI~'-AL-~." 67 See the Technical Subcommittee "Recommendations" un-un-de~--tlTe definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "a type approved for the purpose" and replace with "rated for controlling inductive load(s)." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

600-4: Accept CMP 21 SUBMITTER: CMP 21 PROPOSAL: 67A Delete Section 600-4. ~ I A T I O N : This proposal was presented by CMP 21 member, Walt A. Mueller.

A Task Force has been appointed by the CMP 21 Chairman to study any possible hardships this section has imposed on the sign industry. PANEL RECOMMENDATION: Accept as Revised. 6(]i5--4. Listing Required. Every electric sign of any type, fixed or portable shall be listed and installed in conformance with that l ist ing; unless otherwise permitted by special permission. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 8. NOT VOTING: Duffy.

EXPLANATION OF VOTE: DUFFY: I am no~ voting on this proposal as such action may be

interpreted as self-serving.

600-5: Accept C~ 21 SUBMITTER: Allen KnicK~ehm, Los Angeles NECA PROPOSAL: 68 Delete the reference to "Article 250" and replace w--1-t'h--~-~-ectlon 250-97." Delete Exception Nos. I and 2. SUBSTANTIATION: Problem: Bonding rules for signs, etc., appear in two places and are not the same.

Rules should not be repeated by different C~'s as their proposal shows. Exception No. I does not provide for safety of workers as required by OSHA. Exception No. 2 is provided for by changing the reference to Section 250-97.

I f this proposal is not in compliance with Section 90-3, then Section 250-97 should be deleted and a reference to signs and Section 600-5 should be included in Section 250-2. PANEL RECOMMENDATION: Accept as Revised:

Section 600-5 and Exception No. 1 to remain as is. Revise Exception No. 2 by adding the words "protected from physical damage," a~ter the word "conductors." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 600 -- ELECTRIC SIGNS AND OUTLINE LIGHTING

600-5, Exception No. 2: Reject cMP 21 SUBMITTER: ~Peter Pollak, The Aluminum Association ~ 6 9 After "No. 14" add "copper or No. 12 aluminum . . . . " ~ I A T I O N : This proposal is submitted to clar i fy the proper size equivalent of aluminum conductor for the application. The size limitation is based upon an ampacity requirement which can be met with an aluminum conductor sized to provide the required an~)acity. The panel is referred to the proposed revision in Section 110-5. PANEL RECOMMENDATION: Reject, PANEL COMMENT: Already covered by Section 110-15. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

600-6(c)-(New): Accept , CMP 21 SUBMITTER: R. S. Pinkerton, Electrical Code Advisory Committee for-C-~t-y of Los Angeles PROPOSAL: 70 Add a new (c) as follows: ~ o m p u t e d Load. The load for the required branch circuit installed for thesupply of exterior signs or outline lighting shall be computed at a minimum of 1200 watts. SUBSTANTIATION: Although the Code requires a sign circuit to be installed, i t does not provide for a minimum computed load for this circuit. Unrealistically low loads of 180 or 200 watts have been shown on the in i t ia l installation which has resulted in overloaded feeders when the 'real' sign of 1,000-1,500 watts is installed. The 1,200 watt minimum load is a realist ic value for the average sign installation and wil l prevent many costly feeder changes caused by fai lure to properly provide for the sign load on the in i t ia l installation. PANEL RECOMMENDATION: Accept ~s Revised.

I Change "watts" to "volt-amperes." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

600-6(c)-(New): Reject CMP 21 SUBMITTER: J. J. Kark, National Manufacturers Assn.,

71 Add now (c) as follows: ~ r o u n d - F a u l t CircuAt-lnterrupter Required. Receptacles supplying outdoor portable, cord- and plug-connected signs shall be protected by a ground-fault circuit-interrupter for personnel. SUBSTANTIATION: Portable cord- and plug-connected signs used along the roadside, fed from extension cords at the building pose an unsafe condition. The signs are constantly exposed to vandalism and the elements. Their supply is by flexible cords which may be laid across an active roadway, being repeatedly run over by vehicles. The signs have metal frames and are often on rubber tires. I t wasn't until the 1978 Code that portable signs were required to be grounded. There are numerous signs built before this change which are s t i l l in use. Therefore, i f a line-to-frame fault occurs, a person standing on the ground and touching the frame wil l provide a ground return path. Even i f an equipment ground was installed, the usage conditions make i t unlikely that i t will be adequate for any appreciable time. Attached are copies of newspaper clippings which document three (3) deaths and three (3) shocks.. Many enforcement people have voiced concern regarding this situation. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 73A. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE:~ 8. NEGATIVE: Short.

EXPLANATION OF VOTE: SHORT: I feel that this proposal wil l provide more safety

than Proposal No. 73A which does not protect personnel from damaged cords.

329


ARTICLE 422 -- APPLIANCES

422 - I : Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose IIR-O-I~O-~-AZ'~: I See the Technical Subcommittee "Recofnmendations" under the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the~TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the second sentence. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-3: Accept CMP 10 SUBMITTER: Claude E. Deering, Jr., American Petroleum Institute !~TOITO~-~. " 2 Add the word "classified" in parenthesis after

"hazardous." SUBSTANTIATION: I t is proposed that the word "classified", in parentheses, be inserted after the word "hazardeu~." This is consistent with Article 500, which, is entitled "Hazardous (Classified) Locations." The proposed wording recognizes that a location is not hazardous per se, but is classified depending on the properties of the flammable or combustible substance which may be present, and the likelihood that a flammable or combustible concentration or quantity will be present. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-5(a), Exception No. 2: Accept CMP 10 SUBMII-FER: W. Creighton Schwan, Hayward, CA

I 1~-OPb-~--~. " 3 Place a comma after the words "motor-operated ~ e . " SUBSTANTIATION: As the exception is presently punctuated, a 25% increase in branch circuit rating is required for every appliance "other than a motor-operated appliance that is continuously loaded." Revised as proposed, the phrase "that Is continuously loaded" wil l properly apply to the appliance in the opening phrase, "For an appliance," not to "a motor-operated appl iance." PANEL RECO~AMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-8(d)(I): Accept CMP 10 SUBMITTER: S. Mazzoni, Underwriters Laboratories Inc.

I iSR~P~T~'~AL-~.'4 Add "SO" after "STO." ~ I A T I O N : Type SJ cord is a Junior Hard Service Cord per Table 400-4 of the NEC and Is equivalent to SJO, SJT, SJTO and there is no technical Justification for its exclusion. I believe that i t was the intent of C~-10 that i t be included and its exclusion was inadvertent. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-8(d)(I): Reject CMP 10 SUBMITTER: H. B. Love/B. L. Auger, Michigan Chapter, IAEI

5 Revise to read: -----~Resident ia l food waste disposers'. All such equipment and controls in dwelling type occupancies shall be provided with an independent disconnecting means within sight of the equipment and i t shall be readily accessible. Food waste disposers of one-half horse-power or less shall be wired only with heavy duty 3-wire minimum No. 16 hard service cord and approved cap and three wire "U" slot grounding type receptacles. On new construction, a disconnect switch shall be mounted in the wall adjacent to the sink. SUBSTANTIATION: To assure the unit is always grounded we propose the above. Our experience shows space under the sink is usually used for storage resulting in damage to the connections of any other wiring methods. Now electrical personnel servicing these units often do not restore wiring to i t ' s original condition. The switch provides safety should a foreign object fa l l into the appliance. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's Intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-8(d)(2): Accept CMP 10 SUBMITTER: S. Mazzoni, Underwriters Laboratories Inc.

I ~ 6 Add "SJ" after "STO." ~O~-ST~N-TIATION: Type SJ cord is a Junior Hard Service Cord per Tab.le 400-4 of the NEC and is equivalent to SJO, SiT, SOTO and there is no technical Justification for Its exclusion. I believe that ~t was the intent of CMP 10 that i t be included and its exclusion was inadvertent. PANEL RECOI~4ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-14(a), Exception: Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose PR--R~-~O'~-~.7 See the Technical Subcommittee "Recommendations" un--h-'d-6F-~ITe definition of "Approved for the Purpose" in Article 100. ~ SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article I00. PANEL RECOMMENDATION: Accept as Revised:

Exception: Water heaters with supply water temperature of 180°F or above and a capacity of 60 kW or above and identified as being suitable for this use; and water heaters with a capacity of one gallon or less and identified as being suitable for such use. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-14(b): Accept CMP 10 SUBMITTER: CMP 2

7A Revise (b) as follows: ~ o r a g e - t y p e Water Heaters. All fixed storage-type water heaters having a capacity of 120 gallons or less shall have a branch-circuit rating not less than 125 percent of the nameplate rating of the water heater.

Delete the fine print note. SUBSTANTIATION: For clarif ication of intent. PANEL RECOMMENDATION: Accept the (b) portion of the proposal. PANEL COMMENT: CMP feels the fine print note is necessary and should be retained. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-15(a): Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose

8 See the Technical Subcommittee "Recommendatiens" un--n-d-er--t~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the phrase "approved for the purpose" and replace with "identified as suitable for use with infrared heating lamps rated 300 watts or less. VOTE ON PANEL RECOI~ENDATION: Unanimously Affirmative.

422-15(b), Exception: Accept CMP 10 • SUBMITTER: TSC-Approved for the Purpose

g See the Technical Subcommittee "Recommendations ~ under t--~e deflnlt$on of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Exception: Lampholders identified as suitable for use with infrared heating lamps rated more than 300 watts. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-16: Reject CMP 10 SUBMITTER: G. A. Wintz, Southern California Chapter IAEI !~TOI~-O-S'AL-~. 10 Delete the f i r s t paragraph and replace with:

provisions of Article 250 apply to the grounding of appliances. SUBSTANTIATION: The present wording "Metal frames of electrically heated appliances operating on circuits over 150 volts to ground, shall be grounded in the manner specified in Article 250" is misleading as the requirements of Section 250-42 are more stringent than those of Section 422-16.

The provisions of Section 90-3 do not provide means whereby requirements of Articles 250 and 422 can differ. The proposal is intended to eliminate thls inconsistency. PANEL RECOI~ENDATION: Reject. PANEL CO¥1~ENT: CMP agrees with the intent of the Proposal. See action on Proposal No. IOA, Section 422-16. VOTE ON PANEL RECOI~ENOATION: Unanimously Affirmative.


Co~=~ittee that the Panel correlate with Panel S's Proposal No. 53 on Section 250-60. SUBMITTER: ~ 10 PROPOSAL: IOA Revise as follows:

Grounding. All exposed metal parts of appliances likely to become energized shall be grounded as required in Article 250. J (FPN) See Sections 250-42~ 250-43 and 250-45 for equipment grounding' of refrigerators and freezers and Sections 250-57 and 250-60 for equipment grounding of electric ranges, wall-mounted ovens, counter-mounted cooking units, and clothes dryers. SUBSTANTIATION: ~ 5 is to be advised of this proposal and requested to delete from Section 250-2 "Appliances Section 422-16" and delete Exception No. 2 toSectlon 250-45(b).

178

PANEL RECOMMENDATION: Accept as revised. 422-15. Grounding. Appliances required by Article 250 to be grounded shall have exposed noncurrent-carrying metal parts

~ rounded in the manner specified in Article 250. FPN) See Sections 250-42, 250-43 and 250-45 for equipment

grounding of refrigerators and freezers and Sections 250-57 and 250-60 for equipment grounding of electric ranges, wall-mounted ovens, counter-mounted cooking units, and clothes dryers. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-16: Reject CMP 10 SUBMITTER: International Association of Electrical Inspectors

11 Revise the f i r s t paragraph as follows: Grounding. The provisions of Article 250 apply to the

grounding of appliances. (No change In the Exception and the remainder of the Section)

SUBSTANTIATION: The present wording "Metal frames of electrically heated appliances operating on circuits over 150 volts to ground, shall be grounded in the manner specified in Article 250" is misleading as the requirements of Section 250-42 are more stringent than those of Section 422-16.

The provisions of Section 90-3 do not provide means whereby requirements of Articles 250 and 422 can dif fer. The proposal is intended to eliminate, this inconsistency. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal. See action on Proposal No. IOA. VOTE ON PANEL RECOI~(ENDATION:, Unanimously Affirmative.

PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-27(a): Accept CMP 10 SUBMITTER: Idaho Chapter, IAEI

15 Reword 422-27(a) to include (f) which would then

(a) Appliances shall be considered as protected against overcurrent i f supplied by branch circuits as specified in (e) and (f) below and in Sections 422-5 and 422-6. SUBSTANTIATION: No direct reference is made to requirements for overcurrent protection of water heaters of larger types. By including Part (f) in this section, specific requirements wil l be prescribed. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Jordan.

EXPLANATION OF VOTE: JORDAN: Section-422-27(2) gives requirements for protection

of branch circuits. The (3) references given - "(e), 422-5 and 422-6" - are all requirements for branch circuit protection and not supplementary protection. There is enough confusion in the industry as i t is, concerning the difference between "branch-circuit protection" and supplementary protection." Let's not promulgate the confusion.

422-21(c)-(New): Reject CMP 10 SUBMITTER: H. B. Love/B. L. Auger, Michigan Chapter, IAEI lPITOITO-~XL-T." 12 Add (c) as follows:

T~ Space Heating Equipment (other than electric heat). (1) A readily accessible disconnect switch shall be mounted

on the exterior of the heating equipment or on a surface adjacent to the heating equipment.

(2) Heating equipment which is not readily accessible shall have an additional disconnect installed at the nearest readily accessible location. SUBSTANTIATION: Providing for safety in servicing of the unit, a disconnect shall be located at the unit. Providing for safety of the person using the unit, a disconnect means shall be provided which is readily accessible in the event of f i rmer explosion. PANEL REC~ENDATION: Reject. PANEL COMMENT: The supporting comment does not just i fy the proposed change. Xhe present wording adequately reflects the Panel's intent. See Sections 422-20, 422-21(b), and 422-26. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Riley.

EXPLANATION OF VOTE: RILEY: The International Association of Electrical Inspectors

views this'proposal solely on the merit of: "Personnel Protection" and for no other reason(s).

422-27(f), Exception No. 2 b.: Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose

16 See the Technical Subcommittee "Recommendations" un--n-a'e~-t-~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

b. Elements are completely contained within an enclosure identified as suitable for this use, or . . . . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 424 -- FIXED ELECTRIC SPACE HEATING EQUIPMENT


17 See the Technical Subcommittee "Recommendations" the definition of "Approved for the Purpose" in Article

100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:


422-22(c): Reject CMP 10 SUBMITTER: O. E. Dillon, Border County Div. IAEI

13 Add the words "fastened in place and" after the ~ p l l a n c e . " SUBSTANTIATION: This section is practically unenforceable as t-!~ere is no method of determining the rating of a portable ' appliance which may sometime in the future be plugged into a receptacle. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not just i fy the proposed change. The present wording adequately reflects the Panel',s intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-27: Reject CMP 10 SUBMITTER: C. E. Muhleman, Marion, IN PROPO~ 14 Revise as follows:

Overcurrent Protection. Each appliance of less than 15 amperes load and each cord connected appliance shall have overcurrent protection built into the appliance or its cord cap. Appliances having loads equal to or more than 15 amperes are not connected by cord, may be protected by an overcurrent device in a dedicated branch circuit. These overcurrent devices shall not exceed 150 percefit of the appliance load. The requiraments in (a) thru (d)below, shall apply.

Delete present Ca) and (e). Reidentify remaining paragraphs (b), (c), (d) and ( f ) . SUBSTANTIATION: This prevents small faults from not being detected by a large overcurrent device and will reduce fires and damage to appliances. PANEL RECOMMENDATION: Reject.

179

424-2: Accept CMP 10 SUBMITTER! Claude E. Deering, Jr., American Petroleum Institute PROPOSAL: 18 Add the word "classified" in parenthesis after

"hazardous." SUBSTANTIATION: I t is proposed that the word "classified", in parenthesis, be inserted after the word "hazardous." This is consistent with Article 500, which is entitled "Hazardous (Classified) Locations." The proposed wording recognizes that a location is not hazardous per se, but is classified depending on the properties of the flammable or combustible substance which may be present, and the likelihood that a flammable or combustible concentration or quantity wil l be present. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-3(b)(HOD 1978 NEC): Accept CMP 10 SUBMITTER: International Association of Electrical Inspectors

19 Amend Section 424-3(b), Paragraph 1, Sentence 1, to re--6~-6F:

(b) Branch-Circuit Sizing. The size of branch-circuit conductors and overcurrent protective devices supplying fixed electric space heating equipment consisting of resistance elements with or without a motor shall be computed on the basis of 125-150 percent of the total load of the motors and the heaters. SUBSTANTIATION: I t should be recognized that 125 percent is exacting and practically impossible to obtain. Guide lines were originally provided in Section 210-20(b) of the 1971NEC. However, this was deleted in the 1975 NEC. Under our present requirement, Judgement could rule to pick something less than 125 percent but close to i t and no one can define "close." Anything less than 125 percent may cause nuisance tripping. "125-150 percent"Lwill provide the guide lines that are needed. PANEL RECOMMENDATION: Accept as Revised:

(b) Branch-Circuit Sizing. The ampacity of the branch-circuit

PANEL RECOMMENDATION: Accept as revised. 422-15. Grounding. Appliances required by Article 250 to be grounded shall have exposed noncurrent-carrying metal parts

~ rounded in the manner specified in Article 250. FPN) See Sections 250-42, 250-43 and 250-45 for equipment

grounding of refrigerators and freezers and Sections 250-57 and 250-60 for equipment grounding of electric ranges, wall-mounted ovens, counter-mounted cooking units, and clothes dryers. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-16: Reject CMP 10 SUBMITTER: International Association of Electrical Inspectors

11 Revise the f i r s t paragraph as follows: Grounding. The provisions of Article 250 apply to the

grounding of appliances. (No change In the Exception and the remainder of the Section)

SUBSTANTIATION: The present wording "Metal frames of electrically heated appliances operating on circuits over 150 volts to ground, shall be grounded in the manner specified in Article 250" is misleading as the requirements of Section 250-42 are more stringent than those of Section 422-16.

The provisions of Section 90-3 do not provide means whereby requirements of Articles 250 and 422 can dif fer. The proposal is intended to eliminate, this inconsistency. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal. See action on Proposal No. IOA. VOTE ON PANEL RECOI~(ENDATION:, Unanimously Affirmative.

PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-27(a): Accept CMP 10 SUBMITTER: Idaho Chapter, IAEI

15 Reword 422-27(a) to include (f) which would then

(a) Appliances shall be considered as protected against overcurrent i f supplied by branch circuits as specified in (e) and (f) below and in Sections 422-5 and 422-6. SUBSTANTIATION: No direct reference is made to requirements for overcurrent protection of water heaters of larger types. By including Part (f) in this section, specific requirements wil l be prescribed. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Jordan.

EXPLANATION OF VOTE: JORDAN: Section-422-27(2) gives requirements for protection

of branch circuits. The (3) references given - "(e), 422-5 and 422-6" - are all requirements for branch circuit protection and not supplementary protection. There is enough confusion in the industry as i t is, concerning the difference between "branch-circuit protection" and supplementary protection." Let's not promulgate the confusion.

422-21(c)-(New): Reject CMP 10 SUBMITTER: H. B. Love/B. L. Auger, Michigan Chapter, IAEI lPITOITO-~XL-T." 12 Add (c) as follows:

T~ Space Heating Equipment (other than electric heat). (1) A readily accessible disconnect switch shall be mounted

on the exterior of the heating equipment or on a surface adjacent to the heating equipment.

(2) Heating equipment which is not readily accessible shall have an additional disconnect installed at the nearest readily accessible location. SUBSTANTIATION: Providing for safety in servicing of the unit, a disconnect shall be located at the unit. Providing for safety of the person using the unit, a disconnect means shall be provided which is readily accessible in the event of f i rmer explosion. PANEL REC~ENDATION: Reject. PANEL COMMENT: The supporting comment does not just i fy the proposed change. Xhe present wording adequately reflects the Panel's intent. See Sections 422-20, 422-21(b), and 422-26. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Riley.

EXPLANATION OF VOTE: RILEY: The International Association of Electrical Inspectors

views this'proposal solely on the merit of: "Personnel Protection" and for no other reason(s).

422-27(f), Exception No. 2 b.: Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose

16 See the Technical Subcommittee "Recommendations" un--n-a'e~-t-~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

b. Elements are completely contained within an enclosure identified as suitable for this use, or . . . . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 424 -- FIXED ELECTRIC SPACE HEATING EQUIPMENT


17 See the Technical Subcommittee "Recommendations" the definition of "Approved for the Purpose" in Article

100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:


422-22(c): Reject CMP 10 SUBMITTER: O. E. Dillon, Border County Div. IAEI

13 Add the words "fastened in place and" after the ~ p l l a n c e . " SUBSTANTIATION: This section is practically unenforceable as t-!~ere is no method of determining the rating of a portable ' appliance which may sometime in the future be plugged into a receptacle. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not just i fy the proposed change. The present wording adequately reflects the Panel',s intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

422-27: Reject CMP 10 SUBMITTER: C. E. Muhleman, Marion, IN PROPO~ 14 Revise as follows:

Overcurrent Protection. Each appliance of less than 15 amperes load and each cord connected appliance shall have overcurrent protection built into the appliance or its cord cap. Appliances having loads equal to or more than 15 amperes are not connected by cord, may be protected by an overcurrent device in a dedicated branch circuit. These overcurrent devices shall not exceed 150 percefit of the appliance load. The requiraments in (a) thru (d)below, shall apply.

Delete present Ca) and (e). Reidentify remaining paragraphs (b), (c), (d) and ( f ) . SUBSTANTIATION: This prevents small faults from not being detected by a large overcurrent device and will reduce fires and damage to appliances. PANEL RECOMMENDATION: Reject.

179

424-2: Accept CMP 10 SUBMITTER! Claude E. Deering, Jr., American Petroleum Institute PROPOSAL: 18 Add the word "classified" in parenthesis after

"hazardous." SUBSTANTIATION: I t is proposed that the word "classified", in parenthesis, be inserted after the word "hazardous." This is consistent with Article 500, which is entitled "Hazardous (Classified) Locations." The proposed wording recognizes that a location is not hazardous per se, but is classified depending on the properties of the flammable or combustible substance which may be present, and the likelihood that a flammable or combustible concentration or quantity wil l be present. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-3(b)(HOD 1978 NEC): Accept CMP 10 SUBMITTER: International Association of Electrical Inspectors

19 Amend Section 424-3(b), Paragraph 1, Sentence 1, to re--6~-6F:

(b) Branch-Circuit Sizing. The size of branch-circuit conductors and overcurrent protective devices supplying fixed electric space heating equipment consisting of resistance elements with or without a motor shall be computed on the basis of 125-150 percent of the total load of the motors and the heaters. SUBSTANTIATION: I t should be recognized that 125 percent is exacting and practically impossible to obtain. Guide lines were originally provided in Section 210-20(b) of the 1971NEC. However, this was deleted in the 1975 NEC. Under our present requirement, Judgement could rule to pick something less than 125 percent but close to i t and no one can define "close." Anything less than 125 percent may cause nuisance tripping. "125-150 percent"Lwill provide the guide lines that are needed. PANEL RECOMMENDATION: Accept as Revised:

(b) Branch-Circuit Sizing. The ampacity of the branch-circuit

conductors and the rating or setting of overcurrent protective devices supplying fixed electric space heating equipment consisting of resistance elements with or without a motor shall not be less than 125 percent of the total load of the motors and the heaters. The rating or setting of overcurrent protective devices shall be permitted in accordance with Section 240-3, Exception No. i . PANEL COMMENT: Reaffirm CMP 10 action for Proposal No. 30 (1978 Preprint) for the f i r s t sentence of the f i r s t paragraph of Section 424-3(b). VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Erickson.

EXPLANATION OF VOTE: ERICKSON: Section 330-15 is specific on "maximum continuous

capacities" for conductors. For thls Panel to add a derating factor of 80% is an unnecessary economic penalty. In some instances the branch-circuitprotective device is required to be derated because of other sections of the Code, and this will have some effect on conductor sizing, but that should not lead us to make an across-the-board derating of conductors.

I can support this proposal i f i t is revised to read: (b) Branch Circuit-Sizing. The ampacity of the branch-circuit

conductors supplying fixed electric space heating equipment consisting of resistance elements and one or more motors shall be in accordance with Section 210-22(a). The ampacity of the branch-circuit conductors supplying fixed electric space heating equipment consisting of resistance elements only shall be in accordance with Section 310-15. The rating or setting of overcurrent protective devices shall be in accordance with Section 200-3, Exception No. i and Section 210-22(c) where applicable.

The wire manufacturers do not have a standard production of 2/0 and 3/0 cable required for the 30 kW and 35 kW and larger space heaters. Most of the contractors have to special order this material. The NEC should, as always, give the industry the method for a

safe installation for the protection of the public, but let our inspectors in charge determine the method. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-19(a)(2)c.: Reject CMP 10 SUBMITTER: Robert G.' MacManus, Pawtucket, RI

22 Add a sentence as follows: Where more than one controller is used to control one or

motors, as in the case of a thermostat, aquastat, summer-winter switch or time switch, a single disconnecting means shall be provided that will open the circuit to all controllers and also be capable of being locked in the open position i f not in sight from the controller locations. SUBSTANTIATION: Any of the above controllers may be the motor controller at a given time and i t would be impractical to install a disconnecting means in sight from each. A single lockable switch would prevent a hazard which now exists. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-14: Accept CMP 10 SUBMITTER: O. E. Dillon, Border County Div. IAEI

20 Delete the phrase " l ike ly to become energized." ~ I A T I O N : The use of the words " l ike ly to become energized" renders this section unenforceable. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for CMP I Proposal No. 90 for 110-16(a). PANEL RECOMMENDATION: Accept as Revised. 424-14. Grounding. All exposed "noncurrent-carrying" metal parts of fixed electric space heating equipment l ikely to become energized shall be grounded as required in Article 250. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-19: Reject CMP 10 SUBMITTER: T.H. Halton, Jr., Fort Worth, TX

21 Revise as follows: Disconnecting Means. Means shall be provided to

disconnect all fixed electric space heating equipment from all ungrounded conductors. Where heating equipment is supplied on more than one source, the disconnecting means shall be grouped and identified.

(a) For fixed electric space heating equipment rated at not overdO0 vo!t-amperes or 1/8 horsepower, the branch-circuit overcurrent device may serve as the disconnecting means.

(b) For fixed electric space heating equipment of greater rating, the branch-circuit switch or circuit breaker may, where readily accessible to the user of the equipment, serve as the disconnecting means.

(c) Motor Driven Heating Equipment. A switch or circuit breaker that serves as the disconnecting means for a motor-driven heater having a motor more than I/8 horsepower shall be located within sight of the motor controller.

(d) Unit Switches as'Disconnecting Means. Unit switches with a marked "Off" position, which are part of a fixed heater, that disconnect all ungrounded conductors may be used as the disconnecting means required by the Article when other means for disconnection are provided in the following types of occupancies:

(i) Multifamily Dwellings. In multifamily (mo~e than two) dwellings, the other disconnecting means shall be within the apartment, or on the same floor as the apartment in which the fixed heater is installed, and may also control lamps and appliances.

(2) Two-Family Dwellings. In two-family dwellings, the other disconnecting means may be located either inside or outside of the apartment in which the fixed heater is installed.

(3) Single-Family Dwellings. In single-family dwellings, the service disconnecting means may be the other disconnecting means.

(4) Other Occupancies. In other occupancies, the branch-circuit switch or circuit breaker, where readily accessible to the user of the fixed heater, may be used for the other disconnecting means. SUBSTANTIATION: The members of Code Making Panel No. 10 have been working on this Section for some time, however this is an example of trying to write a Code Section on how to install electrical work. The Code has always been a performance Code, not technical.

This proposal shall let the area inspector determine how to install electrical space heating. The u t i l i t y companies are not trying to require the methods for an installation of space heat now as they have in the past.

424-22(a) Exception-(New)(HOD 1978 NEC): CMP 10 Reject SUBMITTER: J.A. Pietsch, General Electric Company

PROPOSAL: 23 Add exception to Section 424-22(a) as follows: ~ i o n : Where the branch-circuit, short-circuit and ground-fault protector is rated 60 amps or less and 250 volts 6r less, either fuses or inverse time-type circuit breakers maybe installed unless otherwise-limited by marking on the equipment nameplate. SUBSTANTIATION: The intent of this proposal and a related proposal to change Section 440-22(b) is to permit the use of inverse time-type circuit breakers where appropriate on fixed Heating, Air Conditioning and Refrigeration Equipment branch circuits.

Successful results with specific equipments approved as individual types or models for circuit breaker branch-circuit protection have shown that such devices do not constitute a safety hazard. And, the circuit breakers permit improved protection to power ut i l izat ion equipment by disconnecting "a l l " ungrounded supply conductors s!multaneously. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal see action on Proposal No. 24, Section 424-22(a). VOTE ON PANEL RECOMa4ENDATION: Unanimously Affirmative. COMMENT ON VOTE:

JORDAN: My vote is to reject, as is the Panel's vote, but not for the same reason. See Proposal No. 24.

424-22(a), Exception-(New): Accept CMP 10 Secretary's Note: I t was the action of the Correlating

Committee that this Proposal should be clarif ied as not applying to motor operated equipment. Otherwise i t is the responsibility of Panel 11. SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.

24 Add Exception as follows: ~ i o n : Where the branch-circuit, short-circuit and ground-fault protection is rated 60 amps or less and 250 volts or less, and where the available fault current is 5000 amps or less, either fuses or inverse tlme-type c i rcu i t breakers may be installed unless otherwise limited by marking on the equipment nameplate. SUBSTANTIATION: The intent of this proposal and a related proposal to change 440-22(b) is to permit the use of inverse-time type circuit breakers where appropriate on fixed heating, air conditioning and refrigeration equipment branch circuits.

A UL Fact-Finding Report dated November 1, 1976 was conducted to investigate the sui tabi l i ty of inverse-time circuit breakers for these applications.

Unfortunately, close timing between issuance of the Report and the final vote by the panel le f t l i t t l e time for thorough study for the 1978 Code.

A careful review indicates that circuit breakers were total ly acceptable in 97% of the 387 tests summarized in the report. The remaining tests had minor discrepancies.

A f ie ld survey included in the report indicates that over 50% of the defined units installed since 1971 are in fact protected by circuit breakers with no f ie ld problems. PANEL RECOMMENDATION: Accept as Revised:

Delete the word "may" and replace with "shall be permitted to."

180

VOTE ON PANEL RECOMMENDATION: AFFIRMATIVE: 8. NEGATIVE: Casella, Hoeck, Jordan.

EXPLANATION OF VOTE: CASELLA: This proposal would be acceptable i f the wording

"identif ied for group installation" were inserted after the present wording "inverse time type circuit breakers."

HOOCK: I have voted negative on this same Proposal and other similar proposals in the past and feel that this issue should not be asked to be resolved by CMP 10. I believe this is a design problem and should be resolved between the testing agency and equipment manufacturers.

JORDAN: Much rhetoric has been written on this subject, so I shall endeavor to confine my remarks to the bare minimum. This proposal is not new having been f i r s t made in a similar proposal by the same proposer for the 1968 NEC. As I see this proposal, there is intent to circumvent the present Code requirements (namely-Section 430-53(c)(3)) which would allow circuit breakers for the proposed application, should these devices be "approved" for group installation. The NEC is not a testing agency and should not validate product safety or mandate acceptance of a product that has not been able to gain testing lab cert i f ication. I t is my opinion that a nationally recognized testing lab should cert i fy that this application is proper and safe and l i s t and/label said equipment when submitted by the manufacturer. The mechanics are already in the NEC. Why legislate performance by the NEC?

424-22(b) and (c): Accept CMP '10 SUBMIITER: D. C. Rockholm, Underwriters Laboratories Inc. / PROPOSAL: 25 Revise as follows: ~ e s i s t a n c e Elements. Resistance-type heating elements in electric space heating equipment shall be protected at not more than 60 amperes. Equipment employing such elements rated more than 48 amperes shall have the heating elements subdivided, and each subdivided load shall not exceed 48 amperes.

Exception: As provided in Section 424-72(a). (c) Overcurrent Protective Devices. The supplementary

overcurrent protective devices for the subdivided loads specified . . . . SUBSTANTIATION: The present wording of Section 424-22(b) does not place any l imit on the size of overcurrent protecti6n of electric space heating equipment rated 48 amperes or less. I do not believe i t was ever intended to allow such equipment to be protected with a larger size overcurrent protective device than permitted for an identical subdivided load of a large heater. The proposed rewording in Section 424-22(b) would correct ~his apparent oversight but would also require the addition of the words "for the subdivided loads" to 'Section 424-22(c) to define the overcurrent protective devices referenced in this Section. PANEL RECOMMENDATION: Accept as Revised.

Add a paragraph to the end of (b) as follows: Where a subdivided load is less than 48 amperes, the rating of

the overcurrent protective device shall comply with Section 424-3(b). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

clearly. I personally believe that our Code should mainly staj, on the performance side. This change back to the original Code wi l l enable the Inspectors to perform their duties on a more equal and safer installation. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not Justify the proposed change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-22(e): Accept CMP 10 SUBMITTER: D. C. Rockholm, Underwriters Laboratories Inc.

27 Revise as follows: ~ o n d u c t o r s For Subdivided Loads. Field wired conductors between the heater and the supplementary overcurrent devices shall have the same ampacity as required for branch-circuit conductors in accordance with Section 424-3(b) based on the connected load. The supplementary overcurrent protective devices specified in (c) above shall protect these conductors in accordance with Section 240-3. SUBSTANTIATION: The present wording of Section 424-22(e) apparently rules out the use of Exception No. I to Section 240-3, which I do not believe was intended. Furthermore, the Exception to 424-22(e) was apparently based on the Exception to 424-22(d). I t is my understanding that the basis for the exception to 424-22(d) is that on large heaters having individually controlled subdivided loads i t is unlikely that all of these individual loads wil l be energized simultaneously for extended periods of time and therefore the conductors supplying the supplementary overcurrent protective devices would not be carrying the total heater current for extended periods. However, this logic is not applicable to the subdivided loads where i t is quite common for one or more such loads to be energized continuously in large heater (50 Kw or more). PANEL RECOMMENDATION: Accept as Revised:

(el Conductors For Subdivided Loads. Field-wired conductors between the heater and the supplementary overcurrent protective devices shall be sized at not less than 125 percent of the load servedt The supplementary overcurrent protective devices specified in (c) shall protect these conductors in accordance with Section 240-3. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 9. NEC~TIVE: Erickson.

EXPLANATION OF VOTE: ERICKSON: We are sizing conductors in this section and they

do not have to be derated for continuous duty in accordance with Section 310-15. To continually oversize conductors is an unnecessary economic penalty. See comments on Proposal No. 19.

I can support this proposal i f i t is reworded to ~ead: (el Conductors for Subdivided Loads. Field wired conductors

between the heating elements and supplementary overcurrent protective devices shall be sized in accordance with Section 310-15 and shall be protected by the supplementary overcurrent protective devices in accordance with Section 240-3, Exception No. 1.

424-22(c): Reject CMP 10 SUBMITTER: T.H. Halton, Jr.

26 Wording to be deleted. ~ d e d Text: Delete paragraph (c) Overcurrent PrOtection Devices.

i

SUBSTANTIATION: This is a cempanion proposal to c lar i fy the recommendation for the proposal on 424-19.

In the Tarrant County area of Texas we have had complaints by the homeowner trying to replace the fuses and of being shocked. All of their cemplaints were checked and all units were wired according to N.E.C. including the marking on the units with notices to disconnect unit before removing any doors.

The homeowner tries to replace these fuses because he has called in the repairman to f i x his furnace and the repairman does not always disconnect the unit, he will pull the fuses and check them. I f he finds one blown he replaces said fuse and sends a b i l l for or collects for the call. The next time the unit quits, the homeowner goes by the nearest store and wil l purchase enough fuses to replace all fuses in furnace. He attempts to put in new fuses and not being equipped, nor knowing what he is doing, wil l be shocked. The public wil l t ry to do anything to save money. The fuses in the units are a hazard to the public and service men.

The proposed change in Article 424-19 wil l enable the electrical inspector to have installed a sub-panel in the heater closet and connect the electric furnace from that panel.

The heating unit manufacturers are making their units over 20 kW with one feed and two feed connections. This creates a problem for the instal ler. He installs for two feeds and on the f inal finds a one feed. The larger units requiring 30 kW and 35 kW feeds create problems with the 2/0 and 3/o cable as no manufacturer of cable has a standard production of this size cable.

This Section of the N.E.C. as i t is presently in the Code, is another example of writing a technical Code. No reflection on our wonderful Code Panels, they work so hard to write the Code

424-34, Exception-(New): Accept CMP 10 SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn.

28 Add an exception as follows: -~-eption: Panels approved for the purpose shall be permitted

with shorter leads. SUBSTANTIATION: The present wording does not allow for the installation of heating panels approved for the purpose using wiring systems other than 7 foot nonheating leads. The addition of this exception will correct this. PANEL RECOMMENDATION: Accept as Revised:

Exception: Heating panels identified for direct f ie ld connections to the nonheating leads using junction assemblies. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-35 (a): Accept CMP SUBMITTER: TSC-Nominal Voltage PROPOSAL: 29 The second sentence should be revised to read:

wire shall have the following color identification to indicate the circuit voltage on which i t is to be used, etc. SUBSTANTIATION: To conform to the method to express circuit voltage as per guidelines developed by the TSC on nominal voltage. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

10

424-41(e): Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose

30 See the Technical Subcommittee "Recommendations" under the definiton of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100.

181

PANEL RECOMMENDATION: Accept as Revised: Delete the phrase "approved for the purpose" and replace with

"identified as suitable for this use." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-41(f), Exception: Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose

31 See the Technical Subcommittee "Recommendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Exception: Cables identified to be secured at intervals not to exceed 6 feet. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-44(e): Accept CMP 10 SUBMITTER: H.F. van der Voort, Cleveland, OH ]~TOI~'AI~T.. 32 Add "rigid nonmetallic conduit" after ~ d i a t e metal conduit" and "electrical metallic tubing." SUBSTANTIATION: The rigid nonmetallic conduit for this application is Schedule 40 PVC and has excellent mechanical strength; both crush and impact. This strength is equivalent to that of EMT and the proposed wording indicates this. Unless severe physical damage is imminent, protection of the conduit is unnecessary. Carlon tested both Schedule 40 and EMT in its own research faci l i t ies to demonstrate this. The test methods are those calIed for in UL651. The test results are shown on the following table.

I~ACT RESISTANCE MEAS~EMENTS ON PVC SCHEDULE 40 CONDUIT & EbECTRICAL METALLIC TUBING

Percent Decrease in Inside Diameter

DIAMETER @VC SCHEDULE 40 EMT Inches Min. Max. Min. Max.

1/2 4.7 7.2 18.2 25.1 3/4 4.9 6.9 22.6 25.9 1 5.5 5.7 30.0 32.9 I-1/4 4.6 4.8 26.6 27.8 1-1/2 4.7 5.5 43.6 45.1 2 2.1 2.8 55.1 56.6 3 2.5 3.0 53.6 56.0 4 2.0 2.0 45.1 46.6

Crushload in Pounds to Achieve

30% Deflection

DIAMETER PVC SCHEDULE 40 EMT Inches Min. Max. Min. Max.

1/2 2265 2345 2565 2800 3/4 1878 1910 2100 2160 I 1876 2010 2250 2365 1-I/4 1494 1580 2750 2950 1-1/2 1880 1892 1730 1764 2 1208 1276 1280 1296 3 1676 1688 ,880 957 4 1280 1570 785 798

PANEL RECOMMENDATION: 'Accept. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: ERICKSOH: No co~Inent received.


33 See the Technical Subcommittee "Recommendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100.

i PANEL RECOMMENDATION: Accept as Revised: 424-58. Identification. Heaters installed in an air duct shall be identified as suitable for the installation. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-60: Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose PROPOSAL: 34 See the Technical Subcommittee "Recommendations" un--6-d-e-r-~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

Delete the words "approved for the purpose and so marked" and replace with "identified as suitable for use at the elevated temperatures."

Delete the paranthetical phrase "(such as heat pumps)." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmatfve.

424-65: Reject CMP 10 SUBMITTER: R. S. Pinkerton, Los Angeles, CA

35 Add the word "safely" before the word "accessible." SUBSTANTIATION: Duct heater controllers are being installed in locations which have the proper workspace but are impossible to "reach for routine maintenance without subjecting the workman to serious risks of tripping and fai l ing. The present Code requirements provide for a safe workspace about equipment but do not provide for a safe passageway to the workspace. PANEL RECOt~NIENDATION: Reject. PANEL COMMENT: The supporting comment does not just i fy the proposed change. The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-65: Reject CMP 10 SUBMITTER: Southwestern Section IAEI PROPOSAL: 36 Add the word "safely" in front of "accessible" to read: Duct heater controller equipment shall be safely accessible with the disconnecting means installed at or within, site from the controller. SUBSTANTIATION: Duct heater controllers are being installed in locations which have the proper workspace but are impossible to reach for routine maintenance without subjecting the workman to serious risks of tripping and fal l ing. The present Code requirements provide for a safe workspace about equipment but do not provide for a safe passageway to the workspace. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not just i fy the proposed change. The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-71: Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose ~ 3 7 See the Technical Subcommittee "Recommendations o - - ~ o v e d for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised: 424-71. Identification. Resistance-type boilers shall be identified as suitable for the installation. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-72(a), (b), and (c): Accept CMP 10 SUBMITTER: D. C. Rockholm, Underwriters Laboratories Inc. PI~-O]~'~-~." 38 Revise as follows: - - ~ boiler employing reslstance-type immersion heating elements contained in an ASME rated and stamped vessel shall have the heating elements protected at not more than 150 amperes. Such a boiler rated more than 120 amperes shall have the heating elements subdivided into loads not exceeding 120 amperes.

(b) A boiler employing resistance-type heating elements not contained in an ASME rated and stamped vessel, shall have the heating elements protected'at not more than 60 amperes. Such a boiler rated more than 48 amperes wil l have the heating'elements subdivided into loads not exceeding 48 amperes.

(c) The supplementary overcurrent protective devices for the subdivided loads as required by . . . . SUBSTANTIATION: The present wording of Section 424-72(b) does not place any l imit on the size of overcurrent protection of resistance type immersion heating elements in boilers rated 48 amperes or less when the elements are not contained in an ASME rated and stamped vessel. I do not believe i t was ever intended tO a11ow such elements to be protected with a larger size overcurrent protective device than permitted for an identical subdivided load of a larger boiler. The proposed rewording of 424-72(b) is intended to correct this apparent oversight. The proposed rewording to 424-72(a) is for clarif ication and consistency with 424-72(b). The proposed rewording in Section 424-72(a) and (b) would also require the addition of the words "for the subdivided loads" to Section 424-72(c) to define the overcurrent protective devices referenced in this section.

182

PANEL RECOI~ENDATION: Accept as Revised: In the second sentence of (b) change ~will" to "sh~ll." And,

also add a paragraph to (a) as follows: Where a subdivided load is less than 120 amperes, the rating

of the overcurrent protective device shall comply with Section 424-3(b).

Add a paragraph to (b) as follows: Where a subdivided Ibad is less than 48 amperes, the rating of


424-72(e): Accept CMP 10 SUBMITTER: D. C. Rockholm, Underwriters Laboratories Inc. ]~TOPO~'7~-~. 39 Revise as follows: ~ o n d u c t o r s for Subdivided Loads. Field-wired conductors between the heater and the supplementary overcurrent devices shall have the same ampacity as required for branch-circuit conductors in accordance with Section 424-3(b) based on the connected load. The supplementary overcurrent protective devices specified in (c ) above shall protect these conductors in accordance with Section 240-3. SUBSTANTIATION: The present wording of Section 424-72(e) apparently rules out the use of Exception No. 1 to Section 240-3, which I do not believe was intended. Furthermore the Exception to 424-72(e) was apparently based on the Exception to 424-72(d). I t is my understanding that the basis for the exception to 424-72(d) is that on large heaters having individually controlled subdivided loads i t is unlikely that all of these individual loads wil l be energized simultaneously for extended periods of tlme and therefore the conductors supplying the supplementary overcurrent protective devices would not be carrying the total heater current for extended periods. However, this logic is not applicable to the subdivided loads where i t is quite common for one or more such loads to be energized continuously in a large heater (50 Kw or more). PANEL RECOMMENDATION: Accept as Revised:

(e) Conductors for Subdivided Loads. Field-wired conductors between the heater and the supplementary overcurrent protective devices shall be sized at not less than 125 percent of the load served. The supplementary overcurrent protective devices , specified in (c) shall protect these conductors in accordance with Section 240-3. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: ERICKSON: No comment received.

424-80: Accept CMP 10 SUBMITTER: TSC-Nominal Voltage ]I~-OPI~I~-L'~." 40 Add "nominal ~ after the word "volts" in second

SUBSTANTIATION: To conform to the method to express system voltage as developed by the TSC on nominal voltage. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-81: Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose PROPOSAL: 41 See the Technical SubCommittee "Recommendations" un-G~-a-e~'-]~e definition of "Approved for the l)urpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised: 424-81. Identification. Electrode-type boilers shall be identified as suitable for the installation. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-85: Accept CMP 10 SUBMI1-TER: Kenneth W. Cohen, Aerco International, Inc.

42 Revise as follows: ~ o s e boilers designed such that fault currents do not pass through the presssure vessel and the pressure vessel is electrically isolated from the electrodes, all exposed noncurrent carrying metal parts including the pressure vessel, supply and return connecting piping shall be grounded in accordance with Article 250.

For all other designs the pressure vessel containing the electrodes shall be-isolated and electrically insulated fr~n ground. SUBSTANTIATION: Aerco International, Inc. presently manufactures an electrode Hot Water Boiler that is U.L. listed (U.L. File #E-39417)

I have enclosed a pictoral representation of same. We believe the grounding requirement, Para. 424-85 of the 1978

NEC is designed to cover those boilers where fault currents can flow to neutral. However, the code '~oes not specifically address our design, where fault currents cannot flow to ground

183

through the pressure vessel shell. As indicated on the sketch, the halar coated heads and the

polysulfone shield act to form an electrically isolated chamber for the electrode assembly. The PPS bushing insulates the entire electrode assembly from the steel pressure vessel.

The electrically "hot u electrodes are isolated from the support shaft and rotating shaft by ceramic arms supported by polysulfone discs. The rotating shaft i f further isolated by encapsulation in teflon tubing. A top guard of perforated metal enclosing the exposed components prevents personnel from contacting any portion of the assembly. Since the electrode assenfoly is insulated from the inside of the tank, i t is not necessary to bring the neutral from the supply to the boiler. However, we do connect the electrode assembly structure to neutral to prevent any possible personnel hazard. The outer enclosure is locally grounded.

I t is understood that the Electrode Boiler has met the .S amp maximum ground current tests as specified by the Underwriters Laboratories, Inc. The proposed recommended text attempts to address the above problem. PANEL RECO~4ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 426 -- FIXED OUTDOOR ELECTRIC DE-ICING AND SNOW MELTING'EQUIPMENT

426-3 Exception-(New)(HOD 1978 NEC): Reject CMP 10 SUBMITTER: Pipeline Heating Systems, Inc., Brecksville, OH ~ 4 3 Add at end of paragraph: ~ i o n : Skin effect current tracing circuits. See Section 426-34. SUBSTANTIATION: Same as Proposal No. 57 to 1978 preprint. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with intent of proposal. See action on Proposal No. 46. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

"426-23: Reject CMP 10 SUBMITTER: TSC-Approved for the Purpose ~ 4 4 See the Technical Subcommittee "Recommendations" un-'n-de-~'-t-~e definition of "Approved for the purpose u in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved/for the Purpose" in Article 100. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See CMP action on Proposal No. 46.

• VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ERICKSON: I feel that Panel Comment should be changed to "CMP agrees with intent of Proposal." See action on Proposal No. 46.

426-23: Reject CMP SUBMITTER: Warren H. Cook, IEEE ~ 4 5 Revise f i r s t sentence to read: ~ s u p p l y nonheating leads (cold leads) for the electric beating elements shall be suitable for the temperature encountered. SUBSTANTIATION: Present wording allows for only factory assembled units. Currently approved equipment is available which util izes f ield fabrication on nonheatlng leads. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See action on Proposal No. 46. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ERICKSON: Same as for Proposal No. 44. '

10

426 Part O-(New)(HOD 1978 NEC): Accept CMP 10 Secretary's Note: I t was the action of the Correlating

Committee that further consideration be given to the comments expressed in the voting. SUBMITTER: Pipeline Heating Systems, Inc., Brecksville, OH

46 Add a new Part D to Article 426 as follows: D. Skin Effect Current Tracing

426-30. Scope. The provisions of Part D of thls article shall apply to fixed outdoor electric de-icing or snow melting equipment uti l izing a tubular resistive heating element of ferromagnetic material and having within the tubular element an electrically insulated return conductor so arranged that the skin effect of alternating current causes the main heating current to concentrate near the inner wall of the tubular element. 426-31. Insulating Rating.

(a) The electrical insulation of the inner conductor shall have a temperature rating greater than the operating temperature of the cable for the specific system based on the designs and tests of the manufacturer.

(b) The electrical insulation of the inner conductor shall have a voltage rating at any point on the system higher than the operating voltage at that point.

(c) The outer conductor (tubular element) shall not require electrical insulation provided its outer surface is effectively grounded at one or more locations. •

PANEL RECOI~ENDATION: Accept as Revised: In the second sentence of (b) change ~will" to "sh~ll." And,

also add a paragraph to (a) as follows: Where a subdivided load is less than 120 amperes, the rating

of the overcurrent protective device shall comply with Section 424-3(b).

Add a paragraph to (b) as follows: Where a subdivided Ibad is less than 48 amperes, the rating of


424-72(e): Accept CMP 10 SUBMITTER: D. C. Rockholm, Underwriters Laboratories Inc. ]~TOPO~'7~-~. 39 Revise as follows: ~ o n d u c t o r s for Subdivided Loads. Field-wired conductors between the heater and the supplementary overcurrent devices shall have the same ampacity as required for branch-circuit conductors in accordance with Section 424-3(b) based on the connected load. The supplementary overcurrent protective devices specified in (c ) above shall protect these conductors in accordance with Section 240-3. SUBSTANTIATION: The present wording of Section 424-72(e) apparently rules out the use of Exception No. 1 to Section 240-3, which I do not believe was intended. Furthermore the Exception to 424-72(e) was apparently based on the Exception to 424-72(d). I t is my understanding that the basis for the exception to 424-72(d) is that on large heaters having individually controlled subdivided loads i t is unlikely that all of these individual loads wil l be energized simultaneously for extended periods of tlme and therefore the conductors supplying the supplementary overcurrent protective devices would not be carrying the total heater current for extended periods. However, this logic is not applicable to the subdivided loads where i t is quite common for one or more such loads to be energized continuously in a large heater (50 Kw or more). PANEL RECOMMENDATION: Accept as Revised:

(e) Conductors for Subdivided Loads. Field-wired conductors between the heater and the supplementary overcurrent protective devices shall be sized at not less than 125 percent of the load served. The supplementary overcurrent protective devices , specified in (c) shall protect these conductors in accordance with Section 240-3. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: ERICKSON: No comment received.

424-80: Accept CMP 10 SUBMITTER: TSC-Nominal Voltage ]I~-OPI~I~-L'~." 40 Add "nominal ~ after the word "volts" in second

SUBSTANTIATION: To conform to the method to express system voltage as developed by the TSC on nominal voltage. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-81: Accept CMP 10 SUBMITTER: TSC-Approved for the Purpose PROPOSAL: 41 See the Technical SubCommittee "Recommendations" un-G~-a-e~'-]~e definition of "Approved for the l)urpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised: 424-81. Identification. Electrode-type boilers shall be identified as suitable for the installation. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

424-85: Accept CMP 10 SUBMI1-TER: Kenneth W. Cohen, Aerco International, Inc.

42 Revise as follows: ~ o s e boilers designed such that fault currents do not pass through the presssure vessel and the pressure vessel is electrically isolated from the electrodes, all exposed noncurrent carrying metal parts including the pressure vessel, supply and return connecting piping shall be grounded in accordance with Article 250.

For all other designs the pressure vessel containing the electrodes shall be-isolated and electrically insulated fr~n ground. SUBSTANTIATION: Aerco International, Inc. presently manufactures an electrode Hot Water Boiler that is U.L. listed (U.L. File #E-39417)

I have enclosed a pictoral representation of same. We believe the grounding requirement, Para. 424-85 of the 1978

NEC is designed to cover those boilers where fault currents can flow to neutral. However, the code '~oes not specifically address our design, where fault currents cannot flow to ground

183

through the pressure vessel shell. As indicated on the sketch, the halar coated heads and the

polysulfone shield act to form an electrically isolated chamber for the electrode assembly. The PPS bushing insulates the entire electrode assembly from the steel pressure vessel.

The electrically "hot u electrodes are isolated from the support shaft and rotating shaft by ceramic arms supported by polysulfone discs. The rotating shaft i f further isolated by encapsulation in teflon tubing. A top guard of perforated metal enclosing the exposed components prevents personnel from contacting any portion of the assembly. Since the electrode assenfoly is insulated from the inside of the tank, i t is not necessary to bring the neutral from the supply to the boiler. However, we do connect the electrode assembly structure to neutral to prevent any possible personnel hazard. The outer enclosure is locally grounded.

I t is understood that the Electrode Boiler has met the .S amp maximum ground current tests as specified by the Underwriters Laboratories, Inc. The proposed recommended text attempts to address the above problem. PANEL RECO~4ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 426 -- FIXED OUTDOOR ELECTRIC DE-ICING AND SNOW MELTING'EQUIPMENT

426-3 Exception-(New)(HOD 1978 NEC): Reject CMP 10 SUBMITTER: Pipeline Heating Systems, Inc., Brecksville, OH ~ 4 3 Add at end of paragraph: ~ i o n : Skin effect current tracing circuits. See Section 426-34. SUBSTANTIATION: Same as Proposal No. 57 to 1978 preprint. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with intent of proposal. See action on Proposal No. 46. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

"426-23: Reject CMP 10 SUBMITTER: TSC-Approved for the Purpose ~ 4 4 See the Technical Subcommittee "Recommendations" un-'n-de-~'-t-~e definition of "Approved for the purpose u in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved/for the Purpose" in Article 100. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See CMP action on Proposal No. 46.

• VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ERICKSON: I feel that Panel Comment should be changed to "CMP agrees with intent of Proposal." See action on Proposal No. 46.

426-23: Reject CMP SUBMITTER: Warren H. Cook, IEEE ~ 4 5 Revise f i r s t sentence to read: ~ s u p p l y nonheating leads (cold leads) for the electric beating elements shall be suitable for the temperature encountered. SUBSTANTIATION: Present wording allows for only factory assembled units. Currently approved equipment is available which util izes f ield fabrication on nonheatlng leads. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See action on Proposal No. 46. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ERICKSON: Same as for Proposal No. 44. '

10

426 Part O-(New)(HOD 1978 NEC): Accept CMP 10 Secretary's Note: I t was the action of the Correlating

Committee that further consideration be given to the comments expressed in the voting. SUBMITTER: Pipeline Heating Systems, Inc., Brecksville, OH

46 Add a new Part D to Article 426 as follows: D. Skin Effect Current Tracing

426-30. Scope. The provisions of Part D of thls article shall apply to fixed outdoor electric de-icing or snow melting equipment uti l izing a tubular resistive heating element of ferromagnetic material and having within the tubular element an electrically insulated return conductor so arranged that the skin effect of alternating current causes the main heating current to concentrate near the inner wall of the tubular element. 426-31. Insulating Rating.



(c) The outer conductor (tubular element) shall not require electrical insulation provided its outer surface is effectively grounded at one or more locations. •

426-32. Single Cable. A single cable may be used as the internal return conductor i f the provisions of Section 426-31(a) are met. 426-33. Pull Boxes. Pull boxes for the inner cable shall be accessible without excavation by being placed in suitable vaults or on above grade structure. 426-34. Branch-Circuit Requirements. The branch-circuit supplying a skin effect current tracing system shall not be limited in current rating by Section 426-3, but shall meet all other applicable branch-circuit requirements of this Code. 426-35. Above Ground Installations. Skin effect current tracing systems may be installed in exposed locations, such as on substation and bridge structures to prevent fail ing ice provided t~e heating element is grounded at the power feed location ahd at the termination of the circuit. SUBSTANTIATION: Skin effect current tracing has been used with great success in Japan for snow melting on garage ramps, airport aprons, and electrical substation structures. The principle of operation is explained in literature attached to our proposed amendment to Article 427.

This method is especially suitable for heating concrete slabs because the heavy wall steel 'heating elements has the same noncorroding characteristic in concrete that steel reinforcing rod has and is also of adequate strength to be unaffected by shrinkage or settlement of cracks. I t hasthe unique advantage that the inner cable can be replaced and ful l function restored without breaking up the slab i f any maintenance problem ever occurs. The main heating element, being of ful ly welded heavy wall construction, is not subject to failure in service unless there is catastrophic breakage of the slab. The thermal and electrical characteristics of the system are such that several thousand square feet can be heated with 100 watts per square foot frem a single circuit.

A skin effect current tracing heat element, having roughly the same dimensions as rigid conduit, can be installed without mechanical protection in exposed locations and can be useful for the accumulation of ice build up above transformer bushings, walkways, or other places troubled by fall ing ice.

The purpose of each amended paragraph is explained here: 426-31(a). In most cases i t is possible to operate code rated cables at higher currents in skin effect heating systems than permitted by Table 310-16 without exceeding the temperature rating of the cable as given in Table 310-16. Normal code ampacity i s based on three conductors in a conduit and with the thought that heat loss from the conduit might by limited by enclosure within an insulated stud wall, for example. In a skin effect tracing syste~l, one cable, not three, is producing heat. More importantly, the temperature of the raceway is known and bears a definite relationship to the pipeline temperature and the overall thermal parameters of the system. Since cable temperature and not current is the true basis of any rating, i t is possible to design with higher currents when all facts are known; a wide margin for error is thus unnecessary. 426-31(c). Section 310-2 states "Conductors shall be insulated." The heat tube of a skin effect system is in truth insulated by electremagnetic properties; under normal or Yault conditions the outer surface is always isolated (insulated) from the circuit voltage. But in every other application the Code thinks in terms of circuit theory rather than wave theory. In order to avoid possible misunderstandings, this paragraph is included. The presence of a ground assures the absence of voltage. There are technical approaches to this specific situation that are somewhat more definitive, but are fe l t inappropriate fdr the NEC. 426-32. Section 300-20 requires that "all phase wires be grouped" when in a metal raceway "to avoid heating the surrounding metal by induction." The usual situation this section prohibits is obviously hazardous, for very high uncontrolled temperatures are possible. A skin effect tracing system requires a single conductor in a metal tube specifically to create heat in the tube; although not st r ic t ly by induction. This is permissible because the temperature of the system in known, and is part of the design. 426-33. Self explanatory. 426-34. Self explanatory. 426-35. Skin effect current tracing heat elements are always of steel and typically are from 3/4 inch to 2 inches in O.D. and with a wall thickness greater than 0.100 inches~ They thus do not require protection from mechanical abuse in most instances. A single ground wil l assure that no potential can occur on the heating element under normal or fault conditions; a second

~ round is simply a conservative redundancy. ANEL RECOMMENDATION: Accept as Revised.

ARTICLE 426-FIXED OUTDOOR ELECTRIC DE-ICING AND SNOW-MELTING EQUIPMENT

A. General

426-I. Scope. The requirements of this article shall apply to electrically energized heating systems and the installation of these systems;

(a) Embedded in driveways, walks, steps and other areas. (b) Exposed on drainage systems, bridge structures, roofs and

other structures. 426-2. Definitions. For the purpose of this article:

Heating System. A complete system consisting of components such as heating elements, fastening devices, nonheating circuit

184

wiring, leads, temperature controllers, safety signs, junction boxes, raceways and f i t t ings.

Resistance Heating Element. A specific separate element to generate heat which is embedded in or fastened to the surface to be heated.

(FPN) Tubular heaters, strip heaters, heating cable, heating tape, heating panels, are examples of resistance heaters.

Impedance Heating System. A system in which heat is generated in a pipe or rod, or combination of pipes and rods, by causing current to flow through the pipe or rod by direct connection to an ac voltage source from a dual-winding transformer, The pipe or rod shall be permitted to be embedded in the surface to be heated, or constitute the exposed components to be heated.

Skin Effect Heating System. A system in which heat is generated on the inner surface of a ferromagnetic envelope embedded in or fastened to the surface to be heated.

(FPN) Typically, an electrically insulated conductor is routed through and connected to the envelope at the other end. The envelope and the electrically insulated conductor are connected to an ac voltage source from a dual-winding transformer. 426-3. Application of Other Articles. All requirements of this Code shall apply except as specifically amended in this article. Fixed outdoor electric de-icing and snow-melting equipment for use in hazardous (classified) locations shal~ comply with Articles 500 through 516. 426-4. Branch-Circuit Requirements. The ampacity of branch-circuit conductors and size of overcurrent protective devices supplying fixed outdoor electric de-iclng and snow-melting equipment shall be calculated on the basis of 125 peEcent of the total load of the heaters. Fixed outdoor electric de-icing and snow-melting installations shall be permitted to be supplied by 15-, 20-, 25-, 30-, 40-, or 50-ampere circuits i f the circuit suppliesno other load.

Exception: An individual branch ciKcuit shall be permitted to supply any load to a single heating unit.

B. Installation

426-10. General. Equipment for outdoor electric de-icing and snow melting shil l be identified as being suitable for:

l ) I the chemical, thermal and physical environment; and installation in accordance with the manufacturer's

drawings and instructions. 426-11. Use. Electrical heating equipment shall be installed in such a manner as to be afforded protection from physical damage. 426-12..Thermal Protection. External surfaces of outdoor electric de-lcing and snow-melting equipment which operate at surface temperatures" exceedihg 60°C (140°F) shall be physically . guarded, isolated, or thermally insulated to protect against contact by personnel in the area. 426-13. Identif ication. The presence of outdoor electric de-icing and snow-melting equipment shall be evident by the posting of appropriate caution signs or markings where clearly visible. 426-14. Special Permission. Fixed outdoor de-lcing and snow-melting equipment employing methods of construction or installation other than covered by this article may be used only by special permission.

C. Resistance Heating Elements

426-20. Embedded De-icing and Snow-Melting Equipment. (a) Watt Density. Panels or units shall not exceed 120 watts

per square foot of heated area. (b) Spacing. The spacing between adjacent cable runs is .

dependent upon the rating of the cable, and shall be not less than one inch on centers.

(c) Cover. Units, panels or cables shall be Installed: (I) On a substantial asphalt or masonry base at least 2

inches thick and have at least I-1/2 inches of asphalt or masonry applied over the units, panels or cables; or

(2) They shall be permitted to be installed over other approved bases and embedded within 3-I/2 inches of masonry or

'asphalt but not less than 1-1/2 inches from the top surface; or (3) Equipment that has been specially investigated for other

forms of installation shall be installed only in the manner for which i t has been investigated.

(d) Secured. Cables, units and panels shall be secured in place by frames or spreaders or other approved means while the masonry or asphalt finish is applied.

(e) Expansion and Contraction. Cables, units, and panels shall not be installed where they bridge expansion Joints unless adequately protected from expansion and contraction. 426-21. Exposed De-Icing and Snow-Melting Equipment. -

(a) Secured. Heating element assemblies shall be secured to surface being heated by approved means.

th~b)' Overtemperature. Where the heating element is not in direct contact with the surface being heated, the design of the heater assembly shall be such that its te~q~erature limitations shall not be exceeded.

(c) Expansion and Contraction. Heating elements and assemblies shall not be Installed where they bridge expansion joints unless provision is made for expansion and contraction.

(d) Flexural Capability. Where installed on flexible structureS, the heating elements and assemblies shall have a flexural capability compatible with the structure.

426-22. Installation of Nonheating Leads for Embedded Equipment. (a) Grounding Sheath or Braid. Nonheating leads having a

grounding sheath or braid shall be permitted to be embedded in the masonry or asphalt in the same manner as the heating cable without additional mechanical protection.

(b) Raceways. All but one to 6 inches of nonheating leads of Type TW and other approved types not having a ground!ng sheath shall be enclosed in a rigid conduit, electrical metallic tubing~ intermediate metal conduit, or other raceways within asphalt or masonry; and the distance from the factoryspl ice to raceway shall be not less than one inch or more than 6 inches.

(c) Bushings. Insulating bushings shall be used in the asphalt or masonry where leads enter conduit or tubing.

(d) Expansion and Contraction. Leads shall be protected in expansion Joints and where they emerge from masonry or asphalt by r igid conduit, electrical metallic tubing, intermediate metal conduit, other raceways, or other approved means.

(el Leads in Junction Boxes. Not less than 6 inches of free nonheating lead shall be within the junction box. 426-23. Installation of Nonheating Leads for Exposed Equipment.

(a) Nonheating Leads. Power supply nonheating leads (cold leads) for resistance elements shall be suitable for the temperature encountered. Preassembled nonheating leads on approved heaters shall be permitted to be shortened i f the markings specified in Section 426-25 are retained. Not less than 6 inches of nonheating leads shall be provided within the junction box.

(b) Protection. Nonheating power supply leads shall be enclosed in a rigid conduit, intermediate metal conduit, electrical metellic tubing, or other approved means. 426-24. Electrical Connection.

(a) Heating Element Connections. Electrical connections, other than factory connections of heating elements to nonheating elements embedded in masonry or asphalt or on exposed surfaces, shall be made with insulated connectors identified for the use.

(b) Circuit Connections. Splices and terminations at the end of the nonheating leads, other than the heating element end, shall be installed in a box or f i t t i ng i6 accordance with Sections 110-14 and 300-15. 426-25. Marking. Each factory-assembled heating unit shall be legibly marked within 3 inches of each end of the nonheating leads with the permanent identification symbol, catalog number, and ratings in volts and watts, or in volts and amperes. 426-26. Corrosion Protection. Ferrous or nonferrous metal raceways, cable armor, cable sheaths, boxes, f i t t ings, supports and support hardware shall be permitted to be installed i n concrete or in direct contact with the earth, or in areas subject to severe corrosive influences, when made of material suitable for the condition, or when provided with corrosion protection identified as suitable for the condition. 426-27. Grounding.

(a) Metal Parts. Exposed noncurrent-carrying metal parts of equipment l ikely to become energized shall be grounded as required in Article 250.

(b) Grounding Braid or Sheath. Grounding mebns, such as copper braid, metal sheath, or other approved means, shall be provided as part of the heated section of the cable, panel, or unit.

(c) Bonding and Grounding. All noncurrent-carrying metal parts that are l ikely to become energized shall be bonded together and connected to an equipment grounding conductor sized in accordance with Table 250-95, extending to the distribution panelb~ard.

D. Impedance Heating

426-30. Personnel Protection. Exposed elements of impedance heating systems shall be physically guarded, isolated, or thermally insulated with weatherproof jacket to protect against contact by personnel in the area. 426-31. Voltage Limitations. The impedance heated elements shall not operate at a voltage greater than 30 volts ac.

Exception: The voltage shall be permitted to be greater than 30 volts, but not more than 80 volts, i f a ground-fault circuit- interrupter for personnel protection is provided. 426-32. Isolation Transformer. A dual-winding transformer with a grounded shield between the primary and secondary windings shall be used to isolate the distribution system from the heating system. 426-33. Induced Currents/ All current-carrying components shall be installed in accordance with Section 300-20. 426-34. ~Grounding. An impedance,heating system that is operating at a voltage greater than 30, but not more than 80, shall be grounded at designated point(s).

E. Skin Effect Heating

426-40. Conductor Ampacity. The ampacity of the electr ical ly insulated conductor inside the ferromagnetic envelope shall be permitted to exceed the values shown in. Article 310, provided i t is identified as suitable for this use. 426-41. Pull Boxes. Where pull boxes are used they shall be accessible without excavation by location in suitable vaults or above grade. Outdoor pull boxes shall be of watertight construction. 426-42. Single Conductor in Enclosure." The provisions of Section 300-20 shall not apply to the installation of a single conductor in a ferromagnetic envelope (metal enclosure). 426-43. Corrosion Protection. Ferremagnetic envelopes, ferrous

or nonferrous metal raceways, boxes, f i t t ings, supports and support hardware shall be permitted to be installed in concrete or in direct contact with the earth, or in areas subjected to

'severe corrosive influences, where made of material sultable for the condition, or where provided with corrosion protection identified as suitable for the condition. Corrosion protection shall maintain the original wall thickness of the ferromagnetic envelope.

426-44. Grounding. The ferromagnetic envelope shall be grounded at both ends; and, in addition, i t shall be permitted to be grounded at intermediate points as required by its design.

The provisions of Section 250-26 shall not apply to the installation of skin effect heating systems.

(FPN) See Section 250-26(d). F. Control and Protection

426-50. Disconnecting Means. All fixed outdoor de-icing and snow-melting equipment shall be provided with a means for disconnection from all ungrounded conductors. Where readily accessible to the user of the equipment, the branch-circuit switch or circuit breaker shall be permitted to serve as the disconnecting means. Switches used as the disconnecting means shall be of,the indicating type. 426-51. Controllers.

(a) Temperature Controller With "Off" Position. Temperature controlled switching devices which indicate an "off" position and which interrupt line current shall open all ungrounded conductors when the control device is in.the "off" position. These devices shall not be permitted to serve as the disconnecting means unless provided with a positive lockout in the "off" position.

(b) Temperature Controller Without "Off" Position. Temperature controlled switching devices which do not have an "off" position shall not be required t6 open all ungrounded conductors and shall not be permitted to serve as the disconnecting means.

(c) Remote Temperature Controller. Remote controlled temperature actuated devices shall not be required to meet the requirements of Section 426-51(a). These devices shall not be permitted to serve as the disconnecting means.

(d) Combined Switching Devices. Switching devices consisting of combined temperature actuated devices and manually controlled switches which serve both as the controller and the disconnecting means shall comply with all of the following conditions:

(1) Open all ungrounded conductors when manually placed in the "off" position; and

(2) be "so designed that the circuit cannot be energized automatically i f the device has been manually placed in the "off" position; and

(3) be provided with a positive lockout in the "off" position. 426-52. Overcurrent Protection. Fixed outdoor electric de-icing and snow-melting equipment shall be considered as protected against overcurrent where supplied by one of the branch circuits as specified in Section 426-4. PANEL C(}~MENT: Article 426 has been completely revised and augmented by CMP 10. CMP 10 feels that these revisions improve

'and c lar i fy present Article 426 and incorporates the intent of this proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ERICKSON: Although I agree with the panel action on this proposal I would like to comment on certain sections.

Section 426-4: Change f i r s t sentence to read "The ampacity of branch-circuit, conductors supplying fixed outdoor electric de-icing and snow-melting equipment shall be in accordance with Section 310-15. The rating or setting of overcurrent protective devices shall be in accordance with Section 240-3, Exception No. I and Section 210-22(c) where applicable. See Explanation for Vote on Proposal No. 19.

Section 426-31, Exception: The use of the Words "for personnel protection" although not defined by the NEC, may imply to inspectors a 5 n~ device. These devices would be inoperative on an impedance heating circuit since there is more leakage current than 5 mA. What is intended is a GFCI as defined by the NEC which would operate at a lower current to ground than the circuit protective device. I recommend those words be deleted. See Section 680-41(a) for a precedent.

JORDAN: The following co~mnents are editorial: i . I t is suggested that the f i r s t sentence of Section 426-4 be revised to conform with Proposal No. 19 to assure consistency. 2. In Section 426-10(2): Change the word "installation" to

',,installed. u 3. InSection 426-12: Third line; delete word "surface," which is redundant. 4. In Section 426-14: In 3rd line change "may" to "shall." 5. In Section 426-22(a): Last line; change word "mechanical" to "physical," to conform to code nomenclature. 6. The word "approved" is used 5 or 6 times and should be scrutinized to assure conformance with the technical subcommittee's findings on "approved for the purpose:"

185

b

ARTICLE 427 -- FIXED ELECTRIC HEATING EQUIPMENT FOR PIPELINES AND VESSELS

Article 427: Accept CMP 10 Secretary's Note: I t was the action of the Correlating

Conwnittee that further consideration be given to the comments expressed in the voting. SUBMITTER: TSC-Skin Effect Current Tracing

47 Revise as follows: ARTICLE 427-F.IXED ELECTRIC HEATING EQUIPMENT FOR

PIPELINES AND VESSELS

A. General

427-I. Scope. The requirements of this article shall apply to electrically energized heating systems and the installation of these systems used with pipeline and/or vessels. 427-2. Definitions. For the purpose of this article:

(a) Pipeline: A pipeline is a length of pipe including pumps, valves, flanges, control devices, strainers and/or similar equip~nt for conveying fluids.

(b) Vessel: A vessel is a container such as a barrel, drum or tank for holding fluids or other material.

(c) Integrated Heating System: An integrated heating system is a complete system consisting of components such as pipelines, vessels, heating elements, heat transfer medium, thermal insulation, moisture barrier, nonheating leads, temperature controllers, safety signs, junction boxes, raceways and f i t t ings.

(d) Resistance Heating Element: A resistance heating element is a specific separate element to generate heat which is applied to the pipeline or vessel externally or internally. Tubular heaters, strip heaters, heating cable, heating tape, heating blankets, immersion heaters, etc. are examples of resistance

• heaters. (el Impedance Heating System: An impedance heating system is

a system in which heat is generated in a pipeline or vessel wall by causing current to flow through the pipeline or vessel wall by direct connection to an AC voltage source from a dual winding transformer.

(f) Induction Heating System: An induction heating system is a system in which heat is generated in a pipeline or vessel wall by inducing current and hysterlsis effect in the pipeline or vessel wall from an external isolated AC f ield source.

(g) Skin Effect Heating System: A skin effect heating system is a system in which heat is generated on the inner surface of a ferromagnetic envelope attached to a pipeline and/or vessel. An electrically insulated conductor is routed through and connected to the envelope at the far end. The envelope and the electrically insulated conductor are connected to an AC voltage source from a dual-wlnding transformer. 427-3. Application of Other Articles. All requirements of this Code shall apply' except as specifically amended in this article. Cord-connected pipe heating assemblies intended for specific uses and approved for the purpose shall be installed according to Article 422. Fixed electric pipeline and vessel heating equipment for use in hazardous locations shall comply with Articles 500 through 516. \ 427-4. Branch-Circuit Requirements. The minimum size of branch-clrcuit conductors and overcurrent protective devices supplying f ixedelectr ic pipeline and vessel heating equipment shall be calculated on the basis of 125 percent of the total load of the heaters.

B. Installatlon

427-10. General. (a) Equipment Type and Installation Requirements. Equipment

for pipeline and vessel electrical heating shall be (1) of a type compatible with the chemical, thermal and physical environment; and (2) installed in accordance with the manufacturer's drawings and installation instructions.

(b) Equipment Design. Equipment for pipeline and vessel electrical heating shall be used within the limits for which i t has been designed. 427-11. Use. Electrical heating equipment shall be installed in such a manner as to be afforded protection from physical damage. 427-12. Thermal protection. Accessible external surfaces of pipeline and vessel heating equipment which operate at surface temperatures exceeding 60°C (140°F) shall be physically guarded, isolated, or thermally insulated to protect against contact by personnel in the area. 427-13. Identification. The presence of electrically heated pipelines and/or vessels shall be evident by the posting of appropriate caution signs or markings at frequent intervals along the pipeline or vessel. 427-14. Resistance Heating Elements.

(a) Secured. Heating element assemblies shall be secured to the surface being heated by means other than the thermal insulation.

(b) Not in Direct Contact. Where the heating element is not in direct contact with the pipeline or vessel being heated, means shall be proClded to prevent overtemperature of the heating element unless the design of the heater assembly is such that its temperature limitations wil l not be exceeded.

(c) Expansion and Contraction. Heating elements and assemblies-shall not be installed where they bridge expansion joints unless provision is made for expansion ~nd contraction.

186

(d) Flexural Capability. Where installed on flexible pipelines, the heating elements and assemblies shall have a flexural capability compatible with the pipeline.

(el Power Supply Leads• Power supply nonbeating leads (cold leads) for resistance elements shall be suitable for the temperature encountered. Preassembled nonheating leads on approved heaters may be shortened i f the markings specified in Section 427-24 are retained. Not less than 6 inches of nonheating leads shall be provided with the junction box.

(f) Power Supply Leads Protection. Nonheating power supply leads shall be protected where they emerge from electrically heated pipeline or vessel heating units by raceway•

(g) Interconnecting Leads. Interconnecting nonheating leads connecting portions of the heatlng system shall be permitted to be covered by thermal insulation'in the same manner as the heaters. 427-15. Impedance Heating.

(a) Personnel Protection. All accessible external surfaces of the pipeline and vessel being heated shall be physically guarded, isolated, or thermally insulated (with weatherproof jacket for outside installations) to protect against contact by personnel in the area.

(b) Voltage Limitations. The pipeline or vessel being heated and electrical connections to i t shall not operate at a voltage greater than 30 volts AC. Exception No. 1: The voltage may be greater than 30 volts but not more than 80 volts i f ground-fault sensing device with interrupting capability for personnel protection is provided.

(c). Grounding. The pipeline and/or vessel being heated which is operating at a voltage greater than 30 but not more than 80 shall be grounded at one designated point.

(d) Induced Currents. All current-carrying components shall installed in accordance with Section 300-20.

be(el Isolation Transformer. A dual-winding transformer wi~h'a grounded shield between the primary and secondary shall be used to isolate the distribution system from the heating system. 427-16. Induction Heating. This section covers the installation of line frequency induction heating equipment and accessories for pipelines and vessels. See Articl~ 665 for other applications•

(a) Personnel Protection. Induction coils and electrical connections to them which operate or may'operate at a voltage greater than 30 volts AC shall be enclosed in a raceway, nonmetallic or split metallic enclosure, isolated or made weatherproof by locatio o to protect personnel in the area.

(b) Induced Current. Induction coils shall be prevented from inducing circulating currents in surrounding metallic equipment, supports or structures by shielding, isolation or insulation of the current paths. All possible stray current paths shall be bonded to prevent arcing. 427-17. Skin Effect Heating.

(a) Grounding. The ferromagnetic envelope shall be grounded at both ends. The ferromagnetic envelope shall also be permitted to be grounded at intermediate points as required by its design.

(b) Conductor Ampacity. The ampacity of the electrically-lnsulated conductor inside the envelope shall not exceed the rating for which i t was designed, rated and tested.

(c) Pull Boxes. P~ll boxes for pulling the electrically-insulated conductor in the ferromagnetic envelope shall be permitted to be buried under the thermal insulation providing their locations are indicated by permanent markings on the insulation Jacket surface and on drawings. For outdoor installations pull boxes are to be of watertight construction.

(d) Single Conductor in Enclosure. Section 300-20 shall be waived to allow installation of a single conductor in a ferromagnetic envelope (metal enclosure).

C. Construction and Protection

427-20. Disconnecting Means. (a) Switch or Circuit Breaker. Means shall be provided to

disconnect all fixed electric pipeline or vessel heating equipment from all ungrounded conductors. The branch-circuit switch or circuit breaker, where readily accessible to the user of the equipment, shall be permitted to serve as the disconnecting means. Switches used as disconnecting means shall be of the indicating type, and shall be provided with a positive lockout in the "off" position.

(b) Cord-Connected Equipment. The factory-installed attachment plug of cord-connected equipment rated 20 amp or less and 150 volts or less to ground is an acceptable means of disconnection. 427-21. Controls.

(a) Temperature Control with "off" Position.t Temperature controlled switching devices which indicate an "off" position and which interrupt line current shall open all ungrounded conductors when the control device is in this "off" position. These devices shall not serve as a disconnecting means unless provided with a positive lockout in the "off" position.

(b) Temperature Control without "off" Position. Temperature controlled switching devices which do not have an "off" position are not required to open all ungrounded conductors and shall not serve as a disconnecting means.

(c) Remote Temperature Control. Remote controlled ter~oerature actuated devices shall not be required to meet the requirements of Section 427-21 (a) and (b) above. These devices shall not serve as a disconnecting means•

(d) Combined Devices. Switching devices consisting of combined temperature actuated devices and manually controlled switches which serve both as controllers and disconnecting means shall: (1) Open all ungrounded conductors when manually placed in the "off" position, and (2) be so designed that the circuit cannot be energized automatically i f the device has been manually placed in the "off" position, and (3) be provided with a positive lockout in the "off" position. 427-22. Overcurrent Protection. Heating equip~nt shall be protected against overcurrent in accordance with Section 210-20. 427-24. Markings. Each factory-assembled heating unit shall be legibly marked within 3 inches of the end of each power supply nonheating lead with the permanent identification symbol, catalog number, and ratings in volts and watts, or in volts and amperes. 427-25. Electrical Connections.

(a) Nonheating Interconnections. Nonheating interconnections, where required under thermal insulation, shall be made with properly installed insulated connectors approved for the purpose.

(b) Splice Connections and Terminations. Splice connections and terminations outside the thermal insulation shall be installed in a box or f i t t ing in accordance with Sections 110-14 and 300-15. 427-26. Grounding. Exposed noncurrent-carrying metal parts of electric heating equipment which are l ikely to become energized shall be grounded as required in Article 250. 427-30. General. Induction and skin effect heating systems may be operated at voltages over 600 volts. Requirements for circuits and equipment operating at over 600 volts, nominal, are in Article 710. SUBSTANTIATION: We are completing the scope of the relatively new Article 427 which at the present only covers resistance heating, by adding impedance heating, induction heating and skin effect current tracing. PANEL RECOMMENDATION: Accept as Revised:

ARTICLE 427-FIXED ELECTRIC HEATING EQUIPMENT FOR PIPELINES AND VESSELS

A. General

427-1. Scope. The requirements of this article shall apply to electrically energized heating systems and the installation of these systems used with pipelines and/or vessels. 427-2. Definitions. For the purpose of this article: Pipeline. A length of pipe including pumps, valves, flanges,

control devices, strainers and/or similar equipment for conveying fluids. Vessel. A container such as a barrel, drum or tank for holding

fluids or other material. Integrated Heating System. A complete system consisting of

components such as pipelines, vessels, heating elements, heat transfer medium, thermal insulatlon, moisture barrier, nonheating leads, temperature controllers, safety signs~ junction boxes, raceways and f i t t ings. Resistance Heating Element. A specific separate element to

generate heat which is applied to the pipeline or vessel externally or internally.

(FPN) Tubular heaters, strip heaters, heating cable, heating tape, heating blankets, immersion heaters are examples of resistance heaters. Impedance Heating System. A system in which heat is generated

in a pipeline or vessel wall by causing current to flow through the pipeline or vessel wall by direct connection to an ac voltage source from a dual-winding transformer. Induction Heating System. A system in which heat is generated

in a pipeline or vessel wall by inducing current and hysteresis effect in the pipeline or vessel wall from an external isolated ac f ield source. Skin Effect Heating System. A system in which heat is

generated on the inner surface o f a ferromagnetic envelope attached to a pipeline and/or vessel.

(FPN) Typically, an electrically insulated conductor is routed through and connected to the envelope at the other end. The envelope and the electrically insulated conductor are connected to an ac voltage source from a dual-winding transformer. 427-3. Application of Other Articles. All requirements of this Code shall apply except as specifically amended in this art icle. Cord-connected pipe heating assemblies intended for specific use and identified as suitable for this use shall be installed according to Article 422. Fixed electric pipeline and vessel heating equipment for use in hazardous (classified) J locations shall comply with Articles 500 through 516. 427-4. Branch-Circuit Requirements. The ampacity of branch-circuit conductors and size of overcurrent protective devices supplying fixed electric pipeline and vessel heating equipment shall be calculated on the basis of 125 percent of the total load of the heaters.

B. Installation

427-10. General. Equipment for pipeline and vessel electrical heating shall be identified as being suitable.for:

(1) the chemical, thermal and physical environment; and (2) installation in accordance with the manufacturer's

drawings and instructions.

187

427-II. Use. E1ectrlcal heating equipment shall be installed In such a manner as to be afforded protection from physical damage. 427-12. Thermal Protection. External surfaces of pipeline and vessel heating equipment which operate at surface temperatures exceeding 60°C (140°F) shall be physically guarded, isolated, or thermally insulated to protect against contact by personnel in the area. 427-13. Identification. The presence of electrically heated pipelines and/or vessels shall be evident by the posting of appropriate caution signs or markings at frequent intervals along the pipeline or vessel.

C. Resistance Heating Elements.

427-14. Secured. Heating element assen~)lles shall be secured to the surface being heated by means other than the thermal insulation. 427-15. Not in Direct Contact. Where the heating element is not in direct contact with the pipeline or vessel belng heated, means shall be provided to prevent overtemperature of the heating element unless the design of the heater assembly is such that its temperature limitations will not be exceeded. 427-16. Expansion and Contraction. Heating elements and assemblies shall not be installed where they bridge expansion Joints unless provision is made for expansion and contraction. 427-17. Flexural Capability. Where installed on flexible pipelines, the heating elements and assemblies shall have a, flexural capability compatible with the pipeline. 427-18. Power Supply Leads.

(a) Nonheating Leads. Power supply nonheating leads {cold leads) for resistance elements shall be suitable for the temperature encountered. Preassembled nonheatlng lead) on approved heaters may be shortened if the markings specified in Section 427-20 are retained. Not less than 6 inches of nonheatlng leads shall be provided within the Junction box.

(b) Power Supply Leads Protection. Nonheatlng power supply leads shall be protected where they emerge from electrically heated pipeline or vessel heating units by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, or other raceways identified as suitable for the application.

{c) Interconnecting Leads. Interconnecting nonheatlng leads connecting portions of the heating system shall be permitted to be covered by thermal insulation in the same manner as the heaters. 427-19. Electrical Connections.

(a) Nonheating Interconne~tions. Nonheating interconnections, where required under thermal insulation, shall be made with insulated connectors identified as suitable for this use.

(b) Circuit Connections . Splices and terminations outside the thermal insulation shall be installed in a box or f i t t ing in accordance with Sections 110-14 and 300-15. 427-20. Marking. Each factory-assembled heating unit shall be legibly marked within 3 inches of each end of the nonheating leads with the permanent identification symbol, catalog number, and ratings in volts and watts, or in volts and amperes. 427-26. Grounding. Exposed noncurrent-carrying metal parts of electric heating equipment which are likely to beceme energized shall be grounded as required in Article 250.

D. Impedance'Heating

427-25. Personnel Protection. All accessible external surfaces of the pipeline and/or vessel being heated shall be physically guarded, isolated, or thermally insulated (with weatherproof jacket for outside installations) to protect against contact by personnel in the area. 427-26. Voltage~imitations. The pipeline or vessel being heated shall not operate at a voltage greater than 30 volts ac.

Exception : The voltage shall be permitted to be greater than 30 volts but not more than 80 volts i f a ground-fault circult-interrupter for personnel protection is provided. 427-27. Isolation Transformer. A dual-winding transformer with a grounded shield between the primary and secondary windings shall be used to isolate the distribution system from the heating system. 427-28. Induced Currents. All current-carrying components shall be installed in accordance with Section 300-20. 427-29. Grounding. T~he pipeline and/or vessel being heated which is operating at a voltage greater than 30 but not more than 80 shall be grounded at one designated point.

~-- E. Induction Heating

427-35. Scope. This part covers the installation of line frequency induction heating equipment and accessories for pipelines and vessels.

(FPN) See Article 665 for other applications. 427-36. Personnel Protection. Induction coils that operate or may operate at a voltage greater than 30 volts ac shall be enclosed in a nonmetallic or split metallic enclosure, isolated or made inaccessible by location to protect personnel in the area. 427-37. Induced Current. Induction coils shall be prevented from inducing circulating currents in surrounding metallic equipment, supports or structures by shielding, isolation or

insulation of the current paths. Stray current paths shall be bonded to prevent arcing.

F. Skin Effect Heating

427-45. Conductor Ampacity. The ampacity of the electrically-insulated conductor inside the ferromagnetic envelope shall be permitted to exceed the values given in Article 310 provided i t is identified as suitable for this use. 427-46. Pull Boxes. Pull boxes for pulling the electrically insulated conductor in the ferromagnetic envelope shall be permitted to be buried under the thermal insulation providing their locations are indicated by permanent markings on the insulation jacket surface and on drawings. For outdoor installations, pull boxes are to be of watertight construction. 427-47. Single Conductor in Enclosure. The provisions of Section 300-20 shall not apply to the installation of a single conductor in a ferromagnetic envelope (metal enclosure).

Ca) Grounding. The ferromagnetic envelope shall be grounded at both ends and, in addition, i t shall be permitted to be grounded at intermediate points as required by its design. Ferromagnetic envelope shall be bonded at all joints to assure electrical continuitx.

The provisions of Section 250-26 shall not apply to the installation of skin effect heating systems.

(FPN) See Section 250-26(d).

G. Control and Protection

427-55. Disconnecting Means. (a). Switch or Circuit Breaker. Means shall be provided to

disconnect all fixed electric pipelines or vessel heating equipment from all ungrounded conductors. The branch-circuit switch or circuit breaker, where readily accessible to the user

o f the equipment, shall be permitted to serve as the disconnecting means. Switches used as disconnecting means shall be of the indicating type, and shall be provided with a positive lockout in the "off" position.

(b) Cord-and-Plug Connected Equipment. The factory-installed attachment plug of cord- and plug-connected equipment rated.20 amperes or less and 150 volts or less to ground shall be permitted to be the disconnecting means. 427-56. Controls.

(a) Temperature Control with "Off" Position. Temperature controlled switching devices which indicate an "off" position and which interrupt llne current shall open all ungrounded conductors when the control device is in this "off" position. These devices shall not be permitted to serve as the disconnecting means unless provided with a positive lockout in the "off" position.

(b) Temperature Control without "Off" Position. Temperature controlled switching devices which do not have an "off" position are not required to open all ungrounded conductors and shall not be permitted to serve as the disconnecting means.

(c) Remote Temperature Controller. Remote controlled temperature actuated devices shall not be required to meet the requiraments of Section 427-56(a) and (b) above. These devices shall not be permitted to serve as the disconnecting means.

(d) Combined Switching Devices. Switching devices consisting of combined temperature actuated devices and manually controlled switches which serve both as the controllers and the disconnecting means shall cemply with all the following conditions:

(I) Open all ungrounded conductors when manually 'placed in the "off" position; and \

(2) be so designed that the circuit cannot be energized automatically i f the device has been manually placed in the "off" position; and

(3) be provided with a positive lockout in the "off" position. 427-57. Overcurrent Protection. Heating equipment shall be considered as protected against overcurrent where supplied by a branch circuit as specified in Section 427-4. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ERICKSON: Although I agree with panel action on this proposal I would like to co~Tnent on certain sections.

Section 427-4: Change f i r s t sentence to read "The ampacity of branch-circuit conductors supplying fixed electric pipeline and vessel heating equipment shall be in accordance with Section 240-3, Exception No. I and Section 210-22(c) where applicable. See Explanation for Vote on Proposal No. lg.

Section 427-26, Exception: The use of the words "for personnel protection" although not defined by the NEC, may imply to inspectors a 5 n~ device. These devices would be inoperative on an impedance heating circuit since there is mere leakage current than 5 nu~. What is intended is a GFCI as defined by the NEC which would operate at a lower current to ground than the circuit protective device. I recommend those words be deleted., See Section 680-41(a) for a precedent.

Section 427-29: Delete "one" and add (S) at end of sentence to agree with panel decision and Section 426-34.

Section 426-34(a): This should be renumbered 427-48 to agree with panel decision and format established in Section 426-44."

JORDAN: The following comments are editorial:

I . In Section 427-4: Change wording to conform with Proposal No. 19, to assure consistency. 2. In Section 427-12: Second sentence; delete word "surface," which is redundant. 3. In Section 427-16: Third line; make "provision" plural and change verb "is" to "are." 4. In Section 427-56(c): First sentence, third line: Change "(b) above" to read "Section 427-55(b)."

427-I (HOD 1978 NEC): Reject CMP 10 SUBMII'TER: Manufacturing Chemists Association

48 Delete the second sentence of 427-1. ~'I]B'S'~'A~rIATION: There is a need'for recognition of all types of electrical heating in common use today in industry.

There are five methods of electrical heating: (i) impedance heating-current flow through the pipeline or vessel wall as an impedance; (2) induction heating-current induced into the pipe by induction; (3) skin effect-current flow confined by skin effect to the inner wall of a tubular steel element welded to or inside the pipeline; (4) external heating with a heating, cable, heating tape, strip heaters, tubular heaters, heating blankets, etc.; IS) internal heating with a heating cable, tubular heaters, immersion heaters, etc., or by electrically-powered circulating heaters.

The f i f t h line of 427-1 specifically excludes two types of electrical heating. These should be recognized. PANEL RECOMMENDATION:- Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal. See action on Proposal No. 47. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

427-I (HOD 1978 NEC): Reject CMP 10 SUBMITTER: Pipeline Heating Systems, Brecksville, OH

49 Revise the ending of second sentence to read a-a-fTe~-tI~e comma, "other than the impedance method." SUBSTANTIATION: Same as Proposal No. 62 to 1978 Preprint. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal. See action on Proposal No. 47. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

427-3: Accept CMP 10 SUBMITTER:" C1aude'E. Deering, Jr., American Petroleum Institute PI~q~I~TAL-~. • 50 Add the word "classified" in parenthesis after ~ w o r d "hazardous." SUBSTANTIATION: I t is proposed that the word "~lqssified", in parenthesis, be inserted after the word "hazardous." This is consistent with Article 500, which is entitled "Hazardous (Class!fied) Locations." The proposed wording recognizes that a location is not hazardous per se, but is classifed depending on the properties of the flammable or combustible substance'which may be present, and the likelihood that a flammable or combustible concentration or quantity will be present. PANEL RECOMMENDATION: Accept. PANEL RECOMMENDATION: See Proposal No. 47. ~ O N ~ ~ E N D A T I O N : Unanimously Affirmative.

I 427-3: Accept CMP ~I0 SUBMITTER: TSC-Approved for the Purpose I~-0]~-0-~7~-~. • 51 See the Technical Subcommittee "Recommendations" un-un-d-e-r-t-fle definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept.

PANEL COMMENT: See Proposal No; 47, VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

427-3: Reject CMP 10 SUBMITTER: Warren H. Cook, IEEE

52 Change reference from Article 422 to Article 400. SUBSTANTIATION: Article 422 deals with appliances while Article ~00 is flexible cords and cables. PANEL RECOMMENDATION: Reject. I~ANEL COMMENT: The present wording adequately reflects the P a n e l ' s intent. / VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

188

427-4: Reject CMP 10 SUBMITTER: Warren H. Cook, IEEE P R ~ 5 3 Revise 427-4 to read: ~ n i m u m size of branch-circuit conductors supplying fixed electric pipeline and vessel heating equipment shall be calculated on the basis of 125 percent of the total load of the heaters. The size of branch-circuit overcurrent protective devices supplying fixed eIectric pipeline and vessel heating

equipment shall be calculated on the basis of 125 percent of the total load current. SUBSTANTIATION: The use of a minimum requirement for overcurrent protection of branch-circuits could lead to ground currents for extended periods of time. The panel was supplied with a typical circuit of a pipe tracing circuit. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ERICKSON: Although I agree with the panel action on this specific proposal, I also agree with the intent of the proposal. Mr. Cook desires to have minimum sized branch-circuit overload protection to provide the best possible ground-fault protection for resistance heating loads. See comments on Proposal 47 for a suggested solution.

427-12(g)-(New)(HOD 1978 NEC): Reject CMP 10 SUBMITTER: Manufacturing Chemists Association Ph-OI~O-S~CT. 54

Where a pipeline or vessel wall is used as the heating element, the pipeline or vessel shall conform to the following: (1) thermally insulated for safety of personnel; (2) electrically insulated from supporting structures; (3) protected from physical contact by suitable guards or by location; (4) visibly marked as being electrically energized; (5) voltage-to-ground of the pipeline or vessel shall be below 50 volts AC; (6) circuit-grounded or system- grounded in accordance with Section 250-5(a). SUBSTANTIATION: There is no need to recognize installation of equipment used in industry but not previously covered in the NEC. This type of heating has been practiced successfully by industry for many years. The combination of all types of pipeline and vessel heating into a single article is highly desirable. PANEL RECOMMENDATION: Reject. PANEL COt~MENT: See Panel action on Proposal No. ~47. VOTE ON PANEL RECO~IENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ERICKSON: I feel the Panel Comment should be changed to "CMP agrees with intent of proposal." See action on Proposal No. 47.

427-23(a): Accept CMP 10 SUBMITTER: Warren H. Cook, IEEE ~ L : 55 Delete: "and shall be supplied by the heating

manufacturer. ~ SUBSTANTIATION: The National Electrical Code should address i tse l f to safety and not source of supply. PANEL RECOMMENDATION: Accept.

I PANEL COMMENT: See Proposal No. 47. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 8. NEGATIVE: Eichhorn.

J EXPLANATION OF VOTE: EICHHORN: SectTon 427-23(a). As in Proposal 45, the concern

is about general approval for f ield connection of power supply leads to the electric heating elements.

I t is suggested that existing Section 427-23(a) to be used for Section 427-14(e) with this added.-

Exception: "Fieldconnection of power supply nonheating leads (cold leads) to the electric heating elements shall be permitted where the means of connection is identified as suitable for this purpose."

Section 247-20(b). The words "attachn~nt plug of" were omitted between "factory installed" and "cord-and plug-connected equipment."

427-23(b), Exception-(New): Reject CMP 10 SUBMITTER: Warren H. Cook, IEEE

56 Add exception as follows: Exception: Metal conduit or metallic tubing shall not be

required for cord connected equipment when adequately protected by other means. SUBSTANTIATION: The placement of heating wire directly on the vessel to be heated requires a flexible, open connection between. the heating wire and the raceway system. This flexible open connection has been found to be satisfactorily and suitably made by extending the cold leads in protected manner from the heated component to a f i t t ing of the raceway system. A suitable length has been found to be 18 inches maximum. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 47. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


57 See the Technical Subcommittee "Recomendations" under the definition of "Approved for the Purpose" in Article 100.

189

SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept. PANEL COMMENT: See Proposal NO. 47. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

427 Part D-(New)(HOD 1978 NEC): Reject CMP 10 SUBMITTER: Pipeline Heating Systems, Ind., Brecksville OH

58 Add a new Part D to Article 427 as follows:

D. Skin Effect Current Tracing 427-27. Scope. The provisions of Part D of this Article shall apply to fixed pipeline heating systems uti l izing a tubular resistive heating element of ferromagnetic material and having within the tubular element an electrically insulated return conductor so arranged that the skin effect of alternating current causes the main heating current to concentrate near the inner wall of the tubular element. 427-28. Insulating Rating.



(c) The outer conductor (tubular element) shall not require electrical insulation provided its outer surface is effectively grounded at one or more locations. 427-29. Single Cable. A single cable may be used as the internal return conductor i f the provisions of Section 427-28(a) are met. 427-30. Pull Boxes.

(a) For above ground pipelines, pull boxes for the inner cable may be covered by the pipeline thermal insulation provided their locations are suitably indicated.

(b) For below ground pipelines, pull boxes for the inner cable may be covered by the pipeline thermal insulation provided they are of waterproof construction and their locations are indicated on the pipeline drawings. 427-31. Grounding. Each tubular heating element shall be grounded at the power feed point on the pipeline, and additionally may be grounded at other locations. SUBSTANTIATION: Skin effect current tracing was specifically not included in the 1975 Code because there was insufficient experience with such systems at the time the amendments were closed. Such experience is now available.

Attached literature explains the principle of operation, which has the remarkable property of allowing a heating current to flow longitudinally through the Wall of a steel tube even though the outer surface of the tube is at ground potential at all points.

The prime advantage of the.system is the fact that technically and economically i t is entirely feasible to have single circuits up to seven or more miles in length, thus permitting tracing of pipelines across rights-of-way, easements, bodies of water, etc,, where power is not available. By its very nature the system is safe, because all current carrying parts are at all times ful ly enclosed by grounded heavy wall steel raceways or boxes.

The purpose of each amended paragraph is explained here: 427-1. Eliminates the exclusion of skin effect heating from Article 427. 427-28(a). In most cases i t is possible to operate code rated cables at higher currents in skin effect heating systems than permitted by Table 310-16 without exceeding the temperature rating of the cable as given in Table 310-16. Normal code ampacities are based on three conductors in a conduit and with the thought that heat loss from the conduit might be limited by enclosure within an insulated stud wall, for example. In a skin effect tracing system, one cable, not three, is producing heat. More importantly, the temperature of the raceway is known and bears a definite relationship to the pipeline temperature and the overall thermal parameters of the system. Since cable temperature and not current is the true basis of any rating, lit is possible to design with higher currents when all facts are known; a wide margin for error is thus unnecessary. 427-28(c). Section 310-2 states "Conductors shall be insulated." The heat tube of a skin effect system is in truth insulated by electrical magnetic properties; under normal or fault conditions the outer surface is always isolated (insulated) from the circuit voltage. But , every other application the Code thinks in terms of Circuit theory rather than wave theory. In order to avoid possible misunderstandings, this paragraph is included. The presence of a ground assures the absence of voltage. There are technical approaches to this special situation that are somewhat more definitive, but are fe l t inappropriate for the NEC. 427-29. Section 300-20 requires that "all phase wires be grouped" when in a metal raceway "to avoid heating the surrounding metal by induction." The usual situation this section prohibits is obviously hazardous, for very high uncontrolled temperatures are possible. The skin effect tracing system requires a single conductor in a metal tube specifically to create heat in the tube, although not s t r ic t ly by induction. This is permissible because the temperature of the system is

known, and is part of the design. 427-30. Self explanatory. 427-31. Skin effect tracing systems should be grounded at one point, even though they are universally d i rect ly mounted on grounded pipes or vessels. Even in the unlikely occurrence of an ungrounded pipe and a broken ground wire, there wi l l be no harmful closed circui ts i f contacted by personnel or conducting material. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal. See action on Proposal No. 47. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

190

REPORT OF CODE-MAKING PANEL NO. I I CMP 11

ARTICLE 430 -- MOTORS, MOTOR CIRCUITS, AND CONTROLLERS

Diagram 430-I: Accept SUBMITTER: A. P. White, Attleboro, MA

~ M o t o r Feeder Overcurrent Protection TO READ:

CHANGE:

CMP 11

Motor Feeder Short Ciruit and Ground Fault Protection. Motor Branch Circuit Overcurrent Protection TO READ: Motor Branch,Circuit Short Circuit and Ground Fault Protection. Motor Running Overcurrent Protection TO READ: Motor Overload Protection. Inherent Protection TO READ: Thermal Protection.

CHANGE:

CHANGE:

SUBSTANTIATION: Related editorial revisions for the following Sections: Diagram 430-I; Part C Heading; Sections 430-32(a-1), -32(d), -351b), -37, Table 430-37 Heading~ -38, -39, -40, -42(a), -42(b), -42(c), -43, -52, -53(a-3) , -53(c), - 53 (c - I ) , -53(d), -55, -125(a), -152 Table Heading; Example No. 8; 440-21.

Ed i to r ia l revis ion of Ar t i c les 430 and 440 of the 1975 NEC were for c l a r i f i c a t i o n of the terms - overload, overcurrent, and sho r t - c i r cu i t and ground-faul t protect ive device. Since not a l l the changes required were made, th is series of related proposals are submitted to complete the ed i t o r i a l changes and preserve the in tent for the terms "over load," "overcurrent , " and " sho r t - c i r cu i t and ground-faul t " devices.

This fol lows where the ed i tora l revis ions in the 1975 NEC confirmed that "overload ( fo r motors)" in A r t i c l e 430 means current due to overload and f a i l u r e to s ta r t and excludes f a u l t currents caused by short c i r c u i t and ground f a u l t . The ed i to r i a l revis ions in the 1975'NEC replaced references to "motor running overloads" and"motor running overcurrent" with the term, "motor over load," wherever i t was the intent that the currents involved were due to both overload and f a i l u re to s ta r t .

Add i t i ona l l y , the motor branch c i r c u i t protect ive device such as in Part D was confirmed as intended for protect ion against only sho r t - c i r cu i t and ground-faul t currents and excludes overload currents. In contrast , the term, "overeurrent , " includes any current resu l t ing from overload, short c i r c u i t and ground- faul t . The ed i to r i a l revis ions in the 1975 NEC intended to use the term, " s h o r t - c i r c u i t and ground-faul t protect ive device" in place of the term, "overcurrent" wherever i t was the in tent that only f a u l t currents were involved due to short circuit and ground. . , PANEL RECOMMENDATION: Accept as Revised:

The same editorial changes required by this Proposal are also required in additional sections of Articles 430 and 440 as follows: 430-3. In paragraph 2 line i delete the words "running overcurrent" and replace with the word "overload." 430-6 (a). In line 4 delete the words "overcurrent devices" and replace with the words "short-circuit and ground-fault protection."

In lines 6 and 7 delete the words "motor-running overcurrent" and replace with the words "motor overload.~'

430-6 (b). In lines 4 and 5 delete the words "motor running overcurrent" and replace with the words "motor overload."

430-6 (c). In lines 3 and 4 delete the words "overcurrent devices" and replace with the words "short-circuit and ground-fault protection."

430-7 (b). In line 6 delete the word "overcurrent" and replace with the words "short-circuit and ground-fault."

430-7 (d). In lines 5 and 8 delete the we~d "overcurrent" and replace with the words "short-circuit and ground-fault protective."

430-8. In lines 4 and 6 delete the words "motor-running overcurrent" and replace with the words "motor overload."

In line 7 delete the word "overcurrent" and replace with the words "short-circuit and ground-fault."

430-54. In line 2 insert the words "short-circuit and ground-fault" after the words "branch-circuit."

440-22 (b). In line 7 insert the words "short-circuit and ground-fault" after the word "equipment."

Paragraph (b) (1) line 2 insert the words "branch-circuit short-circuit and ground-fault" after the words "setting of the."

Paragraph (b) (2) line 2 insert the words "branch-circuit short-circuit and ground-fault" after the words "setting of the."

Paragraph (b) (2) Exception No. I line 4 delete the word "circui t" after the word "maximum" and replace with the words "branch-circuit short-circuit and ground-fault." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Diagram 430-I: Accept CMP 11 SUBMITTER: TSC-Nominal Voltage ~ITOIR~S-AL-T.'2 In the second line add "nominal" after "600"

SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Diagram 430-1: Reject SUBMITTER: Warren Anderson, Mount Vernon, WA l~TOl~O~rAt-~.'3 Revise diagram as follows: e ~ l ". Part A

Requirements for over 600 volts Part J Protection of l ive parts all voltages Part K Grounding Part L Tables Part M

Rl~tt,~ 014grm IS fo110ml:

SUPPLY

FE£~ OVIS~K:UR ~

NOT~ ~.EO~

ROTOR OI~.Olq~ECTING M£ANS

M~TO~ ~ ~ O r i E N T ~IIEC'TION

MOTCR CCKT~LL£R & MOTOR

RUI~4I~ OV£RCURRINT ~cTIo~

140TOR CI~UIT O~40L~TORS

MOI~}R I¢4ER~$T PROTIECTION ~

$ECOROARY COXTRO~ER

m~T

PART B: $4¢. 430-24. 25,

PART H

PART 0

pAJITS G II F

PART C

PA~T It: SIC. 430-Z2

PART A & C

PA~cr B: S~ . 430-Z3

PART B: S~ . 430-23 & Art.. 470

SUBSTANTIATION: Diagram 430-1 would be easier to understand and add c lar i ty to the code i f i t were redrawn so that the sequence of devices more closely follows the actual alignment of devices that are found in the f ield. PANEL RECOMMENDATION: Reject. PANEL CO~4ENT: Supporting comment is not persuasive as to necessity. No additional clari f ication would be achieved by this Proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-2: Accept CMP 11 SUBMITTER: Edwin H. Luoma, Reliance Electric Co. IsITOIRTS'A~-T.'4 In the second sentence of the f i r s t paragraph add

"overload" after the word "additional." SUBSTANTIATION: The second sentence is not complete in meaning wltnout tne word "overload" as shown in the revised sentence above. We feel the intent of the code would also be satisfied with the addition of the word "overload." PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-2: Reject CMP 11 SUBMITTER: Idaho Chapter IAEI I~RI33R}~FAL-T." 5 In Section 430-2 delete the second sentence and move ~ t sentence to Section 430-52. SUBSTANTIATION: (See proposal for new Exception No. 2 for Section 430-52.) PANEL RECOMMENDATION: Reject. PANEL COMMENT: The revised wording adequately reflects Panel's intent. See Proposal No. 4. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-4: Reject CMP 11 SUBMITTER: Robert G. MacManus, Pawtucket, RI ~ 6 Delete the figure "50" and replace with "25." ~B-STAI~TIATION: The NEC has for many years allowed one piece of equipment to be "in sight from" another piece of equipment i f i t is visible and not more than 50 feet distant. However, the rule does not take ihto consideration the fact that temporary or permanent equipment or material could later block the view and cutting the distance in half would make for much safer conditions. I t will be noted that Section,430-102 no longer allows the discennecting means to be locked in the open position. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting con~nent does not Justify the proposed change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

191

430-5: Accept ~ CMP 11 SUBMITTER: Larry T. Smith and LaVerne E. Stetson, Lincoln, NB I~TOPO-S'A-L-~: 7 Change to include Article675. Electrically ~ r controlled irrigation machines. SUBSTANTIATION: The readers attention should be directed to the provisions of Article 675. Many installers, for example, are not aware of the equivalent current ratings given in Section 675-22. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-7(a)(14)-(New): Reject CMP 11 SUBMITTER: Kenneth L. Paape, Allen-Bradley Co. I~ITOIR)~-~. • 8 Add new (14) as follows: ~ O v e r l o a d relay class, where the motor is not marked "Thermally Protected" or "Impedance Protected." (See Section 430-41). SUBSTANTIATION: A system of class designations, Class 10, 20 or 30, exists for overload relays. .(See paragraphs 23.2 and 36.15 of UL508). The numerals in these class designations (e.g., 10, 20 or 30) indicate the maximum time in seconds required for the overload relay to tr ip at a current which is equal to 600% of the current element rating. Since an overload relay must ultimately tr ip at 100% of its current element rating and within 8 minutes at 200% of its current element rating, a time-current characteristic can be drawn for each overload relay class. With this information the motor manufacturer is the most qualified to select the overload relay class which best matches the motor insulation system and heating characteristics under acceleration, overload, or locked rotor conditions. Neither installers nor inspectors have easy access to the technical details required to select an overload relay of the proper class.

A more detailed explanation of the overload relay class designation system is included with a companion proposal for a new Section 430-41 to require that overload relays be marked with their class designation. The time-current curves of 3 overload relay classes and table of expected motor insulation l i fe at different temperatures prepared for the Section 430-41 proposal are attached.

All overload relay current elements are selected on the basis of their current rating (ultimate t~ip current) regardless of overload relay class, yet overload relays with high class designations require more time to tr ip at 600% of their rating. Relays which take longer to tr ip at 600% of their rating provide more time for the motor and its load to accelerate to ful l speed. Section 430-34 requires that the overload relay have sufficient time delay to permit the motor to start and accelerate its load. Only the motor manufacturer knows the maximum load (in terms of inertia and acceleration time) that the motor can bring up to speed without overheating. The overload relay class that best conforms to the motor capability ought to be shown on the motor nameplate. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel believes that extending the requirements as indicated by this Proposal is not necessary as the Code now permits this marking. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Lopez."

COMMENT ON VOTE: SCHRAM: See explanation of negative vote on Proposal No. 9.

We believe the marked overload relay class should be the maximum class, in accordance with Proposal No. g. EXPLANATION OF VOTE:

LOPEZ: I disagree with the Panel's Recon~nendation since I believe this proposal will improve the motor overload protection. The marking of overload relay class on the motor nameplate will help the users with the selection of the proper overload relay to ut i l ize.

430-7(a)(14)-(New): Reject . CMP 11 SUBMITTER: Marvin T. Stevens, Greendale, WI ~TOFOTATT." 9

Maximum overload relay class, where the motor is not marked "Thermally Protected" or "Impedance Protected."

(FPN) See Sections 430-34 and 430-40. SUBSTANTIATION: This proposal is one of a package of three and should be considered with proposals relating to overload relay class designations submitted for Sections 430-34 and 430-40.

At the time a motor manufacturer designs a motor he takes Into consideration the maximum inertia load that the motor should be capable of accelerating. The motor manufacturer also knows the maximum allowable locked motor time which his motor can endure without undue deterioration of the insulation.

Both the motor acceleration time and the maximum allowable locked rotor time for the motor can be related to the time-current characteristics of overload relays and the overload relay class requirements of ANSI C33.76-1976. Nationally recognized testing laboratories verify time-current characteristics in accordance with ANSI C33.76-1976 before awarding l ist ing to a line of overload relays. Since the system of class designation exists and is based on fundamental data best interpreted by the motor manufacturer, i t would seem prudent to require the maximum overload class to be marked on

motor nameplates where the motor does not include thermal or impedance protection. I t is quite possible today to have an overload relay selected properlywith regard to motor fu l l load current and yet have motor burnout because the wrong class of overload relay was used. Unless the motor is marked with its maximum overload relay class, there is no way for an electrician or inspector to know i f the overload relay is the proper class for the motor. PANEL RECOMMENDATION: Reject. PANEL COMMENT:. The Panel believes that extending the requlrements as indicated by this Proposal is not necessary as the Code now permits this marking. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Schram.

EXPLANATION OF VOTE: SCHRAM: The matching of the locked rotor characteristics of

motors and overload relay protective devices is an important part of motor protection that is not now covered in the NEC. The marking of the maximum overload relay class on the motor would aid in providing proper levels of protection.

430-7(d): Reject CMP 11 SUBMITTER: Richard J. Denny, Air Conditioning & Refrigeration T ~ PROPOSAL: 10 Add a sentence before the last sentence of the ~ r a g r a p h as follows:

In no case shall the marked maximum rating of the circuit overcurrent device be less than the marked minimum supply circuit conductor ampacity. SUBSTANTIATION: The actual marked values may be greater than the calculated minimum, and/or may be less than the calculated maximum. Under the present rules, the marked maximum rating of the overcurrent device (fuse or circuit breaker) could be less than the marked minimum supply circuit conductor ampacity,

.especially since the marked maximum fuse or circuit breaker rating is normally _reduced from the calculated maximum to a standard rating as given in Section 240-6. The possibil i ty of this occurrence is greater when a substantial part of the combination load is electric resistance space heating. There are products on the market with this cross-over of marked limits. Although Section 430-53(c)(4) permits the rating of the fuse or circuit breaker to be increased to the next standard rating higher than the conductor ampacity (by reference to Section 240-3 Exception No. 1), the marked maximum rating of the fuse or circuit breaker cannot be exceeded per Section 430-54. The change is to remove unintended permission for a crossover of the minimum and maximum marked values. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primarily a design consideration. VO~E ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: SCHRAM: Whlle we agree a design consideration is involved, i t

is the design of the marking. We do not believe the Code should permit a marking which in conflict with'the intent, as stated in the proposal.

430-7(d): Reject CMP 11 SUBMITTER: Alton R. Thompson, Durham, NC

11 Add a sentence before the last sentence of the T l - ~ r a g r a p h as follows:

In no case shall the marked maximum rating'of the circuit overcurrent device be less than the marked minimum supply

c i r cu i t conductor ampacity. SUBSTANTIATION: The actual marked values may be greater than the calculated minimum, and/or may be less than the calculated maximum. Under the present rules, the marked maximum rating of the overcurrent device (fuse or circuit breaker) could be less than the marked minimum supply circuit conductor ampacity, especially since the marked maximum fuse or circuit breaker rating is normally reduced from the calculated maximum to a standard rating as given in Section 240-6. The possibil i ty of this occurrence is greatest when a substantial part of the combination load is electric resistance space heating. There are products on the market with this cross-over of marked limits. Although Section 430-53(c)(4) permits the rating of the fuse or circuit breaker to be increased to the next standard rating higher than the conductor ampaclty (by reference to Section 240-3 Exception No. 1), the marked maximum rating of the fuse or circuit breaker cannot be exceeded per Section 430-54. The change Is to remove unintended permission for a crossover of the minimum and maximum marked values. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel comment on Proposal No. 10. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: SCHRAM: See Co n1~ent in Proposal No. 10.

192.

,/

430-10 and Table 430-10-(New): Reject CMP 11 SUBMITTER: K. L. Paape, Allen-Bradley Co. !~TOIRT~:/~-~.. 12 Revise 430-10 by adding a new paragraph a-'fq!-~'6-'t'ITe fine print note as follows:

Where the conductor termination means (lugs) supplied by the manufacturer of a listed motor controller are replaced by other conductor termination means, conductors shall not be deflected at a terminal unless bending space In accordance wlth Table 430-10 is provided. And add a new table as follows:

Table 430-10. Minim~ Wlre Bending Space at Terminals in Inches

AWG or Circular-Mil Wires per Terminal Size of Wire 1 2 3 4 5

14 Not Specified 12-6 1 1/2 4-3 2 2 2 1/2 1 3 0-00 3 1/2 5 7 . . . . 000-0000 4 6 8 . . . . 250-MCM 4 1/2 6 8 10 -- 300-350 MCM . 5 8 10 12 ._ 400-500MCM 6 8 10 12 14 600-700 MCM 8 10 12 14 16 750-900 MCM 8 12 14 16 18 1000-1250 MOM i0 1500-2000 MCM 12

Bending space at terminals shall be measured in a s t ra ight l ine from the end of the lug or wire connector ( in the d i rect ion that the wlre leaves the terminal) to the wall or bar r ie r . SUBSTANTIATION: The conductor termination means furnished with motor cont ro l lers are evaluated as part of the cont ro l le r in order to obtain l i s t i ng by a nat iona l ly recognized test ing laboratory. Most i ns ta l l i ng e lec t r ic ians are not aware that changing the termination of a con t ro l le r n u l l i f i e s th is l i s t i ng .

Fie ld experience has shown that the screw type lugs furnished w l th l i s ted motor cont ro l lers are occasional ly replaced with crimp type lugs at the time the cont ro l le rs are insta l led even though the replacement lugs may not include an an t i - ro ta t ion feature which the or.igianal termination had. When the individual making the i ns ta l l a t i on uses a l is ted lug as a replacement with no concern for i ts length, he can create a s i tuat ion where the wir ing space !s not adequate and the conductors are subject to damage as they are forced between the end of the lug and the wall of the enclosure.

In addition, inadequate wiring space may lead to improper orientation of the new lugs with a resulting loss of electrical clearance. Since nationally recognized testing laboratories l i s t lugs wlth constraint of their length, and only a small percentage of all motor controllers manufactured are used with other than the lugs furnished there is no practical way for a controller manufacturer to anticipate the wiring space that may be required under changed lug conditions. The individual choosing to change the conductor termination should be made responsible for proper lug selection.

Proposed Table 430-10 is based on present Table 373-6(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: Accepted Proposal No. 15. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-10: Reject CMP 11 SUBMITTER: Kenneth L. Paape, Alle~-Bradley Co. PITOPO-~7~-T. 13 Expand Section 430-10 by adding a paragraph and

follows: 430-10 Wiring Space in Enclosures. Enclosures for motor controllers and disconnecting means shall not be used as Junction boxes, auxil iary gutters; or raceways for conductors feeding through or tapping off to the other apparatus unless designs are employed which provide adequate space fop this purpose.

See Section 373-8 for switch and overcurrent-device enclosures. Where the conductor termination means (lugs) supplied by the

manufacturer of a listed motor controller are replaced by other 'lugs, these lugs shall be sized so that wire bending space in accordance with Table 430-10 is available.

Table 430-10 - Minimum Wire Bending Space at Terminals in Inches

Max. Conductor Conductors per Terminal Size

AWG or MCM 1 2 3 IO • Not Speclfled 6 1 1/2 3 2 2 2 i/2 1 3

2/0 3 1/2 4/0 7 7 12 250 MCM 8 I/2 8 1/2 12 350 MCM ' 10 10 15 500 MCM 12 12 15 700 MCM 15 15 18 go0 MCM ' 18 18 21

SUBSTANTIATION: The conductor termination means furnished with motor controllers are evaluated as part of the controller in order to obtain l ist ing by a nationally recognized testing laboratory. Most installing electricians are not aware that changing the termination of a controller nul l i f ies this l ist ing.

Field experience has shown that the screw ttlpe lugs furnished with listed motor controllers are occasionally replaced with crimp type lugs at the time the controllers are installed even though the,replacement lugs may not include an anti-rotation feature which the original termination had. When the individual making the installation uses a listed lug as a replacement with no concern for its length, he can create a situation where the wiring space is not adequate and the conductors are subject to damage as they are forced between the end of the lug and the wall of the enclosure.

In addition, inadequate wiring space may lead to improper orientation of the new lugs with a resulting loss of electrical clearance. Since nationally recognized testing laboratories l i s t lugs with no constraint on their length, and only a small percentage of all motor controllers manufactured are used with lugs other than those furnished, there is no practical way for a controller manufacturer to anticipate the wiring space that may be required under changed lug conditions. The individual choosing to change the conductor termination should be made responsible for proper lug selection.

Proposed Table 430-10 is based on the table recommended by Underwriters Laboratories as a result of a fact=finding investigation sqggested by CMP 11 regarding adequat~ wiring space In enclosures for motor controllers. PANEL RECOMMENDATION: Reject. PANbL COMMENT: Accepted Proposal No. 15. VOTE ON PANEL RECOMMENDATION:' Unanimously Affirmative.

430-10: Reject CMP 11 SUBMITTER: R. E. Smith, Cutler-Hammer Inc.

14 Revise as follows: ~ . Wiring Space in Enclosures.

(a) General. Enclosures for motor controllers and disconnecting means shall not be used as junction boxes, auxil iary gutters, or raceways for conductors feeding through or tapping off to the other apparatus unless designs are employed which provide adequate space for this purpose.

(b) Wire Bending Space. Minimum wire bending space shall be in accordance with Table 430-10(b) and measured in a straight line from the end of the terminal connector, supplied with the controller (In the direction the wire leaves the terminal) to the enclosure wall or barrier. Alternate terminals shall be of a type identified for use with the controller and shall not reduce the minimum wire bending space.

TABLE 430-I0(B). MINIMUM WIRE BENDING SPACE AT TERMINALS OF ENCLOSED MOTOR CONTROLLERS IN INCHES

AWG or Circular-Mil. Wires Per Terminal Size of Wire 1 2

14-I0 not specified . . . . 8-6 1 I /2 . . . . 4-3 2 . . . .

2 2 1/2 . . . . 1 3 . . . .

0-00 3 I/2 . . . . 000-0000 7 7 ' 12

250MCM 8 1/2 8 1/2 12 300-350MCM I0 I0 15 400-500MCM 12 12 15 t 600-700MCM 15 15 18 750-900MCM 18 18 21

SUBSTANTIATION: An Underwriters Laboratories fact-finding investigation has shown the need for a wire-bending space table for motor controllers. The above proposed table was developed, taking into consideration the following diversity factors. The UL investigation has confirmed that these factors have an influence on the amount of wlre-bending space required. Several of these factors are present in any given motor controller installation. I . The depth of motor controller enclosures provides added volume which, allows the forming of wires, sizes AWG 2/0 and smaller, to fac i l i ta te their connection to the controller connectors. 2 . Wire ampacity selection is based on motor horsepower and voltage rating. The value of motor current is always less than the current rating of the standard motor controller which would be used.

Example: A motor rated 50HP at 460 volts (65FLA) requires wire rated at 82 amperes (1.25x65) which fal ls within the ampacity rating of #2AWG copper wire (95A) or #1AWG aluminum wlre (85A).

The standard motor controller with a max. rating of 50HP, 460 volts has a current rating of 90A and is provided with wire connectors capable of accepting #1AWG copper wire. When designed for use with aluminum wire, the wire connector is capable of accepting #2/OAWG aluminum wire. The net result is that the connector wire range of the motor controller usually exceeds the size of the wire required for the installation. The

1 9 3

UL fact-finding investigation indicates that this is an important factor which faci l i tates wire installation. 3. In the wire range of 2/OAWG and smaller, most motor control installations use copper wire. The UL fact-finding investigation indicates that copper wire is easier to manipulate. Further, a smaller size copper wire is generally used for the equivalent ~l~)acity rating of aluminum wire. 4. Motor controllers are designed to permit the additio~of accessories such as control transformers, auxiliary contacts, pushbuttons, selector switches, pi lot lights, etc., which result in oversize enclosures for many applications. 5. Since motor controllers are not permitted to be used as junction boxes by the NEC, only one wire per terminal need be considered for wire sizes 2/OAWG and smaller. 6. Motor controllers are generally easily removed from their enclosures which can improve access to the wire connectors and fac i l i ta te the connection of wires to the connectors. 7. Many motor controllers are designed in a manner which al!ows easy removal of the wire connectors from the coBtroller. The connector can be fastened to the wire and reassembled to the controller. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Accepted Proposal No. 15. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-10(b)-(New): Accept CMP 11 SUBMITTER: Harold E. Whiting, St. Charles, IL !~TOl~O'S'At-~. " 15 Identify present paragraph as (a) General. ~ w (b) and Table 430-I0(b) as follows:

(b) Wire Bending Space in Enclosures. Minimum wire bending space within the enclosures of motor controllers shall be in accordance with Table 430-I0(b) when measured in a straight line from "the end of the lug or wire connector (in the direction the wire leaves the terminal) to the wall or barrier. Where alternate wire termination means is substituted for that supplied by the manufacturer of the controller they shall be of a type identified by the manufacturer for use with the controller and shall not reduce the minimum wire bending space.

Table 430-10(b). Minimum Wire Bending Space at the Terminals of Enclosed Motor Controllers (In Inches)

AWG or Circular-Mil *Wires Per Terminal Size of Wire 1 2

14 - 10 Not specified 8 - 6 1 1/2 4 - 3 2

2 2 I/2 1 . 3

- i / 0 ~ 5 5 - 2 / 0 6 6

3/0-- 4/0 7 7 250 8 8

300 10 10 350 - 500 12 12 600 - 700 14 16 750 - 900 18 1 9

*Where provision for 3 or more wires per terminal exists the minimum wire bending space shall be in accordance with requirements of Article 373. SUBSTANTIATION: A fact finding investigation by a nationally recognized testing laboratory has indicated a need to specify the wire bending space necessary within enclosed motor controllers. Evidence also indicates this space should be different for I and 2 wires per terminal from that required for cabinets and cut out boxes as listed In Table 373-6(a) and therefore a separate table in 430-10 is required.

The table presented in this proposal provides adequate space for wiring by experienced installers using approved wiring techniques without increasing the unsupported lengths of wire to dimensions which might permithazardous deflection during high current fault conditions.

Control of the type of alternate wire termination means must be le f t with the manufacturer of the controller to assure l ist ing requirements and wire bending space requirements of the controller are not v io lated. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOI~ENDATION: Unanimously Affirmative. COMMENT ON VOTE:

SCHRAM: An affirmative vote is cast to support the addition of bending space requirements in Article 430. However, i t should be noted that the proposal differs in several respects fro~ the proposals being considered for Article 373. We believe the requirements in Article 430 would need to treat motor control centers, which have some design elements similar to switchboards and others similar to motor controllers, in a manner consistent with the treatment proposed for Article 373.

430-12(b): Accept CMP 11 SUBMITTER: A. C. Clark, Manufacturing Chemists Assn. !~R-OIs~L-~." 16 Revise as follows: ---Tb-)--l~imensions and Space--Wire-To-Wire Connections. When these terminal housings enclose wire-to-wire connectlons, they

shall have minimum dimenslons and usable volumes in accordance with the following:

(1) For motors rated one horsepower and smaller, having not over four leads and having terminal housing part ial ly or wholly integral with the frame or end shield. The volume of the terminal housing shall be not less than 2 'cubic inches per wire-to-wire connection. The minimum cover opening shall be no less than 1.5 inches.

(2) For alternating current motors, having a maximum of 12 leads entering the terminal box shall incorporate terminal boxes no smaller than as shown in Table 430-12(b)(1).

(3) For direct current motors having a maximum of 6 leads entering the terminal box shall have dimensions and usable volumes not less than shown in Table 430-12(b)(2).

ATTACHMENT A

Table 430-12(b)(1) w

Alternating-Current Motors Motors Over 11 Inches in Diameter

Max. Full-load Current for Three Terminal Usable phase Motors with Box Volumn Max.'of Twelve Minimum Minimum

Leads Dimension ~ubic Inches Inches

Amperes

Typical Maximum

Horsepower Three Phase

230 volt 460 volt

45 2.5 26 15 30 70 3.3 55 25 50

110 4.2 100 40 75 160 5.4 190 60 125 250 7.0 330 100 200 400 9.3 600 150 300 600 10.7 1100 250 500

Table 430-12(b)(2) Direct-Current Motors

Motors Over 11 Inches in Diameter

Maximum Full-load Current for Terminal Box Usable Motors with Minimum Volume

Maximum of Six Leads Dimensions Minimum Inches Cubic Inches

Amperes

68 3.3 5b 105 4.2 100 165 5.4 190 240 7.0 330 375 g.3 600 600 10.7 1100 900 15.0 2000

SUBSTANTIATION:' Most users of motors find the terminal box sizes Ilsted in present Sec, 430-12(b) to be entirely inadequate. This inadequacy stems both from insufficient space for all the wires and splices and from the necessity for oversharp bending of the wires. Both of these contribute to physidal overstressing of the insulation which results in inordinate failure rates of conductors in the termlnal boxes. In seme studies i t has been found that one-quarter of all "motor" failures occurred in the terminal boxes. While failure rate is not a basic criterion of the Code, there is ample evidence in other articles to prove that adequate wiring space is prescribed for freedom from failures, a major cause of f ires; Articles 370, 373 and others require more satisfactory space for making bends and connections.

Knowledgeable users have simply been specifying larger terminal boxes on factory orders to obtain serviceable equipment. Others, and those purchasing motors from stock, discard the original boxes and fabricate more adequate ones for the installation. The manufacturers hold that Original Equipment Manufacturers buy the major proportion of motors, and require the very minimum sizes of terminal boxes. I t must be remembered that few OEM's actually use these items and many do not even wire up the motors. In any event, OEM's do not ordinarily become involved with maintaining the motors, replacing bearings, etc. which require disconnection and reconnection of the motor, involving disassembly and reasse~foly of the wiring In the terminal boxes. For this very important reason, i t is suggested that the OEI~ viewpoint is unsound, and i f Sec. 430-12(b)is based on this, the section would be better deletes from the Code.

194

I t Is well known that the bending of stranded wires more sharply than as outlined i 9 Sec. 373-6 for a single 90 ° bend, or double these dimensions for a 180 ° bend will result in inserviceable operation, through stretching of the outer strands and inordinate pressure on the insulation. Space and size of motor terminal boxes requires that the splices be made up outside the boxes, then formed into the boxes, usually incurring a U-bend. The proposed sizes of the terminal boxes in Sec. 430-12(b) provide space for making these bends and splices without exceeding the bending sharpness specified in Sec. 373-6. PANEL RECOMMENDATION: Accept as Revised:

First two Tables on page 292 in the 1978 NEC to be shown as in Attachment A. Also in Attachment A, Table 430-12(b)(1), column 3 entitled "Usable Volume Minimum Cubic Inches," change fourth figure down from "190" to "180." In same Table, column 2 entitled"Terminal Box Minimum Dimension Inches" change the following: from "4.2" to "4.0," "5.4" to "5.0," "7.0" to "6.0," "9.3 to "7.2" and "10.7" to "8.8."

In Table 430-12(b)(2), column 2 entitled "Terminal Box Minimum Dimensions Inches" change the following: from "4.2" to "4.0," "5.4" to "5.0," "7.0" to "6.0," "9.3" to "7.2," "10.7" to "8.8" and "15" to "10.7." In same Table, column 4 entitled "Usable Volume Minimum Cubic Inches," change third figure down from "190" to "180." VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Wood.

EXPLANATION OF VOTE: WOOD: The revis ion made by CMP 11 does not help to a l l ev ia te

the space problem in smaller sized motors as o r i g i n a l l y proposed. The Panel's revis ions resu l t in V i r t u a l l y no change from present values.

Table 430-12(c)(1): Accept CMP 11 SUBMITTER: TSC-Nomina] Voltage

I ~ 17 Change "volts" in the lef t column heading to read Volts"

SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept as Revised:

I In addition, f i r s t l ine of f i r s t column should read "240 or less" and second line of the f i r s t column "over 240 through 600." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-12(e)-(New): Accept CMP 11 SUBMITTER:, Idaho Chapter IAEI I~TOIsl~S'AT~. • 18 Add a section (e) to Section 430-12. ~ q u i p m e n t Grounding Connections. Equipment grounding connection devices or f i t t ings as required by Section 250-113 shall be provided at motor terminal housings. Such devices or f l t t ings shall be located so that the equipment grounding conductor may be terminated either inside or outside the motor terminal housing. SUBSTANTIATION: Termination f i t t ings for grounding conductors are not provided in motor terminal housings. Use of the cap screws that fasten the motor terminal housing to the motor is a violation of Section 250-i14(a). Th~ connection device or f i t t i ng should be installable for use inside or outside the motor terminal housing. This would then be compatible with the permissive methods of Section 250-79(e) Installation-Equipment Bonding Jumper. PANEL RECOMMENDATION: Accept as Revised:

(e) Equipment Grounding Connections. A means for connection of an equipment grounding conductor in accordance with Section 250-113 shall be provided at motor terminal housings for wire-to-wire connections or fixed terminal connections. The means for such connections shall be permitted to be located either inside or outside the motor terminal housing.

Exception: Where a motor is installed as a part of factory-wired equipment, which is required to be grounded and without additional connection being required at the motor terminal housing during equipment installation, a separate means for motor grounding at the motor terminal housing shall not be required. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-14(a): Reject CMP 11 SUBMITTER: O. E. Dillon Border County Div. IAEI

19 Revise as follows: ~ e n t i l a t i o n and Maintenance. Motors shall be accessible to fac i l i ta te maintenance, such as lubrication of bearing and replacing of brushes can be readily accomplished. Ventilation wil l be sufficient to prevent the temperature rise of the motor from exceeding that temperature for which the motor is rated. SUBSTANTIATION: The use of the words "adequate" and "readily" render thls section legally unenforceable. See the attached opinion of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for CMP 1 Proposal No. go for 110-16(a).

• PANEL RECOMMENDATION: Reject. PANEL COMMENT: No significant contribution to safety would result. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

195

430-16: Reject CMP 11 SUBMITTER: O. E. Dillon, Border County Div. IAEI PITOIRT~_-~.'20 Revise as follows:

Exposure to Dust Accumulation. In locations where dust or f lying material collects on or in motors in such quantities as to cause the motor temperature to rise beyond its rating, a motor that wil l not overheat under the prevailing conditions shall be used. Conditions may require the use of enclosed pipe-ventilated motors, or enclosure in separate dust-tight rooms, ventilated from a source, of clean air. SUBSTANTIATION: The use of the words "seriously interfere" and "dangerous temperatures" renders this section legally unenforecable. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for CMP 1 Proposal No. for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: No significant contribution to safety would result. VOTE ON PANEL RECO~bMENDATION: Unanimously Affirmative.

430-22(a): .Accept CMP 11 SUBMITTER: J. J. Kark, National Electrical Manufacturers ~ o n PROPOSAL: 21 Revise the f i r s t paragraph to read as follows:

Branch-circuit conductors supplying a single "AC" motor, "or a DC motor operating from a source other than a rectif ied single-phase AC supply," shall have an ampacity not less than 125 percent of the motor ful l- load current rating.

Add the following new paragraph between the existing second and third paragraph (retain the existing paragraph entitled "Exception" as the fourth paragraph):

In case of direct-current motors operating from a single-phase power supply, the conductors between the controller and the motor shall have an ampacity of not less than the following percent of the motor ful l- load current ratinggiven in Table 430-147:

(1) Where a rect i f ier bridge of the single-phase half-wave type is used, 190 percent•

(2) Where a rect i f ier bridge of the single-phase full-wave type is used, 150 percent. SUBSTANTIATION: This proposal recognizes the existence of significant form factors for integral-horsepower motors operating from single-phase power supplies and the need t o select conductors on the basis of rms current rather than on the basis of average current. CMP-11 may wish to edi tor ia l ly restructure this section for any c lar i ty believed necessary to incorporate the intent of the proposal. PANEL RECOMMENDATION: Accept as Revised:

Change existing Exception to Exception No. 1 and add the following as Exception No. 2:

Exception No. 2: For direct current motors operating from a rectif ied single-phase power supply, the conductors between the controller and the motor shall have an ampacity of not less than the following percent of the motor ful l- load current rating:

a. Where a rect i f ier bridge of the single-phase half-wave type is used, 190 percent.

b. Where a rect i f ier bridge of the single-phase full-wave type is used, 150 percent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-Part C: Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA PROPOSAL: 22 Revise Part C Title as follows: ~ t o r and Branch Ciruit Overload Protection. SUBSTANTIATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

436-32 (a)(1) : Accept CMP 11 SUBMITTER: A. P. White, At t leboro, NSA I~-R-O-FD-S-A-[-[. " 23 In the last paragraph, delete the words "motor-running" and replace with the word "motor." SUBSTANTIATION: See A. P. White substant iat ion for proposal fo r U1agram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-32(b): Accept CMP 11 SUBMITTER: Roger C. Troupe, Fremont, NB ~ 2 4 Amend section t i t l e to read: One Horsepower or ~ n a u t o m a t i c a l l y Started. SUBSTANTIATION: Section (b) is designed to be more lenient in respect to the overload protection of motors, one horsepower or less, not permanently installed, and within sight from the location of the person starting them. Emendation of the wording in the manner shown wil l make i t specifically understood that paragraph (b) concerns motors started by personal intervention, not just those started by a manual-type controller. (Note:

NONAUTOMATIC, as defined in Article 100.) Additionally, i t will make clear that Sections (b) and (c) outline the required overload protection on all continuous-duty motors rated one horsepower or less. PANEL RECO~IENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-32(b)(1), Exception: Accept CMP 11 SUBMITTER: TSC-Nominal Voltage

25 Change "125 volts" to "127 volts" ~UU$1ANIIATION: To conform to the guidelines established by the TSC on Nomlnal Voltages. PANEL RECOMMENDATION: Accept as Revised:

I "Any such motor shall be permitted on a nominal 120 volt branch circuit protected at not over 20 amperes." VOTE ON PANEL RECO!~ENDATION: Unanimously Affirmative.

430-32(d): Accept CMP 11 SUBMITTER: A. P. White Attleboro, MA

, ~ 26 Delete the word "running." ~!~'ARTIATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-34: Reject CMP 11 SUBMITTER: Charles B. Kish, The Travelers Insurance CoL l~TOI~S'AL-~.27" Delete the reference to "Section 430-32 (a)(1)." ~]I~:'~TI'IATION: While I agree that for motors of one horsepower or less as referred to in Section 430-32 (c)(1) the higher overload relay tr ip settings may be necessary due to heater sizes available, and possibility of a serious accident is not great; the use of oversize heaters on motors over one horsepower referred to in section 430-32 (a)(1) is unwarranted and dangerous. The ~ount of destructive power available in the larger motors, is much greater. This danger is further compounded i f used in a three phase circuit and single phasing is caused by one line opening.

'PANEL RECOMMENDATION: Reject. PANEL COMMENT: No evidence to support the suggested change. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 15. NEGATIVE: Gubany, Kish.

EXPLANATION OF VOTE: GUBANY: I am voting negative on Panel rejection as I agree

with the author's supporting comments. With the ever decreasing size and thermal capacity of motors, i t is more important than ever that.motors be protected at values closer to their name plate ratings.

KISH: Based on my original substantiation remarks for this proposal that I submitted -- "While I agree that for motors of one horsepower or less as referred to in Section 430-32(c)(1)

t he higher overload relay tr ip settings may be necessary due to heater sizes available, and possibility Of a serious accident is not great; the 'use of oversize heaters on motors over one horsepower referred to in Section 430-32(a)(1) is unwarranted and dangerous. The ~ount of destructive power available in the larger motors is much greater. This danger is further compounded i f used in a three phase circuit and single phasing is caused by one line opening." In addition I feel that when larger heaters have to use i t indicates a misapplication of the motor and we should not exceed the normal ,heater s~ze in order to compensate for thls error.

430-34: Reject CMP 11 SUBMITTER: Marvin T. Stevens, Greendale, WI l~TOl~O~FA1-~. • 28

Selection of Overload Relay. . (a) Class Designation. I f not shunted during the starting

period of the motor as provided in Section 430-35, the class designation of the overload relay selected in accordance with Sections 430-32(a)(1) and 430-32(c)(I) shall not exceed the maximum overload relay class shown on the motor nameplate. Fine print note. See Section 430-40 for definitions.

(b) Maximum Protection Rati'oL Where the overload relay selected in accordance with Section 430-32(a)(1) and 430-32(c)(1) is not sufficient to start the motor and accelerate the load, an overload relay with a higher class designation shall be used, provided the conditions of Section 430-34(a) are met. Where the overload relay of the highest permissible class is not sufficient to start the motor or to carry the load, the next higher size overload relay of the highest permissible class as shown on the motor nameplate shall be permitted to be used, provided the rating (tr ip current) of the overload relay does not exceed the following percentage of motor fu11-1oad current rating:

Motors with marked service factor not less than 1.15 . . . . . . . . . . . 140 percent Motors with a marked temperature rise not over 40°C . . . . . . . . . . . . . . 140 percent All other motors . . . . . . . . . . . . 130 percent SUBSTANTIATION: See related proposals for Section 430-7(a), motor namepTate marking, and for Sect!on 430-40, overload relay marking.

Section 430-34 as presently written states that "the overload device shall have sufficient time delay to permit the motor to start and accelerate its load" without providing any means for a user to select an overload relay to meet this requirement. The control industry in NEMA Standard Part ICS 2-222 and a nationally recognized testing laboratory in ANSI C33.76-1976 provide class designations as a way of indicating the time available for the motor to accelerate its load to rated speed.

When a user selects the next higher size overload relay of a lower class designation rather than one with a lower ratio of tr ip ~current to motor full-load current, he sacrifices protection unnecessarily. By taking ful l advantage of an existing class designation system, the user can provide sufficient time for this motor and load to accelerate and s t i l l retain the best running overcurrent protection.

For example, i f a Class 10 overload relay selected in accordance with Section 430-32 does not provide sufficient time for a service factor 1.0 motor to accelerate, present Section 430-34 raises the maximum permissible overload relay tr ip current from 115 percent to 130 percent of motor full-load current. I f the load inertia is within that specified for the motor (as i t should be) then the fault lies with the overload relay and i t must be changed. However by changing to a higher class designation rather than a higher tr lp current, the user can bring his motor up to speed and s t i l l retain 115 percent protection. Typical insulation l i fe for a Class B insulated service factor 1.0 motor when operated at 115 percent of motor full-load current is 5,000 hours compared to go0 hours when operated at 130 percent of motor full-load current.

The ~lass designation system for overload relays provides for motor acceleration without sacrificing running overcurrent protection and should be used to reduce motor burnout, a significant cause of electrical f ires. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primarily a design consideration. ~ R E C O M M E N D A T I O N : Unanimously Affirmative.

430!35{a): Accept CMP 11 SUBMITTER: A. P. White, Attleboro,'MA PROPOSAL: 29 Delete the word "running" in line 2. ~]B'~FA-N-I~IATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-35(a): Accept CMP 11 SUBMITTER: Roger C. Troupe, Fremont, NE PITO-I~]~-~.'30 Amend section to read: Nonautomatically

For a nonautomatically started motor, the running overload protection may be shunted or cut out of the circuit during the starting period, cut out cannot be lef t in the starting position and i f fuses or inverse time circuit breakers rated or set at not over 400 percent of the full-load current of the motor are so located in the circuit as to be operative during the starting period of the motor. SUBSTANTIATION: Substitution of the word, nonautomatlcally, for manually In both instances makes i t readily understood that Sections (a) and (b) are integral.

I t also allows the elimination of the explanatory sentence in parentheses which reads "including starting wlth a magnetic starter having pushbutton control," as the word nonautomatic already has that meaning by the definition given i t in Article 100. PANEL RECOMMENDATION: Accept as Revised:

In third line remove "running" and replace "may" with "shall be permitted to."

In the 4th line replace the comma with "of the motor i f the device by which the overload protection is shunted or." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-35(b): Accept CMP 11 SUBMIT-rER: A. P. White, Attleboro, MA !~TOIR~'A-L-~.31 Delete the word "running" in line one. ~:[]I~'TA]TTIATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

196

430-37: Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA .l~ArOPO-S'AL-~.32 Delete the word "running" In line 2. ~'T;~ITTIATION: See A. P. White substantiation for proposal for Dlagram 430-I PANEl. RECOMMENDATION: Accept. VOTE ON PANEL RECOI~ENDATION: Unanimously Affirmative.

Table 430-37: Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA-

I IJRUPUbAL: 33 Delete the word "running" in the t i t l e . ~'IIb-S"FAI~rIATION: See A. P. White substantiation for proposal for Diagram 430-I. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOP~IENDATION: Unanimously Affirmative.

430-38: Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA

I ~ 34 Delete the word "running" in line 2. ~Jl]~TTA]~I'IATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMI~ENDATION: Unanimously Affirmative.

430-39: Accept CMP 11 SUBMITTER: A. P. White, Attlebo'ro, MA J

I ~ 35 Delete the word "running" in line 2. ~S'~'A]~TIATION: See A. P. White substantiation for proposal for Diagram 430-I. PANEL RECO~HENDATION: Accept as Revised:

I Also delete "Running" in t i t l e . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-40: Accept CMP 11 SUI~HITT£R: A. P. White, Attleboro, MA

I ~ 36 Delete the word "running" in line 2. ~'UI~'A]~IATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430~40: Accept CMP 11 SUBMITTER: Kenneth L. Paape, Allen-Bradley Co. !~TOPO'S'At-~. 37 Add a new paragraph as follows:

overload relays shall be marked with their short-circuit, withstand rating. Where a current element selection table is furnished with the overload relay, showing the current element short-circuit withstand ratings (or a method for determining them) on the table shall be permitted. SUBSTANTIATION: Section 110r10 requires those components that do not play an active role in clearing a short-circuit to have a short-circuit withstand rating which must be considered in selecting an overcurrent device. Manufacturers of thermal overload relays can measure or calculate the amount of energy that each current element can absorb without burnout under short-circuit conditions in order to qualify for l isting by a nationally recognized testing laboratory ( i .e . , select the proper fuse for short-circuit testing). This energy is equal to the resistance of the thermal element multiplied by the I2t let through by the fuse under short-circuit conditions. Hence the short-circuit withstand rating of the current element can be expressed in terms of 12t. Seme overload relay current elements designed foF low ful l load motor currents (wire coil type) can also be destroyed by the mechanical effect of high fault currents, Ip. For such designs a maximum Ip withstand rating would also have to be specified.

Users of motor control equipment have indicated to us that short-circuit withstand ratings ought to be furnished with the overload relay so that those who wish to protect current elements from burnout under short-circuit conditions have the information required to do so., They would install short circuit protective devices that l imit the 12t and Ip to not more than the withstand ratings of the overload relays. L~sted short circuit protective devices are available to provide this level of protection.

Standards' presently used by nationally recognized testing laboratories "permit l isting of controllers with overload relays that burn open and cause arcing under short-circuit conditions. Merely complying with the Code or the information furnished with the overload relay does not provide the user with sufficient information to protect his current elements from burnout i f he considers such protection essential. A standard method of designating the short-circuit rating of thermal overload relays is required so that manufacturers of short-circuit protective devices can respond in like terms. PANEL RECOMMENDATION: Accept. V~TE ON PANEL RECOMMENDATION:

AFFIRMAIIVE: 13. NEGATIVE: Cannady, Mierendorf, White, Wood.

EXPLANATION OF VOTE: CANNADY: I wish to register my vote negative on Proposal No.

37 since this would require a marking that is presently permitted. I t should not be required at this time since I t wil l mislead those in the f ield and become a requirement for inspection where I t is intended only to supply information.

MIERENDORF: Proposal No. 37 deals wlth the important subject of component coordination with. short circuit protective devices under short circuit conditions.

Information regard!ng 12t and I~ let-through values for short circuit protectlve oevlces ?or a range m values of short circuit currents is not yet available.

Because of application problems inherent when information is incomplete, this proposal is not yet appropriate for inclusion in the Code.

WHITE: Such practice is not prohibited by the present Code and application problems are involved which make this proposal inappropriate for the NEC.

WOOD: This proposal should be rejected as thls practice is not presently prohibited by the Code. I t is improbable that the installer wil l have suf~iclent information at the Job-slte to properly implement this type of requirement.

430-40: Reject CMP 11 SUBMITTER: Marvin T. Stevens, Greendale, WI VKUVU3AL: 38 Revise as follows: ~F~J-O'z2RT~-.Thermal Cutouts and Overload Relays.

(a) Protection. Thermal cutouts, overload relays, and other devices for motor-running overload protection that are not capable of opening short circuits shall be protected by fuses or circuit breakers with ratings or settings in accordance with Section 430-52 or by a motor short-circuit protector In accordance with Section 430-52.

Exception No. I : Where approved for group installation and marked to indicate the maximum size of fuse or inverse time circuit breaker by which they must be protected.

Exception No. 2: The fuse or circuit breaker ampere rating shalI be permitted to be marked on the nameplate of approved equiI~nent in which the thermal cutout or overload relay is used.

For instantaneous tr ip circuit breakers or motor short-clrcuit protectors, see Section 430-52.

(b) Overload Relay Class Designation. An overload relay, or the current element selection table that is provided where the overload relay includes replaceable current elements (heaters), shall be marked with its class designation.

Fine print note. Definition: The class designation of an overload relay is a number that indicates the maximum time (In seconds) in which the overload relay wil l function when carrying a current equal to 600 percent of its current rating.

Fine print note. Definition: The current rating of an overload relay is the minimum value of continuously applied current that is expected to cause all like relays to function (tr ip) under designated conditions. This value, for an individual relay, may equal or exceed its ultimate tr ip current under these conditions. SUBSTANTIATION: Related proposals have been submitted (I) to revise Section 430-34 to provide the means by which a user selects the overload relay that has "sufficient time delay to permit the motor to start and accelerate the load" and (2) to add a maximum overload relay class designation to the motor nameplate (430-7(a)). All three proposals should be considered as a package.

The overload relay class designation system offers a way to provide better running overcurrent protection for motors without increasing manufacturing or installation costs. PANEL RECOMMENDATION: Reject. PANEL COI~IENT: Proposal is primarily a design consideration. VUIL ON PANtL RECOMMENDATION: Unanimously Affirmative.

430-41-(New): Reject CMP 11 SUBMITTER: Kenneth L. Paape, Allen~Bradley Co., Milwaukee, WI PROPOSAL: 39 Add new section as follows: ~ . Overload Relay Classes. Overload relays or controllers which include overload relays shall be marked with their class designation. Where a current element selection table is furnished with the overload relays, showing the class designation on the table shall be permitted. SUBSTANTIATION: For many years Underwriters Laboratories had a performance requirement in their standard for Industrial Control (UL503) that required each overload relay to tr ip at 600 percent of its current rating within 30 seconds. The current rating of an overload relay is that current which when continuously applied to the relay wil l ultimately cause i t to tr ip. For a motor having a service factor of 1.0, the minimum ratio of relay rating to motor ful l load current permitted by Section 430-32 is 115 percent. Control manufacturers provide a table which permits the installing electrician to select an overload relay element and automatically comply with this requirement.

When T-frame motors became a major factor in industrial applications, Underwriters Laboratories changed the performance standard to 20 seconds. In order to maintain a UL l ist ing, control manufacturers then had to show that their overload relays responded in not more than 20 seconds to a current equal to 600 percent of the overload relay rating. This change was to

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match the reduced thermal overload capability of T-frame motors. Too many motors were burning out under locked rotor conditions with the 30 second maximum overload relay design.

Concurrently motor manufacturers recognized that some of their motors, particularly those associated with air conditioning and refrigeration equipment had even shorter permissible locked rotor time and they demanded from the control industry a line of overload relays that were called "Fast Tripping." Meanwhile, original equipment manufacturers and industrial users who had high inertia loads attached to their motors realized that very often the new 20 seconds maximum overload relay was too fast and would tr ip out before the motor and its high inertia load came up to speed. They needed a line of "Slow Tripping" overload relays.

A few years ago Underwriters Laboratories, in conjunction with representatives of the control industry, developed the concept of class designations for overload relays. These class designations are in the NEMA Standard for Industrial Control (ICS-1970) and UL508. The essence of the class designation is the maximum time (in seconds) in which the overload relay must operate when subjected to a current equal to 600 Rercent of its current rating. The end result is that Class 10, Class 20, and Class 30 overload relays are available'in today's marketplace.

.Any one of them can be used for a given fu l l load motor current. Thus for any one motor ful l load current a user can select any one of 3 relays, each with the same current rating, but a different class des4gnation. Under continuous overload conditions all 3 relays will ultimately tr ip at the current equal to their common rating, but their response time to a locked rotor or a longer start period is dramatically different.

Attached are the time-current characteristics of the 3 classes of relays, each having the same maximum ultimate tr ip characteristic permitted under Section 430-32 for a service factor 1.0 motor. Also shown on the attachment is a tabulation of the marked decrease in insulation l i fe as a result of subjecting the motor windings to overtemperature. Note that curren~ is expressed as multiples of motor full-load current, not mu~tlples of relay ratings.

Section 430-34 recognizes the problem of bringing a motor and its associated high inertia load up to speed by permitting an increase in the protection factor under such conditions to 130 percent of motor full-load current for a service factor 1.0 motor. We believe that there is less danger of motor burnout and hence a reduced f i re hazard i f instead of moving to an overload relay with higher ultimate tr ip current as provided by Section 430-34, the user would select a higher class designation overload relay. In this way he could obtain more locked rotor time without sacrificing protection under running conditions.

We fe l t that the way to start was to add class designations for overload relays in 2 places in the Code; f i r s t a new section proposed as 430-41, secondly under motor marking requirements (430-7). We fe l t that motor manufacturers and manufacturers of motor ~iven equipment would both know the overload capability and inertia of their equipment and thus be the most qualified to select the class of overload relay that provides optimum protection for the motor and yet precludes the nuisance tripping which necessitated Section 430-34. I t was our hope that once proposals such as we have submitted for Sections 430-7(a) and 430-41 were incorporated Into the Code, consideration could be given to modifying Section 430-34 in some way so as to solve the problem of nuisance tripping without sacrificing running overcurrent protection. PANEL RECOt~MENDATION: Reject. PANEL COMMENT: The CMP believes that'extending the requirements as indicated by this Proposal is not necessary as the Code now permits this marking. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 15. NEGATIVE: Lopez, Schram.

EXPLANATION OF VOTE: LOPEZ: See Comment on Proposal No. 8. SCHRAM: See explanation of negative vote on Proposal No. g.

I believe this proposal should be accepted with a revision to add a definition of the overload relay class designation, such as the f i r s t fine print note included in Proposal No. 38, Section 430-40.

430-42(a): Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA

. ~ 4 0 Delete the word "running" in line 2. ~'I~s'rAI~rFIATION: See A. P. White substantiation for proposal for Diagram 430-I. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-42(a) and (b): Reject CMP 11 SUBMITTER: Warren Anderson, Mount Vernon, WA PRUPOSAL: 41 Delete 430-42(a) and (b) and relocate (c) and (d) ll-6-S'-6~-Ton 430-53. SUBSTANTIATION:

A. 430-4Z{a} and (b) should be eliminated as i t directly contradicts 430-53(a) and (b). 430-53(a) states three rules that motors under I HP must follow. They are: (1) Maximum FLC = 6 amps.

(2) Do not exceed device marking. (3) Individual running overload protection conforms to Section 430-52.

However, 430-42(a) states that you Just have to apply rule (1) and (2) (as listed above) but not (3). This is a direct conflict. Also the overload protection as stated in Section 430-52 is essential and clearly defined in the code.

B. Section 430-42(b) basically restates rule 430-53(a)3, and therefore is unnecessarily redundant, and should be eliminated.

C. Summary: 1. Eliminate Section 430-42(a). 2. Eliminate Section 430-42(b). 3. Move Section 430-42(c) and (d) to 430-53.

PANEL RECOMMENDATION: Reject. PANEL COMHENT: The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-42(b): Accept CMP 11 SUBMITTER: A. P; White, Attleboro, MA ~ 4 2 Delete the word "running" in lines 3 and 5. ~]]~?r~I~rIATION: See A. P. White substantiation for proposal for Diagram 430-I. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously AfFirmative.

430-42(c): Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA

I ~ 4 3 Delete the word "running" in lines 3 and 8. ~I]ITS'FAITTIATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-43: Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA PROPOSAL: 44 Delete the word "running" in llne one. ~'I]I~'II~'FIATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-51: Accept CMP 11 SUBMITTER: CMP 11 PROPOSAL: 44A Add a new sentence between second and third ~ s of the f i r s t paragraph reading: "The devices specified in Part D do not include the types of devices required by-Sections 210-8 and 230-95." SUBSTANTIATION: Officlal Interpretation No. 75-1. PANEL RECOMMENDATION: Accept as Revised:

In Section 430-51, add a new sentence after the second sentence of the f i r s t paragraph reading: "The devices specified in Part D do not include the types of devices required by Sections 210-8 and 230-95. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-52: Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA ~ 4 5 Delete the word "running" in lines 2 and 7. 5UBSrANIIATION: See A. P. White substantiation for proposal for Diagram 430-I. PANEL RECOMMENDATION: Accept as Revised:

Delete the word "running" in lines 2 and 7 of the second paragraph only. In thSrd paragraph, line I , and in last paragraph, line 1, insert the words "short-circuit and ground-faul't" after the words "branch-circuit." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

~30-52: Accept CMP 11 SUBMITTER: TSC-Approved for the Purpose PROPOSAL: 46 See the Technical Subcommittee "Recommendations" under the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

In secona paragraph in lines 3 and 4 and also lines g and 10 (2 places) delete "and i f the combination is especially approved for the purpose"; insert "and" in place of comma in line i ; insert "and" between "conductor" and " i f " in llne 8; add new sentence at end of paragraph, "An instantaneous tr ip circuit breaker or motor short-circult protector shall be used only as part of a combination motor controller which provides coordinated motor branch circuit overload and short-circuit and ground-fault protection."

Make the following additional changes in Section 430-52.

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\

( I) Delete third paragraph and make wording of third paragraph Exception No. 1 to f i r s t paragraph. Delete Exception under existing third paragraph and rearrange as new Exception No. 2 to f i r s t paragraph, as follows: °Exception No. 2: Where the rating specified in Table 430-152 is not sufficient for the starting current of the motor: a. (same as (a) of existing Exception}. b. (same as (b) of existing Exception). c. (same as (e) of existing Exception). d. (same as (f) of existing Exception). ~ Make new Exception No. 3 to f i r s t paragraph, same as Item (d) of existing Exception. Make new Exception to second paragraph as follows: "Exception: Where the setting specified in Table 430-152 is not sufficient for the starting current of the motor, the setting of an instantaneous t r lp circuit breaker shall be permitted to be increased but shall in no case exceed 1300 percent of the moto~ ful l- load current. ~ VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-52: Accept CMP 11 SUBMITTER: Joseph L. Yosafat, General Electrlc Co. ~ 4 7 Add a new paragraph at end of 430-52 as follows: "--S"~Tt-~b-le fuses shall-be permitted in lieu of devices listed in Table 430-152 for an adjustable speed drive system provided that the marking for replacement fuses is provided adjacent to the fuses. SUBSTANTIATION: Fuses now recognized by the Code for short c ircui t protection for adjustable speed drives provide inadequate protection for the drive semiconductors. As semiconductors have very small thermal capacities, very fast acting energy limiting fuses are ~equired.

These same fuses provide adequate short circuit protection for other devices in the branch circuit as these other devices have larger thermal capacities as demonstrated by short circuit tests. These fuses are used only for short circuit protection and are coordinated with other approved means for providing overcurrent protection in.the adjustable speed drive system. Marking wll l assure that the replacement fuses provide the fast protective action required. PANEL RECOMMENDATION: Accept as Revised:

Add a new paragraph at the end of 430-52 as follows: For an adjustable speed drive system, special purpose fuses

for protection of semiconductors shall be permitted in lieu of devices listed in Table 430-152, provided that:

(a) The fuse(s) is part of a controller having motor overload and also short-circuit and ground-fault protection in each conductor.

(b) The combination provides coordinated motor branch circuit overload and short-circuit and ground-fault protection,

(c) Marking for.replacement fuses is provided adjacent to the fuses. VOTE ON PANEL RECOMMENDATION: - AFHRMATIV~: 16.

NEGATIVE: White. EXPLANATION OF VOTE:

WHITE: Thls proposal should be rejected because i t is incomplete and confusing. The proposed format is faulty where i t does not include a requirement for maximum permissible fuse rating as is done for all the other items in Section 430-52. Additionally, there is no reason to l imit this proposal ~o a controller having overload and short circuit and ground faul t protection i f the same limitations on fuse rating apply as for nontime delay fuses in Section 430-52 and Table 430-152, since to do so would prevent the use of other forms of overload protection permitted in Section 430-32. The proposal woul~ therefore become unnecessarily restr ict ive and mandate the addition of one form of protection even though other acceptable protection was provided. I t was indicated during Panel discussion that the maximum fuse rating could be specified to be the same as for nontime delay fuses; the original proposal should be restored with the nontime delay fuse rating limitation added.

430-52: Reject CMP 11 SUBMITTER: J. CannateITi, Gould Inc.

48 Change the wording of paragraph 2 to read: ~ t a n t a n e o u s t r lp circuit breaker shall be used only i f a~justable and motor-running overload protection is provided in each conductor. A motor short circuit protector shall be permitted in lleu of devices listed in Table 430-152 i f motor-running overload protection is provided in each conductor and i f i t wil l operate at not more than 1300 percent of- fu l l - load motor current. SUBSTANTIATION: This would remove the restriction that instantaneous trip" type circuit breakers and motor short circuit protectors need to be in a combination controller. I t will allow both types of devices to be fu l l y UL listed as opposed to being Recognized Components, and be applied as separate devices.

The time'current curve represented by an overload relay and either the instantaneous c.b. or motor short circuit protector provides greater protection for a motor and its branch circuit conductor than the allowed settings or ratings of inverse time c.b. or non-time delay or time delay fuses.

Both the instantaneous c.b. and the motor short circuit• protector have NEC specified high fault limits - 1300% for motor short circuit protectors (430-52) and 1300% for instantaneous.

c.b. (430-52 ex: c). There isn' t any upper l imit specified for the other means of branch circuit protection.

In the overload range, overload relay curves better duplicate motor damage curves and thus can be adjusted to t r ip sooner and provide increased protection.

By allowing the instantaneous t r ip circuit breaker or motor short c ircui t protector to be applied separate from the co{nblnation controller, branch circuit short circuit and ground fault protection will be provided by these devices, while overload protection wll l be provided by the heaters, which are at the load end of the branch circui t . There shouldn't be concern over the protection of the conductors as other sections of the Code allow up to 25 f t . of unprotected feeder taps, with protection at the load end. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The evidence submitted is inconclusive. vuIt ON PANEL RECOI~ENDATION: Unanimously Affirmative.

430-52: RejeCt CMP 11 SUBMITTER: Claude E. Deering, Jr., American Petroleum Institute PRDPOSAL: 49 Delete the words "and ground-fault" in the f i r s t paragraph and in 'two places in the second paragraph. SUBSTANTIATION: The wording of Section 430-52 in the 1978 Code Is the same as in the 1975 Code. I t was changed edi tor ia l ly from the 1971 Code, and the words "and ground fault" were added in three places. The present wording can be interpreted to require special ground-fault protective devices in each motor branch circui t .

Official Interpretation No. 75-I, dated February 18, 1975, stated that i t was not the intent of Section 430-52 of the 1975 Code to require any form of ground-fault protective device beyond that provided by the motor branch-circuit overcurrent device specified in Article 430-52 of the 1971 Code. I t is recommended that specific references to ground faul t protection be eliminated from Section 430-52 to c lar i fy the meaning, in line with Official Interpretation No. 75-1. PANEL RECOi~ENDATION: Reject. PANEL COMMENT: See action on Proposal No. 44A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-52, Exception Nos. 2 and 3: Reject CMP 11 SUBMITTER: Kenneth L. Paape, Allen-Bradley Co. ~ 5 0 Add new exceptions as follows:

Exce~ion No. 2: Where the motor ful l- load current is less than 3.75 amperes in a polyphase motor circui t and the motor

/ controller includes motor-running overcurrent protection in each conductor, an adjustable instantaneous t r ip circui t breaker, not as part of a combination motor controller, shall be permitted to serve as the short-circuit and ground-fault protective device, providedthe length of the conductors between the instantaneous t r ip circuit breaker and the motor controller does not exceed 25 feet, and the conductors are suitably protected from physical damage.

Exception No. 3: Where the motor ful l- load current is' less than 3.75 amperes in a polyphase motor circui t , the rating of an inverse tlme circuit breaker shall not exceed 400 percent of the ful l- load current. SUBSTANTIATION: Section 430-52 requires that the setting of an instantaneous tr ip circuit breaker shall in no case exceed 1,300 percent of motor fu l l load current. Hence the worst case condition permitted by Exception No. 2 proposed above would be an instantaneous t r ip circuit breaker set for 48.62 amperes to protect a motor with ~ ful l- load current of 3.74 amperes, Where the ful l- load current is less than 3.74 amperes, the maximum permissible t r ip s~tting is proportionally less. Motor circui t conductors for motors having a ful l- load current of less than 3.75 amperes have ampacities not less than 15. (Table 310-16 specifies 15 as the minimum ampacity of #14 AWG wire and 21 as the ~npacity of #18 AWG wire, the latter shown only for 90 degrees Celsius insulation.)

The current elements (heaters) for overload relays usually used to provide motor running overcurrent protection in polyphase motor circuits have a resistance inversely proportional to the square of their current rating. Thus the lower the motor ful l- load current, the higher the resistance of the current element.

The smallest standard rating of an inverse time circuit breaker is 15 amperes. Inverse time circuit breakers rated 15 amperes t r ip instantaneously at approximately 105 amperes or more,

As the resistance of the current elements in the circuit increases, the magnitude of any fault which can be produced on the load side of the elements decreases to.the point where i f a short-clrcuit occurs in a 240 volt system supplying a motor with a ful l- load current of one ampere or less, the maximum fault current is not sufficient to activate the instantaneous t r ip mechanism of an inverse time circuit breaker, r~gardless of the short-circuit current available at the line terminals of the circuit breaker. For every supply voltage and any fault current available at the circuit breaker line terminals, there is some overload relay current element appropriate for the motor ful l- load current where there is no instantaneous tripping action by'a 15 ampere inverse time circuit breaker possible, because of the element's resistance. A faul t current greater

199

than 1,300 percent of motor full- load current that is not sufficient to tr ip an inverse" time circuit breaker instantaneously subjects the overload relay element to a current beyond its l imit of self protection and the element burns open before the inverse time portion of the circuit breaker can cause the breaker to t r ip. When the current element burns open i t arcs and usually causes a new short-circuit within the controller enclosure. This second short-circuit is now not limited by the resistance of the current element and the circuit breaker now responds instantaneously, but only after the overload relay has been severely damaged.

Adjustable instantaneous tr ip circuit breakers rated less than 15 amperes are commercially available, some with tr ip settings as low as 7 amperes. By using instantaneous tr ip circuit breakers in lieu of inverse time circuit breakers in motor circuits where the full-load current is less than 3.75 amperes, immediate instantaneous tr ip action by the circuit breaker can be obtained. The risk involved in having up to 25 feet of conductors between a separately mounted instantaneous tr ip circuit breaker and its associated motor controller protected against short circuit and ~round faults at not mere than 324 percent of their mnpacity tworse case is 48.62/15 : 3.24} is less than the 333 percent permittedfor transformer feeder taps by Exception No. 8 under Section 240-21..

The wording of proposed Exception No. 3 is such that i t should encourage development and avai labi l i ty of polyphase inverse time circuit breakers that are rated less than 15 amperes and have time versus current-to-trip characteristics lower than those for inverse time circuit breakers rated 15 amperes. When such circuit breakers are available, they could be recognized as standard sizes in Section 240-6.

Note that this proposal would not restr ict the use of 15 ampere inverse time circuit breakers in single phase motor circuits. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary. The Panel belleves that extending the requirements as intended by this Proposal is not appropriate at this time. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-52, Exception No. 2-(New): Reject CMP 11 SUBMITTER: Idaho Chapter IAEI

51 In Section 430-52 change "Exception" to ~l~-~-~-t-fon No. i . " Add a new Exception No. 2.

Exception No. 2: The values given in Table 430-152 shall not apply to adjustable speed drive motors when the power conversion equipment provides overload protection for the motor. Additional protection is not then required. SUBSTANTIATION: Section 430-52 does not address short-circuit and ground-fault protection for the branch circuits of D.C. motors on the load side of power conversion equipment for . adjustable speed drives. Section 430-2 Adjustable Speed Drive Systems in the f i rs t paragraph, second sentence, gives much inferred requirements. This sentenceshould be deleted from Section 430-2 and moved to Section 430-52 where i t belongs. In the f ield some manufacturers of adjustable speed drive equipment are providing neither overload or short-clrcuit and ground-fault protection for the D.C. motors and branch circuit conductors. This requirement should b~ clarif ied in the proper section of the Code. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel's action on Proposal Nos. 5 and 47, Sections 430-2 and 430-52. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-53(a): Accept CMP 11 SUBMITTER: TSC-Nominal Voltage I~TO]~-O-~L-T. • 52 Revise the text as follows:

"Several motors each not exceeding one horsepower in rating shall be permitted on a nominal 120 volt branch circuit protected at not over 20 amperes or a branch circuit of 600 volts, nominal, or less protected at not over 15 amperes, i f all of the following conditions are met:" SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-53(a)(3): AcE~pt CMP 11 SUBMITTER: A. P. WHite, Attleboro, MA

;I}ITOI~OSAIZ-T. 53 Delete the word "running." ~]B-S"FAI~I'IATION: ,See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept as Revised:

Add to proposal - In paragraph (a)(2) insert the words "short-clrcuit and ground-fault" after the words "branch-clrcuit." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-53(b): Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA

I ~ 5 4 Delete the word "running" in line 4. ~I]ITS'TAI~FIATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept as Revised:

Add to proposal - In line 1 and line 6 insert the words "short-circuit and ground-fault" after the words "branch-circuit." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-53(c): Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA PROPOSAL: 55 Delete the word "running" in lines 2 and 3. ~I]I~TTTI]TTIATION: See A. P. White substantiation for proposal for Diagram 430-1 PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-53(c)(1): Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA PROPOSAL: 56 Delete the word "running" in line one. ~'UI~S'TAITTIATION: See A. P. White substantiation for proposal for Diagram 430-I. - PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-53(c)(3): Reject CMP 11 SUBMITTER: Alton R. Thompson, Durham, NC ]~-O-PO-~'A-L-~." 57 Revise as follows: ~ a c h circuit breaker is.of the inverse time type and, i f rated more than 60 amperes, 'Is approved for group installation. SUBSTANTIATION: When fuses are required, especially on resldent~al a/c units, a raintight pull out or a raintlght switch is used. With a raintight pull out a child can put a screwdriver or a small piece of conducting material into the pull out and get a lethal shock. With a raintlght switch a child can get his whole hand in the switch and get a lethal shock. We are trying to protect small component parts and forgetting our small friends who do not know any better than to open a l id on a switch. In my own experience of 10 years of electrical contracting and specializing in air conditlon.and refrigeration inst~llations, I used inverse time circuit breakers with desirable results. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necesslty. VOTE ON PANEL RECOMMENDATION:

AFFIR~t~TIYE: 14. NEGATIVE: Cannady, White. NOT VOTING: Aquilino.

EXPLANATION OF VOTE: AQUILINO: Conslderable test data has been presented both for

and ~gainst this proposal. In view of the conflicting data, and lacking the fac i l i t ies to confirm the test results myself, I do not feel there is sufficient Justification for either an affirmative or negative vote at 'this time.

CANNADY: I vote against rejecting this Proposal because we have seen very strong evidence that circuit breakers are doing a better Job than fuses in limiting current, interrupting and protecting circuits. I feel that to reject this is discriminating against circuit breakers ~nd showing preferential treatment to fuses. " WHITE: The proposal was shown to be valid by the UL Fact-Finding data and information provided to the Panel on performance of circuit breakers and fuses in that the same level of performance is provided as presently specified.

430-53(c)(3), Exception-(New): Reject CMP 11 SUBMITTER: R.B. Boyd, Jr., Raleigh, NC

58 Add exception as follows: ~ i o n : Each circuit breaker is of the inverse time type and, i f rated more than 60 amperes, is approved for group installation. ~q SUBSTANTIATION: For many years we have treated single phase, Z50 volt window air-conditioning units as a single motor load and permitted branch circuit overcurrent protection to consist of either time limit or inverse time circuit breakers. As far as can be determined, f ie ld experience using such breakers rated at 50 amperes and less has been good. I f this information is correct, then why not permit the smaller inverse time circuit breakers to be used on residential and small commercial branch circuits within the prescribed limits. Also many such fixed installations have been and are being accepted and f ie ld reports do not indicate d i f f icu l t ies resulting from the use of smaller inverse time circuit breakers. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necesslty. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

200

430-53(d): Accept CMP 11 SUBMITTER: A. P. White, Attleboro, HA ~I~TOPO'S'AL-~.sg Delete the word "running" in line 8. SUBSTANTIATION: See A. P. White substantiation for proposal for

Diagram 430-I. PANEL RECOMMENDATION: Accept as Revised:

I Add to proposal - In llne 3 insert the words "sho~t-circuit and ground-fault" after the words "branch-circuit." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-55: Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA

, I ~ 6 0 Delete the word "running" in lines 2 and 4. ~:I]I~"~¢~IATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-59-(New): Reject CMP 11 SUBMITTER: J. M. Rice, Allen-Bradley Co.

61 Add new 430-59 as follows: ~r~o-:5"~]~ -'. Interrupting Rating. Every overcurrent protective device installed in a polyphase motor circuit where the voltage to ground exceeds 250 volts shall be marked with an interrupting rating. SUBSTANTIATION: Section 240-83(c) requires that circuit breakers be marked with their interrupting rating only i f i t is other tha~ 5,000 amperes. Section 240-60(c) requires that fuses be marked with their interrupting rating only i f i t is other than 10,000 amperes. At locations where polyphase power is supplied to motors at 480 and 600 volts there is high probability that the fault current avallable wil l exceed 5,000 amperes. Many wil l exceed 10,000 amperes.

By requiring an interrupting rating to b e marked on the overcurrent protective device there is an automatic reminder to the installer to consider the fault current available at the point of installation. Our company is aware of two cases in the past year where a serious fault occured in an industrial application and the overcurrent protective device did not clear the fault successfully. In both cases personnel were injured. We should not overlook an opportunity to ad d a requirement to the Code that will focus attention on the need to have overcurrent protective devices with interrupting ratings equal to or exceeding the fault current available. PANEL RECOMMENDATION: Reject. PANEL C~ENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOI~MENDATION:

AFPIRMJ~IIV~: 16. NEGATIVE: Gubany. " '

EXPLANATION OF VOTE: GUBANY: I am voting negative on Panel rejection since I agree

with the author's supporting comment. This proposal wil l enhance compliance with 110-9 and 110-10.

430~52(b): Reject CMP 11 SUBMITTER: Robert J. Cunningham, Duquesne Light Company l~ITOl}l~TAt-~ 62 Add a second paragraph, requiring numbering exlstlng paragraph as follows:

(b) Future Additions (1) Existing unnumbered paragraph. (2) When a motor feeder ampacity is oversized by a

specific growth factor in amperes this growth factor shall be added to "the sum of the full-load currents of the other motors of the group" in Section 430-62(a) when determining the feeder protective device rating. SUBSTANTIATION: The purpose of Part E is to allow the ratings of the protective devices on motor feeder circuits to be higher than the conductor ~npacity so that locked rotor current wil l not cause nuisance operation of the protective device during motor starting. When growth factors are designed into a motor feeder i t is intended that motors wil l be added to uti l ize this capacity. This proposal wil l allow the feeder protective device to be selected for the intended load, eliminating future nuisance operations and costly protective device changes, PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

i

430-71(a): Accept CMP 11 SUBMITTER: TSC-Control Circuit Protection PROPOSAL: 63 Delete second paragraph of Section 430-71(a). ~]~'~'AI~I'IATION: Provision covered in TSC Proposal No. 4 for ~evislon of Section 430-72. See 430-72(a). PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Gubany.

EXPLANATION OF VOTE: GUBANY: I am voting negative on Panel acceptance since i t can

be proven that No. 16 and No. 18 wire cannot be protected by a

20 ampere overcurrent protective device against some high impedance faults within the overcurrent devices rating or when hlgh short-circult currents are available. As written, this proposal violates 110-10 and 240-1 of the NEC. Also, circuit transformers cannot be protected by secondary control.circuit protection. A control transformer should have the same protection in a motor controller enclosure as well as any other enclosure. Control transformers should be protected as required in Article 450. Control transformers are a big source of f i re since the primary protection is usually much too great to provide any protection.

430-71(b)-(New): Reject cMP 11 SUBMITTER: A. C. Clark, Manufacturing Chemists Assn. PROPOSAL: 64 Add new (b) as follows: ~ o n d u c t o r size. Motor control circuit cofiductors shall be sized in accordance with Section 310-5.

Exception:' Where the motor control conductors are smaller than No. 14, the provisions of Article 725 shall apply. SUBSTANTIATION: .To correlate with companion proposal for new Exception No. 5 to Section 430-72(a). (See that proposal for additional"substantiation.) Change wil l also correlate with proposed addition of, Section 725-2(e). PANEL RECOMMENDATION: Reject. PANEL COMMENT: See action on Proposals Nos. 63 and 65. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-72: Accept CMP 11 SUBMITTER: TSC-Control Circuit Protection PROPOSAL: 65 Revise as follows: ~ . Overcurrent Protection.

(a)' General. ,A motor control circuit tapped from the load side of a motor branch-circuit short-circuit and ground-fault protective device(s) and functioning to control the motor(s) , connected to that branch-circult shall be protected against overcurrent in accordance with Section 430-72. Such a tapped control circuit shall not be considePed to be a branch-circuit and shall be permitted to be protected by.either a supplementary or branch-circuit overcurrent protective device(s). A motor control circuit other than such a tapped ~ontrol circuit shall be protected against overcurrent in accordance with Section 725-12 or 725-35, as applicable.

(b) Conductor Protection. (1) Conductors larger than No. 14 shall be protected

against overcurrent in accordance with their ampacities. The ampacities for control circuit conductors No. 14 and larger shall be those given in Tables 310-16 through 310-19, without derating factors, and the limitations of Section 310-1 shall not apply.

(2) Conductors of Nos. 18, 16 and 14 shall be considered as protected by an overcurrent device(s) of not more than 20 amperes rating.

Exception No. 1 for (I) and (2} above: Conductors which do not extend beyond the motor control equipment enclosure shall be considered as protected by the motor branch-clrcuit short-circuit and ground-fault protective device(s) where the rating of the protective device(s) is not more than 400 percent of the ampacity of the control circuit conductors for conductors No. 14 and larger; or not more than 25 amperes for No: 18 and 40 amperes for No. 16. The ampacities for conductors No. 14 and larger shall be the values given in Table 310-17 for 60 C conductors.

Exception No. 2 for (1) and (2) above: Conductors of No. 14 and larger which extend beyond the motor control equipment enclosure shall be considered as protected by the motor branch-clrcuit short-circuit andground-fault protective device(s) where the rating of the protective device(s) is not more than 300 percent of the ampacity of the control circuit ~onductors. The ampacities shall be the values given in Table 310-16 for 60 C conductors.

Exception No. 3 for (1) and (2) above: Conductors supplied~by the secondary side of a single-phase transformer having only a 2-wire (single-voltage) secondary shall be considered as protected by overcurrent protection provided on the primary (supply) side of the transformer, provided this protection is in accordance with Section 450-3 and does not exceed the value determined by multiplying the secondary conductor ampacity by the secondary-to-primary voltage ratio. Transformer secondary conductors (other than 2-wire) are not considered to be protected by the primary overcurrent protection.

Exception No. 4 for (1) and (2) above: Conductors of control circuits shall be considered as protected by the motor branch-clrcuit short-circult and ground-fault protective device(s) where the opening of the control circuit would create a hazard, as for example, the control circuit of a f i re pump motor, and the like.

(c) Control Circuit Transformer. Where a motor control circuit transformer is provided, the transformer shall be protected in accordance with Articl~ 450.

Exception No. 1: Where the control circuit transformer is an integral part of the motor controller and is located within the motor controller enclosure, and where an ov~rcurrent device(s) rated or set at not more than 200 percent of the rated secondary current of the transformer Isprovided in the secondary circuit.

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Exception No. 2: Where the transformer supplies a Class 1 power-limited, Class 2 or Class 3 remote control circuit conforming,with the requirements of Article 725.

Exception No. 3: Where protection~is provided by other approved means. \

Exception No. 4: Overcurrent protection shall be omitted where the opening of the control circuit would create a hazard, as for example, the control circuit of a f i re pump motor, and the like. SUBSTANTIATION: For coordination of control circuit requirements. The intent is to apply Section 430-72 to all portions of a control circuit tapped from a motor branch circuit , and to apply Article 725 in all other cases, as specified in Section 430-72(a). Other than editorial changes, the following relates proposed revised Section 430-72 to the 1978 NEC and other TSC proposals.

430-72(a) To coordinate with Article 725, as stated above. See" also TSC Proposal No. 5 for new Section 725-2(e).

430-72(b) (1) - Coordinates provisions from second paragraph, of Section 430-72(a) of 1978 NEC with Section 725-12(a).

430-72(b) (2) - Permits No~. 18 and 16 control circuit conductors and coordinates with Section 725-12(b).

430-72(b), Exception No. 1 - Equivalent to Section 430-72(a), Exception No. 1 in 1978 NEC. The values of 25 amperes for No. 18 and 40 amperes for No. 16 conductors are based on 400 percent of ampacities of 7 and 10 amperes respectively, as specified in Table 400-5, and reflect recognized practice. Reference to Table 310-17 reflects recognized practice.

430-72(b), Exception No. 2 - Equivalent to Section 430-72{a), Exception No. 2 in 1978 NEC. , 430-72(b), Exception No. 3 - Equivalent to Section 43eO-72(b), Exception No. I in 1978 NEC. Same as Section 240-3, Exception No. 5 with word "only" preceding "a 2-wire (single-voltage) secondary . . . . " for clarif ication of intent. See also TSC Proposal No. 7 for new Section 725(a) and (b), Exception No. 3.

430-72(b), Exception No. 4 - Equivalent to Section 430-72(a), Exception No. 4 of 1978 NEC.

430-72(c) - To coordinate with Article 725. See TSC Proposal. No. 9 for new Section 725-12(c).

430-72(c), Exception No. I - Similar to Section 430-72(b) in • 1978 NEC but restricted to (1) control circuits tapped from

motor branch-circuit and (2) transformers integral with motor controller where transformer primary is within controller, not field-wired.

430-72(c), Exception No. 2 - Equivalent to Section 430-72(b), Exception No. 2 in 1978 NEC. Coordinates with Article 725.

430-72(c), Exception No. 3 - Same as Section 430-72(b), Exception No. 3 in 1978 NEC.

430-72(c), Exception No. 4 - Equivalent to Section 430-72(b), Exception No. 4 in 1978 NEC. PANEL RECOfC4ENDATION: Accept as Revised:

In Section 430-/Z[b)(1) of the Proposal, second sentence, a f te r "ampacities" delete the words "for control circuit

l :conductors No. 14 and larger." VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: GUBANY: I am voting against the Panel's acceptance for the

same reasons as for Proposal No. 63.

430-72(a): Reject CMP 11 SUBMITTER: Joseph L. Yosafat, General Electric Co. ~ 6 6 In the second paragraph, before the last three ~ h a l l not apply" add the words "regarding ampacities." SUBSTANTIATION: The purpose of this proposal is to c lar i fy the requirement that only the ampacities stated in Article 310 are

• applicable to the conductors of control circuits within an enclosure. I t is possible to interpret the present wording to mean that all requirements of Article 310, such as minimum size of conductors, are applicable. PANEL RECOMMENDATION: Reject. PANEC COMMENT: See action on Proposals Nos. 63 and 65. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. I

430-72(a), Exception No. 1 and (b), Exception No. 5: Reject CMP 11 SUBMITTER: Joseph L. Yosafat, General Electric Co. PROPOSAL: 67 At the end of (a) Exception No. 1 add, "except

rating or setting of the overcurrent protective device(s) shall not be required to be smaller than 15 amperes."

Add a new Exception No. 5 to (b) as follows: Exception No. 5: The rating or setting of the overcurrent

protective device(s) shall not be required to be smaller than 15 amperes. SUBSTANTIATION: Tables 310-16 through 310-19 do not show ampacltles less than 15 amperes. Conductors having ampacities less than 15 amperes, but not less than one-quarter of this value, are protected to the same degree as is permitted by Exception No. 1 under 430-72(a).

The present requirement is particularly impractical in the

case of small conductors forming an integral part of electronic controls. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See action on Proposals Nos. 63 and 65. VOIE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-72(a) Exception No. 5-(New): Reject CMP 11 SUBMITTER: A. C. Clark, Manufacturing Chemists Assn. l~TO$RZTSSTL-~.68 Add a new exception as follows: ~ i o n No. 5: Where the motor control circuit conductors are smaller than No. 14, overcurrent protection shall be in accordance with Article 725. SUBSTANTIATION: Correlates with proposed additions of Sections 430-.IZ(b} and 725-2(e).

Contrary to published reports, not all remote control circuits must comply with Article 725. Motor-control circuits are an exception to Article 725 unless they cannot be described without empSoying any of the considerations given t6 remote control circuits in Article 725.

The attached problem and analysis* indicates the typical confusion that users face in deciding on the applicabil ity of Article 430F vs. Article 725. Since #14 copper and larger motor cntrol circuits do not meet the parameters of Article 725 and are covered elsewhere in the Code, as indicated in the problem analysis, confusion will be reduced by stating in Article 430F where Article 725 is applicable.

*Attachment has been supplied to CMP members. PANEL RECOMMENDATION: Reject. PANEL COMMENt: See action on Proposals Nos. 63 and 65. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-72(b): Reject CMP 11 SUBMITTER: Paul Hoh, Bussmann Mfg. PROPOSAL: 69 Revise as follows: - ~ h e n a motor control circuit transformer is provided i t shall be protected according to Section 450-3. SUBSTANTIATION: Control transformers are a potential f i re hazard whether they are a motor control transformer or a control transformer for other type(s) of equipment. Control transformers should be protected in compliance with 450-3. The

same level of protection should be afforded control transformers for motor control. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necesslty. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 15. NEGATIVE: Gubany, Kish.

EXPLANATION OF VOTE: - GUBANY: I am voting negative on Panel's rejection since I support the author's reasoning that control transformers should be protected asper Article 450. The transformer does not know where i t is located. I t should be protected on the primary as required in Article 450.

Control transformers are a big source of equipment f i re . Sooner or leter the transformer will break down and should not result in a f i re .

I t can be easily demonstrated that a shorted primary or secondary willcause ignition.

KISH: A transformer should be protected according to Section 450-3 and we should not make an exception without Justification.

430-86(a): Reject CMP 11 SUBMITTER: Robert G. MacManus, Pawtucket, RI PROPOSAL: 70 Delete Section 430-86(a). ~'I]I~S"IS~IATION: Section 430-86(a) allows the motor and driven machinery to be out of sight from the controller location i f the controller disconnecting means is capable of being locked in the open position. A similar condition existed with Section 430-102 previous to the 1965 NEC, but the words "or be arranged to be locked in the open position" was omitted from the 1965 NEC apparently because of a hazard to a man working on the controller. Since the same hazard exists when the motor and driven machinery are out of sight from the controller location, there seems to be an apparent contradiction between Section 430-86 and Section 430-102. PANEL RECOI~ENDATION: Reject. PANEL .COMMENT: The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Wood.

EXPLANATION OF VOTE: WOOD: I am votlng negative on this proposal since I agree

with the Panel's original recommendation to accept as revised. ."Delete Sections 430-86(a) and (b). Section 430-86 to read:

Motor not in Sight from Controller. Where a motor and the driven machinery are not in sight from the controller location a manually operable switch that wil l disconnect the motor from its source of supply shall be placed within sight from the motor location. FPN to remain in Code."

2 0 2 '

430-87, Exception: Accept CMP 11 SUBMITTER: TSC-Nomlnal Voltage ~ROI~}~'AL~T. 71 Change "For motors of 600 volts or less . . . . " to

l ~ r motors rated 600 volts or less . . . . " SUBSTANTIATION: To conform to the guidelines established by the TSC on Nomlnal Voltages. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Aff i rmative.

430-101 FPN-(New): Reject CMP 11 SUBMITTER: Idaho Chapter IAEI I~lTOPO-S']~L-~.'72 Add a third fine print note following Section

See Section 110-23 for disconnecting means for controllers used to control loads other than motor loads. SUBSTANTIATION: To cross reference that a disconnect is requlred In slght from all controllers that serve to govern electrical power. (See proposal for new Section 110-23 Disconnecting Means for Controller.) PANEL RECOMMENDATION: Reject. PANEL COMMENT: Outside the scope of Panel 11. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-102, Exception No. i : Reject CMP 11 SUBMITTER: Joseph L. Yosafat, General Electric Co. ~ 7 3 Revise as follows: ~ i o n No. i : The controller disconnecting means shall be permitted to be out of sight of the controller, provided that the controller is marked with a warning label giving the location and identification of the disconnecting means. The controller disconnecting means shall be capable of being locked in the open positio6. SUBSTANTIATION: The exception permitting the disconnecting means to be out of sight of the controller i f i t is lockable in the open position is equally safe for motor circuits under 600 volts as well as for other controller circuits. Elimination of the "motor circuits over 600 volts" limitation wil l make this section more compatible with Section 430-86(a).

This amendment would provide safety benefits in many industrial fac i l i t ies by permitting grouping of various disconnecting moans in an electrical room wherein maintenance is penformed by qualified personnel. I t also minimizes electrical equipment in areas where unqualified personnel are permitted to work. • PANEL RECOMMENDATION: Reject. PANEL C{X4MENT: The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION:

AFFIRMAIIVE: lb. NEGATIVE: Mierendorf.

EXPLANATION OF VOTE: MIERENDORF: The requirements of Proposal No. 73 to provide a

warning label and locking means when the controller disconnecting means is out of sight of the controller is considered to be of less danger to personnel than relying on the disconnecting means being "in sight of" the controller.

In multi-motor installations, many switches look alike and could easily lead to confusion when trusting to an "in sight of" situation.

Another indirect undesirable consequence of rejection of this proposal is the possibil i ty of controllers being located in undesirable environments, with attendant risks of malfunction in order to have the associated disconnect moans located "in sight of" the controller.

430-109, Exception No. 5: Accept CMP 11 SUBMITTER: Ralph H. Lee, Lee Electrical Eng., Inc. ~ 7 4 Revise as follows: ---E'R'Ce~ion No. 5: For motors of portable appliances rated at 2 horsepower or less and 300 volts or less, an attachment plug and receptacle having ratings no less than the motor ratings shall be permitted to serve as the disconnecting means. SUBSTANTIATION: This proposal is intended to c lar i fy a condltlon presently misinterpreted in Code application. For example, a "portable motor" is interpreted, even in legal actions, as one which is movable, even by use of powered hoisting apparatus, such as fork l i f t trucks, and weighing a ton or more. This is patently beyond the intent of the Code, which intended "portable" to accompany the definition of "Appliance, Portable: which is actually moved or can easily be moved--in normal use." Thls'indicates that the appliance may be moved while in use, such as a portable electric d r i l l , saw, vacuum cleaner, concrete finisher or the like, not.a piece of equipment weighing a ton or more and movable only with powered hoisting equipment.

This rewording and limit o~the exception is in general agreement with Exception 2, especially in view of the control device being separate from the disconnecting means.

Lacking a direct definition for "portable," reference must now be made, by some parties, to Webster, which includes as an example, "a portable schoolhouse." To prevent misuse with the attendant hazards, positive definition of the intended scope of

the exception is required. Further Supporting Comment, Not for inclusion in "Preprint":

The loophole created by this lack of positive definition of "portable" has been taken advantage of by a major electrical manufacturer with extensive Code representation, to the extent that hazards to its e~oloyees are greatly increased. (One lost an arm, largely because of non-lockability of cord and plug.) This company looks on "portable" with the example il lustrated by Webster, and its legal representatives defend this position on that basis. I t cites legal references to "portable cranes" as an example of use of this word. On this basis, even an electric locomotive could be considered as "portable." PANEL RECOMMENDATION: Accept as Revised.

For a cord- and p]ug-connected motor an attachment plug and receptacle having ratings no less than the motor ratings shall be permitted to serve as the disconnecting means. A horsepower rated attachment plug and receptacle shall not be required for a motor rated 2 horsepower or less. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: SCHRAM: A negative vote is cast to draw attention to the fact

that receptacles and attachment plugs rated over 60 amperes may be marked "For Disconnect Use Only" and not be rated or intended for current interrupting. Also, attachment plugs and receptacles rated 60 amperes or less are tested at 150 percent of rating. Since we believe the intent of Exception No. 5 was to permit the plug and receptacle to be the disconnect means for cord- and plug-connected appliance only, in accordance with Article 422, we recommend consideration of the following for the second sentence of the Panel Recommendation.

"A horsepower rated attachment plug and receptacle shall not be required for a cord- and plug-connected appliance in accordance with Section 422-22.

430-110(c)(1): Reject CMP 11 SUBMITTER: J. J. Kark, National Electrical Manufacturers ~ o n PROPOSAL: 75 Change the reference to "Table 430-151" in third paragra--~-~h to read "Table 440-XX." SUBSTANTIATION: See NEMA Proposal on Table 430-151. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Proposal No. 85A. VOTE ONPANEL RECOMMENDATION: Unanimously Affirmative.

430-110(c)(I), Exception: Accept CMP 11 Secretary's Note: I t was the action of the Correlatin'g

Committee that the Panel review the Recommendation to c lar i fy the use of "shall be permitted to be" and the units to be compared. SUBMITTER: Richard J. Denny, Air Conditioning & Refrigeration T ~ PROPOSAL: 76 Revise as follows: ~ i o n : Where part of the concurrent load is resistance load, and where the disconnecting means is a switch rated in horsepower and amperes, the horsepower rating of the switch "is permitted to be" not less than the combined load of the motor(s), "provided" the ampere rating "is" not less than the locked-rotor current o f the motor(s) plus the resistance load. SUBSTANTIATION: Change is for permissive wording. Section 430-110(c)(1) provides for adequate rating of disconnect without application of exception. When motor load is small with respect to resistance heater load, exception may permit lower adequate rating of disconnect; however, when motor load is larger with respect to resistance heater load, application of exception could result in higher rating of disconnect than necessary. PANEL RECOIeJ4ENDATION: Accept as Revised:

Exception: Where part of the concurrent load is resistance load, and where the)disconnecting means is a switch rated in horsepower and amperes, the horsepower rating of the switch shall be permitted to be not less than the combined load of the motor(s), i f the ampere rating of the switch is not less than the locked-rotor current of the motor(s) plus the resistance load. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-113, Exception No. 2-(New): Reject CMP 11 SUBMITTER: A.C. Clark, Manufacturing Chemists Assn. PRDPOSAL: 77 Add exception as follows: ~ i o n No. 2: In industrial establishments only, where conditions of maintenance and supervision assure that only qualified persons wil l service the installed motor and motor-operated equipment, all disconnecting means shall be permitted to be remotely located provided the disconnecting means for other than control and signal devices is capable of being locked in the open position. SUBSTANTIATION: In industrial establishments, the term motor-operated equipment sometimes covers such a broad scope as to make the provisions of Section 430-113 overly restr ict ive. For example, an extruder is a piece of motor-operated equipment that consists of a motor drlve and several sectlons of electrlc

203

heaters around the extruder barrel. Established industry practice has been to use motor and heater disconnects that are remotely located and capable of being locked open. Section 430-113 now prohibits this.

A second example of motor-operated equipment is a motor driven conveyor with photocell sensors along the conveyor. For these photocells there is no safety need to require a local disconnect for these photocells. Established industry practlce has been to use disconnects that are remotely located. These remote disconnects are often contained in a panelboard and are generally of the non-lockable type.

A motor i tsel f often contains RTD's, thermistors, or switches within the motor housing. Established industrial practice has been to use only remote disconnects for these sensors.

Industrial establishments have followed the above established practices for years and have achieved an excellent safety record where the equipment is serviced by qualified personnel. For such reasons, Section 430-113 is overly restrictive and should be changed by the proposed Exception 2. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Dye.

EXPLANATION OF VOTE: DYE: I contend that operator safety is jeopardized as the'

Code now stands requiring disconnect switches adjacent to the motor or motor operated equipment for each source of energy.

In the f i r s t place the .number of switches required would block the operator's view of the process especially in multi-motor (up to 100 or more motors per line) processes such as steel, auto, chemical, and paper.

In the second place the danger to an operator of pulling a DC f ie ld switch on a DC motor or a synchronous motor is great. I t would also be dangerous to the operator i f he pulled the disconnect switch on safety devices such as pressure,/flow, zero speed, o~ photocell switches.

The hostile operating floor environment (o i l , d i r t , corrosive chemical, and hazardous atmospheres) that these switches would be located in wil l lead to early failure. This is a hazard to operators from an electrical energy release and from malfunctions of safety devices.

430-113, Exception No. 2-(New): Accept CM~ 11 SUBMITTER: Alton R. Thompson, Durham, NC l~TO]~I~SKL-T.'78 Add~an exception as follows: ---E'x~e-p~-ion-No. 2: A separate disconnecting means shall not be required for a Class I I or Class I l l remote-control circuit of 50 volts or less. SUBSTANTIATION: This would resolve a lot of problems in the f ie ld where now a disconnect is required. Class 2 and Class 3 circuits of 50 volts or less would not create a shock hazard, f i re hazard, or a mechanical hazard. This exception is needed to clear up confusion by specifically permitting what is generally being excepted. PANEL RECO~IENDATION: Accept as Revised:

Change "Class I I and Class I l l " to "Class 2" and after "circuit" change the rest of the sentence to read "conforming

lwith Article 725, rated not more than 30 volts and which is ~isolated and ungrounded." I Change existing exception to Exception No. i and add the Iproposed exception as Exception No. 2. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ANANIAN: My reason for voting affirmative on the proposal is that i t provides some rel ief relative to alleviating the necessity to supply immediately adjacent disconnects for some Class 2 circuits used in control and monitoring systems. However, in my voting affirmative to reject Proposal No. 77, I feel this proposal should be expanded to include the following additional exceptions:

Exception No. 3: External interlock control circuits and monitoring circuits operating at less than 150 volts need not be disconnected provided that the circuit conductors are grouped, identified and covered and a warning "label is attached adjacent to the equipment enclosure disconnect(s) identifying the source and location of the interlock contacts and monitoring circuits.

Exception No. 4: Separately excited synchronous and direct current motors need not have their f ield circuits disconnected provided that a warning label is attached adjacent to the f ie ld terminal box identifying the location of the remote source disconnecting means capable of being locked in the open position.

My substantiating comments for proposing to add Exceptions No. 3 and No. 4 are:.

Section 430-113, as written, is so broad and far reaching as to be impractical. For example, the term "energy," unless defined as to magnitude and potential, would include any device such as thermo-couple outputs which potential is in mil l ivolts creating no hazard. Also included would be telemetering circuits, proximity switch outputs, sensor outputs, dry safety control interlock contacts, etc. In an integrated process or highly automated assembly or manufacturing operation, a central control system could have many sources of energy. I t would be highly impractical and essentially not feasible to provide disconnects on ali of these sources. Greater hazards would be created in the event ~hat a safety interlock were lef t open

after servicing the equipment. The switch could fa i l or become inoperative due to a loose wire or contamination resulting in the opening of a cr i t ical interlock circuit which may result in extensive damage to a process or create an explosion hazard. In hazardous areas, explosion-proof switch devices would need to be added, increasing the hazard potential in these areas. As more terminations and switches are added, re l iab i l i t y decreases.

Industry has been operating for decades without providing immediately adjacent disconnecting means from each source of electrical energy relative to control and monitoring circuits with a good safety record. There is no Justification to impose this high cost, impractical requirement on industry and

commerce. In many applications, this Panel member feels strongly that a greater hazard would be created by str ict adherence to Section 430-113 in its present form.

430-122: Reject CMP 11 SUBMITTER: L. A. Burton, Oconomowoc, WI !~rO~'O-S'At-~.79 Add a new sentence as follows: The controller ~ s o be marked with the fuse designation which wil l properly coordinate the fuse with the interrupting rating of the contractor.

• SUBSTANTIATION: Although the control manufacturer's literature may contain sufficient information to make a proper fuse selection, this information is not l ikely to be available to the inspection authority or to an electrician when a fuse is replaced.

I f the contacts of instantaneous relays (e.g., groundrfault relays) are in the control circuit or i f the control voltage for the contactor is obtained from the power systems through a control transformer, there is an opportunity for a serious mishap to occur under fault conditions. The contactor wil l begin to open at the inception of the fault.

I f the total clearing time of the fuse exceeds the contactor minimum dropout time, the contactor wil l attempt to interrrupt the fault current while the fuse is melting or arcing. I f the fault current is greater than the interrupting rating of the contactor, the fault wil l not be cleared by the contactor. Ionized gases from a contactor which is fai l ing to interrupt may result in other flashovers within the controller, possibly ahead of the fuses.

The interrupting rating and opening time of contactors vary with manufacturer and cannot be controlled by Industry Standards. For example, a commercially available contactor has an interrupting rating of 4400 amperes at rated voltage and an opening time of .020 seconds. The attached* clearing time-current curves for Motor Starter Current Limiting fuses show that this contactor cannot be used with 9R, 12R, 18R, or 24R fuses, because fault currents in the cross-hatched area wil l not be cleared by these fuses in the time i t takes for the contactor to open. Under-these fault conditions, there is no coordination and the contactor would be placed in the position of attempting to interrupt a current higher than its rating. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primarily a design consideration. VDTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: GUBANY: I am voting negative on Panel's rejection since I

agree with the author's substantiating comment. I t is very timely that equipment be adequately marked for proper protection in order for the installation to comply with Section 110-10 and Section 240-2. The proper matching of overcurrent protective devices with the withstand ratings of equipment and components should'be made very obvious.

430-125(a): Accept " CMP 11 SUBMITTER: A. P. White, Attleboro, MA I~TO]~[-T.'80 Delete the words "running overcurrent (overload)"

l an-6-d--~e~Face with the word "overload." SUBSTANTIATION: See A. P. White substantiation for proposal for Diagram 430-I. PANEL RECOMMENDATION: Acceptas ~evised:

I Revise proposal to read - In lines 2 and 3 delete the words "motor-running overcurrent (overload)" and replace with the word "overload." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

i

430-132(d), (e), and (f)-(New): Reject CMP 11 SUBMI1-FER: R. S. Pinkerton, Los Angeles, CA IMTOI~S'A~-T.'81 Add new (d), (e), and (f) as follows: --'T-d-F--Motor control equipment which is accessible to unqualified persons shall be enclosed and shall be arranged to be operated, including the resetting of overcurrent protective devices, from the outside of the enclosing case.

Exception No. I : The resetting means need not be externally operable provided the disconnecting means is part of the controller and is so interlocked that the controller door cannot be opened when any bare parts are energized in the controller enclosure.

Exception No. 2: Elevator control equipment located as

204 J

providedkln Article 620 need not be enclosed. (e) Where mechanical equipment such as valves, guages,

regulators or similar equipment which requires manual adjustment are installed within the same enclosure with live parts, barriers shall be provided to separate llve parts from mechanical equipment.

(f) Where two or more contactors or other controllers are installed in the same cabinet or other enclosure, suitable barriers shall be installed between them.

Exception: Where all the devices in the enclosures serve a single machine and are simultaneously de-energized by a single disconnecting means, barriers wil l not be required. SUBSTANTIATION: In the normal process of operating many types of machines, frequent overloads require resetting of the motor overload device or replacing fuses., Rarely is time taken to call an electrician for this simple operation and the machine operator resets the equipment. As people are operating this equipment who are unqualified in terms of electrical hazards, i t is necessary to specify and provide control equipment which is total ly enclosed and the necessary resetting can be acc6mpllshed without exposing the operator to energized live parts.

Furthermore, controller enclosures frequently contain mechanical equipment which requires adjustment or contains several controllers for independently operating machines. Mechanics for the machines should not be exposed to live energized parts when they turn a v~Ive or set regulator or manually adjust mechanical equipment. Maintenance electricians should not be required to replace motor controllers or replace parts where there are adjacent non-barriered and energized motor controllers. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primarily a design consideration. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

430-132(d), (e), and (f)-(New): Reject CMP 11 SUBMII-I'ER: Southwestern Section IAEI I~-01~17TL-~.'82 (d) Motor control equipment which is accessible ~ l i f i e d persons shall be enclosed and shall be arranged to be operated, including the resetting of overcurrent protective devices, from the outside of the enclosing case.

Exception No. I : The resetting means need not be externally operable provided the disconnecting means is part of the controller and is so interlocked that the controller door cannot be opened when any bare parts are energized in the controller enclosure.

Exception No. 2: Elevator control equipment located as provided in Ar{icle 620 need not be enclosed.

(e) Where mechanical equipment such as valves, gages, regulators or similar equipment which requires manual adjustment are installed within the same enclosure with live parts, barriers shall be provided to separate live parts from mechanical equipment.

(f) Where two or more contactors or other controllers are installed in the same cabinet or other enclosure, suitable barriers shall be installed between them.

Exception: Where all the devices in the enclosures serve a single machine and are simultaneously de-energized by a single disconnecting means, barriers wil l not be required. SUBSTANTIATION: In the normal process of operating many types • of machines, frequent overloads require resetting of the motor overload device or replacing fuses. Rarely is time taken to call an electrician for this simple operation and the machine operator resets th 9 equipment. As people are operating this equipment who.are unqualified in terms of electrical hazards, i t is necessary to specify and provide control equipment which is total ly enclosed and the necessary resetting can be accomplished without exposing the operator to energized live parts.

Furthermore, controller enclosures frequently contain mechanical equipment which requires adjustment or contains several controllers for independently operating machines. Mechanics ~or the machines should not be exposed to live energized parts when they turn a valve or set a regulator or manually adjust mechanical equipment. Maintenance electricians should not be required to replace motor controllers or replace parts where "there are adjacent non-barriered and energized motor controllers. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is primarily a design consideration. VOTE ON PANEL RECOMMENDATION: Unanimousl~ Affirmative.

430-145(a) FPN-(New): Accept CMP 11 SUBMITTER: Idaho Chapter IAEI l~TOl~)-S'At-~.'83 Add a fine print note following Section

~ i o n 430-12(e)for grounding connection devices or I f i t t ings required at motor terminal housings. SUBSTANTIATION: To cross reference the grounding termination requirements at motor terminal housings of the preceding proposal. (See proposal 430-12(e). PANEL RECOMMENDATION: Accept as Revised:

I Modify by changing or f i t t ings" to "means." "devices VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 430-149: Accept CMP 11 SUBMITTER: J. J. Kark, National Electrical Manufacturers iITg~-6~Ta-~'fon PROPOSAL: 84 Remove the four columns and the heading for ~ o u s Type Unity Power Factor Amperes. Remove the + reference at the bottom of the Table..

l SUBSTANTIATION This synchronous motor portion of the two-phase Table 430-14B should either be revised to show voltages of 230, 460 and 575 with currents for these voltages or the columns should be eliminated.

By the time of issue of the 1981 Code, i t is the opinion of the Submitter that there wil l be practically no need for this information. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 430-151: Reject CMP 11 SUBMITTER: J. J. Kark, National Electrical Manufacturers 7T~B~l'a-t-Ton PROPOSAL: 85 Remove this Table from Article 430 and add the

of this Table as Table 440-XX in Article 440. SUBSTANTIATION: Some confusion has developed because the present NEMA fable for locked-rotor.current differs some from the values in Table 430-151. As part of Article 430, the Table 430-151 has been considered as a specification for general purpose motors, whereas, the Table is intended for use in conversion between current and hp ratings of other branch circuit components. Changes in the values in Table 430-151 are not practical because of numerous approvals of apparatus based on these currents which are known to provide satisfactory applications.

Correlating changes are required in Sections 430-110 and 440-12.. PANEL RECOMHENDATION: Reject. PANEL COMMENT: See Proposal No. 85A. VOlE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Table 430-151: Accept CMP 11 SUBMITTER: CMP 11

85A Revise t i t l e of Table and add Fine Print Note,

Table 430-151. Conversion Table of Locked-Rotor Currents for Selection of Disconnecting Means and Controllers as determined from horsepower and voltage rating. For use only with Sections 450-110, 440-12 and 440-41.

Motor Locked-Rotor Current Amperes* Single Phase Two or Three Phase

Max.HP 115v 230v 115v 200v 230v ' 460v 575v Rating

58.8 29.4 82.8 41.4 96 , 48 120 60 144 72 204 102 336 168 480 240 600 300

24 33.6 43.2 62 81

13.8 12 6 4.8 1/2 19.3 16.8 8.4 6.6 3/4 24.8 21.6 10.8 8.4 I 35.9 31.2 15.6 12.6 1 1/2 46.9 40.8 20.4 16.2 2 66 58 26.8 23.4 3

105 91 45.6 36.6 5 152 132 66 54 7 1/2

193 168 84 66 10 290 252 126 102 15 373 324 162 132 20 469 408 204 162 25 552 480 240 192 30 718 624 312 246 40 B97 780 390 312 . 50

1063 924 462 372 60 1325 1152 576 462 75 1711 1488 744 594 100 2153 1872 936 750 125 2484 2160 1080 864 150 3312 2880 1440 1152 200

(FPN) *These values of motor locked-rotor current are-. approximately 6 times the full-load current values given in Tables 430-148 and 430-150.

SUBSTANTIATION: See Substantiation for Proposals 85 and 9g, and to correlate with values in Tables 430-148 and 430-150. PANEL RECOMMENDATION: Accept. vuIE ON PANEL RECOI~MENDATION: Unanimously Affirmative.

• Table 430-152: Accept CMP 11 SUBMITTER: A. P. White, Attleboro, MA

I ~ 86 In the t i t l e , add the words, "Short-Circuit," and ~-G'~o-6-6"~ault '' after the words "Branch-circuit." SUBSTANTIATION: See A. P. White substantiation for proposal for ulagram 4~U-I. PANEL RECOMMENDATION: Accept. VUIL UN PANtL RECUMMLNDATION: Unanimously Affirmative.

205

ARTICLE 440 -- AIR-CONDITIONING AND REFRIGERATING EQUIPMENT

440-3(b): Reject • CMP 11 SUBMITTER: Richard J. Denny, Air Conditioning & Refrigeration T ~ PROPOSAL: 87 Add a sentence before the iast sentence as

In no case shall the ma~ked maximum rating of the branch-circuit short-circuit and ground-fault protective device be less than the marked minimum supply circuit conductor ampacity. [ . SUBSTANTIATION: The actual marked values may be greater than ~ m i n i m u m , and/or may be less than the calculated maximum. Under the present rules, the,marked maximum rating of the branch-circuit short-circuit and ground-fault protective device (fuse or circuit breaker) could be less than the marked minimum supply circuit conductor ampacity, especially since the marked maximum fuse or circuit breaker rating is normally redbced from the calculated maximum to a standard rating as given in Section 240.6. The possibility of this occurrence is greatest when a substantial part of the combination load is electric resistance space heating. There are heat pumps on the market with this cross-over of marked limits. Although Section 440-22(b) permits the rating of the fuse or circuit breaker to be increased to the next standard rating higher than the conductor ampacity (by reference to Section 430-53, which references Section 240-3 Exception No. I ) , the marked maximum rating of the fuse or circuit breaker cannot be exceeded. The change is to remove unintended permission for a crossover of the minimum and maximum marked values. PANEL RECOMMENDATION: Reject. ~ANEL COMMENT: See Panel comment on Proposal No. 10. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: SCHRAM: While we agree a design consideration is involved, i t

is the design of the marking. We do not believe the Code should permit a marking which is in conflict with the intent, as stated in the proposal.

440-3(b): Reject CMP 11 SUBMITTER: Alton R. Thompson, Durham, NC I~rOIR~-~.~ Add a sentence before the last sentence as

In no case shall the marked maximum rating of the branch-circuit, short-circuit and ground-fault protective device be less than the marked minimum supply circuit conductor amapcity. SUBSTANTIATION: The actual marked values may be greater than the calculated minimum, and/or may be less than the calculated maximum. Under the present rules, the marked maximum rating of the branch-clrcuit, short-circuit and ground-fault protective device (fuse or circuit breaker), could be less than the marked minimum supply circuit conductor ampacity, especially since the marked maximum fuse or circuit breaker rating is normally reduced from the calculated maximum to a standard rating as given in Section 240-6. The possibility of this occurrence is greatest when a substantial part of the combination load is electric resistance space heating. There are heat pumps on the market with this cross-over of marked limits. Although" Section 440-220(b) permits the rating of the fuse or circuit breaker to be increased to the next standard rating higher than the conductor ampacity (by reference to Section 430-53, which references Section 240-3 Exception No. I ) , the marked maximum rating of the fuse or circuit breaker cannot be exceeded. The change is to remove unintended permission for a cress-over of the minimum and maximum marked values. PANEL RECOMMENDATION: Reject. I PANEL COMMENT: See Panel comment on Proposal No. 10. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: SCHRAM: See Comment on Proposal No. 88.

440-12(a)(2) and (b)(1)b.: Reject CMP 11 SUBMITTER: J. J. Kark, National Electrical Manufacturers ~ o n PROPOSAL: go Change the references to "Table 430-151" to read ~Ta~Te-i[40-XX." SUBSTANTIATION: See NEMA Proposal - on Table 430-151. PANEL RECO~ENDATION: Reject. PANEL COMMENT: See Proposal 85A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

440-12(b)(1), Exception: Accept CMP 11 Secretary's Note: I t was the action of the Correlating

Committee that the Panel review the Recommendation to clar i fy the use of "shall be permitted to be" and the units to be compared. SUBMITTER: Richard J. Denny, Air-Conditioning & Refrigeration

PROPOSAL: 91 Revise as follows: x - - ~ i o n : Where part of the concurrent load is a resistance load and the disconnecting means is a-switch rated in horsepower and amperes, the horsepower rating of the switch "is permitted to" be not less than the combined load to the motor-compressor(s) and other motor(s) at the locked-rotor condition, "provided" the ampere rating is not less than this locked-rotor load plus the resistance load. SUBSTANTIATION: Change is for permissive wording. Section 440-12(b)(1) provides for adequate rating of disconnect without application of exception. When motor load is small with respect to resistance heater load, exception may permit lower adequate rating of disconnect; however, when motor load ~ larger with respect to resistance heater load, application of exception could result in higher rating of disconnect than necessary. PANEL RECOMMENDATION: Accept as Revised:

Exception: Where part of the concurrent load is a resistance load and the disconnecting means is a switch rated in horsepower and amperes~ the horsepower rating of the switch shall be permitted to be not less than the combined load to the motor-compressor(s) and other motor(s) at the locked-rotor condition, i f the ampere rating of the switch is not less than this locked-rotor load plus the resistance load. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


Cor~nittee that the Panel review the Recommendation with respect to the fine print note. SUBMITTER: L~uis Miraglia, Boston, MA ~-R-O-F~'A-L-~.'92 Delete the word "readily." ~]~r~'~I~I'IATION: In my opinion refrigerators have had outlets behind them for years. I have yet to hear of any person who has been injured from such an installation:

Household refrigerators should be considered as an applicance occupying dedicated space as per 210-25(b) (second paragraph). PANEL RECOMMENDATION: Accept asRevised:

Change Section 440-14 to read: Location. A disconnecting means shall be located within sight from and readily accessible from the air-conditioning or refrigerating equipment. Add an exception reading:

Exception: Cord- and plug-connected appliances. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

SCHRAM: The only change in Section 440-14 is to add the exception. The present fine print note should be retained.

440-21: Accept • .CMP 11 SUBMITTER: A. P. White, Attl~boro, MA l~TO!~O~'Al~.'g3" Delete the word "overcurrent" in line one. ~'I~']7~rIATION: See A. P. White substantiation for proposal for Diagram 430-I. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative:

440-3(c) FPN: Reject CMP 11 SUBMITTER: W. L. Howard, General Electric Co. P]TOI~T~L-~." 89 Revise the last sentence of fine print note as

The value of the branch-circuit selection current will never be less than the rated load current. SUBSTANTIATION: Present wording would have the effect of arbitrar i ly adding some value of current to a rated load current which is already greater than or equal to 64.1% of the maximum continuous current of the compressor. PANEL RECOI~ENDATION: Reject. PANEL COMMENT: The present wording adequately ~eflects the Panel's intent. VOTE ON PANEL RECO~@IENDATION: Unanimously Affirmative.

440-22(b) Exception No. 3-(New~(HOD 1978 NEC): Accept CMP 11 Secretary's Note: I t was the action of the Correlating

Committee that this Proposal be reported as a "reject," because less than two-thirds of the members eligible to vote have not voted in the affirmative. SUBMITTER: J. A. Pietsch, General Electric Company ~ 9 4 Add Exception No. 3 to Section 440-22(b) as TBT~.

Exception No. 3: Where the branch circuit, short-circuit and ground-fault protection is rated 60 amps or less and 250 volts or less, either fuses or inverse-time type circuit breakers may be installed unless otherwise .li@ited by marking on the equipment nameplate. SUBSTANTIATION: The intent of this proposal and a related proposal to change Section 424-22(a) is to permit the use of inverse time t~q~e circuit breakers where appropriate on fixed Heating, Air Conditioning and Refrlgeration Equipment branch circuits.

206

Successful results with specific equipments approved as individual types or models for circuit breaker branch circuit protection have shown that such devices do not constitute a safety hazard. And, the circuit breakers permit improved protection to power ut i l izat ion equipment by disconnecting all ungrounded supply conductors simultaneously. PANEL RECOMMENDATION: Accept as Revised.

Change 60 amps. to 50 amps. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 7. NEGATIVE: Ananian, Gubany, Kish, Lawry, Myers, O'Brien,

Osborn, Smith. NOT VOTING: Aquilino, Lopez.

COP~MENT ON VOTE: SCHRAM: We believe the data submitted supports acceptance of

the proposal without the reduction to 50 amperes. WOOD: I have voted in the affirmative on this proposal since

i t is generally known that a large percentage of these installations have been installed with circuit breaker protection.

There appears to be very l i t t l e evidence of this type installation causing or contributing to loss of l i fe or f i re .

Through the various test data supplied to the Panel i t has become apparent to me that no overload devices, fuses or circuit breakers, provide adequate protection on multi-motor circuits.

This Panel should review its position regarding protection on all types of multi-motor circuits as i t appears that damage to circuit components is prevalent when any single overload device is used. EXPLANATION OF VOTE:

ANANIAN: In reviewing the Fact-Finding Report conducted by UL for the Air Conditioning and Refrigeration Institute and subsequent tests conducted by fuse and circuit breaker manufacturers, i t appears that inadvertent use of either 60 ampere fuses or circuit breakers may result in equipment component and/or wire damageand burning. One would have to conclude that the equipment branch-circuit/short-circuit and ground fault protective devices used in these tests, whether fuse or circuit breaker, cannot assure the protection of No. 18 nor No. 16 tap conductor wires nor certain components. Small wire sizes, overload heaters and contactors have limited thermal

~ t c ~ ; ~ Y a n ~ h ~ r ~ l ~ i ~ t ~ t e c ~ X ~ e ~ , W ~ a ~ h are

conditioning equipment incorporating multi-motor loads or motors mixed with other loads and ut i l iz ing reduced wire size tap conductors in compliance with 430-53(d) would appear to need to be tested as an integrated and coordinated system ut i l iz ing

"specific branch circuit protective devices. The circuit components and associated wiring would need to be tested at both low and high level fault currents to verify 12T withstand and thermal ratings approved for the installation by a recognized testing laboratory.

AQUILINO: Considerable test data has been presented both for and against this proposal. In view of the conflicting data, and lacking the fac i l i t ies to confirm the test results myself, I do not feel there is sufficient just i f icat ion for either an affirmative or negative vote at this ~ime.

GUBANY: I am voting against acceptance of Proposal No. 94 for the following reasons:

I . This is the same type of proposal which was declared nonconsensus for the 1978 Code.

2. No new substantiating data was submitted at the last OMP 11 meeting to refute the ARI/UL Fact-Finding Report which recorded destroyed and damaged air-conditioning and electric furnace components. Section 110-10 requires component protection and 240-2 requires protection of equipment, not " destruction.

3. Using 50A, 60A and even IOOA overcurrent devices to protect No. 18 and No. 16 wire is out of concert with other sections of the NEC as well as the intent of the NEC which limits the protection to 20A as in 240-4, such as in fixtures and approved cords for appliances which generally do not exceed six (6),feet. Even in 725-12, where the conductors leave the enclosure, the overcurrent protection is limited to 20A.

K . 4. The change from 60A to 50A branch clrcult doesn't change the damage and destruction recorded in the ARI/UL Fact-Finding Report of 1978 and no new Fact-Finding Report was submitted on component protection. An air-conditioner or any other equipment can have any size branch circuit.

5. The owners" or users' equipment or property should not be permitted to be subjected to the damage and destruction reported in the 1978 ARI/UL Fact-Finding Report using circuit breakers.

NOTE I : Section 240-2 refers to Protection of Equipment, not destruction. Also, note 240-1, the word "protection" is prominent.

NOTE 2: This Proposal is for all practical purposes the same as Proposal No. 57 which the Panel voted to reject.

KISH: Approval for either fused or inverse-time type circuit breakers should not get a blanket approval. While tests were run on specific fuses and circuit breakers to show their worthiness, approval should come only from recognized testing laboratories for each grouping.

LAWRY: I t has been suggested that test data submitted to CMP 11 indicates that circuit breakers are as safe as fuses for group motor installations and consequently, as for fuses, should be recognized for group installations without specific approval for that purpose. In my opinion, the test data indicates that both fuses and circuit breakers should be approved for group

installation, or possibly group installations should even be prohibited.

LOPEZ: I am abstaining from voting on this proposal and deferring this to the judgment of other Panel members who have the specialized know how and experience relative to the application and protection of the equipment covered by this proposal.

MYERS: Circuit breaker test data submitted at the Panel meeting was impressive but i t was a test of only one manufacturers circuit breaker. I f this proposal is approved i t would give blanket approval to all circuit breakers. I feel this is a problem that must be resolved between the manufacturers and a recognized testing agency, not the CodeLMaking Panel.

O'BRIEN: Our position is to reject Proposal No. 94 due to insufficient evidence to support the suggested changes. I t is our position that the consumer is better protected withthe present language in the Code.

OSBORN: Data submitted puts serious doubts on the advisabil ity of multi-motor branch circuit with any type of overcurrent protection. CMP 11 now should restudy multi-motor branch circuit protection.

SMITH: The present wording of the proposal automatically qualifies inverse-time type circuit breakers for the purpose. The NEC should not be the judge of a products ab i l i ty to perform adequately or safely. The agency to perform the above should be a recognized testing laboratory.

I f the capability of the circuit breaker to protect is demonstrated and documented then this proposal is acceptable.

440-22(b), Exception No. 3-(New): Reject • CMP 11 SUBMITTER: J.J. Kark, National Electrical Manufacturers Assn. Pl~-OlTO-S'XL-~.95 Add Exception No. 3 as follows:

~"xc-eption No. 3: Where the branch-circuit, short-circuit and ground-fault protection is rated 60 amps or less and 250 volts or less, and where the available faul t current is 5000 amps or less, either fuses or inverse-time type circuit breakers may be installed unless otherwise limited by marking on the equipment nameplate. SUBSTANTIATION: The intent of this proposal and a related proposal to cnange 424-22(a) is to permit the use of inverse-time type circuit breakers where appropriate on fixed heating, air conditioning and refrigeration equipment branch circuits.

A UL Fact-Finding Report dated Nov. 1, 1976 was conducted to investigate the sui tabi l i ty of inverse-tlme circuit breakers for these applications.

Unfortunately~ close timing between issuance of the Report and the final vote by the panel le f t l i t t l e time for thorough study for the 1978 Code.

A careful review indicates that circuit breakers were tota l ly acceptable in 97% of the 387 tests summarized in the report. The remalning tests had minor discrepancies.

A f ie ld survey included in the report indicates that over 50% of the defined units installed since 1971 are in fact protected by circuit breakers with no f ie ld problems. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See action on Proposal No. 94. ,VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

440-52(b), Exception: Reject CMP 11 SUBMITTER: R. L. Eichhorn, Whirlpool Corp. ~ 9 6 Revise exception by adding: ~ o n 20-, 30-, 40-, or 50-ampere single-phase branch circuits as provided in Section 440-56." SUBSTANTIATION: This is a correlating proposal to the proposal to add Section 440-56 Cord-and-Attachment Plug-Connected Motor-Compressors and Equipment on 20-, 30-, 40-, or 50-Ampere Branch Circuits. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

440-55 and (b): Reject CMP 11 SUBMITTER: Richard J. Denny, Air Conditioning & Refrigeration T ~ PROPOSAL: 97 Revise as follows: 7F4-O-z-5=~F~ - . Cord-and-Attachment Plug Connected Motor-Compressors and Equipment on 15-, 20-, 30-, 40- or 50-Ampere Branch Circuits. Overload protection for motor-compressors and equipment that are cord- and attachment plug-connected and used on 15-or 20-ampere 120-volt, or 15-, 20-, 30-, 40- or 50-ampere 208-or 240-volt, single-phase, branch circuits as permitted in A~ticle 210 shall be permitted as indicated in (a), (b) and (c) below.

(b) The rating of the attachment plug and receptacle shall not exceed 20 amperes at 125 volts or 50 amperes at 250 volts. SUBSTANTIATION: Equipment for circuits larger than 20 amperes require additional testing to meet the present code requirements. 440-22(b), Exception No. 2 provides for such equipment to be considered as a single motor.

Section 210-21(b)(I) and Tables 210-21(b)(2) and 210-21(b)(3)

207

allow for individual branch circuits and matching plug receptacles up to 50 amperes.

Further, Section 210-23 states " I t shall be acceptable for an individual branch circuit to supply any load for which i t is rated."

The overload protection need only protect the equipment per 440-52(a). The protection of the branch circuit and control apparatus required under 440-52(b) is not needed since i t is

,provided by the branch circuit protection. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

440-56-(New): Reject CMP 11 SUBMITTER: R. L. Eichhorn, Whirlpool Corp.

98 Add a new sentence as follows: 2RFO-z~T~ --. Cord-and Attachment Plug-Connected Motor-Compressors and Equipment on 20-, 30-, 40-, 50-Ampere Branch Circuits. Overload protection for motor-compressors and equipment that are cord-and attachment plug-connected, approved for the purpose, and used on 20-, 30-, 40-, or 50-amphere 208- or 24D-volt, single-phase branch circuits as permitted in Article 210 shall be permitted as indicated in (a), (b), and (c) below.

(a) The motor compressor shall be provided with overload protection as specified in Section'44O-52(a). Both the controller and motor overload protective device shall be approved for installation with the short-circuit and ground-fault protective.device for the branch circuit to which the equipment is connected.

(b) The rating of the attachment plug and receptacle shall not exceed 50 amperes at 250 volts.

(c) The short-circuit and ground-fault protective device protecting the branch circuit shall have sufficient time delay to permit the motor-compressor and other motors to start and accelerate their loads. SUBSTANTIATION: Cord-and attachment-plug connected equipment for circuits 20 amperes and larger may require additional testing to meet the existing code requirements. This additional testin~ is considered unnecessary since f ield experience with well over a million room air conditioners rated over 15 amperes to 40 amperes and not tested in accordance with the existing code have not ~hown any safety problems due to this lack of testing. Results of an AHAM survey of manufacturers disclosed this information.

Section 440-22(b), Exception No. 2 provides for such equipment to be considered a single motor for the purpose of specifying branch-circuit short-circuit and ground-fault protection. Section 210-21(b) (I) permits a single receptacle installed on an individual branch circuit up to the rating of the branch circuit and up to 50 amperes.

See correlating proposal for revision of section 440-52(b) Exception. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

Change line I f i r s t paragraph word: "Running" to "Overload." Change lines 2 and 3 f i r s t paragraph words: "running

overcurrent" to "overload." Change lines I and 2 second paragraph words: "overcurrent" to

"short-circuit and ground-fault." Change lines i and 3 third paragraph words: "overcurrent" to

"short-circuit and ground-fault." Change line 1 fourth paragraph word: "overcurrent" to

"short-circuit and ground fault ." SUBSTANTIATION: See A. P. White substantiation for proposal for Diagram 430-1. PANEL RECOMMENDATION: Accept as Revised.

In Chapter 9, Example 8 change the following'to read: Change the heading "Overcurrent Protection" to "O~erload and

Short-Circuit and Ground-Fault Protection. Change subheading "Running" to "Overload." Add to paragraph 1, before "the 25-h.p. motor," "Where

protected by a separate overload device." In the 1st sentence add after "42.5 amperes.", "(Section

430-32(a)(i))." In the second sentence before "the 30-h.p. motor," add "Where

protected by a separate overload device." Also in the second sentence add after "not over'50 amperes.", ,"(Section 430-32(a)(i))."

At the end of paragraph I , add a new sentence to read: For a motor marked "thermally protected" overload protection is provided by the thermal protector (see Sections 430-7(a)(12) and 430-32(a)(2)). Change second subheading "Branch Circuit" to read "Branch Circuit, Short-Circuit and Ground-Fault."

In subheading "Feeder Circuit" add to the end of paragraph "(Section 430-62(a)). ~ VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

SCHRAM: The Panel Recommendation should be to add the changes identified to thechanges proposed.

WHITE: The Panel Recommendation revision should be in addition to the original proposal and not as a replacement. Otherwise, the revision contemplated in Proposal No. 100 would be incomplete.

Table 440-XX-(New): 'Reject CMP 11 SUBMITTER: J. JL Kark, National Electrical Manufacturers ~ o n PROPOSAL: 99 Use the complete contents of Table 430-151 from

Code with the following t i t l e : TABLE 440-XX. Conversion Table of Locked-Rotor

Currents for Selection of Disconnecting Means and Controllers

As determined from horsepower and voltage rating. For use only with Sections 430-110, 440-12 and 440-41. SUBSTANTIATION: The addition of the purpose of the Table to the bold face heading should eliminate any confusion about the use of the Table in application of the Code. Also, see the comment on the NEMA proposal - on Table 430-151. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Proposal No. 85A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


Chapter 9, Example No. 8: Accept CMP 11 Secretary's Note: I t was the action of the Correlating

Committee that the responsibility for the Examples has been assigned to the Chairman of the Panel and the Secretary of the Correlating Committee. SUBMITTER: A. P. White, Attleboro, MA Lb-R~-POSAL: 100 Change in t i t l e word: "Overcurrent" to overload ~ t - C i r c u i t and Ground-Fault."

Change in line I f i r s t paragraph words: "running overcurrent" to "overload."

Insert in l~ne 2 f i r s t paragraph words: "short-circuit and ground-fault ahead of "protection."

Change heading "Overcurrent Protection" to "Overload and Short-Circuit and Ground-Fault Protection." Under heading Overeurrent Protection-

208


ARTICLE445 -- GENERATORS

445-I: Reject CMP 22 SUBMITTER: Idaho Chapter IAEI ]5~-Olb-O-S'A~-~." 1 Amend Section 445-1 to include Article 240. ~]I~rANTIATION: 240-21 tel ls us all conductors shall be protected at point of supply. The inherent design of a

~ enerator only protects the generator i tsel f . Nowhere in r t ic le 445 does i t give any specific overcurrent protection for

the conduEtor leading from the generator. These generators can be changed in the f ield to a larger

generator without any knowledge of conductor ~npacity or overcurrent requirements thereby causing an overload on the conductors and creating a f i re hazard. In some installations the conductors leading from the generator to the f i rs t overcurrent device is greater than 100 feet.

See Proposal No. 3 for 445-5. "PANEL RECOMMENDATION: Reject. PANEL COMMENT: Unduly restricting design for larger units where other methods to prevent overloading of conductors have shown to be adequate. Supporting comment is not persuasive. This article outlines requirements for protection of generators. Other sections of the NEC cover conductor overcurrent protection. Modifications of systems must be reviewed completely for compliance with all rules applicable in the NEC. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: g. NEGATIVE: Flach.

EXPLANATION OF VOTE: FLACM: I don't think adding Article 240 to the l is t of other

Articles will create any controversy. By doing this, Code users wil l be alerted to the fact that the inherent design of a generator does not protect conductors connected to the generator output terminals.

445-5: Reject CMP 22 SUBMITTER: George W. Flach, New Orleans, LA

2 Revise by adding "and neutral" after "phase ~ r s . " The sentence will then read: "The ampacity of the phase conductors and neutral from the generator terminals to the f i r s t overcurrent device shall not be less than 115 percent of the nameplate current:rating of the generator. SUBSTANTIATION: Clarification. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal see actlon on Proposal No. 2A, Section 445-5. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

445-5: Accept CMP 22 SUBMITTER: CMP 22 I~TOITO-S')~-~. " 2A Add a sentence to the end of 445-5 as follows:

be permitted to size the neutral conductors in accordance with Section 220-22. SUBSTANTIATION: To clarify requirements for sizing the neutral. To be consistent in sizing the neutral with other sources and distribution methods. PANEL RECOMMENDATION: Accept as revised. I t shall be permitted to slze the neutral conductors in accordance with Section 220-22. Conductors which must carry ground-fault currents shall not be smaller than required by Section 250-23(b). PANEL COII~ENT: Where the generator neutral is not grounded at Its terminal, the neutral cohductor must be of adequate size to carry ground-fault current. VOTE ON PANEL RECO~B~ENDATION: Unanimously Affirmative.

445-5: Reject CMP 22 SUBMITTER: Idaho Chapter IAEI

3 Amend 445-5 by adding another sentence stating ~ d u c t o r shall not be over 25 feet in length and shall terminate with a single circuit breaker or a single set of fuses that will limit the load to the ampacity of the conductors." SUBSTANTIATION: 250-5(d) states that generators are a separately derived system. I f they are such we should have some rules for giving the conductors from the generator proper protection. There are times when i t is hard to install an overcurrent device at the generator location. I f we used a 25 foot tap rule from the generator to the overcurrent device i t would prevent installations of great distance from the generator to the overcurrent device.

240-21 tel ls us all conductors shall be protected at point of supply. The inherent design of a generator only protects the generator i tsel f . Nowhere in Article 445 does i t give any specific overcurrent protection for the conductor leading from the generator.

See Proposal No. 1 for 445-I. PANEL RECOMMENDATION: Reject PANEL COMMENT: Unduly restricting design for larger units where, other methods to prevent overloading of conductors have shown to

be adequate. Overcurrent protectioh should be as close as practicle, but 25 feet is too restrictive. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 8. NEGATIVE: Flach, Scalone.

EXPLANATION OF VOTE: FLACH: I agree that 25 feet may be too short for large

machines, but there should be some statement in the Article which requires overcurrent protection for the conductors connected to the generator.

SCALONE: The installation of an unprotected feeder for great distances within a building might cause a greater threat to human l i fe such as f i re , explosion or electrocution, than would be caused by the lack of emergency power. I suggest modifying the proposed wording:

"The length of exposed feeder installed from the generator terminals to the f i r s t overcurrent protective device shall not exceed 25 feet."

445-6: Accept CMP 22 SUBMITTER: TSC-Nominal Voltage I~TOIR)~L-~.4 Change "generators of more than 150 volts to grou-~-u-6~--to read "generators operated at more than 150 volts t o

iground., SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 480 - - STORAGE BATTERIES

480-5(b):Accept CMP 22 SUBMITTER: TSC-Nominal Voltage I~ROIoI)~3~-~. • 5 Add "nominal" after "24 volts" to read "(24 vo-'61"t-~7-5, nominal)." SUBSTANTIATION: To conform to the guidelines established by the i TSC on Nominal Voltages. PANEL RECOI~MENDATION: Accept VOTE ON PANEL RECOMMENDATION: Unanimously AffirmatiVe.

ARTICLE 700 -- EMERGENCY SYSTEMS

Article 700: Reject CMP 22 SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn. ]~-OPO~'-A-L-~.'6 Cemblne Articles 700 and 750. ~'I]I)'S'TA)~TIATION: Adopt the report of CMP TSC to combine Articles 700 and 750 r Complete text as shown on pages 391, 392, 393, 394 of the "Preprint of the proposed amendments for the 1978 National Electrical Code." NFPA NO. 70 PR 78.

The present separation of the articles, both of which deal with alternate power sources and distribution systems intended to be functional when normal power supplies are disrupted, is i l logical and is a source of conflict in application and enforcement.

The TSC report was well conceived and the integrated subject matter provides a much more coherent coverage of alternate Power Systems. The supporting comment by CMP 22 which accompanied the proposal thoroughly covers the subject and is s t i l l pertinent.

The Correlating Co¢mnittee (see Secretary's note) apparently agreed with the developed material, but unfortunately the assignment to "process new material in the appropriate articles" was not accemplished. Such action to pull apart the work of the TSC would be ill-advised and would destroy the logical arrangement. PANEL RECOMMENDATION: Reject PANEL COMMENT: See CMP action on Proposal No. 7. The Correlatlng ~emmittee has instructed CMP 22 to keep the articles separate. VOTE ON PANEL RECO~ENDATION: Unanimously Affirmative. COW,lENT ON VOFE:

FLACH: Separating this proposal as has been done in Proposal NOS. 21A through 21S should reduce this confusion between requirements for emergency, legally required stand-by, and optional stand-by systems.

Article 700 and 750-(New)(HOD 1978 NEC): Reject CMP 22 SUBMITTER: CMP 22 RTOIIO~3XLr~. • 7 Report of CMP TSC to combine Articles 700 and 750

ARTICLE 700 - ALTERNATE POWER SYSTEMS A. General

' 700-1. Scope. The provisions of this article apply to the installation, operation, and maintenance of systems consisting of circuits and equipment intended to distribute and control electr ici ty for illumination and/or power when the normal supply or system is interrupted. Unless specifically referenced, these provisions do not apply to health care fac i l i t ies which are covered by Article 517. j 700-2. An alternate power system shall be classified as one of the following:

332


ARTICLE 450 -- TRNASFORMERS AND TRANSFORMER VAULTS

450-1, Exception No. g-(New): Reject CMP 13 SUBMITTER: J. D. Riley, Industrial Gas Cleaning Institute

1 Exception No. g: Transformer used as controlled power supplles for electrostatic precipitators. SUBSTANTIATION: To exempt electrostatic preciptator power supplies from any require~nts for protection from explosion, f i re and/or tank rupture such as9 Vaults, pressure rel ief vents, space separation, barriers, water spray systems, enclosures, dikes, basin or trapped drains.

Such requirements are being enforced by so~ interpreters of NEC Articles 450-23, 450-24, 450-25 and 450-26.

Industrial Electrostatic Precipitator Power Supplies are not used as transformers in the normal sense, but rather as sources of hlgh voltage (35,000-75,000 volts) and low current (less than 3 amps) power for operation of electrostatic precipitators. In such use they are connected to a sophisticated, automatic primary control system complete with overload protection, secondary current sensing and spark sensing and limiting circuitry which effectively prevents the occurrence of conditions which would cause explosions within thetank.

Operating experience since the early 1goD's in thousands of applications has yielded no known occurrences of explosions of electrostatic precipitator power supplies. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Total exem1~tion from all requirements of Article 450 is not justi f ied in view of the possible significant amount of combustibles involved. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-2 (New): Accept CMP 13 Secretary's Note: I t was the action of the Correlating

Committee that further consideration be given to the comments expressed in the voting and that the Panel put the references to the various standards into fine print notes rather than a mandatory requirement. SUBMITTER: CMP 13 PROPOSAL: 33 (CMP I) Add a new paragraph after Exception No. 2 as-~-T611-ows:

As used in the Article the term f i re resistant means a construction having a minimum f i re rating of one hour, unless specified otherwise according to ASTM Standard E 119-75; Fire Tests of Building Construction and materials, NFPA 251-1972; also Methods of Fire Tests of Building Construction and Materials ANSI A2.1-1972. SUBSTANTIATION: C~ 1 referred Proposa.l No. 33 for a new definition for "Fire-resistant construction" to CMP 13 for action.. PANEL RECOMMENDATION: Accept VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COF~MENT ON VOTE:

O'NEILL: The wording of the new paragraph needs to be revised. The phrase "unless specified otherwise" is improperly located., A suggested wording may be: "As used in the Article the term f i re resistant means a construction having a minimum " f i re rating of one hour according to ASTM . . . . and Materials, ANSI A2.1-1972, unless otherwise specified in the text.

i •

450-2, Exception Nos. 1 and 2: Accept CMP 13 SUBMITTER: TSC-Nominal V~ltage

I ~ 2 In Exception Nos. I and 2 add "nominal" after ~'6"O0"-~[ts. , SUBSTANTIATION: To obtain uniformity of voltage levels and ratings throughout the Code., PANEL RECOMMENDATION: Accept. yOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-3: Reject CMP 13 SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn. ]~TOPO-S'~I[-T 4 Add a new sentence as follows: ~ o n d a r y side of a transformer shall be permitted to be protected by one or more secondary overcurrent devices where secondary taps are not over 10 feet long and the total capacity of the protective devlce(st does not exceed 125 percent of the transformer rating. SUBSTANTIATION: There are problems in this area in the interpretation of this section as to when secondary overcurrent protection is required when secondary taps are involved. We believe this proposal wil l correct the problem, and Is consistent with Sections 240-3 and 240-21. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Already~overed by Section 240-21. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-3(a): Accept CMP 13 SUBMITTER: TSC-Nomlnal Voltage •

5 Add "neminal" after "600 volts" in (at, (a t ( I t , an---~2 ) SUBSTANTIATION: To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECO~IENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimogsly Af f i rmat ive.

l

450-3(a) and Table 450-3(a)(2): Accept' CMP 13 SUBMITFER: F. L. Cameron, NEMA SG-2 High Voltage Fuse Technical

~PROPOSAL: 6 450-3(a)(1) - Change 150 percent to 250 percent. ~ n No. I to above - Change 150 percent to 250 percent.

Table 450-3(a)(2): Under the column: Primary, Over 600 Volts, Fuse Rating - Change 200 percent to 300 percent. Under the column: Secondary, Over 600 Volts, Fuse Rating - Change 150 )ercent to 250 percent and change 125 percent to 225 percent. SUBSTANTIATION: Prior to 1975, the allowable fuse sizing was permitted to be as large as 250 percent of the rated primary current of the transformer. Because of some reputed troubles with transformers rated 600 volts or less, the value was reduced to 125 percent. There had been no reported cases of di f f icul t ies with high voltage equipments uti l izing the 250 percent value. The institution of low ratio values for high voltage transformers does, i tse l f , lead to problems when the primary protection consists of high voltage fuses. \

Example: 1. The inherent overload capacity of the transformer cannot be util ized when the ratio of fuse rating to transformer rating is low. Transformers are large devices with a significant thermal capacity. Fuses are small in mass and cannot handle the same degree of overloading. This severely, and unnecessarily, limits the user.

Example: 2. A low ratio of fuse to transformer rating sometimes leads to melting of the fuses on inrush when the transformers are energized. Some transformers today allow inrush currents of 35-40 times the fu l l load rating current. High voltage fuses confronted with this type of melting wil l react, at best, by nuisance tripping and may even fa i l to adequately clear the hlgh voltage circuit i f the in i t ia l energy is inadequate to fu l ly burn-back the fuse element(s). PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-3(b): Accept C~ 13 SUBMITTER: TSC-Nominal Voltage

7 Add "nominal" a f ter "600 vol ts" in (b), (b)(1), an-~d-TB)T2). SUBSTANTIATION: To obtain uniformity of voltage levels and ratings throughout the Code, PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-3: Reject CMP 13 SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn.

3 Add a new sentence as follows: ~ o r m e r secondary conductors (other than 2 wire) are not considered to be protected by the primary overcurrent protection. SUBSTANTIATION: There are problems in this area in the interpretation of this section as to when secondary overcurrent protection is required. We believe this addition will correct the problem, also i t is consistent with the Exception No. 5 of Section 240-3. PANEL RECOMMENDATION: Reject. • PANEL COMMENT: "Already covered by Section 240-3. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

211

450-3(b)(I), Exception No. 1: Reject CMP 13 SUBMITTER: Idaho Chapter IAEI

8 Delete f i r s t sentence and rewrite to read: Where rated primary of a transformer is 9 amperes or more, an

overcurrent device rated or set at not more than 125 percent of this current rating shall be.permitted. (The rest of the Section to remain unchanged.) SUBSTANTIATION: Permitting the primary overcurrent protection of a transformer to be increased 125 percent above its primary rating does not seem to be out of line but'when considering the supporting comment for Proposal No. 7, Page 178 in the Preprint for the 1975 Code, i t does, however, lose us in a lot of mathematical figures, as you will note from the following exerpt:

Due to the required derating of overcurrent devices fu l l use of transformer design capacity is not now possible. As an example, a 30kVA, 3-phase, 208-volt transformer has, a full-load secondary current of 83.33 amps; 125 percent of this value is 104.16. I f a fused switch were used for secondary protection, the largest size standard fuse that could be used and not exceed the 104.16 amps is IOD amps. However, UL Standard 98, Section

214 and NEMA Standard KS 1-1969 Section 2.80(b) states: "A fused switch shall be marked as a part of the electrical

rating: Continuous Load Current not to exceed 80 percent of the Rating of Fuses Employed in other than Motor Circuits."

Therefore, the maximum load that could be supplied is 80 amps or 96 percent of the transformer design capacity.

The proposal would allow 100 percent use of transformer design capacity and be consistent with similar provisions for motors (Section 430-52) and conductors (Section 240-5, Exception No. 1).

The comment draws a lot of sympathy in that the 80 percent continuous duty factor permitted only 96 percent use of the transformer design but failed to mention the fact that by going, to the nex't larger size its rating with continuous loading permitted to 120 percent. Take the case of dry transformers which are designed with a high heat rise with all this high temperature wire insulation that is available. With all this design focused on a 100 percent operation factor is does not seem logical to push this heat rise another 20 percent providing the overcurrent device is loaded properly to 80 p~rcent (continuous load). Overcurrent protection is an item the Code relies on as, a safety factor when something out of the ordinary develops or is faulted into a circuit. I t seems that we have not only lost a partial but a great deal of the safety when this protection can be increased to 150 percent of the rating of a transformer when i t is for the purpose of recovering only 4 percent of the transformer design.

The last paragraph of the 1974 Preprint supporting comments included herein is not only in error, i t serves as the piece o f wool over the eyes because i t actually permits from 120 to 150 percent loading of the transformer instead of the 100 percent heralded in the comments. Actual in the f ield experience is that the overcurrent device is taken at face value (rating) and in many cases the transformers are operating at over a 100 percent with the permitted 125 percent factor. -

Just because the 125 percent mistake has been made in the past and has warped all face values out of proportion to where ampacity ratings are becoming a farce, are we committed to continue to do so especially when transformers of 112 1/2 KVA rating and less are not required in a f i r e resistant room? PANEL RECOI~MENDATION: Reject. PANEL COMaMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOP~4ENDATION: Unanimously Affirmative.

450-5: Accept CMP 13 SUBMITTER: TSC-Nominal Voltage

I PROPOSAL: 9 In the f i r s t line add "nominal" after "600 volts." ' ~ I A T I O N : .To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECO~MENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-8: Accept CMP 13 SUBMI1-TER: O. E. Dillon, Border County Div. IAEI !~ITO]~-O-S-AI--~. • 10 Revise as follows: 450-8. Ventilation. The ventilation shall be adequate to dispose of the transformer full-load losses without creating temperature rise which is in excess of the transformer rating. SUBSTANTIATION: The use of the word "excessive" renders this section legally unenforceable. See the attached ppinion* of the San Diego City Attorney.

• See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Accept as Revised:

Fine Print Note to remain. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-21: Accept CMP 13 SUBMITTER: W. Creighton Schwan, Hayward, CA PROPOSAL: 11 Designate the f i r s t two paragraphs as (a) and (b) resp-~vely, and designate the two exceptions as Exceptions to (b). SUBSTANTIATION: Neither of the two exceptions apply to the f i r s t paragraph. The suggested editorial revisions wil l eliminate confusion for Code users. PANEL RECOMMENDATION: Accept as Revised:

Assign t i t les to (a), (b), and (c). l~I Not over 112 I/2 kVA.

Over 112 1/2 kVA (c) Over 35,000 volts

Exceptions Nos. l and 2 shall apply to (b) only. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-21: Reject P CMP 13 SUBMI1-TER: TSC-Nominal Voltage ~ 12 In the last paragraph add "nominal" after "35,000

SUBSTANTIATION: To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECO~MENDATION: Unanimously Affirmative.

I 450-22: Accept CMP 13 SUBMITTER: R. S. Pinkerton, Los Angeles, CA I~TOI}-O~'AL-:-.'13 Add a paragraph as follows: ~ o r m e r s exceeding 112 1/2 kVA shall not be located within 12 inches of combustible materials, buildings, f i re escapes, roofs, or door or window openings unless separated therefrom as specified by Section 450-21. SUBSTANTIAT~QN: A transfQr:mer, which has a seriOUS internal. ~ c a ~ I UTTer the same Tire nazaro to adjacent combustible ~aterials when installed outdoors as i t does when installed ~ndoors. Therefore, the spacing or separation from combustible materials should be the same. PANEL RECOMMENDATION: Accept as Revised:

I "Transformers exceeding 112 1/2 kVA shall not be located within 12 inches of combustible materials of buildings." PANEL COI~MENT: Panel agrees with intent of Proposal, but feels its scope was too broad as submitted. VOTE ON PANEL RECO~ENDATION:

AFFIRMATIVE: 12. NEGATIVE: Boyd.

EXPLANATION OF VOTE: , i BOYD: Support proposal as submitted. Prescribed clearance to

window and door openings reasonable.

450-22: Reject CMP 13 SUBMII-fER: Southwestern Section IAEI

14 Add the following to Section 450-22: --'T-~a-ns-irormers exceeding 112 I/2 kVA shall not be located within 12 inches of combustible materials, buildings, f i re escapes roofs or door or window openings unless separated therefrom as specified by Section 450-21. SUBSTANTIATION: A transformer which has a serious internal fault can offer the same f i re hazard to adjacent combustible materials when installed outdoors as i t does when installed indoors. Therefore, the spacing or separation from combustible materials should be the same. PANEL RECO~MENDATION: Reject. PANEL COI~MENT: This Proposal is identical to Proposal No, 13. See Panel's action on Proposal'No. 13. VOTE ON PANEL RECOI~MENDATION:

AFFIRMATIVE: 12. NEGATIVE: Boyd.

EXPLANATION OF VOTE: BOYD: Same comment as In Proposal No. 13.

450-23: Reject CMP 13 SUBMITTER: Jerome M. Frank, Square D Co.

15 In the second sentence of the f i r s t paragraph ~ t h e words "and'rated over 35,000 volts." SUBSTANTIATION: Since there are no NEMA or ANSI Standards for determining flammability, there are no test methods to determine i f the various liquids meet the requirements of thls paragraph. Preliminary tests made by Factory Mutual indicated that these liquids failed the tests given to them. These liquidsdo burn more readily than Askarel. Article 450-23 at the present time permits transformers with these nonpropagatlng liquids being placed in hazardous environments that contain flammable material like paper dust, wood pulp, coal dust, etc. withoutrequiring the use of a fireproof vault. Since a nonpropagating liquid can burn for a period of time before the flame is extinguished, paper dust, wood dust, coal dust, etc. could be ignited and cause a f i re even though the nonpropagating liquid went out. I t is my understanding that at the present time there are no NEMA or ANSI or any other Standard that covers the cr l ter la for defining, testing and grading dielectric fluids used in transformers where flammabl]ity is a cr i t ical factor. I t is also my understanding that industry standards for such fluids have never been formulated to insure safety and re l iabi l i ty .

I t would seem prudent that transformers containing these liquids be placed in a fireproof vault until such time that flammability standards have been developed and these liquids tested and found satisfactory. PANEL RECOI~ENDATION: Reject. PANEL CDMM~NT: me supporting comment does not just i fy the proposed change. VOTE ON PANEL RECO~ENDATION: U11animously Affirmative.

212

450-23: Accept CMP Secretary's Note: I t was the action of the Correlating

Committee that further consideration be given to the comnents expressed in the voting. SUBMITTER: ~ 13

15A Revise f i r s t paragraph to read: -'ITi-~--~'ire Polnt Liquid-Insulated Transformers. Traosformers insulated with a liquid identified for use in nonconfoustible buildings of a specific height, housing noncombustible

' occupancies, and having a f l re point not less than 300°C shall be permitted. Such transformers installed indoors and rated over 35,000 volts shall be installed in a vault. Delete second paragraph.

SUBSTANTIATION: Since all the Askarel substitutes developed to date wil l burn to some degree, installations uti l izing these fluids should not be permitted in combustible buildings or those housing combustible occupancies unless provided with an automatic f i re extinguishing system or installed in a vault.

The abi l i ty of a noncombustible building to withstand a transformer insulating f luid f i re depends upon the type of construction (steel, concrete, etc.), building height, the convective and radiative heat release rates per unit area of the f luid and the surface area of the containment (curbing).

On that basis,leach installation should be evaluated individually depending upon these four factors. The heat release rates per unlt area should be determined by a recognized testing laboratory in accordance with a standard procedure. I f found excessive, than protection, In the form of an automatic extinguishing system or a vault, should be provided similar to that for a combustible building or occupancy.

Allowing the use of any substitute f luid without some form of f i re protection may, in some instances, result in a severe exposure to l l fe and propertyshould an internal fault result in a transformer f i re. PANEL RECOMMENDATION: Accept as Revised:

Revise 450-23 from NEC as follows: i "Transformers insulated with a listed liquid having a fine ;point not less than 300°C shall be permitted to be installed l indoors without vaults i f provided with a liquid confinement a~ea and protected by an automatic f i re extinguishing system.

Such transformers when installed indoors and rated over 35,000 volts shall be installed in a vault complying with Part C of this Article. "

Transformers installed outdoors shall comply with Section 450-27." VqTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: g. NEGATIVE: Boyd, Mattson, Thomas, Tudor.

COMMENT ON VOTE: ROBINSON: The purpose of this and similar proposals to the

1981 and earlier codes has been to promote the acceptance of a safe alternate to ASKAREL as a transformer insulating f luid for use outside of vaults. While we believe the wording proposed here is too restr ict ive, until such authorities as F.M. and U.L. resolve the technical problems, we have no alternative, in the interest of safety, but to support the Panel. EXPLANATION OF VOTE:

BOYD: Am opposed to the panel proposal because i t does not include provisions for less stringent requirements for a very desirable "askarel substitute" which has been or may be developed.

MATTSON: The 'intent of the Task Force I is lost in the proposal as i t is worded.

An exception is needed to clar i fy the totalconcept. Tests conducted by Factory Mutual Research indicate that some of the high f i re point insulated liquids are suitable for installation in non-combustible buildings with non-combustible occupancies without automatic f i re extinguishing systems depending on the heat release rate of the liquid and the height of the building.

The following is recommended: 450-23 (as is) Exceptions: Transformers insulated with listed liquids

suitable for use in a non-combustlble building and a non-combustible occupancy area shall be permitted to be installed, without an automatic f i re extinguishing system or vault. (Remaining text of Proposal 15A - as is).

THOMAS: To approve this CMP recommendation, which wouJd require ~hat al! l iquid-f i l led transformers containing a liquid with a fire-point not less than 300°C be diked and sprinklered, would be to ignore work that has been done and is s t i l l underway at Factory Mutual Research. FMR is now evaluating substitute liquids on the bas~s of" their use in non-combustible buildings With non-combustible occupancies.

To approve this latest revision by" the CMP would be to violate the spir i t of what has been done and would create an inconsistency between theNEC and what the insurers find acceptable.

The original proposal, which recognizes the importance of the building structure and its contents, is much more acceptable to NEFtA. I t at least sets the stage for later to supply details in the NEC such as building construction, roof height, building contents, type of liquids, f ire-point of liquids, etc.

TUDOR: The recommended rewording of the proposal by the panel is too restrictive. The recommendation of the Subcommittee investigating this proposal was that i f a transformer was installed in accordance with the requirements of the l isting of" the liquid in the transformer, the unit could be installed without an automatic f i re extinguishing system or vault. No increase in safety has been gained by the elimination of this

13 exception to the general rule. Something has been lost, however. At the present time there

are millions of gallons of PCB's in Askarel-filled transformers in this country. The Environmental Protection Agency has promulgated rules which encourage the elimination of this environmental hazard. By requiring an automatic f l re extinguishing system or vault for these transformers, should the user decide to replace them with a high f i re point liquid-insulated tFaqsformer or to remove the PCB-containing Askarel In a unit and replace i t with a high f i re point liquid, the proposed requirement wil l make i t economically unfeasible to make this change. This, in turn, wil l mean that many Askarel-fiIled transformers, which otherwise would have been replaced or retrof i l led, wil l remain in service, thereby maintaining a serious environmental hazard and, incidentally, subjecting the user to stringent reporting rules to the EPA and forcing him to maintain a possibly catastrophic l i ab i l i t y on his system.

450-23: Reject CMP 13 SUBMITTEd: TSC-Neminal Voltage PROPOSAL: 16" In the f i r s t paragraph add "nominal" after ~T~F~-O~-volts." SUBSTANTIATION: To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECOI~ENDATION: Reject. PANEL C~ENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOI~IENDATION: Unanimously Affirmative.

450-23: Reject CMP 13 Secretary's Note: I t was the action of the Correlating

Co~ittee that this Proposal be correlated with Proposal No. 15A. SUBMITTER: TSC-Approved for the Purpose PROPO~ 17 See the Technical Subcommittee "Recommendations" un--n-d-e-r-t-~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose = in Article 100. PANEL RECOMMENDATION: Reject. FANEL. COMMENT: See Panel action on Proposal No. 15A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-23: Reject CI~ ~ 13 SUBMITTER: Tor Orbeck, Dow Corning Corp. PITO]~'At-~." 18 Revise as follows: ~[Io~0-~72-~-~-. Tranformers Installed Indoors. Transformers insulated with an insulating liquid of "labeled" and "listed" f i re characteristics, having a f i re point of nQt less than 300°C, and "approved for the purpose" shall be permitted to be instaTled indoors or outdoors. The required protection of such a transformer installation is described in the "approval principles" which relates f i re characteristics o~ liquids to potential f i re hazards of transformers and determines which insulating liquids can be used and the protection i f required. Transformers rated over 35,000 volts and used indoors shall be installed in a vault. SUBSTANTIATION: I t is our understanding that to assess the f i re hazard of an insulating liquid in its use enviroment in an electrical installation, i t is necessary to consider the following characteristics of a material: I . Ease of ignition - Flash point

Auto ignition temperature Hot manifold ignition Transformer explosion tests

2. Fire growth - Fire point 'Large-scale f i re tests Transformer explosion tests

3. Elame spread Large-scale f i re tests 4. Heat release Heat of co~oustion

Rate of burning , Effects on materials and people

5. Extinguishment - Field tests 6. Smoke NBS smoke chamber test

obscuration of vision animal tests { eye i r r i tat ion

toxicity 7. Fire gases - Qualitative and quantitative

(Smoldering and analysis burning conditions) Animal exposure tests

8. Oxygen depletion - Large-scale tests Limiting oxygen index (Effects on people)

The material evaluation must f inal ly be related to use environment through: I . Consideration of appiication and quantities involved 2. Consideration of building and location of equipment /

We also know that the Factory Mutual Research organization has a project to develop principles by selecting the most important of these test methods to be used for a listing or labeling system for insulating liquids.

At present Section 450-23 reads as follows:

213

450-23. High Fire Point Liquid-insulated" Transformers. Transformers insulated with a nonpropagating liquid approved for the purpose, having a f i re point not less than 3DO°C, shall be permitted to be installed indoors or outdoors. Such transformers installed indoors and rated over 35,0(0) volts shall be installed in a vault.

For the purposes of this article, a nonpropagating liquid shall be one which, when subjected to a source of ignition, may burn but the flame wil l not spread from the source of ignition.

In this description the terms "high f i re point liquid" and "nonpropagating" do not adequately describe the above f i re characteristics of a liquid nor the associated f i re hazard in their electrical use environment.

• he proper description of the f i re properties of a fiquid must be strongly connected with the term "approved for the purpose." This term is defined in Article 100 as follows:

Approved for the Purpose: Approved for a specific purpose, environment, or application described in a particular Code requirement.

Suitability of equipment or materials for a specific purpose, environment or application may be determined by a nationally recognized testing laboratory, inspection agency or other organization concerned with product evaluation as part of its l isting and labeling program. (See "Labeled" or "Llsted'.)

Labeled: Equipment or materials having a label, symbol, or other identifying mark of a nationally recognized testing laboratory, ihspection agency, or other organization concerned with product evaluation that maintains periodic inspection of production of labeled equipment or materials and by whose labeling is indicated compliance with nationally recognized standards or tests to determine suitable usage 4n a specified manner.

Listed: Equipment or materials included in a l i s t published by a nationally recognized testing laboratory, inspection agency, or other organization concerned with product evaluation that maintains periodic inspection of production of listed equipment or materials, and whose listing states either that the equipment or materials meets nationally recognized standards or has been tested and found suitable for use in a specified manner.

The means for identifying listed equipment may vary for each testing laboratory, inspection agency, or other organization concerned with product evaluation, some of wMch do not recognize equipment as listed unless i t is also labeled. The authority having Jurisdiction should ut i l ize the system employed by the listing organization to identify a listed product.

Approval Principle: The term approval principle implies a third party determination of selected f i re characteristics, of approved liquids and of required protection. We believe at the present UL and FM have the capability to perform this function. PANEL RECOMMENDATION: Reject. PANEL ~OMHENT: See Panel action on Proposal No. 15A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-24: Reject C~ 13 SUBMITTER: Charles B. Kish, The Travelers Insurance Co. ]IITOIIO~CL-~. 19 Add a new second paragraph as follows: Areas con--EnI'a'rnTng Askarel transformers should never have drain or other pipe holes to the outside that would a11ow liquid to escape. Proper diking or other means of containing total liquid spillage should be constructed. Handling and disposal of spilled liquid should be to legal guidelines. SUBSTANTIATION: "Askarel" is a PCB (polychlorinated biphenyl) which is sometimes mixed with chlorobenzene to glve particular viscosity characteristics. PCB has been on the E.P.A. (Environmental Protection Agency) Toxic Pollutant List for several years. I t is an incredible stable chemical composition that could gradually accumulate in certain ecological systems. Any spillage would be a hazard to health and expenslve to clean up. PANEL RECOMMENDATION: Reject. pANEL COMMENT: This Proposal could result in conflict with later EPA Guldelines. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-24: Reject ? CMP 13 SUBMITTER: TSC-Nominal Voltage

20 In the penultimate line add "nominal" after

SUBSTANTIATION: To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately,~eflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-25, Exception No. 2: Accept CMP 13 • SUBMITTER: TSC-Nomlnal Voltage

21 Revise the f i r s t l ine as fo l lows: x ~ l o n No. 2: Where the nominal voltage does not exceed 600, etc. SUBSTANTIATION: To obtain unlformlty of voltage levels and ratings throughout the Code. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOIe~ENDATION: Unanimously Affirmative.

214

450-26: Accept . CMP 13 Secretary's Note: I t was the action of the Correlating

Committee that i t questions the need for all of the diagrams and requests the Panel to review them to see i f they can be removed. SUBMITTER: O. E. Dillon, Border County Oiv. IAEI ~ 2 2 Revise as follows: ~I~'~T~L~-6"~-.Oil,lnsulated Transformer Installed Outdoors. Oil-Insulated transformers shall not be installed.

I . Within 3 feet horizontal distance of any building wall. ) 2.. Within 10 feet horizontal distance of any required exit.

3. Within 20 feet vertical distance of any building overhang. 4. Within 10 feet radial distance of any window. The authority having Jurisdiction may consider f ire-resistive

barrier, alternate sprinkler systems, etc., as equivalent )rotection for the conditions so indicated. SUBSTANTIATION: The vagueness of this language £enders this section legally unenforceable~ See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). i PANEL RECOMMENDATION: Accept as Revised: 450-26. Oil-lnsulated Transformers Installed Outdoors. Combustible material, combustible buildings and parts of buildings, f i re escapes, and door and window openings shall be safeguarded from fires originating in oil-insulated transformers installed on roofs, attached to, or adjacent to a building or combustible material in conformance with the following:

(a) Space.Separatlon for Non-Combustible Construction. Oil-insulated transformers shall be permitted to be located directly adjacent to non-combustible walls provided the following clearances are maintained from doors, windows and other building openings:

(1) Oil-lnsulated transformers shall not be'located within a zone extending 20 feet outward and 10 feet to either side of a building door. See Figure 1.

F NONCOMBUSTIBLE WALL FDOOR OPENING

,1,1,,111111,. I V i l l i / I l l I I I / l l / / x l

' ~ ,o,~ i ooo, i . _ , o , I # /

IA I " i - - " - w , o , . - ' - - / / '

Fi~ll'e I

j . . . ~ l I L ~ .

(2) Ol1-1nsulated transformers shall not be located within a zone extending 10 feet outward and 10 feet to either side of an air intake opening. I f the air intake opening is above the transformer, there shall be a 25 feet vertical distance from the opening to the transformer. See Figure 2,

7 NwOAI~70MBUSTIBLE X AIR INTAKE OPENING

~ l l l l i l l l l l A ' " l l l l i i l l l l l l i l l l l ~

t

(3) Oil-lnsulated transformers shall not be located within a zone extending I0 feet outward and 3 feet to either side of a building window or opening other than an air intake. See Figure 3.

~ 'NONCOMBUSTIBLE WALL " X WINDOW OPENING

~ l ' i l l l l l l l l l l l l J V I I I I l I I I I J p; ' ] WIDTH o

• ~. Figure 3

[]

(4) Where the space separations above cannot be attained, f i re resistant barriers or automatic water spray systems shall be permitted to be installed as safeguards. Where a barrier is used, i t shall extend to a projection line from the corner of the transformer to the furthest corner of the window, door or

i opening. The height of the barrier shall be I foot above the top of the transformer. See Figures 4 and 5.

F WINDOW OR OPENING

J v / / / / / / / / / / / / J

OST,8 WALL \ \

• % f WINDOW OR OPENING

Jv///////////A I ~ I ~1

~[-~1I Figure 5

I

(b) Space Separation fo r Combustible Construction. , {1) Oi l - insulated transformers rated 100 kVA or less shall

~e located according to the provisions set for th fo r noncombustible construction.

(2) Oil-insulated transformers of more than 100 kVA rating shall be located according to the provisions set forth for noncombustible construction but not closer than 10 feet from the building wall.

(3) Where a roof of co(nbustible material or an overhang of combustible material is 20 feet or more above the top of an oil-insulated transformer, the required horizontal distances shall be measured from the building wall. See Figure 6 - Dimension "A." .

Where a roof of combustible material or an overhang of combustible material is less than 20 feet above the top of an oil-insulated transformer, the required horizontal distances shall be measured from the farthest projection of the overhang. SeeiFigure 6 - Dimension "B."

~ _ _ _ _ Figure 6

i • ._~LEARANCE

• I A "

/ / / / / / / / . / / / / / / / / / / / /

(4) Where these space separations cannot be attained, f ire-resistant barriers or automatic water spray systems shall be permitted to be installed as the required safeguards. Where a barrier is used, i t shall extend 3 feet beyond each side of the transformer. The height of the barrier shall be 1 foot above the top of the transformer. See Figure 7.

f COMBUSTIBLE WALL (SOLID OR WITH WINDOW OR OPENING)

~ v / / / / / / / / / l l / / / / / / / / / / / / ~

Figure 7

(c) On Roofs. Oil-insulated transformers installed on roofs shall meet the requirements of this section and the floor requirements of Section 450-42.

(d) Fire Escapes. Oil-insulated transformers shall be located such that a minimum clearance of 20 feet is maintained from f i re escapes at all times.

(e) Oil Enclosures. Where oil frem a ruptured transformer :tank can drain into the protected zones listed above, oi l enclosures that confine the oil shall be installed. Oil enclosures shall be permitted to consist of f i re resistant dikes, curbed areas or basins, or trenches f i l l ed with coarse stone. Oil enclosures shall be provided with trapped drains where the exposure and quantity of oil is such that removal of the oil is important.

(f) On Poles, Structures or Underground. Transformers installed on poles, structures or underground shall conform to the National Electrical Safety Code, ANSI C2-1977. VOTE ON PANEL RECOICMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Jefferson, Mattson, Thomas.

EXPLANATION OF VOTE: JEFFERSON: The f i re potential of o i l - f i l l ed transformers is

well known and well-documented. However, I do not feel that this proposal offers any improvement in safety over the present code. The only factors considered are the type of building construction. The proposal makes no distinction as to building occupancy, residential, commercial or industrial; Building use; does not consider proximity to structures other than %uildings"; and does not consider the volume of oil present. I also object to the format and feel i t is a bad precedent for the NEC. I also anticipate a flood of future proposals, additions and exceptions, attempting to address every conceivable building feature. This proposal is in confl ict with Article 90-1 (c) which states, "This code is not intended as a design specification nor an instruction manual for untrained persons."

MATTSON: Negative vote would change to an affirmative i f recognition were to be made of size of the units. At presen~ 450-26 allows any transformer to be installed in accordance with t e x t . By changing the t i t l e the size could be limited. I t is recognized that the intent of the proposal is for small

units. This philosophy may be lost or misinterpreted in the future.

Suggest t i t l e be changed to: 450-26 Oil-lnsulated Transformer Under 10,000 kVA Installed Outdoors.

lllOMAS: Although proposed revision provides additional detail, thereis no technical substantiation for the selected dimensions.

2 1 5

450-26, FPN-(New): Reject CMP 13 SUBMITTER: Samuel S. Levinrad, VA, Wash., DC ~ 2 3 Add a fine print note as follows:

Transformer high pressure rel ief valves and high voltage current limiting fuses are recognized safeguards for preventing catastrophic transformer fai lure. SUBSTANTIATION: I t is recommended that Section 450-26, Oil-lnsulated Transformers Installed Enclosures, be revised to be consistent with the latest technology and established engineering practice. Oil-insulated transformers (padmount transformers) are presently being installed adjacent to school buildings, townhouses a~d single family residences. They are installed in shopping center parking lots and in other areas readily accessible to the general public.

S6ction 450-26 reflects the reco~endatfons contained in "Recommended Good Practice for Transformer and Switchgear Installations", published by Factory Mutual Insurance Association. At the time that this document was written, i t was the only guide for designers with respect to f i re safety. However, we feel i t should have been updated. Since the National Electrical Code and NFPA have no jurisdiction in the updating of the aforementioned document, i t is our feeling that the National ElectriCal Code should become current with present day practices. Today's emphasis for increased safety margins on electric u t i l i t y distribution systems has led to a rapid growth in the use of current-limiting fuses for the protection of distribution systems.

Available distribution system fault current has increased signif icantly because system voltages have increased, and higher MVA capacity station transformers are being installed. This has resulted in potential faul t duties that exceed the capability of low-cost fuses historical ly used to protect distribution transformers. A major limitation of the expulsion fuse is its inabi l i ty to l imit current; as a result, tremendous amounts of energy can be fed into a fault. I f the fault occurs in a transformer, there is the possibi l i ty of a disruptive fai lure endangering l i fe and property. Current-limlting fuses offer a unique advantage in their ab i l i ty to limit the let-through current and energy within safe limits with silent, non-venting operation. Thus, increased emphasis on safety (accelerated by the development of pad~ounted equipment which can be applied in close proximity to the general public) has caused u t i l i t y . engineers to specify current-limiting fuses to prevent these potentially violent tank failures. When a current-limiting fuse is applied to a circui t , not only can the current be substantially limited, but the arcing time is also decreased. I t follows then that the energy imparted to a fault can be l substantially reduced, since i t is proportional to the let-through current squared and the total clearing time. This reduction of energy makes i t possible to protect distribution equipment from disruptive failures and hence to improve system safety margins. Consequently,'the abi l i ty of the transformer t o

,withstand faults without catastrophic fai lure can be immensely improved through the.proper application of current-limiting

) fuses. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Transformer high pressure rel ief valves are a requirement of ANSI C57.12.22-1969. The use of high voltage current limiting fuses is a system design consideration. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-27-(New): Reject CMP 13 SUBMITTER: O. E. Dillon, Border County Div. IAEI PROPOSAL: 24 Add new section as follows: TS"O'z'27q - . Installation of Transformers in Outdoor Enclosure: General. Where transformers are installed in an outdoor enclosure, the enclosure shall consist of a substantial fence not less than 8 feet high. The fence shall be so constructed that persons cannot readily climb i t . Where any exposed current-carrying part is more than 8 feet above the ground, the height of the fence shall be not less than 10 feet, unless the Fence is located more than 5 feet horizontally from the nearest such current-carrying part. The fence i f of metal shall be grounded in accordance with Article 250. The gate shall be kept locked, and a permanent sign legible at 12 feet shall be posted on the gate, gorbidding unauthorized persons to enter. No fence shall be required where all current-carrying conductors and parts entering the transformers are lead-sheathed and protected from physical damage, or are enclosed in metal raceway; the sheath, or the metal raceway, shall be wiped-in or screwed to the transformer cases, making a watertight construction, and all sheaths or raceways and the cases of the transformers shall be effectively grounded.

When the enclosure is adjacent to platforms, balconies, roofs, windows or doors, suitable screens shall be provided to prevent persons coming into contact with current-carrying parts, or bring conducting materials into contact with them. SUBSTANTIATION: The vagueness of this language renders this section legally unenforceable. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: Already covered by Sections 110-30 through 110-34, No additional clarif ication would be achieved by this proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-27-(New): Accept CMP 13 SUBMITTER: John C. Dutton, Rome, GA ][R-O-PD-~ki-?. • 25

Noncombustible Insulant Transformers. Transformers with a noncombustible dielectric f luid approved for the purpose shall be permitted to be installed indoors or outdoors. Such transformers.installed indoors and rated over 35000 volts shall be installed in a vault.

For the purposes of this section, a noncombustible dielectric f luid is one which does not have a flash point or autoignition temperature, and is not flammable in air. SUBSTANTIATION: Recent regulatory actions have eliminated the use of PCB's (one of the constituents of askarel liquids) in new transformers, requiring the development of new types of transformers and the formulation of new dielectrics.

The wording of NEC Article 450, Part B is the basis for acceptance of stated transformer designs and specified dielectrics. Transformers using a noncombustible dielectric fluid are available, and the proposed NEC section will provide acceptance of installations util izing these new types of transformers. PANEL RECOMMENDATION: Accept as Revised:

Change lines I-3 to read: Nonflammable fluid-insulated transformers. Transformers insulated with a dielectric f luid identified as nonflammable shall be..." In second paragraph, change the word "noncombustible" to "nonflammable." Renumber from "450-27" to "450-24." Renumber existing 450-24, 450-25, and 450-26 to 450-25, 450-26 and 450-27. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 12. NEGATIVE: Thomas.

EXPLANATION OF VOTE: THOMAS: The revision of this section, as proposed by CMP-13,

would be acceptable I f the proposed second paragraph were revised as follows:

For the purposes of this section, a nonflammable dielectric fluid is one which does not have a flash point or f i re point below boiling and has an autoignltion temperature greater than lO00°F (538°C).

450-28-(New): Reject CMP 13 SUBMII-[ER: O. E. Dillon, Border County Div. IAEI

26 Add new section as follows: Installation of Transformers on Poles. Where

transformers are installed on poles or pole structures, ANSI C2-1977, Rules fop Overhead Electric Line Construction of the California Public Ut i l i t ies Commission shall apply. SUBSTANTIATION: The vagueness of thls language renders thls

section legally unenforceable. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: Panel feels subject is adequately covered. VOTE ONPANEL RECOMMENDATION: 'Unanimously Affirmative.

450-29-(New): Reject CMP 13 SUBMITTER: O. E. Dillon, Border County Div. IAEI

27 Add new section as follows: ~[5~0U~2"9-[ - . Installation of Transformers on a Roof. Transformers may be installed on the roof of a building, where the structure of the building is of sufficient strength to carry the additional weight of the transformers and their enclosures and the equipment used in connection therewith under the following conditions:

(a) Dry-type and askarel-insulated transformers shall be in approved weatherproof enclosures.

(b) Where oil-insulated transformers are installed and the roof is of two-hour f lre-resist lve construction, the enclosure shall conform to Sub-article 450-C, as applicable. Where a fence enclosure is provided, a curb shall be provided high enough to contain the oil from the largest of the o i l - f i l l ed transformers, but in no case less than six inches high. A drain shall be provided from the enclosures to carry any oll which i t may contain well away from the building. Where the roof is not of two-hour f lre-resist lve construction, the enclosures shall conform to Sub-article 450-C, as applicable. SUBSTANTIATION: The vagueness of this language renders thls section legally unenforceable. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Reject; PANEL COMMENT: The intent is covered by Panel action on Proposal No. 22. VOTE ON PANEL RECOMMENDATION: Unanlmously Affirmative.

450-41: Reject CNP 13 SUBMITTER: O. E. Dillon, Border County Oiv. IAEI

28 Delete 450-41. ~]B~-YA-N~'IATION: The use of the word "practicable" renders this section legally unenforceable. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for proposal for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450~42, Exception: Reject CMP 13 SUBMITTER: Jerome M. Frank Sorgel, Div/Square D Co.

29 Delete the exception. ~O~-~TANTIATION: Section 450-25 requires that oll-lnsulated transformers installed indoors be placed in a vault. The tank of an o i l - f i l l ed transformer under fault conditions can rupture and burning oil can be emitted. Oil floats on water and burning oil would f loat on water and spread throughout a building. I t does not make engineering sense to reduce the flre-resistance rating from three hours down to one hour under the above conditlons.

In addition, since transformer vaults contain other electrical gear which could produce serious and hazardous conditions i f exposed to water, automatic sprinkling of vaults containing electrical equipment is highly undesirable and should not be permitted by the Natlonal Electrical Code. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-42, Exception: Accept CMP 13 SUBMITTER: Arthur F. Clchy, Fenwal, Inc., Ashland, MA

I ~ 30 Revise exception as follows: x - - -~-~ lon: Where transformers are protected with automatic sprinkler, water spray, carbon dloxtde or halon, construction of one-hour rating shall be permitted. SUBSTANTIATION: Since the writ ing of thts code, halon has been selected as the extinguishing agent on numerous transformer vault instal lations. As an exemple, attached sheets representing installations in transformer vaults by ~emval, Inc. have been supplied to the panel. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

BECKMANN: Reco,mend "vault" be added before "construction."

216

450-43, Exception: Accept CMP 13 SUBMITTER: Arthur F. Cichy, Fenwal, Inc., Ashland, MA FR-O-PO~I~C~." 31 Revise exception as follows: x--E'-x~eptiOn: Where transformers are protected with automatic sprinkler, water spray, carbon dioxide or halon, construction of one-hour rating shall be permitted. SUBSTANTIATION: Since the writing of this code, halon has been selected as the extinguishing agent on numerous transformer vault installations. As an example, attached sheets ~/ representing installations in transformer vaults by Fenwal, Inc. have been supplied to the panel. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-43(b): Reject CMP 13 SUBMITTER: D. F. Wartzok, Fort Wayne, IN !~R-O-PO-S-AL: 32 Add a new paragraph to existing subpart (b) as

A vault for transformers using PCB-based cooling f luid shall have a door s i l l or curb of sufficient height to confine within the vault the f luid from a l l of the transformers. End of conduits extending through the floor shall be at a height not less than the door s i l l or curb height. SUBSTANTIATION: The Federal Toxic Substances Control Act contains specific requirements regarding the handling and disposal of polychlorlnated biphenyls, commonly known as PCB's which are considered hazardous to the environment. Large liquld-cooled transformers sometimes contain a cooling f luid which is based on PCB.

The present wording in Article 450-43(b) does not adequately protect against the escape of PCB-based transformer cooling fluids into the environment. The proposed additional paragraph specifies vault construction so that the PCB-based transformer cooling f luid from all transformers in a vault (instead of Just the largest) wil l b~dequately retained in case of transformer tank rupture or leakage, until i t can be cleaned up. PANEL RECOMMENDATION: Reject. PANEL COMMENT: This Proposal could result in conflict with later EPA Guidelines. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450145(e): Accept CMP 13 SUBMITTER: J. Brooks Semple, ASHRAE/NFPA Std. 90A ~ A L : 33 Delete "automatic closing dampers of not less than No. 10 MSG steel." Insert "Fire dampers which comply with Paragraph 3-3.7.1.2 of NFPA 90A. N SUBSTANTIATION: 1. Present wording does not comply with other NFPA standards

2. IOMSG steel is a material specification and there is no substantiation of its effectiveness to stop f i re .

3. Para. 3-3.7.1.2 is a performance specification which includes substantiation of its effectiveness. PANEL RECOMMENDATION: Accept as Revised:

(el Dampers. All ventilation openings to the indoors shall be provided with automatic closing f i re dampers that operate in response to a vault f i re . Such dampers shall possess a standard f i re rating of not less than 1 I/2 hours. Fine Print Note: See Standard for Fire Dampers, ANSI Z233.1-1972. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-46, Exception-(New): Reject CMP 13 SUBMITTER: Charles B. Kish, The Travelers Insurance Co.

34 Add a new exception as follows: ~ i o n : Areas containing Askarel transformers should never have drain or other pipe holes to the outside that would allow liquid to escape. Proper diking or other means of containing total liquid spillage should be constructed. Handling and disposal of spilled liquid should be to legal guidelines. SUBSTANTIATION: "Askarel" is a PCB (polychlorinated biphenyl) which is sometimes mixed with chlorobenzene to give particular viscosity characteristics. PCB has been on the E.P.A. (Environmental Protection Agency) Toxic Pollutant List for several years. I t Is an incredible sta~le chemical composition that could gradually accumulate in certain ecological systems. Any spillage would be a hazard to health and expensive to clean up. PANEL RECOMMENDATION: Reject. PANEL COMMENT: This Proposal could result in conflict with later EPA Guidelines. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-XX: Reject CMP 13 SUBMITTER: R. C. Cathcart, Kalamazoo, MI

35 Amend Section 450 to state specifically the ~ f the NEC with respect to protecting the primary and secondary transformer windings (themselves) frem overcurrent, with the object being to make a clear distinction from the overcurrent consideration for the primary and secondary circuit conductors which are involved with tranformer installations. This should focus on whether transformers designed for a

balanced load should, necessarily be protected against possible damage from arbitrar i ly applying an unbalanced load which does not exceed the nominal rated load of the transformer but may seriously overload portions of its windings. SUBSTANTIATION: I believe that the trade magazines, In the last year or so, have cultivated a hopeless state of confusion in the minds of many electrical inspectors and electrical engineers about the Code requirements which apply to the installation of transformers. In essence, the thrust of the published articles seems to have i t that the Code required primary overcurrent protection called for in Section 450 must be augmented, as a general rule, by secondary-slde overcurrent devices to protect the "secondary circuit conductors" to conform to Section 240 regardless of th E ampacity of these conductors, the rating of the transformer or the maximum current that the primary overcurrent would permit to become available to the secondary terminals 'under any arbitrar i ly imposed load conditions.

I t seems to be ignored, that there is generally no reason to expect that a transformer serving a normally balanced load wil l ever have the load spontaneously revert to any seriously unbalanced condition due to some secondary circuit defect. In other words, there is no reason to expect that the complication or added expense of providing secondary overcurrent protection can be Justified as anything other than an academic argument. In the final analysis, any person sufficiently inept to intentionally apply a seriously unbalanced load to a susceptible transformer could be expected to also bypass the safeguards intended to protect either the transformer or circuit conductors. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel is uncertain of the intent of the Proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 460 -- CAPACITORS

460-6(a): Accept ~ 13 SUBMITTER: TSC-Nominal Voltage

I ~ 36 In the second line add "nominal" after "50 volts." ~7]I~SnFA-N7"IATION: To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

460-Part A: Accept CMP 13 SUBMITTER: C~ 13 I~TOI}I~'AL-~. • 36A Revise Tit le of Part A to read: 600 Volts,

and Under. SUBSTANTIATION: To comply with the Technical Subcommittee recommendation on nominal voltages. PANEL RECO~'6VlEMDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

460-7: Accept CMP 13 SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn. I}IIOI~)-S'A-L-~: 37 Revise as follows: ~ P o w e r Factor Correction-Motor Circuit. The total kilovar rating of capacitors that are connected on the load side of a motor controller shall not exceed the value required to raise the no-load power factor of the motor to unity. Capacitors so connected shall be permitted only in applications where the motor is not subject to unusual switching service such as plugging, rapid reversals, reclosings, Jogging, or other similar operations which could generate over-voltages and over-torques.

Delete the exception. SUBSTANTIATION: The service conditions cited in italicized "Exception u as not permitted when capacitors not exceeding 50 percent of the kVA rating of the motor input are used are equally unacceptable when capacitor rating is selected on basis of limiting motor no-load power factor to unity. We believe these application guides have been followed in the past when using capacitors for motor power factor correction~ Citing the unacceptable service conditions only in the italicized "Exception," by inference, implies such service conditions are acceptable when capacitor rating is set to l imit motor no-load power factor to unity. With capacitor ratings so set and with capacitors connected on load side of motor controller, over-voltages and over-torques could also be generated i f the motor is subject to plugging, rapid reversals, rec)osings, Jogging, etc.

I f capacitor ratings up to 50 percent of the kVA rating of the motor input are permitted to be connected on load side of motor controller, the motor is subjected to an over-voltage limited only by saturation ~ach time the motor is disconnected. These over-voltages may range from 1.2 to 1.6 times normal voltage and wil l contribute to premature failure of the motor insulation system.

.Moreover, setting capacitor rating as 50 percent of the kVA rating of the motor input does not afford, in most cases, an appreciable gain in power factor over that achieved by setting capacitor rating to l imit motor no-load power factor to unity. In support of the preceding sentence, Exhibit A (attached)

217

450-43, Exception: Accept CMP 13 SUBMITTER: Arthur F. Cichy, Fenwal, Inc., Ashland, MA FR-O-PO~I~C~." 31 Revise exception as follows: x--E'-x~eptiOn: Where transformers are protected with automatic sprinkler, water spray, carbon dioxide or halon, construction of one-hour rating shall be permitted. SUBSTANTIATION: Since the writing of this code, halon has been selected as the extinguishing agent on numerous transformer vault installations. As an example, attached sheets ~/ representing installations in transformer vaults by Fenwal, Inc. have been supplied to the panel. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-43(b): Reject CMP 13 SUBMITTER: D. F. Wartzok, Fort Wayne, IN !~R-O-PO-S-AL: 32 Add a new paragraph to existing subpart (b) as

A vault for transformers using PCB-based cooling f luid shall have a door s i l l or curb of sufficient height to confine within the vault the f luid from a l l of the transformers. End of conduits extending through the floor shall be at a height not less than the door s i l l or curb height. SUBSTANTIATION: The Federal Toxic Substances Control Act contains specific requirements regarding the handling and disposal of polychlorlnated biphenyls, commonly known as PCB's which are considered hazardous to the environment. Large liquld-cooled transformers sometimes contain a cooling f luid which is based on PCB.

The present wording in Article 450-43(b) does not adequately protect against the escape of PCB-based transformer cooling fluids into the environment. The proposed additional paragraph specifies vault construction so that the PCB-based transformer cooling f luid from all transformers in a vault (instead of Just the largest) wil l b~dequately retained in case of transformer tank rupture or leakage, until i t can be cleaned up. PANEL RECOMMENDATION: Reject. PANEL COMMENT: This Proposal could result in conflict with later EPA Guidelines. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450145(e): Accept CMP 13 SUBMITTER: J. Brooks Semple, ASHRAE/NFPA Std. 90A ~ A L : 33 Delete "automatic closing dampers of not less than No. 10 MSG steel." Insert "Fire dampers which comply with Paragraph 3-3.7.1.2 of NFPA 90A. N SUBSTANTIATION: 1. Present wording does not comply with other NFPA standards

2. IOMSG steel is a material specification and there is no substantiation of its effectiveness to stop f i re .

3. Para. 3-3.7.1.2 is a performance specification which includes substantiation of its effectiveness. PANEL RECOMMENDATION: Accept as Revised:

(el Dampers. All ventilation openings to the indoors shall be provided with automatic closing f i re dampers that operate in response to a vault f i re . Such dampers shall possess a standard f i re rating of not less than 1 I/2 hours. Fine Print Note: See Standard for Fire Dampers, ANSI Z233.1-1972. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-46, Exception-(New): Reject CMP 13 SUBMITTER: Charles B. Kish, The Travelers Insurance Co.

34 Add a new exception as follows: ~ i o n : Areas containing Askarel transformers should never have drain or other pipe holes to the outside that would allow liquid to escape. Proper diking or other means of containing total liquid spillage should be constructed. Handling and disposal of spilled liquid should be to legal guidelines. SUBSTANTIATION: "Askarel" is a PCB (polychlorinated biphenyl) which is sometimes mixed with chlorobenzene to give particular viscosity characteristics. PCB has been on the E.P.A. (Environmental Protection Agency) Toxic Pollutant List for several years. I t Is an incredible sta~le chemical composition that could gradually accumulate in certain ecological systems. Any spillage would be a hazard to health and expensive to clean up. PANEL RECOMMENDATION: Reject. PANEL COMMENT: This Proposal could result in conflict with later EPA Guidelines. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

450-XX: Reject CMP 13 SUBMITTER: R. C. Cathcart, Kalamazoo, MI

35 Amend Section 450 to state specifically the ~ f the NEC with respect to protecting the primary and secondary transformer windings (themselves) frem overcurrent, with the object being to make a clear distinction from the overcurrent consideration for the primary and secondary circuit conductors which are involved with tranformer installations. This should focus on whether transformers designed for a

balanced load should, necessarily be protected against possible damage from arbitrar i ly applying an unbalanced load which does not exceed the nominal rated load of the transformer but may seriously overload portions of its windings. SUBSTANTIATION: I believe that the trade magazines, In the last year or so, have cultivated a hopeless state of confusion in the minds of many electrical inspectors and electrical engineers about the Code requirements which apply to the installation of transformers. In essence, the thrust of the published articles seems to have i t that the Code required primary overcurrent protection called for in Section 450 must be augmented, as a general rule, by secondary-slde overcurrent devices to protect the "secondary circuit conductors" to conform to Section 240 regardless of th E ampacity of these conductors, the rating of the transformer or the maximum current that the primary overcurrent would permit to become available to the secondary terminals 'under any arbitrar i ly imposed load conditions.

I t seems to be ignored, that there is generally no reason to expect that a transformer serving a normally balanced load wil l ever have the load spontaneously revert to any seriously unbalanced condition due to some secondary circuit defect. In other words, there is no reason to expect that the complication or added expense of providing secondary overcurrent protection can be Justified as anything other than an academic argument. In the final analysis, any person sufficiently inept to intentionally apply a seriously unbalanced load to a susceptible transformer could be expected to also bypass the safeguards intended to protect either the transformer or circuit conductors. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel is uncertain of the intent of the Proposal. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 460 -- CAPACITORS

460-6(a): Accept ~ 13 SUBMITTER: TSC-Nominal Voltage

I ~ 36 In the second line add "nominal" after "50 volts." ~7]I~SnFA-N7"IATION: To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

460-Part A: Accept CMP 13 SUBMITTER: C~ 13 I~TOI}I~'AL-~. • 36A Revise Tit le of Part A to read: 600 Volts,

and Under. SUBSTANTIATION: To comply with the Technical Subcommittee recommendation on nominal voltages. PANEL RECO~'6VlEMDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

460-7: Accept CMP 13 SUBMITTER: J. J. Kark, National Electrical Manufacturers Assn. I}IIOI~)-S'A-L-~: 37 Revise as follows: ~ P o w e r Factor Correction-Motor Circuit. The total kilovar rating of capacitors that are connected on the load side of a motor controller shall not exceed the value required to raise the no-load power factor of the motor to unity. Capacitors so connected shall be permitted only in applications where the motor is not subject to unusual switching service such as plugging, rapid reversals, reclosings, Jogging, or other similar operations which could generate over-voltages and over-torques.

Delete the exception. SUBSTANTIATION: The service conditions cited in italicized "Exception u as not permitted when capacitors not exceeding 50 percent of the kVA rating of the motor input are used are equally unacceptable when capacitor rating is selected on basis of limiting motor no-load power factor to unity. We believe these application guides have been followed in the past when using capacitors for motor power factor correction~ Citing the unacceptable service conditions only in the italicized "Exception," by inference, implies such service conditions are acceptable when capacitor rating is set to l imit motor no-load power factor to unity. With capacitor ratings so set and with capacitors connected on load side of motor controller, over-voltages and over-torques could also be generated i f the motor is subject to plugging, rapid reversals, rec)osings, Jogging, etc.

I f capacitor ratings up to 50 percent of the kVA rating of the motor input are permitted to be connected on load side of motor controller, the motor is subjected to an over-voltage limited only by saturation ~ach time the motor is disconnected. These over-voltages may range from 1.2 to 1.6 times normal voltage and wil l contribute to premature failure of the motor insulation system.

.Moreover, setting capacitor rating as 50 percent of the kVA rating of the motor input does not afford, in most cases, an appreciable gain in power factor over that achieved by setting capacitor rating to l imit motor no-load power factor to unity. In support of the preceding sentence, Exhibit A (attached)

217

depicts motor power factor improvement over load range from 0 to 125 percent load with corrective kVAR at value to:

(a) raise motor no-load power factor to unity; (b) equal 50 percent of the kVA rating of the motor input.

In the f i r s t two examples depicted, 7.5 HP, 1200 RPM & 10 HP, 900 RPM ratings, the motor no-load KVAR is more than 50 percent of the kVA rating of the motor input. In these cases, which are typical of ones having inherently low motor power factor and where power factor improvement would be most beneficial, the italicized "Exception" is simply not applicable and thus affords no potential for additional gain in power factor improvement.

In the second two examples, 40 HP, 1200 RPM & 200 HP, 1800 RPM ratings, corrective kVAR as value to raise motor no-load power factor to unity yeilds better power factor improvement up through 75 percent load than attained by corrective KVAR equal to 50 percent of the kVA rating of the motor input. For loads above 75 percent, the converse is true, but there is no notable overall difference ih power factor improvement between the two approaches.

I PANEL RECOMMENDATION: Accept as Revised: Insert in f i r s t sentence between "motor to" the words "branch

circuit ." VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Beckmann, Jefferson, Tudor.

EXPLANATION OF VOTE: BEC!<MANN: I rejected this proposal because I believe that

insufficient documentation has been received to Justify changing the Code for motors rated 600 volts nominal or less and not exceeding 50 HP. Documentation has been received from Industry indicating l i t t l e or no trouble from using the present Code at these ratings.

I would agree to accepting the proposed change i f i t included the following exception:

Exception: When motor ratings do rbot exceed 600 volts nominal and 50 horsepower; capacitors not exceeding 50 percent of the kVA rating of the motor input shall be permitted to be connected on the load side of the motor controller.

JEFFERSON: I agree with NEMA that the wording of the exception in the present code can and has led to improper interpretation of the entire article. However, I do not think this proposal is the solution to the problem. The effect of the entire article is to restr ict the optimum use of capacitors by attempting to reduce the potential for errors by untrained persons. As a compromise, shbrt of eliminating the article, I • could support an article consisting of the First sentence of the proposal as revised and adding a fine print note pointing out the necessity for special consideration when the motor is subject to unusual switching service.

TUDOR: This proposal is unnecessarily restrictive. The present requirements are sufficient for a safe installation.

460-7: Reject . CM@ 13 SUBMITTER: E. Griffy, I l l , Oklahoma City, OK ]~-O!51~TA-C~. • 38 Revise to read:

The total kIlovar rating of capacitors that are connected on the load side of a motor controller shall not exceed the value required to raise the power factor of the motor branch circuit to unity. SUBSTANTIATION: Nothing can be done to change the power factor of the MOTOR unless Capacitors are interposed in the Motor Windings, or, Power Factor Improvement Capacitors are attached to the Motor Housing or, incorporated within the Motor Housing, or, the Motor is a Synchronous Motor. The ONLY "Power Factor" that is altered is the Power Factor of the Motor Branch Circuit.

I'm sure you'll agree that the wording of the National Electrical Code should be as technically correct as humanly

l ossible to avoid confusing those users of the National lectrical Code who are not current-"Capacitor," or, Motor

Engineers, and who, not being fluent with vector algebra, might be misled by the present wording.

I recognize the t i t l e of 460-7 includes the wording "motor circuit, ° but feel my suggestion is a warranted improvement. PANEL RECO~ENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal; see action on Proposal No. 37. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

460-B(c)(1),(2),and(3): Accept C~ 13 SUBMITTER: Stanley K. Hall, Duquesne Light Company ]~-OII~'TAt-~. • 39 Revise as follows: - ~ i s c o n n e c t i n g Means.

(I) A disconnecting means shall be provided in each ungrounded conductor to simultaneously open all ungrounded conductors for each capacitor bank.

(2) The disconnecting means shall be permitted to disconnect the capacitor from the line as a regular operating procedure.

(3) The rating of the disconnecting means shall not be less than 135 percent of the rated current of the capacitor. SUBSTANTIATION: This proposal wil l eliminate single pole switching of low voltage capacitors. This practice is already obsolete and not in general use. This is already a requirement for capacitors over 600 volts. Art. 460-24 (a).

The most important reason for this change is that single pole switching of low voltage capacitors is hazardous. Single pole equipments are usually open type knife switches where normal switching or closing on faults could cause arcs, splattering molten metal or flying parts. The workman may not open all ungrounded poles and leave the capacitor energized when i t should be de-energized. PANEL RECOMMENDATION: Accept as Revised:

I Change (2) to read: "The disconnecting means shall open all ungrounded conductors simultaneously." The rest of the Code remains the same. VOTE ON PANEL RECOI~ENDATION: Unanimously Affirmative.

ARTICLE 470 -- RESISTORS AND REACTORS

470, Part A: Reject SUBMITTER: TSC-Nominal Voltage PROPOSAL: 40 Revise the t i t l e as Follows:, ~ 0 0 Volts, Nominal, or Less SUBSTANTIATION: To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECO~ENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

CMP 13

ARTICLE 710 -- OVER 600 VOLTS, NOMINAL GENERAL

710-2: Reject CFP 13 SUBMITTER: H.K. Glenn, Pacific Coast Electrical Assn. ~ 4 1 Revise as follows:

Provisions applicable to specific types of installation are included in Section 710-2 interrupting rating and . . . . SUBSTANTIATION: The Pacific Coast Electrical Association has , ~ ~ p - r o p o s a l to Panel No. I Section 110-9 proposing that closing and momentary ratings be added to that section to cover all devices that interrupt current at fault levels. We believe that interrupting rating should be covered in one place only, namely Section 110-9. See Pacific Coast Electrical Assn. proposal for Section 710-21. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

710-I: Accept CMP 13 SUBMITTER: C~ 13

I ~ 41A Add the word "nominal" after 600 volts. . ~'I]I~'FA}[TIATION: To'comply with the Technical Subcem~nittee's recommendations on nominal voltage. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

710-2: Accept SUBMITTER: TSC - Skin Effect Current Tracing P-h--O-P~-~A~-~-.'42 Add "Article 427, Fixed Electric Heating ~ t for Pipelines and Vessels." SUBSTANTIATION: To correlate with proposed revisions for Article 427. PANEL RECOI~ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

CMP 13

710-2: Accept C~ 13 SUBMITTER: C~ 13 I~TO-h-O-S~A-CT.'42A Add "Article 364, Busways" to Article 710-2 after X-~'T'c~-'347, Rigid Nonmetallic Conduit. SUBSTANTIATION: To be consistent with panel action on Proposal No. 44. PANEL RECOI~ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

710-3(a) and (b): Accept CMP 13 SUBMITTER: H. F. van der Voort, Cleveland, OH l~J~rO-F~B~-~." 43 Add the words "in rigid nonmetallic conduit u to the f i r s t sentence, paragraph "(a) Aboveground Conductors" after "in intermediate metal conduit" and before "in cable trays."

In paragraph "(b) Underground Conductors," amend the last sentence before Table 710-3(b) b~ deleting the words "encased in not less than 3 inches of concrete." SUBSTANTIATION: Schedule 40 rigid PVC conduit is suitable in applications where the potential exceeds 600 volts. High voltage, high current short circuit tests were conducted on 4 inch Schedule 40 Rigid PVC Conduit under a wide •range of conditions. The results prove that the conduit exhibits l i t t l e or no signs of deterioration or physical damage due to the explosions and high temperatures. The report of the results of

218

\

depicts motor power factor improvement over load range from 0 to 125 percent load with corrective kVAR at value to:

(a) raise motor no-load power factor to unity; (b) equal 50 percent of the kVA rating of the motor input.

In the f i r s t two examples depicted, 7.5 HP, 1200 RPM & 10 HP, 900 RPM ratings, the motor no-load KVAR is more than 50 percent of the kVA rating of the motor input. In these cases, which are typical of ones having inherently low motor power factor and where power factor improvement would be most beneficial, the italicized "Exception" is simply not applicable and thus affords no potential for additional gain in power factor improvement.

In the second two examples, 40 HP, 1200 RPM & 200 HP, 1800 RPM ratings, corrective kVAR as value to raise motor no-load power factor to unity yeilds better power factor improvement up through 75 percent load than attained by corrective KVAR equal to 50 percent of the kVA rating of the motor input. For loads above 75 percent, the converse is true, but there is no notable overall difference ih power factor improvement between the two approaches.

I PANEL RECOMMENDATION: Accept as Revised: Insert in f i r s t sentence between "motor to" the words "branch

circuit ." VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 10. NEGATIVE: Beckmann, Jefferson, Tudor.

EXPLANATION OF VOTE: BEC!<MANN: I rejected this proposal because I believe that

insufficient documentation has been received to Justify changing the Code for motors rated 600 volts nominal or less and not exceeding 50 HP. Documentation has been received from Industry indicating l i t t l e or no trouble from using the present Code at these ratings.

I would agree to accepting the proposed change i f i t included the following exception:

Exception: When motor ratings do rbot exceed 600 volts nominal and 50 horsepower; capacitors not exceeding 50 percent of the kVA rating of the motor input shall be permitted to be connected on the load side of the motor controller.

JEFFERSON: I agree with NEMA that the wording of the exception in the present code can and has led to improper interpretation of the entire article. However, I do not think this proposal is the solution to the problem. The effect of the entire article is to restr ict the optimum use of capacitors by attempting to reduce the potential for errors by untrained persons. As a compromise, shbrt of eliminating the article, I • could support an article consisting of the First sentence of the proposal as revised and adding a fine print note pointing out the necessity for special consideration when the motor is subject to unusual switching service.

TUDOR: This proposal is unnecessarily restrictive. The present requirements are sufficient for a safe installation.

460-7: Reject . CM@ 13 SUBMITTER: E. Griffy, I l l , Oklahoma City, OK ]~-O!51~TA-C~. • 38 Revise to read:

The total kIlovar rating of capacitors that are connected on the load side of a motor controller shall not exceed the value required to raise the power factor of the motor branch circuit to unity. SUBSTANTIATION: Nothing can be done to change the power factor of the MOTOR unless Capacitors are interposed in the Motor Windings, or, Power Factor Improvement Capacitors are attached to the Motor Housing or, incorporated within the Motor Housing, or, the Motor is a Synchronous Motor. The ONLY "Power Factor" that is altered is the Power Factor of the Motor Branch Circuit.

I'm sure you'll agree that the wording of the National Electrical Code should be as technically correct as humanly

l ossible to avoid confusing those users of the National lectrical Code who are not current-"Capacitor," or, Motor

Engineers, and who, not being fluent with vector algebra, might be misled by the present wording.

I recognize the t i t l e of 460-7 includes the wording "motor circuit, ° but feel my suggestion is a warranted improvement. PANEL RECO~ENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal; see action on Proposal No. 37. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

460-B(c)(1),(2),and(3): Accept C~ 13 SUBMITTER: Stanley K. Hall, Duquesne Light Company ]~-OII~'TAt-~. • 39 Revise as follows: - ~ i s c o n n e c t i n g Means.

(I) A disconnecting means shall be provided in each ungrounded conductor to simultaneously open all ungrounded conductors for each capacitor bank.

(2) The disconnecting means shall be permitted to disconnect the capacitor from the line as a regular operating procedure.

(3) The rating of the disconnecting means shall not be less than 135 percent of the rated current of the capacitor. SUBSTANTIATION: This proposal wil l eliminate single pole switching of low voltage capacitors. This practice is already obsolete and not in general use. This is already a requirement for capacitors over 600 volts. Art. 460-24 (a).

The most important reason for this change is that single pole switching of low voltage capacitors is hazardous. Single pole equipments are usually open type knife switches where normal switching or closing on faults could cause arcs, splattering molten metal or flying parts. The workman may not open all ungrounded poles and leave the capacitor energized when i t should be de-energized. PANEL RECOMMENDATION: Accept as Revised:

I Change (2) to read: "The disconnecting means shall open all ungrounded conductors simultaneously." The rest of the Code remains the same. VOTE ON PANEL RECOI~ENDATION: Unanimously Affirmative.

ARTICLE 470 -- RESISTORS AND REACTORS

470, Part A: Reject SUBMITTER: TSC-Nominal Voltage PROPOSAL: 40 Revise the t i t l e as Follows:, ~ 0 0 Volts, Nominal, or Less SUBSTANTIATION: To obtain uniformity of voltage levels and ratings throughout the Code. PANEL RECO~ENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

CMP 13

ARTICLE 710 -- OVER 600 VOLTS, NOMINAL GENERAL

710-2: Reject CFP 13 SUBMITTER: H.K. Glenn, Pacific Coast Electrical Assn. ~ 4 1 Revise as follows:

Provisions applicable to specific types of installation are included in Section 710-2 interrupting rating and . . . . SUBSTANTIATION: The Pacific Coast Electrical Association has , ~ ~ p - r o p o s a l to Panel No. I Section 110-9 proposing that closing and momentary ratings be added to that section to cover all devices that interrupt current at fault levels. We believe that interrupting rating should be covered in one place only, namely Section 110-9. See Pacific Coast Electrical Assn. proposal for Section 710-21. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel does not agree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

710-I: Accept CMP 13 SUBMITTER: C~ 13

I ~ 41A Add the word "nominal" after 600 volts. . ~'I]I~'FA}[TIATION: To'comply with the Technical Subcem~nittee's recommendations on nominal voltage. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

710-2: Accept SUBMITTER: TSC - Skin Effect Current Tracing P-h--O-P~-~A~-~-.'42 Add "Article 427, Fixed Electric Heating ~ t for Pipelines and Vessels." SUBSTANTIATION: To correlate with proposed revisions for Article 427. PANEL RECOI~ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

CMP 13

710-2: Accept C~ 13 SUBMITTER: C~ 13 I~TO-h-O-S~A-CT.'42A Add "Article 364, Busways" to Article 710-2 after X-~'T'c~-'347, Rigid Nonmetallic Conduit. SUBSTANTIATION: To be consistent with panel action on Proposal No. 44. PANEL RECOI~ENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

710-3(a) and (b): Accept CMP 13 SUBMITTER: H. F. van der Voort, Cleveland, OH l~J~rO-F~B~-~." 43 Add the words "in rigid nonmetallic conduit u to the f i r s t sentence, paragraph "(a) Aboveground Conductors" after "in intermediate metal conduit" and before "in cable trays."

In paragraph "(b) Underground Conductors," amend the last sentence before Table 710-3(b) b~ deleting the words "encased in not less than 3 inches of concrete." SUBSTANTIATION: Schedule 40 rigid PVC conduit is suitable in applications where the potential exceeds 600 volts. High voltage, high current short circuit tests were conducted on 4 inch Schedule 40 Rigid PVC Conduit under a wide •range of conditions. The results prove that the conduit exhibits l i t t l e or no signs of deterioration or physical damage due to the explosions and high temperatures. The report of the results of

218

\


ARTICLE445 -- GENERATORS

445-I: Reject CMP 22 SUBMITTER: Idaho Chapter IAEI ]5~-Olb-O-S'A~-~." 1 Amend Section 445-1 to include Article 240. ~]I~rANTIATION: 240-21 tel ls us all conductors shall be protected at point of supply. The inherent design of a

~ enerator only protects the generator i tsel f . Nowhere in r t ic le 445 does i t give any specific overcurrent protection for

the conduEtor leading from the generator. These generators can be changed in the f ield to a larger

generator without any knowledge of conductor ~npacity or overcurrent requirements thereby causing an overload on the conductors and creating a f i re hazard. In some installations the conductors leading from the generator to the f i rs t overcurrent device is greater than 100 feet.

See Proposal No. 3 for 445-5. "PANEL RECOMMENDATION: Reject. PANEL COMMENT: Unduly restricting design for larger units where other methods to prevent overloading of conductors have shown to be adequate. Supporting comment is not persuasive. This article outlines requirements for protection of generators. Other sections of the NEC cover conductor overcurrent protection. Modifications of systems must be reviewed completely for compliance with all rules applicable in the NEC. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: g. NEGATIVE: Flach.

EXPLANATION OF VOTE: FLACM: I don't think adding Article 240 to the l is t of other

Articles will create any controversy. By doing this, Code users wil l be alerted to the fact that the inherent design of a generator does not protect conductors connected to the generator output terminals.

445-5: Reject CMP 22 SUBMITTER: George W. Flach, New Orleans, LA

2 Revise by adding "and neutral" after "phase ~ r s . " The sentence will then read: "The ampacity of the phase conductors and neutral from the generator terminals to the f i r s t overcurrent device shall not be less than 115 percent of the nameplate current:rating of the generator. SUBSTANTIATION: Clarification. PANEL RECOMMENDATION: Reject. PANEL COMMENT: CMP agrees with the intent of the Proposal see actlon on Proposal No. 2A, Section 445-5. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

445-5: Accept CMP 22 SUBMITTER: CMP 22 I~TOITO-S')~-~. " 2A Add a sentence to the end of 445-5 as follows:

be permitted to size the neutral conductors in accordance with Section 220-22. SUBSTANTIATION: To clarify requirements for sizing the neutral. To be consistent in sizing the neutral with other sources and distribution methods. PANEL RECOMMENDATION: Accept as revised. I t shall be permitted to slze the neutral conductors in accordance with Section 220-22. Conductors which must carry ground-fault currents shall not be smaller than required by Section 250-23(b). PANEL COII~ENT: Where the generator neutral is not grounded at Its terminal, the neutral cohductor must be of adequate size to carry ground-fault current. VOTE ON PANEL RECO~B~ENDATION: Unanimously Affirmative.

445-5: Reject CMP 22 SUBMITTER: Idaho Chapter IAEI

3 Amend 445-5 by adding another sentence stating ~ d u c t o r shall not be over 25 feet in length and shall terminate with a single circuit breaker or a single set of fuses that will limit the load to the ampacity of the conductors." SUBSTANTIATION: 250-5(d) states that generators are a separately derived system. I f they are such we should have some rules for giving the conductors from the generator proper protection. There are times when i t is hard to install an overcurrent device at the generator location. I f we used a 25 foot tap rule from the generator to the overcurrent device i t would prevent installations of great distance from the generator to the overcurrent device.

240-21 tel ls us all conductors shall be protected at point of supply. The inherent design of a generator only protects the generator i tsel f . Nowhere in Article 445 does i t give any specific overcurrent protection for the conductor leading from the generator.

See Proposal No. 1 for 445-I. PANEL RECOMMENDATION: Reject PANEL COMMENT: Unduly restricting design for larger units where, other methods to prevent overloading of conductors have shown to

be adequate. Overcurrent protectioh should be as close as practicle, but 25 feet is too restrictive. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 8. NEGATIVE: Flach, Scalone.

EXPLANATION OF VOTE: FLACH: I agree that 25 feet may be too short for large

machines, but there should be some statement in the Article which requires overcurrent protection for the conductors connected to the generator.

SCALONE: The installation of an unprotected feeder for great distances within a building might cause a greater threat to human l i fe such as f i re , explosion or electrocution, than would be caused by the lack of emergency power. I suggest modifying the proposed wording:

"The length of exposed feeder installed from the generator terminals to the f i r s t overcurrent protective device shall not exceed 25 feet."

445-6: Accept CMP 22 SUBMITTER: TSC-Nominal Voltage I~TOIR)~L-~.4 Change "generators of more than 150 volts to grou-~-u-6~--to read "generators operated at more than 150 volts t o

iground., SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 480 - - STORAGE BATTERIES

480-5(b):Accept CMP 22 SUBMITTER: TSC-Nominal Voltage I~ROIoI)~3~-~. • 5 Add "nominal" after "24 volts" to read "(24 vo-'61"t-~7-5, nominal)." SUBSTANTIATION: To conform to the guidelines established by the i TSC on Nominal Voltages. PANEL RECOI~MENDATION: Accept VOTE ON PANEL RECOMMENDATION: Unanimously AffirmatiVe.

ARTICLE 700 -- EMERGENCY SYSTEMS

Article 700: Reject CMP 22 SUBMITTER: H. K. Glenn, Pacific Coast Electrical Assn. ]~-OPO~'-A-L-~.'6 Cemblne Articles 700 and 750. ~'I]I)'S'TA)~TIATION: Adopt the report of CMP TSC to combine Articles 700 and 750 r Complete text as shown on pages 391, 392, 393, 394 of the "Preprint of the proposed amendments for the 1978 National Electrical Code." NFPA NO. 70 PR 78.

The present separation of the articles, both of which deal with alternate power sources and distribution systems intended to be functional when normal power supplies are disrupted, is i l logical and is a source of conflict in application and enforcement.

The TSC report was well conceived and the integrated subject matter provides a much more coherent coverage of alternate Power Systems. The supporting comment by CMP 22 which accompanied the proposal thoroughly covers the subject and is s t i l l pertinent.

The Correlating Co¢mnittee (see Secretary's note) apparently agreed with the developed material, but unfortunately the assignment to "process new material in the appropriate articles" was not accemplished. Such action to pull apart the work of the TSC would be ill-advised and would destroy the logical arrangement. PANEL RECOMMENDATION: Reject PANEL COMMENT: See CMP action on Proposal No. 7. The Correlatlng ~emmittee has instructed CMP 22 to keep the articles separate. VOTE ON PANEL RECO~ENDATION: Unanimously Affirmative. COW,lENT ON VOFE:

FLACH: Separating this proposal as has been done in Proposal NOS. 21A through 21S should reduce this confusion between requirements for emergency, legally required stand-by, and optional stand-by systems.

Article 700 and 750-(New)(HOD 1978 NEC): Reject CMP 22 SUBMITTER: CMP 22 RTOIIO~3XLr~. • 7 Report of CMP TSC to combine Articles 700 and 750

ARTICLE 700 - ALTERNATE POWER SYSTEMS A. General

' 700-1. Scope. The provisions of this article apply to the installation, operation, and maintenance of systems consisting of circuits and equipment intended to distribute and control electr ici ty for illumination and/or power when the normal supply or system is interrupted. Unless specifically referenced, these provisions do not apply to health care fac i l i t ies which are covered by Article 517. j 700-2. An alternate power system shall be classified as one of the following:

332

1 ARTICLE 500 -- HAZARDOUS (CLASSIFIED) LOCATIONS

500-1: Accept CMP 14 SUBMITTER: CMP 14 PROPOSAL: IA Add the following at end of fine print note ~ g to NFPA No. 493: and Installation of Intr insical ly Safe Instrument Systems in Class I Hazardous Locations ANSI/ISA RP 12.6-1976. \ SUBSTANTIATION: No reference or informatlon on installation requirements for intr insical ly safe systems. ANSI/ISA RP 12.6 is such a Standard. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


Committee that further consideration be given to the comments expressed in the voting. SUBMITTER: CMP 14 PROPOSAL: IB In f i r s t paragraph add: "due to flammable vapors, combustible dust, or ignit ible fiber~ or f lyings." SUBSTANTIATION: The existing statement in the f i r s t paragraph is not complete. The only f i re and explosion hazards covered by Articles 500-503 are due to flammable vapors, combustible dust, or ignit ible fibers or flyings. See 510-1 for similar statement for Articles 511 through 517.

I PANEL RECOMMENDATION: Accept as Revised: Add the words "gases or" after "flammable" in Proposal.

VOTE ON PANEL RECOMMENDATION: AFFIRMATIVE: 17. NEGATIVE: Conaway.

EXPLANATION OF VOTE: CONAWAY: I have voted negative as I belie@e that the proposal

should be changed to include flammable liquids. Liquids are mentioned in paragraph 2.

The proposal should read: "Due to flan~nable vapors or liquids, combustible dust, or ignitable fibers or f lyings."

i t has an e lec t r i ca l res is t i v i t y equal to or less that 102 ohm-cm.

Group F - that a dust be classified e lectr ica l ly , semi-conductive i f i t has an electrical res is t iv i ty equal to'or less than 108 ohm-cm, but greater than 102 ohm-cm.

Group G - that a dust be classified electr lcal ly non-conductive i f i t has an electrical res is t iv i ty greater than

~U~L KtcOMMENOATION: Accept as Revised:' In Group P, remove the words "or any similar dust" and replace

with the word "and." Add to the definition of Group F: " . . .but equal to or less than 108ohm-cm.. Add the words "or combustible" to Group G before the word "plastics" and remove the comma after "plastics." VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Adams, Magison.

COMMENT ON VOTE: EWERS: I would l ike to point out a problem that •arises with

this classification. Coal and coke dust is now classified as Group F. However, with this proposal coal dust may be in Group F or in Group G depending on moisture content.

SHORT: This proposal clari f ies the classification of dusts. My concern js that there is no reference table that gives the res is t iv i ty of dusts which is readily available to the user. EXPLANATION OF VOTE:

ADAMS: I believe that by adding a highly technical specification for grouping dusts, even in a fine print note, the true explosive potential of the materials are lost. The grouping in this proposa! is questionable and to make this change at this time, with almost sure revision in the next Code, would be a mistake.

MAGISON: Proposal No. 3 provides quantitative definitions of Groups E, F and G, and is therefore a significant improvement over the language of the 1978 NEC. However, Proposal No. 5 is a mere significant improvement in that i t clearly distinguishes between conductive dusts and nonconductive dusts, and is therefore in accord with Proposal No. 18 as modified by the Panel.

500-1, FPN: Accept CMP 14 SUBMITTER: Howard P. Kempsell, Chairman of NFPA Sectional

on Chemistry Laboratories PROPOSAL: 2 Add new paragraph to fine print note as follows: ]~o-r-eTe~trical classification of laboratory areas, see Standard for Fire Protection of Laboratories Using Chemicals NFPA 45-1975. SUBSTANTIATION: Chemistry Laboratories have tradit ional ly been considered non-hazardous (non- classified) areas, as far as electrical equipment is concerned. This recognizes the relat ively small quantities of flammable liquid that might be involved in a spil l and the presence of other more obvious sources of ignition, such as hot plates or bunsen burners (both of which are indispensable laboratory equipment). PANEL RECOMMENDATION: Accept as Revised: Add reference to NFPA 45-1975 to l i s t on page i48 of the NEC. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

500-2: Accept CMP 14 SUBMITTER: E. C. Magison, Honeywell Inc. PROPOSAL: 3 Revise definitions of Groups E, F, and G as

Group E: . . .s imi lar ly hazardous characteristics having res is t iv i ty of 102 ohm-cm or less.

Group F: ...explosion hazard, or any similar dust having res is t iv i ty greater than 102 ohm-cm but less than lOB ohm-cm.

Group G: . . . f lour , starch, grain, plastics, or chemical dusts having res is t iv i ty greater than 108 ohm-cm. SUBSTANTIATION: This recommendation moves the National Electrical Code toward a more definit ive classification of dusts. The prevalence of dust in industrial processes ( i .e . , plastic dust, wood dust, etc., which are not presently classified by the Code) dictates a more precise classification based on reliable scientif ic cr i ter ia that wil l aid users of the National Electrical Code.

The National Academy of Sciences (NAS), under contract by the Occupational Safety and Health Administration, set up a Dust Test Equipment Panel, staffed by prominent experts who studied the various methods used for testing the characteristics of dusts. An objective of this study is to be better able to classify the various dusts according to the Groups E, F, and G for hazardous locations, as presently described in the NEC. The test procedure for evaluating the res is t iv i ty of dust used was the hotplate method being proposed as the International Electrotechnical Cofmnission test method by Working Group No. 2 of Subcommittee 31H. Details of the method are explained in the attached report.*

*Attached report has been supplied to CMP. The in i t ia l study ~ndicated that the present Groups E, F, and

G in Article 500 of the NEC were classified according to: Ignition temperature of the dusts, and electrical conductivity

of the dusts (page 2 of the report). In analyzing various methods pertaining to the electrical

res is t iv i ty of dusts, one important conclusion of the study would better define the res is t iv i ty of dusts within the Groups.

Group E - that a dust be classified electr ical ly conductive i f

500-2: Accept CMP 14 SUBMITTER: CMP 14

3A Reword third fine print note to read: ~ u r p o s e s of testing, approval, and area classification various air mixtures . . . . "

• SUBSTANTIATION: For clari f ication. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

500-2: Accept CMP 14 SUBMITTER: Idaho Chapter IAEI

4 In Section 500-2(a) second line, delete the word ~ o n " and replace i t with the words "explosive, combustible or igni t ib le." In the third line delete the word "or," place a comma after the word "dust," and add "f iber or f lyings." In the f i f t h line delete the word "or," delete the period after the word "dust" and add a comma and add the words "f iber or f lyings."

The f i r s t paragraph of Section 500-2(a) would then read: "Equipment shall be approved not only for the class of

location but also for the explosive, combustible, or ignit ible properties of the specific gas, vapor, dust, f iber or flyings that. will be present. In addition, equipment shall not have exposed any surface that operates at a temperature in "excess of the ignition temperature of the specific gas, vapor, dust, f iber, or f lyings." SUBSTANTIATION: Class I l l locations have an approval for class propertles as well as Class I and Class I I locations. The properties-(fiber and flyings) of ignitibles in Class I l l locations have been lef t out of the wording in this section and should not be excluded. The addition of the words "explosive, combustible, or ignit ible" is the wording used in Section 500-4, 500-5 and 500-6 to describe the properties in Class I , Class I I and Class I l l locations. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

/ I

500-2: Reject CMP 14 SUBMITTER: Ernest C. Magison, Honeywell, Inc. ~ 5 Change definition to read: ~ E : Atmospheres containing metallic dusts or conductive carbonaceous dusts which have more than 8 percent total volati le material (Carbon black per ASTM D1620, charcoal, coal and coke dusts per ASTM D27~). Conductive dusts are those whose res is t iv i ty is equal to or less than 105 ohm-centimeters.

Delete Group F definition. SUBSTANTIATION: This proposal is aimed at providing a quantitative definition of conductive dusts and simplifying Class I I requirements. There is in practice l i t t l e use made of the destinction between Group E (metallic) and Group F (carbonaceous) dusts. The distinction is between conductive (E and F) and non-conductive (G) dusts.

The proposed dividing line of 105 ohm-centimeters is based

225

on values presented in ISA SP12.10, Area Classification of Hazardous Dust Locations, 1973 and studies conducted by the National Research Council Committee on Evaluation of Industrial Hazards during the past two years. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Reject in deference to Proposal No. 3. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 17. NEGATIVE: Magison. ,

COMMENT ON VOTE: ADAMS: My affirmative vote to reject this proposal is for

much the same reason as Proposal No. 3 and illustrates the possi61e conflicts. EXPLANATION OF VOTE:

MAGISON: This proposal is in accord with Proposal No. 18 as modified by the Panel. I believe that no significant confusion will result from elimination of Group F. Apparatus approved for Group F only is almost certainly intended primarily for use in the presence of coal dusts which would be Group G under the proposed definition. The disposition of apparatus presently approved for Group F, but not for Group E, could be covered by a new paragraph in 500-2(a):

"Equipment approved for Group F, but not Group E, in accordance with earlier editions of this Code, shall not be used in Group E locations i f the hazard is due to metallic dusts. Such equipment may be used in Group E locations where the hazard is due to carbonacious dusts."

500-2, FPN: Reject CMP 14 SUBMITTER: Douglas R. Pratt, Dow Corning Corp.

6 Revise fine print note as follows: r ~ p G: Atmospheres containing flour, starch, grain, or ,

other dusts with similar characteristics. SUBSTANTIATION: Recently we have been involved in the classification of production faci l i t ies in which combustible elemental silicon is present in a dust form. Dust particle size ranges from 1 to 90 microns, with the bulk of samples at approximately 35 microns.

Diff iculty was encountered with the application of Section 500-2, describing the various "Groups" of hazardous dust materials. In an effort to determine the particular "Group" into which elemental silicon would fa l l , we turned to definitions developed by the Instrument Society of America, Standard S 12.10, dated 10/73, basing classifications upon conductivities of dusts in controlled conditions.

I t was discovered, as a result of tests performed by Hazards Research Corp., that combustible elemental silicone described above, behaves similar to agricultural, plastic and other "non-conductive" dusts, lying well within "Group G."

We would also like to encourage the adoption of the ISA Standard 12.10, or the development of a similar standard, to assist institutions in correctly classifying their faci l i t ies by better defining the National Electrical Code's Class I I Groups. PANEL RECOMMENDATION: Reject PANEL COMMENT: Reject in deference to Proposal No. 3. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 17. NEGATIVE: Adams.

EXPLANATION OF VOTE: ADAMS: I think this proposal should be accepted, modified to

read: " . . .or other dusts with similar hazardous characteristics."

500-2 FPN: Accept CMP 14 Secretary's No~e: I t was the action of the Correlating

Committee that the Panel make editorial adjustment to make the fine print note a sentence. SUBMITTER: E. C. Magison, Honeywell Inc.

7 In the fourth paragraph after reference to Table ~ d : For groups E, F and G see Table 500-2(c). And add now Table 500-2(c) to include the dusts.now listed in the Fire Protection Handbook, classified as indicated. SUBSTANTIATION: I t is recommended that the various dusts listed in the National Fire Protection Association's Fire Protection Handbook, 14th Edition, pages 3-107 through 3-114 be included in the National Electrical Code. The National Academy of Sciences under contract by the Occupational Safety and Health Administration has classified the dusts within the scope Groups E, F, and G in the Code as well as by the data concerning dust resist ivi ty (another recommendation).

There is a need for a more definitive dust classification within the National Electrical Code. The prevalence of dusts in industrial processes ( i .e . , plastic dust, wood dust, etc., which are presently not classified) dictates a more precise classification based on reliable scientific cr i ter ia and information. This listing would faci l i tate easier referencing and better application of the National Electrical Code. I t is therefore recommended that these dusts be included in the National Electrical Code as classified in the attached l ist ing.*

*Attached listing supplied to CMP ~:mbers. I PANEL RECOMMENDATION: Accept as revised:

~th-e-f-ou-rt-h p-a~-agraph after reference to Table 500-2 add: "For Groups E, F and G, see Table 500-2(a)." Add now Table 500-2(a) as follows:

Table 500-2(a) Dusts by Groups Group E Atmospheres

Metals: Aluminum, atomized collector fines Aluminum, Flake, A 422 extra fine lining, polished Boron, amorphous, commercial (85% B) Iron, hydrogen reduced (98% Fe) Iron, carbonyl (99% Fe) Magnesium, milled, Grade B Thorium (contains 1.2% 02) Thorium hydride (contains 0.94% H2) Tin atomized (96%~Sn, 2% Pb) Titanium (99~ Ti) Titanium hydride (95% Ti, 3.8% H2) Uranium Uranium hydride Vanadium (86.4% V) Zirconium, prepared from hydride (contains 0.-3% 02) Zirconium, hydride (93.6% Zr. 2.1% H)

Alloys and Compounds: Aluminum-lithium alloy (15% Li) Aluminum-manganese alloy (Do~m~etal) ' Aluminum-silicon alloy (12% Si) . Group F Atmospheres

Carbonaceous" Dusts: Charcoal, hardwood mixture Gilsonite, Utah Pitch, coal tar

~ sphalt, blown petroleum resin itch, petroleum

Coal, Kentucky (Bituminous) Coal, Pennsylvania, Pittsburg (Experimental Mine Coal) Lignite, California.

Group G Atmospheres

Agricultural Dusts: Almond shell Apricot pit Cellulose Cellulose, alpha Cellulose, flock, fine cut Cherry pit Cinnamon Citrus peel Coca bean shell Cocoa, natural 19% fat Coconut shell Coffee, ful l roasted Corn Corncob gri t Corn, dextrine pure Cornstarch commercial product Cornstarch (thru No. 325 Sieve) Cork dust Cottonseed meal Cube root, South American Flax shive Garlic, dehydrated Grain dust, winter wheat, corn, oats Guar seed Gum, arabic Gum, karaya Gum, Manila (copal) Gum, tragacanth Hemp hurd Lycopodium Malt barley i Milk, skimmed Pea flour Peach pit shell Peanut hull Peat, sphagnum, sun dried Pecan nut shell Pectin (from ground dried apple pulp) Potato starch, dextrinated Pyrethrum, ground flower leaves Rauwolfia vomitoria root Rice Rice bran Rice hull Safflower meal Soy flour Soy protein Sucrose, chemically pure Sucrose Sugar, powdered Tung kernels, oil free Walnut shell, black

-Wheat, untreated Wheat flour Wheat gluten, gum Wheat starch, edible Wheat starch, allyl chloride treated Wheat straw

226

Wood, birch bark ground Wood flour, white pine Yeast, torula

Chemicals: Acetoacetanilide • Acetoacet-o-toluidine (2 methylacetoacetanilide) Acetoacet-p~phenetidide Adipic acid Anthranilic acid Aryl nltroso methyl amide Azelaic acid a.a' Azoisobutyronitrile Benzoic acid Benzotriazole Bis-phenol A I o-Chloroacetoacetanilide )-Chloroacetoacetanilide Dehydroacetic acid Diallyl phthalate Dicumyl peroxide suspended on CaCO 3 (40-60) Dicyclopenladiene dioxide Dimethyl isophthalate 3, 5 dinitrobenzoic acid Dinitrotoluamide (35 dinitro ortho toluamide) Diphenyl Ditertiary butyl para cresol Ethyl hydroxyethyl cellulose Fumaric acid Hexamethylene tetramine Hydroxethyl cellulose Isatoic anhydride DL-Methionine Nitrosoamine Para oxy benzaldehyde Para phenylene diamine (milled)' Para tert iary butyl benzoic acid Pentaerythritol Phenyl beta naphthylamine Phthalic anhydride Phthalimide Salicylanilide Sorbic acid Stearic acid, aluminum salt (aluminum tristearate Stearic acid, zinc salt (zinc stearate) Sulfur Terephthalic acid

Drugs: 2-Acetylamino-5-nitcothiazole, NHCOCH 3 1 S-C=N-CH=C-NO 2 2-Amino-S-nltrotheazole, NH 2 S-C:N-CH:C-NOo Aspirin (Acetylsal icycl ic Acid o-CH3cooc6H~cooH Gulosonic acid, diacetone C1~H1,rm~n Mannitol (hesahydric alcohol) CH~ c~ HOH 2 (C )4CH2OH' Nitropyridone L-Sorbose (CIoH1104N3)

Vitamin BI, menonitrate. ~12H170N4SN03 Vitamin C, ascorbic acla u6~806

Dyes, Pigments and Intermediates: I , 4-Diamino-2, 3-dihydroanthraquinone (90%) I

methylamino-anthraquinone (10%) (Violet 200 dye) I , 4-Di'-p-toluidineanthra-quinone (70%), B

naphthalene-azo-dimethyl-aniline (30%) (green base harmon dye) 1-Methyla~inoanthraquinone (red dye intermediate) B-naphthalene-azo-dimethylaniline

Alloys and Compounds: Calcium s i l i c ide Ferromanganese~ medium carbon Ferrotitanium (19% Ti, 74.1% Fe, 0.~6%C)

Pesticides: Benzethonium Chloride Bis (2-hydroxy-5~chlorophenyl) methane Dleldrin (~2H80~I~ 20% (50% Combustible 30% inert) 2,6 Di-terzlary-ou~#l-paracresom Ferric dimethyldithiocarbamate (Ferbam). Manganese vanicde ((CH31 ~ NC(~I~ ~M- 1Naphthyl-N-methylcar6A~a~e'{"~e~)n W) 15% (85% inert) 3, 4, 5, 6 tetrahydro-3, 5-dimethyl-2H-1, 3, 5 thiadeazine

2 thione, ("Craig" No. 974) 5% (95% inert) a, a' Trithiobis (N, N-dimethyl-thioformamide)

Thermoplastic Resins and Molding Compounds:

Group I. Acetal Resins Acetal, linear (Polyformaldehyde)

Group.II. Acrylic Resins Methyl methacrylate polymer. Methyl methacrylate-ethyl acrylate copolymer Methyl methacrylate-ethyl acrylate-styrene copolymer Methyl methacrylate-styrene-butadiene-acrylonitrile copolymer Methacrylic acid polymer, modified Acrylamide polymer Acrylonitr.ile polymer Acrylonitri le-vinyl pyridine copolymer

227

Acrylonitri le-vinyl chloride-vinylidene chloride Acrylonitri le-vinyl chloride-vinylidene chloride copolymer

(70-20-I0)

Group I l l , Cellulosic Resins Cellulose acetate Cellulose triacetate Cellulose acetate butyrate Cellulose propionate, 0.3% free' hydroxyl Ethyl cellulose 5-10 micron dust Methyl cellulose Carboxy methyl cellulose, low viscosity, 0.3 to 0.4%

substitution, acid product Hydroxyethyl cellulose-mono sodium phosphate sizing compound

Group IV. Chlorinated Polyether Resins Chlorinated polyether alcohol

Group VI. Nylon (Polyamide Resins) Nylon (polyhexamethylene adipamide) polyme~

Group VII. PolycarbOnate Resins !Polycarbonate o

Group VIII. Polyethylene Resins Polyethylene, hl-pressure process Polyethylene, low-pressure process Polyethylene wax, low molecular weight

Group X. Polypropylene Resins Polypropylene (contains no antioxidant)

Group XI. Rayon Rayon (viscose) flock, 1.5 denier, 0.020 inch maroon

Group XII. Styrene Polymer and Copolymer Resins Polystyrene molding compound Polystyrene latex, spray-dried, contains surfactants Styrene-acrylonitrile copolymer (70-30) Styrene-butadiene latex copolymer, over 75% styrene, alum

coagulated

Group XIII. Vinyl Polymer and Copolymer Resins Polyvinyl acetate Polyvinyl acetate alcohol Polyvinyl butyral Vinyl chloride-acrylonitrile cSpolymer, water emulsion ~ product (60-40) Vinyl chloride-acrylonitrile copolymer, water emulsion product

(33-67) Polyvinyl-chloride-dloctyl phthalate mixture (67-33) Vinyl toluene-acrylonitrile-butadiene copolymer (58719-23)

Thermosetting Resins and Molding Compounds:

Group I. Alkyd Resins Alkyd molding compound, mineral f i l l e r , not self-extinguishing

Group II. Allyl Resins A l l y l alcohol derivative CR-39, (from dust collector)

Group I l l . Amino Resins (Melamine and Urea) Urea formaldehyde molding cempound, Grade I I , fine

• Urea formaldehyde-phenol formal-dehyde molding compound, wood flour f i l l e r

Group VI. Epoxy Resins Epoxy, no catalyst, modifier~or additives Epoxy-bisphenol A mixture

Group V. Furane Resins '. Phenol furfural

Group VI. Phenolic Resins Phenol formaldehyde Phenol formaldehyde, l-step Phenol Tormaldehyde, 2-step Phenol formaldehyde molding compound, wood flour f i l l e r Phenol formaldehyde, polyalkylene polyamine modified

Group VII. Polyester Resins Polyethylene terephthalate Styrene modified polyester-glass fiber mixture (65-35)

Group VIII. Polyurethane Resins (Isocyanate) Polyurethane foam (toluene diiso-cyanate-polyhydroxy

with fluorocarbon blowing agent), not f ire retardant Polyurethane foam (toluene diiso-cyanate-polyhydroxy

with fluorocarbon blowing agent),'f ire retardant

Special Resins and Molding Compounds:

Group I. Cold Molded Resins Petroleum resin (blown asphalt, regular)

Group If. Coumarone-lndene Resins Coumarone-lndene, hard

Group I l l . Natural Resins Cashew oi l phenolic, hard Lignin, hydrolized-wood-type, fines Rosin, DK Shellac Soldium resinate, dry size grade XXX

Group VI. Rubber Rubber, crude, hard Rubber, synthetic,.hard, contains" 33% sulfur

Group V. Miscellaneous Resins Alkyl ketone dimer sizing compound, dimer dispersed on s i l i ca (50-50) Chlorinated phenol (bis 2-hydroxy-5 chlorophenyl methane) Ethylene oxide polymer Ethylene-maleic anhydride copolymer Styrene-maleic anhydride copolymer Petrin acrylate monomer, crude

Add a fine print note at the end of Table 500-2(a) as follows: "Atmospheres containing charcoal, coal or coke dusts which

have more than 8 percent total vo la t i le material ,(ASTM D271) or atmospheres containing these dusts sensitized by other materials so that they present an explosion hazard:" PANEL COMMENT: I t is the Panel's view that i t is inappropriate to expand the tables of classif ied materials in the'NEC. The number of hazardous gases, vapors and dusts is so great that the classif ications should be given in another NFPA publication. Such a publication would also benefit the user because i t could also explain the basis for the classi f icat ion scheme. The Panel recommends strongly that documents such as Report NMAB 353-1, "Matrix of Combustion-Relevant Properties and Classif ication of Gases, Vapors and Selected Solids," published by the National Researc h Council be used as a basis for a new NFPA publication or a revision of 325M.

However, because the public at present views the NEC as the source of material classif icat ions, i t is essential that the l i s ts be included in the 1981NEC. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 15. NEGATIVE: Adams, Conaway, Ewers.

COMMENT ON VOTE: HALL: Fine print should fol low Group F. MAGISON: I agree with proposal to l i s t additional dusts, but

" believe that the addition of the FPN after the table is unnecessary because i t duplicates information in the definit ions of the Groups.

MILLER: The f ine print note which is part of the Panel Recommendation needs some edi tor ia l ~djustment to make i t into a sentence. EXPLANATION OF VOTE:

ADAMS: I believe that this proposal should be rejected. The extensive table of dusts is something that should be in a handbook and not in the NEC. I do not believe in putting material in the NEC temporarily.

CONAWAY: The table material was not available prior to-the May'1979, meeting so material could not be studied prior to the meeting.

Great long l i s ts of dust by catagory do not belong in the Code. Where w i l l the l i s t stop. Proposed l i s t just scratches the surface of materials that could be l isted.

By l is t ing certain materials, do we infer that anything'not l isted is nonhazardous.

For certain resins and molding cempounds, there is a breakdown by Group I - - XII, etc. There is nd explanation of what these are.

EWERS: Inclusion of a l l the materials l isted is too rest r ic t ive in many cases. I t would unnecessarily c lassi fy many locations that are not a f i r e or explosion hazard.

Table 500-2: Accept CMP 14 SUBMITTER: E. C. Magison, Honeywell Inc.

8 Add the following materials in the groups ~ d :

Arsine - B Propyl Nitrate - B Ethyl Mercaptan - Ethyl Sulfide - C Hydrogen Cyanide - C Ethylene Glycol Monomethyl Ether - D

SUBSTANTIATION: Under the auspices of the National Academy of Sciences, the Underwriters Laboratories Inc. has investigated arsine, ethylene glycol monomethyl ether, ethyl mercaptan, ethyly sulf ide, hydrogen cyanide, and propyl ni trate for the purposes of classifying them within the National Electr ical I Code's hazardous locations, Groups A, B, C and D. The results of the investigation are attached.*

I t is recommended, based on the Underwriters Laboratories Inc.'s investigation and test results, that these 6 chemicals be included in the revision of the NEC in the Groups, as designated in the report.

*Attachments have been supplied to CMP. PANEL RECOMMENDATION: Accept.

PANEL COMMENT: See Panel Comment on Proposal No. 7. VOTE ON PANEL RECOMMENDATION:


COMMENT ON VOTE: MILLER: Although I am voting in the aff irmative, I believe

more c la r i f i ca t ion is needed on the handling of flammable liquids versus combustible liquids as defined in NFPA 321. EXPLANATION OF VOTE:

ADAMS: Although these 6 chemical compounds have been tested and f i t very well into Table 500-2, I think that the additions w i l l continue to the point of swamping the NEC with handbook type material.

Table 500-2: Accept SUBMITTER: E. C. Magison, Honeywell Inc. ]~TOI}~FA-L-~.'9 Add the following materials in the Groups l-6Bl-E~1-6d:

Nonane - D Cyclohexane - D Cyclohexene - D Methylcyclohexane - D Turpentine - D Butylene - D 1-Pentene - D Mexene - D Heptene - D Octene - D Nonene - D Tripropylene - D Decene - D Dipentene.- D Undecene - D Tetrapropylene -D Tridecene - D ,Tetradecene - O Methylacetylene - C Ethyl Benzene - D Curnene - D Cymene - D r Tert-butyltoluene - O Diethylbenzene - D Styrene - D a-Methylstyrene - D Vinyltoluene - D Liquif ied petroleumgas - D Methyl acetylene - Propadiene (MAPP gas)-C Naphtha, coal tar - D Naphtha, petroleum - D Stoddard solvent - D O-Terphenyl - D m-Terphenyl - D p-Terphenyl - D isopropyl alcohol - O Hexanol - D Methyl amyl alcohol - D Ethyl butanol - D Methyl isobutyl carbinol - D Methyl cyclohexanol - D Diacetone alcohol - D Propionaldehyde - C iso-butyraldehyde - C Valeraldehyde - C 3-methyl butyTaldehyde - C iso-pentyl aldehyde - C 2-ethylhexaldehyde - C iso octyl aldehyde - C 2-ethyl-3 propyl-acrolein - C Glyoxal - C Glutaraldehyde - formic acid - D Propionic acid - D Acrylic acid (inhibited) - D Acetic anhydride - D Methyl formate - D Ethyl formate - D Methyl acetate - D n-propyl acetate - D isopropyl acetate - D n-butylacetate - D sec-butylacetate - O Tert-butylacetate - D" n-amylacetate - D isoamylacetate - D sec-amylecetate - D sec-hexylacetate - D methyl acrylate - D n-butyl acrylate (inhibited) - D iso-butyl acrylate (inhibited) - D methyl methacrylate -D o-dimethyl phthalate - 0 Butyl benzyl phthalate-O Methyl formal - C propyl formal - C n-Butylformal - C iso-butyl formal - C

CMP 14

, 2 2 8

• Phenyl ether - D 2-hydroxyethyl ac ry la te - D 1,4-dioxane (diethylene dioxide) - C Glycidol - C Diglycidyl ether - C Isopropyl glycidyl ether ~ C Furfural - C n-Ethyl morpholine - C Methyl chloride - D Methylene chloride - D Ethyl chloride - D 1,1-dichloroethane - D Methyl chloroform - D 1,1,2 - Trichloroethane - D 1,2,3 Trichloropropane - D 1,2 - dichloroethylene - D Vinylidene chloride (inhibited) - D trichloroethylene - D Al ly l chloride - D 1,3 - Dichloropropene - D Chloroprene - D Ethylene chlorohydrin - D Methyl bromide - D Ethyl bromide - D Chlorobenzene - D p-dichlorobenzene - D Methyl iodide - D 1,3, dichloro-5,5-dimethyl hydantoin - D Methylamine - D Isopropylamine - D Butylamine - D Hexamethylamine diamine - D Diethylaminoethanol - D Xylldine - D Anisidine - D p-phenylene diamine - D Hydrazine - C Monomethylhydrazene - C Nitromethane - C Nitroethane - C 1 1-Nitropropane - C p-nitrochlorobenzene - O p- Nitro anil ine - D Acetoni tr i le - D Tetramethyl succinonitr i le - D Methyl isocyanate -D Propylene imine - C Hexamethylenimine - C Dimethyl Acetamide -D Dimethyl formamide - D Tetra-ethyl lead - C Tetra-methyl lead - C Ethyl s i l i ca te - D Dibutylphosphate - D

Tr iphenyl phosphate - D Dimethyl 1,2-dibromo-2-2-dichlorethyl phosphate (dibrom) - D Dimethyl sulfate - D a l l y l propyl disulf ide - C i

SUBSTANTIATION: This recommendation moves the NEC toward a more comprehensive and usable standard regarding i ts application to vapors and gases in hazardous locations. Under contracts with the U.S Coast Guard (completed) add more recently, the ' Occupational Safety and Health Ac~ninistration (not completed), the National Academy of Sciences (NAS) has sought a more

' inclusive c lassi f icat ion of gases and vapors, as defined in the National Electr ical Code as Groups A, B, C, and D in hazardous locations.

The present NEC groupings do not include the many gases and vapors present in industry today that are capable of c lassi f icat ion through appropriate procedures. The NAS has undertaken the objective of c lassi f icat ion, and although the document is s t i l l undergoing some review, these recommendations are proper for inclusion in the NEC.

I t is recommended, therefore, that a l l the gases and vapors indicated above, which are contained in the attached* published matrix, as well as the draft matrix, noted in the "NAS Classif ication" column as either A,.B, C, D, or A, B, C, D, be added to the l i s t of "gases and vapors in the pr~en~ N~C.- The remaining gases and vapors marked with an asterisk (*) , brackets ( ),. a dagger ( t ) , or a double le t te r (X(X), are not recommended for the inclusion at this time.

*Attachments have been supplied to CMP. PANEL RECOMMENDATION: Accept as Revised: •

Delete the following from the l i s t : Tridecene - D Tetradecene - D Styrene - D Naphtha, petroleum - D O-Terphenyl - D m-Terphenyl - D p-Terphenyl - D Methyl cyclohexanol 2-ethyl 3 propyl-acrolein - C n-butylacetate o-dimethyl phthalate - D xyl idine - D p-phenylene diamine - D p-nitrochlorobenzene - D

/J

p-Nitro anil ine - D Tetra-ethyl lead - C Oimethyl sulfate -,D

Add the following to the l i s t : 2LPentanone - D 2-Hexanone - D 2-Heptanone - D Diisobutyl ketone - D 3-Heptanone - D Ethyl sec-amyl ketone - D Cyclohexanone - D 0 methyl syclohetanone - D dichloroethyl ether - D PANEL COMMENT: See Panel Comment on Proposal NoL 7. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Adams, Conaway.

'COMMENT ON VOTE: SCHRAM: My notes show ansidine was also to be deleted.

EXPLANATION OF VOTE: ADAMS: These 136 chemical compounds should not be included in

Table 500-2. The information belongs in the publication of The National Academy of Science who developed the l i s t .

CONAWAY: See comments for Proposal No. 7. Where does'it a l l end. What about materials not proposed for Table that are hazardous.

Materials l isted in Proposal No. g duplicate items already in existing Table.

Styrene Naphtha Petroleum Pet ro leum Naphtha Isopropyl Alcohol 2 -- Propanol (isopropyl alcohol)

The entire l i s t needs further review. The l is t ing of stoddard solvent is questioned. I f the l i s t is added, some logical manner of l is t ing should be

used.

Table 500-2: Accept CMP 14 SUBMITTER: P. J. Schram, Underwriters Laboratories Inc.

I ~ 10 Delete "sec-butyl alcohol" from the second column. ~ I A T I O N : Editorial correction. "Sec-butyl alcohol" is same material as "2-butanol (secondary butyl alcohol)" in the second column, second l ine of Table 500-2. Apparently when sec-butyl alcohol was added to Table 500-2 in 1978 Edition of NEC as per Proposal No. 10, fact that 2-butanol (secondary butyl alcohol) was already in Table 500-2 was overlooked. PANEL RECOMMENDATION: Accept. VOTE" ON PANEL RECOMMENDATION: Unanimously Affirmative.

500-2(a): Reject CMP 14 SUBMITTER: Idaho Chapter IAEI

11 Revise (a) as follows: ~ e n t shall be approved not only for the class of location but also for the "explosive, combustible, or ignitable" properties of the specific gas, vapor dust, " f iber or f l y ings" ' that w i l l be present. In addition, equipment shall not have exposed any surface that operates at a temperature in excess of the ignit ion temperature of the specif ic gas, vapor, dust, " f iber , or f ly ings." SUBSTANTIATION: Class I l l locations have an approval for class properties as well as Class I and Class I I locations. The properties ( f iber and f ly ings) of ignitables in Class I l l locations have been l e f t out of the wording in this section and should not be excluded. The addition of the words "explosive, combustible, or ignitable" is the wording used in Section 500-4, 500-5 and 500-6 to describe the properties in Class I , Class I I , and Class I l l locations. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Already covered by Proposal No. 4. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

500-2ia) ,and (b): Accept CMP 14 SUBMITTER: G. A. Karstens, AmeriCan Feed Manufacturers ~ o n , F. Lind~olm, Association of Operative Mi l lers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 12 Revise (a) as follows: "--Ta~--~pproval for Class and Properties. In Class I locations equipment shall be approved not only fo r the location but also for the explosion properties of the specific gas or vapor. In - Class I I or I l l , Division 1 locations equipment shall be approved for .the dust-ignit ion-proof properties of the COmbustible oust or easily ign i t ib le f ibers or f ly ing fines that w i l l be present.

Revise (b) as follows: (b) Marking. In Class I locations approved equipment shall

be marked to show the Class, Group and operating temperature, or temperature range, based on operation in a 40°C ambient. In Class I I and I l l , Division 1 l~cations approved equipment shall be marked to show the Cl#ss, Group and operating temperature, or temperature range based on operation in a 40°C ambient.

229

SUBSTANTIATION: I t is the understanding of our organizations that~we do not need labeled equipment in Class I ] and Class I l l Division 2 locations. As a result we are recommending this wording to avoid any possible confusion regarding the type of equipment to be used in Division 1 or ~ locations. PANEL RECOMMENDATION: , Accept as revised: Disregard proposed changes to Section 500-2(a) and revise proposed changes to Section 500-2(b) as follows: No change in Paragraph I and revise Exception No. 3 to read:

Exception No. 3: Fixed general purpose equipment in Class I locations other than fixed lighting fixtures which is acceptable for use in Class I Division 2 locations . . . .

Add an Exception No. 4 as follows: Exception No~ 4: Fixed dust t ight equipment other than fixed

lighting fixtures which are acceptable for use in Class I I Division 2 and Class I l l locations shall not be required to be marked with the Class, Group, Division or operating temperature. PANEL COMMENT: The Panel agrees that some equipment for use in Class I I Division 2 and Class I l l locations need not be specifically marked. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 17. NEGATIVE: Miller.

COMMENT ON VOTE: EWERS: In Section (b) I believe the wording "based on

operation in a 40°C ambient" (2 places) should be changed to "referenced to a 40°C ambient." Thi~ will agree with the Panel Recommendation in Proposal No. 13. EXPLANATION OF VOTE:

MILLER: I am of the opinion that the exceptions should'be worded to indicate that they do not apply to listed equipment.

500-2(b): Accept , CMP 14 SUBMITTER: R. Y. Newton, General Electric Co.

13 Revise f i r s t paragraph as follows: ~ e d equipment shall be marked to show the Class, Group, and operating temperature or temperature range, based on operation in a specified ambient temperature range, for which i t is approved. SUBSTANTIATION: The present statement regarding ambient temperature for equipment operation in Hazardous Locations f i r s t appeared in the 1971 Code when equipment marking of approved temperature ranges by identification numbers per Jable 500-2b was adopted. I t appears to+say that the equipment is approved only i f operating in a 40°C ambient temperature and neither higher nor lower temperatures. This was the interpretation on occasion by Underwriters Laboratories.

UL adopted as standard in 1975 that Class I Gp. D & Class I I Gp. E. F. and G motors approved for 40ec ambient hazardous locations were suitable for operation in an ambient tamperature range of-25°C to 40°C. P. J. Schram of UL, who is presently on Code Panel 14, is familiar with this.

"Operation in a 40°C ambient" can only be an academic statement and not a realist ic statement. In my opinion there is a need on the part of specifiers, equipment manufacturers, users, and regulating authorities for a clear statement that equipment for hazardous locations is approved based on a specifi'ed ambient temperature range. PANEL RECOMMENDATION: Accept as Revised:

"Approved equipment shall be marked to show the Class, Group, and operating temperature, or temperature range referenced to a 40°C ambient." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

500-2(c) and 502-I: Reject CMP 14 SUBMITTER: E. C. Magison, Honeywell Inc.-

15 In the f i r s t paragraph of 500-2(c) add: ~ s t s the temperature marking shall be at least 25°C lower than the layer ignitiontemperature at the dust to be encountered. The ignition temperature for which equipment was formerly approved is given in the Table below: (use Table 502-1). In the fourth paragraph of 502-1 delete Table 502-1 and reference to i t . SUBSTANTIATION: The inclusion of plastics dusts and other dusts in Group G requires that more f l e x i b l i l i t y of selection of equipment surface temperatures for Class I I equipment be available.

I f a dust has a low melting point, a low layer ignition temperature, or exhibits a change in form, such as foaming, the equipment surface temperature must be appropriately limited. This temperature may be lower than those now recognized to be safe for flours, grain dusts, etc. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Already covered by Section 500-2(a). VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

500-4(a)(I): Accept CMP 14 SUBMITTER: CI~ ~ 14

15A Revise 500-4ia)(1) to read: ~ n which hazardous concentrations of flammable gases or vapors exist under normal operating conditions; or". SUBSTANTIATION: Panel is of opinion that woFding of 500-4(a)(I) and 500-5(a)(1) should be of a similar nature. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ADAMS: My notes indicate "hazardous" should be changed to "ignitable."

EWERS: The word "hazardous" should be changed to "ignitable" to agree with Proposal No. 1.

SCHRAM: To be consistent with the Panel Recemmendation on Proposal No. 1, the word "hazardous" preceding "concentrations" should be changed to "ignitable."

Q

500-5(a)(i): Accept CMP 14 SUBMITTER: G. A. Karstens, American Feed Manufacturers ~-s-~--Tai-~on, F. Lindholm, Association of Operating Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 16 Revise (1) as follows:

I I , Division 1 location is a location: (1) in which combustible dust is in the air under normal operating conditions . . . . " SUBSTANTIATION: The wording in this particular paragraph has led to some confusion between the intent of 500-5(a) and 500-5(b). I t is fe l t that by changing this wording there will be less misunderstanding as to the definition of Class.I], Division I and Class I f , Division 2 locations. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COGENT ON VOTE:

HALL: I t is noted that a semicolon appears between condition (1) and condition (2). This was considered an editorial change when P~nel 14 made editorial changes on the 1975 Code. Since i t is a substantive change, I believe the comma should replace the semicolon.

500-2(b): Reject CMP 14 SUBMITTER: Joseph L. Yosafat, General Electric Co. ]~rOl~'~B~--~." 14 + Revise f i r s t paragraph as follows:

Approved equipment shall be marked to show the Class, Group, maximum temperature and the maximum ambient temperature for which i t is approved. SUBSTANTIATION: The present statement regarding ambient temperature for equipment operation in Hazardous Locations f i r s t appeared in the 1971 Code when equipment marking of approved temperature ranges by identification numbers per Table 500c2b was adopted., I t appears to say that the equipment is approved only i f operating in a 4O°C ambient temperature and neither higher nor lower temperatures. This was the interpretation on occasion by Underwriters Laboratories. +

A nationally recognized testing laboratory adopted as standard in 1975 that Class I Gp. D & Class I I Gp. E, F, and G motors approved for 40°C ~bient hazardous locations were suitable for operation in an ambient temperature range of -25°C to +40°C. P.J. Schram, who is presently on Code Panel 14, is familiar wit~ this.

"Operation in a 40°C ambient" can only be an academic statement and not a realist ic statement. There is a need on the part of specifiers, equipment manufacturers, users, and regulating authorities for a clear statement of suitable ambient temperatures for electrical equipment in hazardous locations. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Committee action on Proposal No. 13. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

500-5(a), FPN: Reject . CMP 14 SUBMITTER: Douglas R. Pratt, Dow Corning C6rp. I~TO-P-O-~FAt-~." 17 Add the words "and inorganic" following the word- " o r g Y " in the second paragraph. SUBSTANTIATION: Recently we have been involved in the classlficatlon of production fac i l i t ies in which combustible elemental.silicon is present in a dust form. Dust particle size ranges from 1 to 90 microns, with the bulk of samples at approximateJy 35 microns.

Di f f icul ty was encountered with the application of Section 500-2, describing the various "Groups" of hazardous dust materials. In an effort to determine the particular "Group" into which elemental silicon would fa l l , we turned to definitions developed by the Instrument Society of America, Standard S 12.~0, dated 10/73, basing classifications upon conductivities of dusts in controlled conditions.

I t was discovered, as a result of tests performed by Hazards Research Corp., that combustible elemental silicone described above, behaves similar to agricultural, plastic and other "non-conductive" dusts, lying well within "Group G."

We would also like to encourage the adoption of the ISA Standard 12.10, "or the development of a'similar standard, to assist institutions in correctly classifying their fac i l i t ies by better defining the National Electrical Code's Class I ] Groups. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 3. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

230

500-5(a) and (b): Accept CMP 14 SUBMITTER: G. A. Karstens, American Feed Manufacturers ~ o n , F. Lindholm, Association of Operating Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 18 Delete the fine print notes in both of these paragraphs. SUBSTANTIATION: The wording as is in the ~ine print notes was prepared some 25 years ago. There has been l i t t l e or no change in this wording. Since that particular time, there has been a great deal of change in the industry's operation, and the wording as is can be misleading. PANEL RECOMMENDATION: Accept as Revised:

I Delete the FPN in Section 500-5(b). Delete f i r s t paragraph of FPN in Section 500-5(a). Retain the second paragraph and change next to last sentence to read: "Electrically conductive dusts are dusts with a resist iv i ty less than 105 ohm-cm." VOTE ON PANEL RECO~ENDATION:

AFFIRMATIVE: 15. NEGATIVE: Conaway, Short. NOT VOTING: Adams.

EXPLANATION OF VOTE: ADAMS: I am not voting on this Proposal because the proposed

revision would remove Class I I Division 1 locations. I would favor the original proposal more.

CONAWAY: I am voting negatively on this proposal. I could accept the elimination of the f i r s t paragraph of the

FPN for 500-5(a) i f the second paragraph was retained. I could also accept the elimination of the FPN following

250-5(b) i f i t was not tied to 250-5(a). SHORT: There Is no justi f ication to accept 105 ohm

centimenters as the cutoff point for conductive dusts. This proposal would in effect divide Group F into two groups.

500-5(b): Accept CMP 14 SUBMITTER: G. A. Karstens, American Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 19 Revise as follows: ~ s I I , Division 2 location is a location in which combustible dust wil l not normally be in suspension in the air or wil l not be likely to be thrown into suspension by the normal operation of equipment or apparatus in quantities sufficient to produce explosive or ignitable mixtures, but (I) where spillage that may occur wil l be readily removed and where the accumulation of dusts wil l not be sufficient to interfere with the normal operation of electrical equipment or apparatus; or (2)" where such deposits or accumulations of combustible dust on, in or in the vicinity of electric equipment might be ignited by arcs, sparks or burning material from the failure or abnormal operation of suchequipment. SUBSTANTIATION: The wording as changed better describes the condition that exists in present Class I f , Division 2 locations. PANEL RECOMMENDATION: Accept as Revised:

I Revise 1978 NEC by adding Mter "equipment or apparatus" in 500-5(b)(1) "under normal operating conditions; or." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. CO~ENT ON VOTE:

SHORT: Although i t is recognized that the wording here is a marked improvement over that presently in the 1978 NEC, further improvement wil l be achieved by the following revised wording:

A Class I I , Division 2 Location is a location in which: (I) Combustible dust will not normally be in suspension in

the air in quantities sufficient to produce explosive or ignitable mixtures, and dust accumulations are normally insufficient to interfere with the normal operation of electrical equipment or other apparatus.

(2) Dust may be in suspension in the air as a result of infrequent malfunctioning of handling or processing equipment, and dust accumulations resulting therefrom may be ignitable by abnormal operation or failure of electrical equipment or other apparatus.

500-6(a) FPN: Accept CMP 14 SUBMITTER: Idaho Chapter IAEI

20 In Section 500-6(a) fine print note, in the third ]Tne--o~-the f i r s t paragraph after "clothing manufacturing plants," add the words "sawmills and other woodworking locations." The third line would then read: "mills; f lax processing plants; clothing manufacturing plants; sawmills and other woodworking locations."

In the second paragraph in the last line after the word "excelsior," add the words "sawdust, woodchips,".' The last line wo~Id then read: "baled waste kapok, Spanish moss, excelsior, sawdust, woodchips, and other materials of similar nature." SUBSTANTIATION: The additional wording is needed to stress the f i re hazards existing in sawmill locations from fibers and flyings. Fibers and flyings from green timber will dehydrate and carbonize in a short period of time, and, being an organic material, is highly susceptable to spontaneous ignition. The wording "woodworking plants" does not give an indication that sawmills should be included in this class. In the industry, woodworking plants are generally considered to be those locations where wood products are finished after the original milling of the raw timber. Sawdust and woodchips that are

fibers and flyings in sawmills are not mentioned in the second fine print note paragraph in Section 500-6(a). I t is obvious that many types of fibers and flyings are not mentioned, but one as prevalent in many areas as sawdust and woodchips should be mentioned there.

Change woodworking plants to woodworking locations because woodworking locations other than woodworking plants present the same hazards as do the woodworking plants. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 15. NEGATIVE: Adams, Conaway, Ewers.

EXPLANATION OF VOTE: ADAMS: I think the addition of sawmills and "sawdust and

woodchips is too far-reaching. CONAWAY: I am voting negatively on this Proposal since I feel

further revision is needed. The present section l ists clothing manufacturing p!ants. Clothing plants such as shirt factories, dress factories, suit manufacturers, etc., do not have hazards needing Class I l l , Division I installations. Basic text i le manufacturing fac i l i t ies are and should be covered but clothing manufacturing plants should not be.

EWERS: I believe i t is too restrictive to include all small woodworking operations in Class I l l , Division I .

500-6(a) FPN: Reject CMP 14 SUBMITTER: Idaho Chapter IAEI PROPOSAL: 21 In the f i r s t paragraph of the fine print note, delete tne words "woodworking plants" and replace with the words "sawmills and other woodworking locations."

In the second paragraph, add the words "sawdust, woodchips" after the word "excelsior." SUBSTANTIATION: The additional wording is needed to stress the f i re hazards existing in sawmill locations from fibers and flyings. Fibers and flyings from green timber will dehydrate and carbonize in a short period of time, and, being an organic material, is highly susceptible to spontaneous ignition. The wording "woodworking plants" does. not give an indication that sawmills should be included in this c lass. / In the industry, woodworking plants are generally considered to be those locations where wood products are finished.after the original milling of the raw timber. Sawdust and woodchips that are fibers and flyings in sawmills are not mentioned in the second. fine print note paragraph in Section 500-6(a). I t is obvious that many types of fibers and flyings are not mentioned, but one as prevalent in many areas as sawdust and woodchips should be mentioned there.

Change woodworking plants to woodworking locations because woodworking locations other than woodworking plants present the same hazards as do the woodworking plants. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 20, Section 500-6(a).FPN. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

500-7-(NOW): Reject , CMP 14 SUBMITTER: R. S. Pinkerton, Los Angeles, CA' L~R-O]~O~-A-C-~. • 22 Add ~ now section as follows: -~-O~[17-[--.Wiring and Equipment Above Hazardous Locations.

(a) All fixed wiring installed in the open space above hazardous locations shall be in metallic raceways, Type MI cable or ALS cable. Cellular metal floor raceway may be used only for supplying ceiling' outlets or extensions to the area below the floor, but such raceway shall have no connections leading into or through any hazardous locations above the floor.

(b) Equipment which may produce arcs, sparks or particles of hot metal, such as lamps, lampholders for fixed lighting, cutouts, switches, receptacles, charging panels, generators, motors or other rotating equipment having make-or-break or sliding contacts shall be of the total ly enclosed type or shall

, be provided with suitable guards or screens to prevent the escape of sparks or hot metal particles. SUBSTANTIATION: This proposal is intended to correct an omission in the Code which does not generally recognize and provide for the hazard of dropping molten metal or hot metal particle into hazardous vapors when overhead electrical wiring or equipment above" and out of the hazardous location, develops a fault. This requirement is found in certain specific locations but. i t should be stated in Article 500 for all hazardous locations as the danger is the same. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 17. NEGATIVE: Boylston.

EXPLANATION OF VOTE: BOYLSTON: Requirements for wiring above all classified

locations is not well understood by those using the NEC. These requirements should be covered in Article 500 to provide the needed emphasis.

231

500-7-(New): Reject CMP 14 SUBMITTER: Southwestern Section IAEI PROPOSAL: 23 500-7. Wiring and Equipment Above Hazardous

(a) All fixed wiring installed in the open space above hazardous locations shall be in metallic raceways, t~pe MI cable or ALS cable. Cellular metal floor raceway may be used only for supplying ceiling outlets or extensions to the area below the floor, but such raceway shall have no connections leading into or through any hazardous locations above the floor.

(b) Equipment which may produce arcs, sparks or particles of hot metal, such as lamps, l ampholders for fixed lighting, cutouts, switches, receptacles, charging panels, generators, motors or other rotating equipment having make-or-break or sliding contacts, shall be of the tota l ly enclosed type or shall be provided wSth suitable guards or screens to prevent the escape of sparks or hot metal particles. SUBSTANTIATION: This proposal is intended to correct an emission in the Code which does not generally recognize and provide for the hazard of dropping molten metal or hot metal particle into hazardous vapors when overhead electrical wiring or equipment above and out of the hazardous location, develops a fault. This requirement is found in certain specific locations but i t should be stated in Article 500 for all hazardous locations as the danger is the same. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting co~ent is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 17. r NEGATIVE: Boylston.

COMMENT ON VOTE: JORIMAN: The submitter of this proposal was to supply

additional information to support the Code change. As none was received the IAEI Code Panel member had no choice but to concur with the rest of the Panel and reject Proposal No. 23. EXPLANATION OF VOTE:

BOYLSTON: See Comment-on Proposal No. 22.

ARTICLE 501 -- CLASS I LOCATIONS

501-3(a): Accept CMP SUBMITTER: D. H. Mclntosh, E. I. du Pont de Nemours & Co.

24 Revise f i r s t sentence of second paragraph as

Enclosures approved for Class I , Division, 1 locations include: (a) explosion-proof enclosures, and (b) purged and pressurized enclosures. SUBSTANTIATION: To c lar i fy intent. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

14

501-3(b)(6)(2): Accept CMP 14 SUBMITTER: TSC-Nominal Voltage

I ~ 25 Add "nominal" after "120 volts." SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. PANEL COMMENT: CMP 14 recommends that by changing Section 110-4 to read "Throughout this Code the voltage considered shall be the nominal system voltages at which the circuit operates" would eliminate the need to add nominal each time voltage is used. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

SOI-4(a) and (b): Reject CMP 14 SUBMITTER: John J. Brett,'Berger Industries, E.T.P. Div. PR]~P-O-~A-L-~. • 26 Revise (a) and (b) as follows: ~ s s I Division I locations, threaded rigid metal conduit, threaded steel intermediate metal conduit with integral or associated couplings or type MI cable with termination f i t t ings approved for the location shall be the wiring method employed. SUBSTANTIATION: We have tested our product ourselves and find i t conforms to the requirements laid down by U.L. We have requested U.L. to set up a fact finding investigation and testing for our product. PANEL RECOMMENDATION: Reject. PANEL COMMENT: No evidence to support the suggested change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-4(b): Accept CMP 14 SUBMITTER: TSC-Nominal Voltage

I ~ 27 I~ the last paragraph add "nominal" after "600

SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. PANEL COMMENT: See Panel Comment on Proposal 25. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-4(b), Exception No. 2-(New): Reject CMP i% SUBMITTER: James M. Daly, The Okonite Co. PROPOSAL: 28 Delete last paragraph of 501-4(b). Replace with a new exception as follows:

Exception No. 2: Where installed in cable tray, Type MV single conductors and multiconductor cables rated 2001 Volts and over shall have metallic shielding on each conductor. Multiconductor Type MC cable with a continuous metallic sheath shall be permitted to have nonshielded conductors. SUBSTANTIATION: The existing text requires the use of shielded conductors, both single and multiconductor, 'in cable trays for over 600 Volts. The intent is correct, namely to provide a ground path for fault currents without an external arc. Non-shielded single conductors and multiconductor cables would arc to the tray and should be shielded, however, multiconductor cables enclosed in a smooth metallic sheath or a welded and corrugated metallic sheath as defined for Type MC cable in Section 334-22 would have the sheath as a shield to safely conduct fault currents and contain any arc within the cable. The two sheaths specified provide a grounding path in excess of Table 250-95. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Already covered by f i r s t paragraph of s.ame Section. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-5(a)(1), Exception-(New): Accept CMP 14 SUBMITTER: P. J. Schram, Underwriters Laboratories Inc. ]~TO]~'A-L-~." 29 Add a new exception as follows: --l~-xc-epl~ion: Conduit runs entering an explosion-proof enclosure for switches, circuit breakers, fuses, relays, or other apparatus which may produce arcs or sparks need not be sealed i f the current interrupting contacts are:

a. Enclosed within a chamber hermetically sealed against the entrance of gases or vapors; or,

b. Immersed in oil in accordance with Section 501-6(b)(1) and (2). SUBSTANTIATION: We believe i t is the intent of the f i r s t sentence of Section 501-5(a)(1) and Section 501-5(a)(2) to require seals in conduit runs 1 1/2-inch trade size and smaller only when the conduit runs enter enclosures containing a source of ignition under normal operating conditions. The Code does not require seals on conduit runs 1 1/2-inch trade size and smaller entering explosion-proof junction boxes i f the boxes contain only wiring and splices. I f the interruption of current occurs within an hermetically sealed chamber or the contacts are properly oil immersed, there is no ignition s~urce under normal operating conditions, and the construction is essentiallx the same as an explosion-proof outlet box containing only wiring and splices.

Conductors which may be flexed as a condition of normal operation, such as mercury-tube switch leads, could eventually fa i l and result in arcing, but we do not believe i t was the original intent of the Code to consider such leads as "apparatus which may produce arcs, sparks, or high temperatures." For example, the Code does not appear to require !eads in explosion-proof f lexible connection f i t t ings which may be flexed under normal conditions to be sealed.

We believe that Section 501-B(a)(1) of the Code should be clarif ied so that specifiers, installers, and inspectors will have a clear indication as to whether or not seals are required in' conduit runs entering explosion-proof enclosures housing mercury-tube switches, and in similar situations, and so that testing laboratories such as Underwriters Laboratories Inc. wil l be able to publish more detailed test requirements for such products based on the intended method of installation. I f i t is the intent of the Code that seals be required in such circumstances (the above proposal is based on seals not being required), the Code should be revised to so indicate. PANEL RECOMMENDATION: Accept as Revised:

Between the words "runs" and "entering" add the words "1 I/2 inches and smaller". VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-5(a)(S)-(New): ReJect ' CHP 14 SUBMITTER: Robert G. MacManus, Pawtucket, RI

30 Add a new (5) as follows: T~TT-Nember of Conductors Allowed In One Sea]. The number of

conductors allowed in any one seal shall be limited to nine. SUBSTANTIATION: No restriction has ever been placed on the number of conductors in a raceway which is required to be sealed. I t would be next to impossible to make an effective seal with the installation of a large number of conductors. As an example, 154 No. 14 conductors may be installed in a 2 inch conduit. The writer has seen 83 conductors in a combination of No. 14 - No. 12 and No. 10 wires. A seal was attempted in order to comply w~th Section 501-5(a)(2). PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is too restr ict ive. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

232

500-7-(New): Reject CMP 14 SUBMITTER: Southwestern Section IAEI PROPOSAL: 23 500-7. Wiring and Equipment Above Hazardous

(a) All fixed wiring installed in the open space above hazardous locations shall be in metallic raceways, t~pe MI cable or ALS cable. Cellular metal floor raceway may be used only for supplying ceiling outlets or extensions to the area below the floor, but such raceway shall have no connections leading into or through any hazardous locations above the floor.

(b) Equipment which may produce arcs, sparks or particles of hot metal, such as lamps, l ampholders for fixed lighting, cutouts, switches, receptacles, charging panels, generators, motors or other rotating equipment having make-or-break or sliding contacts, shall be of the tota l ly enclosed type or shall be provided wSth suitable guards or screens to prevent the escape of sparks or hot metal particles. SUBSTANTIATION: This proposal is intended to correct an emission in the Code which does not generally recognize and provide for the hazard of dropping molten metal or hot metal particle into hazardous vapors when overhead electrical wiring or equipment above and out of the hazardous location, develops a fault. This requirement is found in certain specific locations but i t should be stated in Article 500 for all hazardous locations as the danger is the same. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting co~ent is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 17. r NEGATIVE: Boylston.

COMMENT ON VOTE: JORIMAN: The submitter of this proposal was to supply

additional information to support the Code change. As none was received the IAEI Code Panel member had no choice but to concur with the rest of the Panel and reject Proposal No. 23. EXPLANATION OF VOTE:

BOYLSTON: See Comment-on Proposal No. 22.

ARTICLE 501 -- CLASS I LOCATIONS

501-3(a): Accept CMP SUBMITTER: D. H. Mclntosh, E. I. du Pont de Nemours & Co.

24 Revise f i r s t sentence of second paragraph as

Enclosures approved for Class I , Division, 1 locations include: (a) explosion-proof enclosures, and (b) purged and pressurized enclosures. SUBSTANTIATION: To c lar i fy intent. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

14


I ~ 25 Add "nominal" after "120 volts." SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. PANEL COMMENT: CMP 14 recommends that by changing Section 110-4 to read "Throughout this Code the voltage considered shall be the nominal system voltages at which the circuit operates" would eliminate the need to add nominal each time voltage is used. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

SOI-4(a) and (b): Reject CMP 14 SUBMITTER: John J. Brett,'Berger Industries, E.T.P. Div. PR]~P-O-~A-L-~. • 26 Revise (a) and (b) as follows: ~ s s I Division I locations, threaded rigid metal conduit, threaded steel intermediate metal conduit with integral or associated couplings or type MI cable with termination f i t t ings approved for the location shall be the wiring method employed. SUBSTANTIATION: We have tested our product ourselves and find i t conforms to the requirements laid down by U.L. We have requested U.L. to set up a fact finding investigation and testing for our product. PANEL RECOMMENDATION: Reject. PANEL COMMENT: No evidence to support the suggested change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-4(b): Accept CMP 14 SUBMITTER: TSC-Nominal Voltage

I ~ 27 I~ the last paragraph add "nominal" after "600

SUBSTANTIATION: To conform to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. PANEL COMMENT: See Panel Comment on Proposal 25. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-4(b), Exception No. 2-(New): Reject CMP i% SUBMITTER: James M. Daly, The Okonite Co. PROPOSAL: 28 Delete last paragraph of 501-4(b). Replace with a new exception as follows:

Exception No. 2: Where installed in cable tray, Type MV single conductors and multiconductor cables rated 2001 Volts and over shall have metallic shielding on each conductor. Multiconductor Type MC cable with a continuous metallic sheath shall be permitted to have nonshielded conductors. SUBSTANTIATION: The existing text requires the use of shielded conductors, both single and multiconductor, 'in cable trays for over 600 Volts. The intent is correct, namely to provide a ground path for fault currents without an external arc. Non-shielded single conductors and multiconductor cables would arc to the tray and should be shielded, however, multiconductor cables enclosed in a smooth metallic sheath or a welded and corrugated metallic sheath as defined for Type MC cable in Section 334-22 would have the sheath as a shield to safely conduct fault currents and contain any arc within the cable. The two sheaths specified provide a grounding path in excess of Table 250-95. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Already covered by f i r s t paragraph of s.ame Section. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-5(a)(1), Exception-(New): Accept CMP 14 SUBMITTER: P. J. Schram, Underwriters Laboratories Inc. ]~TO]~'A-L-~." 29 Add a new exception as follows: --l~-xc-epl~ion: Conduit runs entering an explosion-proof enclosure for switches, circuit breakers, fuses, relays, or other apparatus which may produce arcs or sparks need not be sealed i f the current interrupting contacts are:

a. Enclosed within a chamber hermetically sealed against the entrance of gases or vapors; or,

b. Immersed in oil in accordance with Section 501-6(b)(1) and (2). SUBSTANTIATION: We believe i t is the intent of the f i r s t sentence of Section 501-5(a)(1) and Section 501-5(a)(2) to require seals in conduit runs 1 1/2-inch trade size and smaller only when the conduit runs enter enclosures containing a source of ignition under normal operating conditions. The Code does not require seals on conduit runs 1 1/2-inch trade size and smaller entering explosion-proof junction boxes i f the boxes contain only wiring and splices. I f the interruption of current occurs within an hermetically sealed chamber or the contacts are properly oil immersed, there is no ignition s~urce under normal operating conditions, and the construction is essentiallx the same as an explosion-proof outlet box containing only wiring and splices.

Conductors which may be flexed as a condition of normal operation, such as mercury-tube switch leads, could eventually fa i l and result in arcing, but we do not believe i t was the original intent of the Code to consider such leads as "apparatus which may produce arcs, sparks, or high temperatures." For example, the Code does not appear to require !eads in explosion-proof f lexible connection f i t t ings which may be flexed under normal conditions to be sealed.

We believe that Section 501-B(a)(1) of the Code should be clarif ied so that specifiers, installers, and inspectors will have a clear indication as to whether or not seals are required in' conduit runs entering explosion-proof enclosures housing mercury-tube switches, and in similar situations, and so that testing laboratories such as Underwriters Laboratories Inc. wil l be able to publish more detailed test requirements for such products based on the intended method of installation. I f i t is the intent of the Code that seals be required in such circumstances (the above proposal is based on seals not being required), the Code should be revised to so indicate. PANEL RECOMMENDATION: Accept as Revised:

Between the words "runs" and "entering" add the words "1 I/2 inches and smaller". VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-5(a)(S)-(New): ReJect ' CHP 14 SUBMITTER: Robert G. MacManus, Pawtucket, RI

30 Add a new (5) as follows: T~TT-Nember of Conductors Allowed In One Sea]. The number of

conductors allowed in any one seal shall be limited to nine. SUBSTANTIATION: No restriction has ever been placed on the number of conductors in a raceway which is required to be sealed. I t would be next to impossible to make an effective seal with the installation of a large number of conductors. As an example, 154 No. 14 conductors may be installed in a 2 inch conduit. The writer has seen 83 conductors in a combination of No. 14 - No. 12 and No. 10 wires. A seal was attempted in order to comply w~th Section 501-5(a)(2). PANEL RECOMMENDATION: Reject. PANEL COMMENT: Proposal is too restr ict ive. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

232

501-5(c)(2): Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose

31 See the Technical Subcommittee "Reco~ndations" un-u'n-~--r'-i~e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

(2) Compound. Sealing compound shall be approved and shall provide a seal against passage of gas or vapors through the seal f i t t ing , shall not be affected by the surrounding atmosphere or liquids, and shall not have a melting point of less than 93°C (200°F). VOTE ON PANEL RECOMMENDATION: Unanimously Aff irmative.

501-5(e)(2): Reject CMP 14 SUBMITTER: C.E. Muhleman, Marion, IN PI~rOIIO-S'-At-~ 32 Revise as follows: - - T ~ - - Installed ca~les which limit gas or vapor flow through the cable core t o 0.007 cubic feet per hour (0.0551 x 106 cubic metre per second) at a pressure of 6 inches of water (1490 pascals) at 60~F (15.5°C) shall not be required to be sealed except as required in (e)(1) above. SUBSTANTIATION: The new wording is intended to assure that the cables are intact even after the rigors of installation. The new wording also avoids the ambiguous phrase "gas/vapor-tight continuous sheath." PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necesslty. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ADAMS: The parenthetical phrase "0.007 cubic feet per hour of air at a pressure of 6 inches of water" causes great concern and I believe i t should be lef t out. The gas passing through the interstices of the wire strands is included in the above phrase but when referred to the seal f i t t ing I t is not included.

501-5(e)(4) FPN: Reject CMP 14 SUBMITTER: K.C. Starkey, The Rockbestos Co. I~-O-P-O-~FA-C~- 33 Revise fine print note as follows: ~ e a t h mentioned in (d) and (e) above may be either metal or a nonmetallic material . i f approved for the purpose. SUBSTANTIATION: Cables with a gas/vapor tight continuou~ sheath that are sealed in the hazardous location need not be scaled when they leave the hazardous location. This applies to continuous metallic sheathed cable and Type TC cable that is approved for the purpose.

In the case of a continuous metallic sheath cable the continuous metal sheath provides the gas/vapor tight sheath. In approved nonmetallic Type TC cable the cable jacket provides this gas/vapor tight sheath.

However in a noncontinuous metallic sheathed cable such as interlock armor the gas/vapor tight barrier must be provided by the nonmetallic Jacketing material.

With a continuous metallic sheath cable a Jacket, when provided, is for mechanical and/or corrision protection.

Therefore the impervious Jacket over an interlock cable construction should re(Iuire the same type and thickness as a Type TC cable.

A comparison between the UL required Jacket thickness for mechanical and/or corrosion protection of continuous sheathed metallic cable and the gas/vapor tight Jacket of a Type TC cable is listed below.

CONTINUOUS METAL SHEATH CABLE

Core O.D. Jacket Thickness

0-0.425 40 mils 0.426-0~750 50 mils 0.751-1.500 50 mils 1.501-2.250 60 mils 2.251-3.000 75 mils 3.001-& larger 85 mils

NONMETALLIC TYPE TC CABLE

Core O.D. Jacket Thickness

0-0.425 45 mils 0.426-0.700 60 mils 0.701-1.500 80 mils 1.501-2.500 110 mils 2.501-& larger 140 mils

PANEL RECOMMENDATION: Reject. PANEL COMMENT: Supporting comment is not persuasive as to necessity. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-6(b): Accept CMP 14 SUBMITTER: W.A. Short, Crouse-Hinds Company P ~ . 34 Add a new 501-6(b)(5): ---(TT-~uses Internal to Lighting Fixtures. Listed cartr idge fuses shall be permitted within lighting fixtures. SUBSTANTIATION: The principal reason for internal fusing of lighting fixtures is to remove the faulty f ixture from the circuit before i t results in a branch circuit outage, and darkness in an entire area.

U/L requires that listed cartridge fuses (such as Buss KTK) be f i l l ed with quartz or other granular matter which prevents flame from erupting from the cartridge. PANEL RECOMMENDATION: Accept as Revised:

Substitute the word "Approved" for the word "Listed" and add the words " f i l led with noncembustible granular material" between the words "fuses" and "shall." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

MILLER: Although I am voting affirmatively, I believe the Panel Recommendation restricts the design more than necessary. A more general statement of desired performance would be preferable.

501-6(b)(3): " Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose

35 See the Technical Subcommittee "Recommendations" un-un'd'e'r--'t-F1e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

In line 4 delete "for the purpose and." In line 5 delete " i f they are approved for the purpose,." VOTE ON PANEL RECOMMENDATION: Unanimously Aff irmative.

501-8(b): Reject CMP 14 SUBMITTER: Ct~ ° 14

35A Revise 501-8(b)Motors and Generators, Class I , ~ 2 . Add a third paragraph as follows:

In Class I , Division 2 locations, motors, generators and other rotating electric machinery not approved for Class I, Division 1 locations shall be permitted only i f :

I . Ignition temperature of the gas or vapor involved is 280°C (536°F) or higher, and

2. Nameplate is marked not over 80°C temperature rise (85°C for total ly enclosed nonventilated construction) by resistance at 100% lo~d or goac temperature rise by resistance at Service Factor load, or

3. Nameplate is marked to indicate Class A or Class B Insulation System and Maximum Ambient Temperature.

Exception: Motors and generators with Class F or Class H Insulation System or in installations involving gases or vapors having ignition temperatures below 280°C (536°F) shall be permitted i f the maximum rated load operating temperature of any exposed surface (including internal parts of all constructions) wil l not exceed 80 percent of the ignition temperature in degrees Celsius oh the gas or vapor involved. SUBSTANTIATION: The present wording of 501-8(b) was based on relation of exposed motor surface temperatures and gas or vapor ignition temperatures prevalent some years ago; under the conditions then existing, experience has proven that the present wording of this section of the Code provided safe installations.

However, the ignition temperature of some of the newer gases is approaching the operating temperature of some higher temperature capability motors. Under these more recent conditions, safety hazards may exist when applying non-explosion-proof motors per the present wording of the Code.

The proposed change, then, limits use of open or non-explosion-proof enclosed motors in Class I , Division 2 locations to the combination of vapor ignition temperature and motor operating temperature consistent with past practice, or provides a safe system by limiting motor temperatures to 80 percent of the gas or vapor ignition temperature. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Already covered by Section 500-2(a) and (c). VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: SHORT: The referenced 500-2(a) and (c) are effective for

listed or certif ied equipment, but wil l in no way, prevent the application of standard and/or stock squirrelcage motors in Class I f , Division 2 areas. Only a specific limitation in 501-8(b) can be effective in minimizing this potential hazard.

501-8ib): Accept CMP 14 SUBMITTER: CMP 14

F R TOI~S'31t-~: 35B Revise the last part of the last sentence of paragraph one to read ".. .are provided with enclosures approved for Class I Division 2 locations in accordance with Section 501-3(b)."

233

SUBSTANTIATION: To correct error made by Panel in 1978 NEC. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-9(a)(3): Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose Ri~-RO-POSAL: 36 See the Technical Subcommittee "Recommendations" ~ e definition of "Approved for the Purpose" in Article lOO, ,

SUBSTANTIATION: See the TSC "findings ''~ under the definition of "Approved for the Purpose" in Article 100: PANEL RECOMMENDATION: Accept as Revised:

In line 8 delete "for the purpose and." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501~9(a)(4): Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose ~OSAL: 37 See the Technical Subcommittee "Recommendations" un--6-de-{~-F[e definition of "Approved for the Purpose" in Article I00, SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

In line 2 delete "for the purpose and." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-9(b)(3): Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose

38 See the Technical Subcommittee "Recommendations" ~ e r the definition of "Approved for the Purpose" in Article I00. -~ SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article I00. PANEL RECOMMENDATION: Accept as Revised:

I In line 6 insert "an approved" before " f i t t ing" and delete "approved for the purpose." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

\ 501~9{b)(4): Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose

39 See the Technical Subcommittee "Recemmendations" j ~ e definition of "Approved for the Purpose" in Article

100, SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in A~ticle 100.

I PANEL RECOMMENDATION: Accept as Revised: Delete paragraph and renumber (5) and (6) to (4) and (5).

PANEL COMMENT: This paragraph does not seem to provide any specific hazardous location requirements. General requirements for support of light fixtures appear elsewhere in the Code. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-10(b)(1)a: Accept CMP 14 SUBMITTER: O. E. Dillon, Border County Div. IAEI

I ]~TOI~S'Ai-[." 40 In the f i r s t sentence, delete the words "in degrees Celsius"; also delete the words "l ikely to be" and replace with the words ;'which is." SUBSTANTIATION: The use of the word "likely" renders this section legally unenforceable. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. ~EI substantiation for CMP 1 Proposal No. 90 for 110-16(a). PANEL RECOMMENDATION: Accept as Revised:

Leave in "in degrees Cels!us." PANEL COMMENT: The words "in degrees Celsius" are essential, since 80 percent of a temperature in degrees Fahrenheit and 80 percent of a temperature in degrees Celsius are not the same temperature. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501;11, Exception No. 2-(New): Accept CMP 14 Secretary's Note: I t was the action of.the Correlating

Committee that further consideration be given to the co,1~ents expressed in Mr. Schram's voting. SUBMITTER: H. W. T. Dutton, Chicago, IL

41 Add new exception as follows: ~ i o n No. 2: Electric submersible wastewater pumps with means for automatic removal without entering or'dewatering the wet-pit shall be considered portable uti l ization equipment. In Class I , Div. 1 locations, the pumps (unless approved for the location) shall remain completely submerged under all operating conditions with the liquid level at least four inches above "any portion of the pump--excepting the extra hard-usage cord or cable. See Section 501-13 for flexible cords exposed to liquids having a deleterious effect on the conductor insulation. SUBSTANTIATION: For over 30 years electric submersible pumps

uti l izing extra hard-usage multicondutor cords and cables have been used extensively and successfully in the United States and throughout the world. They are being used in various configurations in such diverse fields as mining, contracting (building, road, and excavating), dewater!ng, deep-well, and wastewater handling (stormwater, sewage, industrial effluent, etc.).

Especially with the advent of OSHA, and it~ support of the NEC, more and.more inspection and standards authorities are expecting specific guidance from NEC in areas not previously explicit ly defined. I t is the intention of the suggested ~endment to provide this speciflc guidance.

Many authorities in the wastewater f ield (sewage, stormwater, etc.) in recognizing especially the contribution to maintenance of submersible pumps, have stipulated that in any wet-well installation they be easily removed without the need for personnel to enter or dewater the wet-well. This is provided by all member companies in the industry by means of guide-rail remote guidance system and a simple automatic discharge connection system which allows indexing and a tight connection (or removal) to be automatically accomplished between the pump discharge flange and the effluent piping flange.

In order to maintain the workability of the system and the intent of the specifying Authorities, i t is imperative that flexible cord or cable be used between the place where the service enters the wet-well from the pump control (gas-tight conduit seal or--in the case of Class I, Division I locations--explosion-proof junction or splice box hard wired to the pump cable with a suitable compression cable-entry) and the pump cable-entry assembly.

This will allow the pump to be l i f ted from the wet-well through the opened cover in the access frame in the ~round-level slab by its chain or wire-rope without personnel entering or dewatering the wet-well.

In the case of Class I , Division 1 locations, the pump is either explosion-proof and suitable for the installation (there are none Approved at the present time) or redundant low-level shut-off sensing is provided which guarantees the uppermost portion of a standard submersible pump is always,submerged. These approaches are specified and accepted by the Administrative Code for the State of Wisconsin and the Department of Industrial Safety for the State of California for some time. .

Extra hard-usage cord and cable of the S, SO, ST, STO, W, G, PCG, etc., classes have been used for many years in submersible wastewater handling with a perfect safety record in classified locations. Certainly the application is one where the usage is far less demanding than others like coal mining and general contracting where these same cables have been universally accepted (MESA, Penna. Bureau of Mines, etc.) and successful. PANEL RECOMMENDATION: Accept as Revised:

Revise Exception by adding a new paragraph as follows: "Electric submersible pumps with means for removal without

entering the wet-pit shall be considered portable uti l ization equipment." VOTE ON PANEL RECO~ENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ADAMS: I favor the intent of the Proposal but I feel that the Exception should be in two parts with one part in Section 501-I0(a).

SCHRAM: My notes indicate the Panel Recemmendation was to add the quoted paragraph to Section 501-11, not to the Exception to Section 501-11.

501-16(b): Accept CMP 14 SUBMITTER: Robert B. West, St. Louis, MO ~ 4 2 Revise the last sentence as follows: ~ f l e x i b l e conduit is used as permitted in Section 501-4(b), internal or external bonding jumpers complying with the provisions of Section 250-79 shall be installed in parallel with the conduit.. And add a fine print note as follows:

See Section 250-78. SUBSTANTIATION: The present wording does not cover all of the requirements fo~ bonding jumpers. For, exa,~)le, Section 250-79(e) requires external equipment bonding jumpers to be not more than 6 feet in length and t 9 be routed with the conduit. The bonding jumpers that are required for flexible conduit should comply with Section 250-79 which specifies the material, attachment methods, size, and installation requirements for equipment bonding jumpers.

The proposed fine-print reference to Section 250-78 correlates with the bonding requirements for hazardous locations that are specified in Article 250. PANEL RECOMMENDATION:. Accept. VOTE ON PANEL RECOF~4ENDATION:


EXPLANATION OF VOTE: ADAMS: Section 501-I refers to the general rules of this Code

and I do not think these bonding requirements are of a nature peculiar to Class I locations.

234

501-16(c): Accept CMP 14 SUBMITTER: Robert B. West, St. Louis, MO

43 Revise as follows: ~ i g h t n i n g Protection. Each ungrounded service conductor of a wiring system in a Class I location, where supplied from an overhead line in an area where lightning disturbances are prevalent, shall be protected by a surge arrester that complies with the provisions of Article 280. The surge arresters shall be connected to the service conductors at an accessible point on the load side of the service drop, and the arrester grounding connections shall compl~ with the applicable provisions of Article 280. SUBSTANTIATION: A CMP 5 Subcommittee has submitted proposals to update Article 280 to current nomenclature and practices. Article 280 covers the selection, installation, and connection of surge attesters. The proposed revision has references to Article 280 which makes the selection, installation, and connection of surge arresters in Class I locations consistent with the updated provisions in Article 280. PANEL RECOMMENDATION: Accept as Revised:

In the last sentence delete "at an accessible point on the load side of the service drop." VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: ADAMS: Section 501-I refers to the ~eneral rules of this Code

and I do not think the Lightning Protection requirements are of a nature peculiar to Class 1'locations.

501-16(d): Accept CMP 14 SUBMITTER: Robert B. West, St. Louis, MO IqTOlffO'S'A'CT. " 44 Revise as follows: "~----Grounded Service Conductor, Connections at Service Equipment.. Where a Class I location is supplied from an alternating-current service and the supply system is solidly grounded, the grounded service conductor shall be run to each service according to the requirements in Section 250-23(b) and shall be grounded according to the requirements in Section 250-23(a). Bonding connections to the grounded service conductor at the service equipment shall comply with Sections 250-50(a) and 250-53. Metal enclosures for service conductors and service equipment shall be bonded in accordance with the applicable provisions in Article 250, Part G.

Exception: Where the installation complies with all of the conditions specified in Section 501-16(f) and the system grounded conductor is not used as a circuit conductor, a grounded service conductor shall not be required to be run to the service eFl. uipment. SUBSTANTIATION: This proposed revision correlates with my proposal to revise the text of Section 501-16(f). The proposed rewording and the references to sections in Article 250 clarif ies the intent of Section 501-16(~) because the referenced sections contain complete specifications for the general requirements that are covered in the present text. The proposed revision does not change the intent of the present text. PANEL RECOMMENDATION: Accept as Revised:

Change reference to 501-16(f) in the Exception to 501L16(e) to correlate with Proposals 45 and 46. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-16(e): Accept CMP 14 SUBMITTER: Robert B. West, St. Louis, /40

45 Delete Section 501-16(e). ~ I A T I O N : The grounded service conductor of a grounded system is required to be run to each service by the provisions of Section 250-23(b), so the condition stated in Section 501-16(e) is not permitted. Article 250 also contains adequate provisions for grounding and bonding that apply to Class I locations. For example, Section 250-23(a) requires the grounded ~ervice conductor to be grounded at each service. Sections 250-50(a), 250-50(b), 250-53(a), and 250-53(b) cover bonding and interconnections between the equipment grounding conductors, the grounded service conductor, the grounding electrode conductor, and the service equipment enclosures. Sections 250-71, 250-72, 250-75, 250-76, 250-77, 250-7B, and 250-79 cover bonding requirements for the noncurrent-carrying metal parts of equipment, raceways and other enclosures on the supply side and on the load side of the service equipment.

My proposed revision for Section 501-16(f) covers conditions which must be complied with where a grounded service conductor of a grounded system is not run to the service equipment. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

501-16(f): Accept ; CMP 14 SUBMITTER: Robert B. West, St. Louis, /40 PROPOSAL: 46 Revise the text of (f) as follows:

in the application of Section 250-21, i t is necessary to abandon the grounding and'bonding connections to the grounded service conductor that are specified in (d) above, the installation shall comply with all of the following conditions:

(I) The grounded service conductor shall be connected to a grounding electrode at the transformer supplying the service.

(2) A grounding conductor shall be run with the service conductors from the supply transformer to the service equipment, and shall be sized in accordance with the requirements for sizing the grounded service conductor in Section 250-23(b). The grounding conductor shall be bonded to the grounded service conductor at the transformer supplying the service and to the equipment grounding conductor(s) at the service equipment.

(3) The service equipment enclosures, the grounding conductor specified in (2) above, and the equipment grounding conductor(s) shall be bonded together and connected to a grounding electrode by a grounding electrode conductor. SUBSTANTIATION: Objectional currents over the grounding conductors are caused by multiple grounding connections to the system grounded conductor, which is the grounded service conductor in Section 5O1-1B(d). One way to prevent these obJectional currents from flowing is to ground the grounded

service conductor at the supply transformer only, and abandon the grounding connections to the grounded service conductor that are specified in Sections 250-23(a), 250-50(a), and 250-53".

I t is perfectly safe to ground the grounded service conductor at the supply transformer only, provided the conditions stated in (2) and (3) of the proposed revision are met. These conditions assure an adequate conductor for ground-fault current to flow from the service equipment to the supply transformer, and the potential between the service equipment enclosures and ground wil l not be unsafe during ground-fault, conditions. ~The surge arresters that are specified in Section 501-16(c) provide additional protection at the service equipment by .limiting voltages due to lightning and line surges.

The present wording of Section 501-16(f) requires the grounded service conductor to be grounded at the service equipment i f the supply system is grounded at any other point. This multiple system grounding requirement is l ikely to cause objectional currents over the grounding conductors i f the service conductors a÷e installed in metal raceways from the service supply to the service equipment.

This proposal correlates with'my proposal to revise Section 501-16(d). PANEL RECOMMENDATION: Accept as Revised:

I The t i t l e of this Section wil l be: "Multiple Grounds." In order to correlate with Proposal 45, the number of this Section will be 501-16(e). VOTE ON PANEL RECOMMENDATION: Unanimpusly Affirmative.

501-17-(New): Reject CM~ 14 SUBMITTER: Kenneth L. Paape, Allen Bradley Co. !~-O-P-O-S-A[-~.'47 Add new section as follows:

Ground-Fault Protection of Equipment, Class I , Divisions I and 2.

Ca) Ground-fault protection shall be provided for each solidly grounded branch circuit where conductors are not protected against overcurrent i~ accordance with their ampacities and the circuit is rated more than 50 volts to ground, but not exceeding 600 volts phase-to-phase in a Class I , Division 1 or 2 location. The ground-fault protection shall operate to open all ungrounded conductors of the faulted circuit. The maximum setting of the ground-fault protection shall be 10 amperes. Anytime-delay in the operation of the ground-fault protection shall be coordinated with the interrupting rating of the branch-circuit disconnecting or controlling means and the rating or setting of the device that provides overcurrent protection for the branch circuit.

Exception No. I : Where the circuit overcurrent protective device has a rating mr setting not exceeding 100 ~eres .

Exception No. 2: Where an orderly shutdown is required. (See Section 240-12).

(b) The ground-fault protection system installed shall meet the performance requirenients of Section 230-95 (b) and (c). SUBSTANTIATION: I t has long been recognized in the electrical industry that arcing ground faults occur which damage equipment extensively because the. ground fault current is limited by the impedance of rigid conduit or is not sustained for a sufficient period of time to cause the overcurrent protective device to clear the fault. As a consequence, damage such as shown in the attached photographcan occur with the emission of sparks and molten metal. Such emission can ignite vapors or gases which may be ~present in Class I HazardousLocations. The higher the rating or setting of the overcurrent protective device the greater the probability of extensive damage before the overcurrent protective device responds to the ground-fault current.

Each of the exceptions to the general rule of protecting conductors against overcurrent in accordance with their ampacities (see Section 240-3) exists for a good purpose, but involves some degree of risk. Motor branch circuits are particularly vulnerable because motor driven equipment often includes a source of vibration which in turn can cause insulation to abrade in conduit with the result as shown in the photograph. Providing ground-fault protection for equipment in such situations wil l reduce the risk inherent in circuits where conductors are not protected in accordance with their ampacities.

Similar proposals have been submitted for Class I I and Class I l l hazardous locations.

235 r

PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not jus t i fy the proposed change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 502 -- CLASS I I LOCATIONS

502-I: Reject CMP 14 SUBMITTER: G. A. Karstens, American, Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 48 " After the third paragraph add a paragraph as

For further information see NFPA 496 Purged and Pressurized Enclosures for Electrical Equip~mnt - 1974. SUBSTANTIATION: Material in this bulletin will aid materially in describing the proper requirements for motor control centers for Class I I locations. PANEL RECOMMENDATION: Reject. PANEL COMMEN~: Already covered by Section 500-I. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-i: Accept CMP 14 Secretary's Note:. I t was the action of the Correlating

Committee that the Panel shall .review their Recommendation with a view towards correcting grammatical errors. SUBMITTER: W.A. Short, Crouse-Hinds Company

49 Add a new sentence to the end of 502-1: --~r~-e-Fe-are only Division 1 locations where Class I I , Groups E and F dusts are present. See Section 500-5(a)3. SUBSTANTIATION: The information in 500-5(a)3 is not well understood in the industry. This wording does not change the intent, but helps to c lar i fy the information already in the Code. PANEL RECOMMENDATION: Accept as Revised:

After "dusts" add "having a resist iv i ty less than 105 ohm-cm." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


50 Add "nominal" after "600 volts." ~O~-S~I~NTIATION: To conform'to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. PANEL COMMENT: See Panel Comment on Proposal 25. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-4: Accept CMP 14 SUBMITTER: CMP 14 PITOI}'O-~TAL-~: 51A Revise second sentence to read: "Cable tray

I ~ t be permitted in Class I f , Division 1 or 2 locations. SUBSTANTIATION: Cable trays are dust collectors and should not be used in Class I I areas. • PANEL RECOMMENDATION: Accept as Revised:

"Tray" should read "trays." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-4(a): Reject CMP 14 SUBMITTER: K. C. Starkey, The Rockbestos Co.

52 Revise f i r s t sentence of (a) as follows: In Class I f , Division 1 Iocatidns, threaded rigid metal

conduit, threaded steel intermediate metal conduit, Type MI, or Type MC cable employing a continuous smooth or corrugated aluminum sheath with termination f i t t ings approved for the location shall be the wiring method employed. SUBSTANTIATION: Type MC cable employing a continuous smooth or corrugated aluminum sheath has a tight f i t t i ng core and is sheathed in an impervious aluminum tube that has superior crush and impact resistance. I t has been used widely in Class I , Division 2 and Class I I , Division 2 locations by the petroleu M , petrochemical, coal and grain industries. Present continuous welding methods make i t possible to maintain the accurate OD of the cable sheath within the UL Standard 886 for maximum diametric clearance for cylindrical joints. In earlier manufacturing processes this was not possible; therefore, the termination f i t t i ng manufacturers could not properly design a termination f i t t i ng with prope~ barrel length and clearance to comply with the UL Standards.

Termination f i t t i ng manufacturers, including Crouse-Hinds, have assured us that i f the sheath OD can be held constant, a termination f i t t i ng can be designed to comply with UL Standards.

The acceptance of Type MC cable employing a smooth or corrugated aluminum sheath for use in Class I I , Division i locations will provide "an alternate wiring system that is saYe and economical to instal l . The sheath provides a completely impervious tube from connection to ~onnection and with approved termination f i t t ings Will eliminate the possibil i ty of dusts entering the system through joints and couplings.

We are submitting the following UL Test Reports* relative to the physical properties of continuous aluminum sheathed Type MC cable including impact, crushing, flexing and dielectric withstand;

*Reports have been-supplied to CMP. chairman. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel does not ~gree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-3: Accept j CMP 14 SUBMITTER: Robert'B. West, St. Louis, MO PROPOSAL: 51 Revise as follows: T - 3 . Surge,Protection, Class I I , Divisions I and 2. In geographical locations where lightning disturbances are prevalent, and where supplied by overhead services, electric systems in Class I I locations shall be protected against high-voltage surges. This protection shall include surge arresters, interconnectlon of all grounds, and surge-protective capacitors. Surge arresters, including their installation and connections, shall comply with Article 280.

Surge-protective capacitors shall be of a type designed for the specific duty. The capacitor grounding conductors shall be connected to the grounding ~onductors for the surge arresters. Surge-protective capacitors" shall be connected to each ungrounded service conductor at the service entrance or service equipment. The capacitors shall be protected by 30-ampere fuses of suitable type and voltage rating, or by automatic circuit breakers of suitable type and rating. Where fuse protection is provided, a disconnecting means shall be installed to disconnect the fuses from the ungrounded service conductors. SUBSTANTIATION: The proposed revision uses the term "surge arresters" and. references Article 280 which covers the selection, installation, and connection of surge arresters. A CNP 5 Subcommittee has submitted proposals to update Article 280 to current nomenclature and ~ractices. The grounding connections for surge arresters are adequately covered in Article 280 so i t is unnecessary to cover thegrounding interconnections again in Section 502-3.

The third paragraph in the present text of Section 502-3 is not enforceable and shouldbe deleted.

The present text requires circuit protection devices for surge-protective capacitors. I f fuses are used, a means should be provided to disconnect the fuses and capacitors. I t is recommended that CMP 14 review the requirement that fuses by exactly 30 amperes while circuit breakers have no specified current rating. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative."

502-4(b): Reject CMP 14 SUBMITTER: James M. Daly~ The Okonite~Co.

53 Revise as follows: " . . . or Type MI, MC, SNM, i5"CTC -, or MV cable with approved termination f i t t ings shall be the wiring method employed. Type MI, MC, SNM, PLTC, or MI/ cable shall be permitted to be installed in cable tray systems and shall be installed in a manner to avoid tensile stress at the termination f i t t ings . " , SUBSTANTIATION: These cable types are permitted in Class I , Division 2 locations and i t is consistent to also permit their use in Class I I , Division 2 locations. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Cable trays are dust collectors and should not , be used in C las~ I I areas. Note Panel's action on Proposal No.' 51A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502:5: Accept,' CMP 14 Secretary's Note: I t was the action of the Correlating

Co{~nittee that further consideration be given to the comments expressed in Mr. Schramts voting. SUBMITTER:' G. A. Karstens, American Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 54 Delete Section 502-5. ~ I A T I O N : In Class I I , Division i Iocatiohs i t is necessary that motors be adequately sealed in the terminal box and equipment is designed to be dust-tight. In.Class I I , Division 2 locations dust is normally not in suspension. I t is my understanding that there have been some problems with vertical or horizontal runs that may be just short of the requi~ed length. Dust unlike vapors does not travel within the conduit and does not offer a serious problem. PANEL RECOMMENDATION: Accept as Revised:

"Where a raceway provides communication between an enclosdre ;that is required to be dust ignition proof and an enclosure in l:an unclassified locat#on, seals will not be required."

VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

SCHRAM: The Panel Recommendation is not clear. My notes indicate i t was to add the quoted paragraph to Section 502-5.

236

PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not jus t i fy the proposed change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 502 -- CLASS I I LOCATIONS

502-I: Reject CMP 14 SUBMITTER: G. A. Karstens, American, Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 48 " After the third paragraph add a paragraph as

For further information see NFPA 496 Purged and Pressurized Enclosures for Electrical Equip~mnt - 1974. SUBSTANTIATION: Material in this bulletin will aid materially in describing the proper requirements for motor control centers for Class I I locations. PANEL RECOMMENDATION: Reject. PANEL COMMEN~: Already covered by Section 500-I. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-i: Accept CMP 14 Secretary's Note:. I t was the action of the Correlating

Committee that the Panel shall .review their Recommendation with a view towards correcting grammatical errors. SUBMITTER: W.A. Short, Crouse-Hinds Company

49 Add a new sentence to the end of 502-1: --~r~-e-Fe-are only Division 1 locations where Class I I , Groups E and F dusts are present. See Section 500-5(a)3. SUBSTANTIATION: The information in 500-5(a)3 is not well understood in the industry. This wording does not change the intent, but helps to c lar i fy the information already in the Code. PANEL RECOMMENDATION: Accept as Revised:

After "dusts" add "having a resist iv i ty less than 105 ohm-cm." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


50 Add "nominal" after "600 volts." ~O~-S~I~NTIATION: To conform'to the guidelines established by the TSC on Nominal Voltages. PANEL RECOMMENDATION: Accept. PANEL COMMENT: See Panel Comment on Proposal 25. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-4: Accept CMP 14 SUBMITTER: CMP 14 PITOI}'O-~TAL-~: 51A Revise second sentence to read: "Cable tray

I ~ t be permitted in Class I f , Division 1 or 2 locations. SUBSTANTIATION: Cable trays are dust collectors and should not be used in Class I I areas. • PANEL RECOMMENDATION: Accept as Revised:

"Tray" should read "trays." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-4(a): Reject CMP 14 SUBMITTER: K. C. Starkey, The Rockbestos Co.

52 Revise f i r s t sentence of (a) as follows: In Class I f , Division 1 Iocatidns, threaded rigid metal

conduit, threaded steel intermediate metal conduit, Type MI, or Type MC cable employing a continuous smooth or corrugated aluminum sheath with termination f i t t ings approved for the location shall be the wiring method employed. SUBSTANTIATION: Type MC cable employing a continuous smooth or corrugated aluminum sheath has a tight f i t t i ng core and is sheathed in an impervious aluminum tube that has superior crush and impact resistance. I t has been used widely in Class I , Division 2 and Class I I , Division 2 locations by the petroleu M , petrochemical, coal and grain industries. Present continuous welding methods make i t possible to maintain the accurate OD of the cable sheath within the UL Standard 886 for maximum diametric clearance for cylindrical joints. In earlier manufacturing processes this was not possible; therefore, the termination f i t t i ng manufacturers could not properly design a termination f i t t i ng with prope~ barrel length and clearance to comply with the UL Standards.

Termination f i t t i ng manufacturers, including Crouse-Hinds, have assured us that i f the sheath OD can be held constant, a termination f i t t i ng can be designed to comply with UL Standards.

The acceptance of Type MC cable employing a smooth or corrugated aluminum sheath for use in Class I I , Division i locations will provide "an alternate wiring system that is saYe and economical to instal l . The sheath provides a completely impervious tube from connection to ~onnection and with approved termination f i t t ings Will eliminate the possibil i ty of dusts entering the system through joints and couplings.

We are submitting the following UL Test Reports* relative to the physical properties of continuous aluminum sheathed Type MC cable including impact, crushing, flexing and dielectric withstand;

*Reports have been-supplied to CMP. chairman. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The Panel does not ~gree with the supporting comment. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-3: Accept j CMP 14 SUBMITTER: Robert'B. West, St. Louis, MO PROPOSAL: 51 Revise as follows: T - 3 . Surge,Protection, Class I I , Divisions I and 2. In geographical locations where lightning disturbances are prevalent, and where supplied by overhead services, electric systems in Class I I locations shall be protected against high-voltage surges. This protection shall include surge arresters, interconnectlon of all grounds, and surge-protective capacitors. Surge arresters, including their installation and connections, shall comply with Article 280.

Surge-protective capacitors shall be of a type designed for the specific duty. The capacitor grounding conductors shall be connected to the grounding ~onductors for the surge arresters. Surge-protective capacitors" shall be connected to each ungrounded service conductor at the service entrance or service equipment. The capacitors shall be protected by 30-ampere fuses of suitable type and voltage rating, or by automatic circuit breakers of suitable type and rating. Where fuse protection is provided, a disconnecting means shall be installed to disconnect the fuses from the ungrounded service conductors. SUBSTANTIATION: The proposed revision uses the term "surge arresters" and. references Article 280 which covers the selection, installation, and connection of surge arresters. A CNP 5 Subcommittee has submitted proposals to update Article 280 to current nomenclature and ~ractices. The grounding connections for surge arresters are adequately covered in Article 280 so i t is unnecessary to cover thegrounding interconnections again in Section 502-3.

The third paragraph in the present text of Section 502-3 is not enforceable and shouldbe deleted.

The present text requires circuit protection devices for surge-protective capacitors. I f fuses are used, a means should be provided to disconnect the fuses and capacitors. I t is recommended that CMP 14 review the requirement that fuses by exactly 30 amperes while circuit breakers have no specified current rating. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative."

502-4(b): Reject CMP 14 SUBMITTER: James M. Daly~ The Okonite~Co.

53 Revise as follows: " . . . or Type MI, MC, SNM, i5"CTC -, or MV cable with approved termination f i t t ings shall be the wiring method employed. Type MI, MC, SNM, PLTC, or MI/ cable shall be permitted to be installed in cable tray systems and shall be installed in a manner to avoid tensile stress at the termination f i t t ings . " , SUBSTANTIATION: These cable types are permitted in Class I , Division 2 locations and i t is consistent to also permit their use in Class I I , Division 2 locations. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Cable trays are dust collectors and should not , be used in C las~ I I areas. Note Panel's action on Proposal No.' 51A. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502:5: Accept,' CMP 14 Secretary's Note: I t was the action of the Correlating

Co{~nittee that further consideration be given to the comments expressed in Mr. Schramts voting. SUBMITTER:' G. A. Karstens, American Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 54 Delete Section 502-5. ~ I A T I O N : In Class I I , Division i Iocatiohs i t is necessary that motors be adequately sealed in the terminal box and equipment is designed to be dust-tight. In.Class I I , Division 2 locations dust is normally not in suspension. I t is my understanding that there have been some problems with vertical or horizontal runs that may be just short of the requi~ed length. Dust unlike vapors does not travel within the conduit and does not offer a serious problem. PANEL RECOMMENDATION: Accept as Revised:

"Where a raceway provides communication between an enclosdre ;that is required to be dust ignition proof and an enclosure in l:an unclassified locat#on, seals will not be required."

VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

SCHRAM: The Panel Recommendation is not clear. My notes indicate i t was to add the quoted paragraph to Section 502-5.

236

502-6(b): Accept CMP 14 SUBMITTER: G. A. Karstens, American Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 55 Revise (b) as follows: ~ s s I f , Division 2 locations, enclosures for fuses, switches, circuit breakers, and motor controllers, including pushbuttons, relays and similar devices shall be so designed that: (1) there are no knockout holes provided in the enclosure, (2) be constructed of substantial sheet metal with continuous welded seams, (3) be gasketed with closed cell expanded cellular rubber gasket of the oil/flame resistant type, (4) where dust-tight mechanisms are involved they shall be mounted through holes that are gasketed with a closed cell expanded cellular rubber gasket of the oil/flame resistant type, (5) doors shall be similarly gasketed, and where hinged shall be hinged for horizontal opening and be supplied with an external fastener that requires a tool to open, (6) provisions shall be made for external mounting. SUBSTANTIATION: The above wording provides a much clearer understanding of the intent of the enclosures for fuses, switches, circuit breakers,and motor controllers including pushbuttons and relays and similar devices to be used in Class I I , Division 2 locations than that used i'n 502-6(a)(2) in the present Code.

*See proposals for Sections 502-7(b)(I) and 502-I0(b)(3). PANEL RECOMMENDATION: Accept as revised:

In the third line substitute the word "dust tight" for the 'balance of the paragraph after the words "shall be." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-10(b)(3): Accept C iMP SUBMITTER: G. A. Karstens, American Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J.. Healy, Grain Elevator and Processing Society PROPOSAL: 58 Delete the reference "Section 502-6(a)(2)" and ~ w i t h "Section 502-6(b). SUBSTANTIATION: The above wording provides a much clearer understanding of the intent of the enclosures for fuses, switches, circuit breakers and motor controllers including pushbuttons and relays and similar devices to be used in Class I I , Division 2 locations than that used in 502-6(a)(2) in the present Code.

*See proposals for Sections 502-6(b) and 502-7(b)(I). PANEL RECOMMENDATION: Accept as .Revised: '

Replace the words "comply with Section 502-6(a)(2)" with "be idust tight . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

14

502-11(a)(3): Accept CMP 14 SUBMII'TER: TSC-Approved for the Purpose ~ 5 9 See the Technical Subcammittee'"Recommendations" under the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article i00. r PANEL REC~NDATION: Accept as Revised:

lq line 7 delete for the purpose and." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-7(b)(I): Accept CMP 14 SUBMITTER: G. A. Karstens, American Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 56 Delete the reference, "Section 502-6(a)(2)" and ~ w i t h "Section 502-6(b)." SUBSTANTIATION: The above wording provides a much clearer understanding of the intent of the enclosures for fuses, switches, circuit breakers and motor controllers including pushbuttons and relays and similar devices to be used in Class I I , Division 2 locations than that used in 502-6(a)(2) in the present Code.

*See proposals for Sections 502-6(b) and 502-10(b)(3). PANEL RECOMMENDATION: Accept as Revised:

I Revise Section 502-7(b)(1) to read: Switching mechanisms (including,overcurrent devices) associated with control transformers, solenoids, impedance coils, and resistors shall be provided with dust-tight enclosures. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-8(b): Accept CMP 14 SUBMITTER: G. A. Karstens, American Feed Manufacturers ~ o n , F. Lindholm, Association of Operative Millers, J. Healy, Grain Elevator and Processing Society PROPOSAL: 57 Revise (b) as follows: -'-IL'l~-~-II, Division 2. In Class I I , Division 2 locations, motors, generators and other rotating electrical equipment shall be total ly enclosed non-ventilated, total ly encl'osed pipe ventilated, or total ly enclosed fan cooled for w~ich maximum ful l load external surface temperature shall not exceed 120°C (248°F) when operating in free air (not dust blanketed). SUBSTANTIATION: We have found in many instances that various authorities are of the opinion that the only motor suitable for Class I I , Division 2 locations with the wording of Section 502-8(b) as is would be a labeled motor. I t is our contention that labeled motors are not required for use in Class I I , Division 2 atmospheres, and the above wording is intended to note such. In addition, experience of the industry over many

• years denotes that the TEFC motor has operated in Class I I , Division 2 locations with good experience. PANEL RECOMMENDATION: Accept as Revised:

"Class I f , Division 2. In Class I I , Division 2 locations, motors, generators and other rotating electrical equipment shall be total ly enclosed nonventilated, total ly enclosed pipe ventilated, total ly enclosed fan cooled or dust-ignition-proof for which maximum ful l load external temperature shall not exceed 120°C (248°F) when operating in free air (not dust blanketed) and shall have no external openings.

Change Exception (b) to read: ".. .within dust-tight metal housings..." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative. COMMENT ON VOTE:

ADAMS: My notes have the Exception to read: ".. .within dust-tight housings."

SHORT: The Wording here is a marked improvement over that presently in 1978 NEC. However, further improvement wil l be achieved bythe ~ollowing revisions:

(1) Add the following sentence after the words "...and shall have no external openings...": "Normally arcing or sparking parts shall be enclosed in tight metal housings."

(2) In Exception (b) the present 1978 NEC wording "tight metal housings" should be retained instead of changing to "dust-tight housings."

502-11(a)(4): Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose I~-R'O-P-O-S~-~.'60 See the Technical Subcommittee "Reco~nmendations" ~ e definition of "Approved for .the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Art icl e I00.

I PANEL RECOMMENDATION: Accept as Revised: In line 2 delete "for the purpose and."


592-11(b)(4): Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose PITOP'o-SrAl_-~.'61 See the TechniCal Subcommittee "Recommendations" ~ e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100.

. PANEL RECOMMENDATION: Accept as Revised: I In line 7 add "an approved" before " f i t t ing" and delete

"approved for the purpose." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-11(b)(5): Accept CMP 14 SUBMII-TER: TSC-Approved for the Purpose ~-R'O-FO-~-A[-~: 62 See the Technical Subcommittee "Recommendations" un--n-de~-~ITe definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of l'Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I} Delete paragraph and renumber (6) to (5). 'PANEL COMMENT: This paragraph does not seam to provide any specific hazardous location requirements. General requirements for support of light fixtures appear elsewhere in the Code. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-16(b): Reject CMP 14 SUBMITTER: Joseph S.'Dudor, Fluor Engineers and Constructors,

PROPOSAL: 63 Revise last sentence as follows: f lexible conduit is used as permitted in Section 502-4,

internal or external bonding jumpers with proper f i t t ings shall be provided. SUBSTANTIATION: Revise Section 502-16(b) to have language consistent with revision made to Section 501-16(b) in the 1978 NEC. The same problem and the same materials are used in applications in both Class I and Class I I locations andrthe Code rules governing their use should be the same where possible. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Covered by Proposal No. 64. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-16(b): Accept CMP 14 SUBMI1-TER: Robert B. West, St. Louis, MO I~qTOITO-S'At-~. • 64 Revise the last sentence as follows:

l--I~h-e'~e--flexible conduit is used as permitted in Section 502-4,

/ 2 3 7 /

internal or external bonding jumpers complying with the provisions of Section 250-79 shall be installed parallel with the conduit. And add a fine print note as follows:

See Section 250-78. SUBSTANTIATION: The requirements for flexible conduit bonding jumpers should be the same in Sections 501-16(b) and 502-16(b).

The proposed rewording is consistent with my proposal to revise the last sentence in 501-16(b). PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION:


EXPLANATION OF VOTE: ADAMS: I do not believe the proposed revision adds to the

clar i ty of this section.

/

502-16(c): Accept CMP 14 SUBMITTER: Robert B. West, St. Louis, MO i~R-O-~O-S~AL-~. • 65 Delete Section 502-16(c) "S~]I~'TAI~TIATION: This section is unnecessary because lightning protection in Class I I locations is adequately covered in Section 502-3. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-16(d): Accept CMP 14 SUBMITTER: Robert B. West, St. Louis, MO P'FR-O-~'O-S'A-L-~.'66 Revise as follows: ~ r o u n d e d Service Conductor, Connections at Service Equipment. Where a Class I I location is supplied from an alternating-current service and the supply system is solidly grounded, the grounded service conductor shall be run to each service according to the requirements in Section 250-23(b) and shall be grounded according to the requirements in Section 250-23(a). Bonding connections to the grounded service conductor at the service equipment shall comply with Sections 250-50(a) and 250-53. Metal enclosures for service conductors and service equipment shall be bonded in accordance with the applicable provisions in Article 250, Part G.

Exception: Where the installation complies with all of the conditions specified in Section 502-16(f) and the system grounded conductor is not used as a circui~ conductor, a grounded service conductor shall not be required to be run to the service equipment. SUBSTANTIATION: This proposed revision correlates with my proposal to revise the text of Section 502-16(f). The proposed rewording and the references to sections in Article 250 clarif ies the intent of Section 502-16(d) because the referenced sections contain complete specifications for the general requirements that are covered in the present text. The proposed revision does not change the intent of the present text. PANEL RECOMMENDATION: Accept as Revised.

Change the Section number to 502-16(c) to correlate with iProposal 65, and change 502-16(f) in the Exception to 502-16(d) to correlate with Proposal Nos. 67 and 68. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

502-16(e): Accept CMP 14 SUBMITTER: Robert B. West, St. Louis, MO

67 Delebe Section 502-16(e) ~'I]I~'FAI~rIATION: The grounded service conductor of a grounded system is required to be run to each service by the provisions of Section 250-23(b), so the condition stated in Section 502-16(e) is not permitted. Article 250 also contains adequate provisions for grounding and bonding that apply to Class I I locations. For example, Section 250-23(a) requires the grounded service conductor to be grounded at each service. Sections 250-50(a), 250-50(b), 2SO-53(a), and 250-53(b) cover bonding and interconnections between the equipment grounding conductors, the grounded service conductor, the grounding electrode conductor, and the serviceequipment enclosures. Sections 250-71, 250-72, 250-75, 250-76, 250-77, 250-78, and 250-79 cover bonding requirements for the noncurrent-carrying metal parts of equipment, raceways and other enclosures on the supply side and on the load'side of the service equipment.

My proposed revision for Section 502-16[f) covers conditions which must be complied with where a grounded service conductor of a grounded system is not run to the service equipment. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously Aff i rmative..

502-16(f): Accept CMP 14 SUBMITTER: Robert B. West, St. Louis, MO

. ~ 68 Revise the text of (f) as follows: Where, in the application of Section 250-21, i t is necessary

to abandon ~he grounding and bonding connections to the grounded service conductor that are specified in (d) above, the installation shall comply with all of the following conditions:

(I) The grounded service conductor shall be connected to a

238

grounding electrode at the transformer supplying the service. (2) A grounding conductor shall be run with the service

conductors from the supply transformer to the service equipment, and shall be sized in accordance with the requirements for sizing the grounded service conductor in Section 250-23(b). The grounding conducto~ shall be bonded to the grounded service conductor at the transformer supplying the service, and to the equipment grounding conductor(s) at the service equipment.

(3) The service equipment enclosures, the grounding conductor specified in (2) above, and the equipment grounding conductor(s) shall be bonded together and connected to a grounding electrode by a grounding electrode conductor. SUBSTANTIATION: Objectional currents over the grounding conductors are caused by multiple grounding connections to the system grounded conductor, which is the grounded service conductor in Section 502-16(d). One way to prevent these objectional currents from flowing is to ground the grounded service conductor at the supply transformer only, and abandon the grounding connections to the grounded service conductor that are specified in Sections 250-23(a), 250-50(a), and 250-53.

I t is perfectly safe to ground the grounded service conductor at the supply transformer only, provided the conditions stated in (2) and (3) of the proposed revis!on are met. These conditions assure an adequate conductor for ground-fault current to flow from the service equipment to the supply transformer and the potential between the service equipment enclosures and ground will not be unsafe during ground-fault conditions. The surge protection that is specified in Section 502-3 provides additional protection at the service equipment by limiting voltages due to lightning and line surges. .

The present wording of Section 502-16(f) requires the grounded service conductor to be grounded at the service .equipment i f the supply system is grounded at any other point. This multiple system grounding requirement is l ikely to cause obJectional current over the grounding conductors i f the service conductors are installed in metal raceways from the service supply to the service equipment.

This proposal correlates with my proposal to revise Section 502-16(d). PANEL RECOI~ENDATION: Accept as Revised: • The t i t l e of this Sectionwill be "Multiple Grounds." In order to correlate with Proposal Nos. 65, 66 and 67~ the number of this Section wi l l be 502-16(d). Change (d) to (c) in the f i r s t sentence oF the Proposal to correlate with Proposal Nos. 65 and 66. VOTE ON PANEL RECOI~MENDATION: Unanimously Affirmative.

502-17-(New): Reject CMP 14 SUBMITTER: Kenneth L. Paape, Allen Bradley Co. PITOIIO'~L-~. • 69 Add new section as follows: ~'O-'~I'/~'-.Ground-Fault Protection of Equipment, Class I, Divisions I and 2.

(a) Ground-fault protection shall be provided for each solidly grounded branch circuit where conductors are not protected against overcurrent in accordance with their ampacities and the circuit is rated more than 50 volts to ground, but exceeding 600 volts phase-to-phase in a Class I, Division 1 or 2 location. The ground-fault protection shall operate to open all ungrounded conductors of the faulted circuit. The maximum setting of the ground-fault protection shall be 10 amperes. Any time-delay in the operation of the ground-fault protection shall" be coordinated with the interrupting rating of the branch-circuit disconnecting or controlling means and the rating or setting of the device that provides overcurrent protection for the branch circuit.

Exception No. i : Where the circuit overcurrent protective device has a rating or setting not exceeding 100 an~oeres.

Exception No. 2: Where an orderly shutdown is required. (See Section 240-12.)

(b) The ground-fault protection system installed shall meet the performance requirements of Section 230-95 (b) and (c). SUBSTANTIATION I t has long been recognized in the electrical industry that arcing ground faults occur which damage equipment extensively because the ground fault current is limited by the impedance of rigid conduit or is not sustained for a sufficient period of time to cause the overcurrent protective device to clear the fault. As a consequence, damage such as shown in the attached photograph can occur with the emission of sparks and molten metal. Such emission can ignite vapors or gases which may be present in Class I Hazardous Locations. The higher the rating O r setting of the overcurrent protective device the greater the probability of extensive damage before the overcurrent protective device responds to the ground-fault current.

Each of the exceptions to the general rule of protecting conductors against overcurrent in accordance with their ampacities (See Section 240-3) exists for a good purpose, but involves some degree of risk. Motor branch circuits are particularly vulnerable because motor driven equipment often includes a source of vibration which in turn can cause insulation to abrade in conduit with the results as shown in the photograph. Providing ground-fault protection for equipment in such situations wil l reduce the risk inherent in circuits where conductors are not protected in accordance with their an~)acities..

Similar proposals have been sub(nitted for Class I I and Class I l l hazardous locations.

PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not jus t i f y the proposed change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 503 -- CLASS I l l LOCATIONS

503-9(c)~ Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose

70 See the Technical Subcommittee "Recommendations" un-u-~-d~-~-]~e definition of "Approved for the Purpose" =in Article 100. SUBSTANTIATION: See the TSC "findings" under the definiti'on of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I In line 6 insert "an approved" before " f i t t ing" delete "approved for the purpose." VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

503-9(d): Acce~t CMP 14 SUBMITTER: TSC-Approved for the Purpose

71 See the Technical Subcommittee "Recommendations" un'un-d-er-tF1e definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised:

I Delete paragraph and change (e) to (d). PANEL COMMENT: This paragraph does not seem to provide any specific hazardous location requirements. General requirements for support of l ight fixtures appear elsewhere in the Code. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

503-17-iNew): Reject ' ,~/ CMP 14 SUBMITTER: Kenneth L. Paape, ellen Bradley Co.

72 Add new section as follows: 5--0-3--Z17~ - . Ground-Fault Protection of Equipment, Class I l l , Divisions i and 2.

(a) Ground-fault protection shall be provided for each solidly grounded branch circuit where conductors are not protected against overcurrent in accordance with their ampacities and the circuit is rated more than 50 volts to ground, but exceeding 600 volts phase-to-phase in a Class I l l , Division 1 or 2 location. The ground-fault protection ~hall operate to open all ungrounded conductors of the faulted circuit . The maximum setting of the ground-fault protection shall be 10 amperes. Any time-delay in the operation of the ground-fault protection shall be coordinated with the interrupting rating of the branch-circuit disconnecting or controlling means and the rating or setting of the device that provides overcurrent protection for the branch c i r c u i t .

Exception No. I : Where the circuit overcurrent protective device has a rating or setting not exceeding 100 amperes.

Exception No. 2.: Where an orderly shutdowd is required. (See Section 240-12). 501-17-(New)

(b) The ground-fault protection system installed shall meet the performance requirements of Section 230-95 (b) and (c). SUBSTANTIATION I t has long been recognized in the electrical industry that arcing ground faults occur which damage equipment extensively because the ground fault current is limited by the impedance of rigid conduit or is not sustained for a sufficient period of time to cause the overcurrent protective device to clear the fault. As a consequence, damage such as shown in the attached photograph can occur with the emission of sparks and molten metal. Such emission can ignite fibers or flyers which may be present in Class I l l Hazardous Locations. The higher the rating or setting of the overcurrent protective device the gPeater the probability of extensive damage before the overcurrent protective device responds to the ground-fault current.

Each of the exceptions to the general rule of protecting conductors against overcurrent in accordance with their ampacities (see Section 240-3) exists for a good purpose, but involves some degree of risk. Motor branch circuits are particularly vulnerable because motor driven equipment often includes a source of vibration which in turn can cause insulation to abrade in conduit with the results as shown in the photograph. Providing ground-fault protection for equipment in such situations wil l reduce the risk inherent in circuits where conductors are not protected in accordance with their ampacities.

Similar proposals have been submitted for Class I and Class I I hazardous locations. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not jus t i f y the ' proposed change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

239

ARTICLE 511 -- COMMERCIAL GARAGES, REPAIR AND STORAGE

511-2(f): Accept CMP 14 SUBMITTER: TSC-Approved for the Purpose PITOPI~SAL-~: 73 See the Technical Subcommittee "Recommendations" under the definition of "Approved for the Purpose" in Article 100. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article lOO. PANEL RECOMMENDATION: Accept as Revised:

I In line 7 insert "suitable" between "other" and "material" delete "approved for the purpose."


.ARTICLE 513 -- AIRCRAFT HANGARS

513-5(c): Accept CMP 14 SUBMITTER: O. E. Dillon, Border County Div. IAEI

74 Delete the words "that are or may be." SUBSTANTIATION: The use of the words "or may be" renders this section legally unenforceable. See the attached opinion* of the San Diego City Attorney. ,*See Border County Div. IAEI substantiation for CMP 1 Proposal

No. 90 for 110-16(a). PANEL RECOMMENDATION: Accept as Revised:

"Portable lamps that are used within a hangar shall be approved for the location in which they are used." PANEL COMMENT: Panel recommends review of Section 513-5 by N~PA Committee 409, basically to review use of portable equipment in hangars VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

513-8: Reject CMP 14 SUBMITTER: O. E. Dillon, Border County Div. IAEI ~ 7 5 Delete 513-8. S ~ I A T I O N : This section is practically unenforceable unless the jurisdiction has the man- power to make routine inspection of aircraft in aircraft hangers. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for C~ 1 Proposal No. 90 for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting comment does not jus t i f y the proposed'change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.


76 Delete 513-9. ~ I A T I O N : This section is practically unenforceable unless the Jurisdiction has the man- power to make routine inspection of aircraft in aircraft hangers. See the attached opinion* of the San Diego City Attorney.

*See Border County Div. IAEI substantiation for C~ 1 Proposal No. go for 110-16(a). PANEL RECOMMENDATION: Reject. PANEL COMMENT: The supporting c~Tfnent does not jus t i f y the • proposed change. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 514 -- GASOLINE DISPENSING AND SERVICE STATIONS ~°

514-2: Accept CMP 14 SUBMITTER: Edward C. Sommer NFPA No. 30 S/C General Storage ~ o m b . Liquids PROPOSAL: 77 Delete Section 514-2(a) through (g) andreplace

following:' The following table shall be applied where Class I liquids are

stored, handled or dispensed and shall be used to delineate and classify service station areas for the purpose of electrical equipment under normal circumstances. I t is based on the premise that the installation meets all requirements of NFPA No. 30. Should this not be the case, the inspector shall have the authority to determine the extent of the classified area. A classified area shall not extend beyond an unpierced wall, roof or other solid partit ion. SUBSTANTIATION: NFPA No. 30 S/C General Storage and Handling of Flammable and Combustible Liquids has the basic responsibility for classification of electrical areas in service stations. The present text in No. 70 is not in complete agreement with No. 30 and thus presents a conflict. This can be eliminated by:

(1) Revision of the existing test in No. 70, or (2) by dropping requirements contained in these articles and referencing No. 30, or (3) by incorporating the table contained in No. 30 into 514-2 of No. 70.

Of the three approaches, number 3 is probably the most attractive since i t eliminates the confl ict and provides information to the inspector without the need for an additional reference code. Updating as changes may be made in No. 30 is not a significant problem sinceboth codes are close in cycles.

















239





































239





































239





































239





















There is a further advantage since the table proposed for inclusion in No. 70 is more complete and covers classified areas

n o t presently covered in No. 70. "PANEL RECOMMENDATION: Accept as Revised: I Substitute the words "The following table" with "Table

514-2". Incorporate Table 7-1 from NFPA 30 into 514-2 of NFPA 70. (See enclosed editorial modifications.) In line 3 change "station" to "stations" and delete remainder of Proposal. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 16. NEGATIVE: Adams. ,

COI~MENT ON VOTE: gWERS: The last sentence of the proposal should remain: "A

classified area shall not-extend beyond an unpierced wall, roof

or other solid part i t ion." See write-up that was used at the Denver meeting of CMP 14. See also the f i r s t paragraph of Panel Recommendation on Proposal No. 87.

SCHRAM: My notes indicate the change in line 3 was to change "service station areas" to "service stations." EXPLANATION OF VOTE:

ADAMS: I think a better resolution of the differences between NFPA 30 and this section would be a reference to NFPA 30 at this point. I am opposed to copying other NFPA publications in the NEC.

Class

UNDERGROUND TANK

Fill Open ing

V e n t - Discharging U p w a r d

DISPENSING UNITS (except overhead type)

Pits

Dispenser

Table 514 -2

I Locat ions - - S e r v i c e S t a t i o n s

" -¢ -~ ' Class I, Group D Divifion ; ~ , Class I Location

Any pit , box or space below grade level, any part of which is within thc Division I or 2 ,I __i

Up to 18 inches above grade Icvcl within a horizontal radius of 10 feet from ,a loose fill connect ion and within a horizontal radius o f 5 feet from a fight fill connection.

With in 3 feet of open end of vent, ex tending in all directions. ~

/Uat"-k~etween 3 feet and 5 feet " ( ~pace I of open end of vent , ex tending in all directions.

fiocation. 1 h •

1 Any pit, box or space below grade level, any p a r t of which is within the Division 1 or 2 c ' . : -2

1 T h e ~ w i t h i n a dispenser enclosure up to 4 feet vertically above the base except tha t ...c-- defined as Division 2. Any . . . . I /.._~r'~_~..~ wi thin a nozzle boot.

2 Am~f ' -w i th in a dispenser enclosure above the Division 1 a,,,.FA,,~ ~imm a ~ .p~.er ~ c a t i o n . ] enclosure isolated f rom D,vision 4Lbpaces j 1 by a solid par t i t ion or a solid nozzle boot bu t no t complete ly su r rounded by Division 1 ~ | / 0ca t i0n l Within 18 inches horizontal ly in .~ -

all directions f rom the Division 1 ~ 1 0 c a t i 0 ~ J at, ml'/~at~ect wlthtrr the mspenser enclosure. Wi th in 18 inches horizontal ly in

, all directions from~ the opening of a nozzle boot not isolated by a vapor- f ight par t i t ion, excent ~at ion tha t the dassi t led ~Nd--~nneed n~t 1 be ex tended a round a 90* o r grea te r corner .

rlocation

240

Table 514-2 --. continued

Location

Class I, Group D Division

Extent of 4 m ~ C l a s s

Outdoor

INDOOR with Mechanical Ventilation

with Gravity Ventilation

Up to 18 inches above grade level within 20 feet horizontally of any edge of enclosure.

Up to 18 inches above grade or f loor level within 20 feet horizontally of any edge of enclmure.

Up to 18 inches above grade or floor level within 25 feet horizontally of any edge of enclosure.

DISPENSING UNITS~ O v z a ~ m ~ Tcp~ Within the dispenser enclosure

and 18 inches in all directions from the enclosure where not suitably cut off by ceiling or wall. All electrical equipment integral with the dispensing hose or nozzle.

extending-- 2 feet horizontally in all directions beyond the Division 1 * N d anna exfend- hag to grade below this cJa~ifled

UI) to 18 inches above grade level within 20 feet horizontally measured from a point vertically below the ecl. ge of any dispenser enclosure.

R~uo~g Puup - - C ~ o o R 1 Any pit, box or space below grade level ff any part is within a horizontal distance of 10 feet from any edge of pump.

Within 3 feet of any edge of pump, extending in all directions. Also up to 18 inches above grade level within 10 feet horizontally from any edge of pump.

]~LlluOTg PuMP -- INDOOR Entire jmr 'GTthin any pit.

Within 5 feet of any edge of p.ump, extending in all direc- uons. Also up to 3 feet above floor or grade level within 25 feet horizontally from any edge of pump.

I Location

IA space_] - ~l ocationJ

~ocation. l

241

Table 514-2 - - continued

Location

Chins I , Group D Division ~ C l a s s I Location

LUBRICATION OR SERVICE Roou -- with Dispensing

, Dispenser for Class I Liquids

I

2

2

Any pit within any unventilated area.

Any pit with ventilatiofi.

up to 18 inches above floor or grade level and 3 feet horizontally from a lubrication pit.

Within 3 feet of any fill or dispensing point, extending in all directions.

LUBRICATION OR SERVIC~g ROOM -- WITHOUT DISPENSING Entire ~ w i t h i n any pit used

for lubrication or similar services where Oasa I liquids may be re- leased.

~ R t l u p to 18 inches above any such pit, and extending a distance of 3 feet horizontally from any edge Of the pit.

SPECIAL ENCLOSURE INSmR { 1 Entire enclosure. Btm.DmO PEa 7-2.2

SALES, STORAGE AND ~ If there is any opening to these REST ROOMS 0 r d i n a r y rooms within fife extent of a Di-

vision 1 q ~ g - t h e entire room shall be classified as Division I.

. spac

[location; 7

VAPOR PROCESSING SYSTEMS Prrs

VAPOR PROCESSING F_.,QUIP M~gNT LOCATIgD WrrHm PaOTRO~W ~CLOSLrgES

Any pit, box or space below grade level, any par t of which is r~. a t i 0 n' ~ within a Division 1 oi 2 ~ a ~ @ ' = = = = = ~ I 0C

or which houses any equip- L. ment used to t ransport or process vapors.

Within any protective enclosure housing vapor processing equipment.

242 i

T a b l e 514-2 - - c o n t i n u e d

Class I, Group D

l ~ t i o n Division ~ . . E x t e n t o f

- ~ - - :_-_ , C l a s s I L o c a t i o n

" VAPOR PROC~SSINO F_.~QuiP MENT NOT WITHIN PROTECTV,'E ENCLOSURZS (excludin~

piping and combustion devices

The space within 18 inches in all directions of equipment containing ' flammable vapor or liquid extending to grade level. Up to 18 inchea above grade level within 10 ft. horizontally of the vapor processing equipment.

EQUIPMENT ENCLOSURES

Any a~E-within the enclosure where vapor or liquid is present under normal operating conditions.

~The entire ~ f ' ~ w i t h i n the enclosure other than Division 1.

VACUUM ASSIST BLOWERS

The space within 18 inches in all directions extending to grade level. Up to 18 inches above grade level within 10 feet horizontally,

243

514-2(a): Reject CMP 14 SUBMITTER: Gene Mittermaier, Gasoline Pump Manufacturers Assn.

78 Revise as follows: --T~T--I~ispenser. The area within a dispenser e~closure ~p to 4 feet vert ical ly above the base and the area within a nozzle boot is a Class I , Division 1 location, except that area defined as Division 2.

The following areas are considered Division 2: Areas within a dispenser enclosure above the Division i area. Areas within a dispenser enclosure isolated from Division I by a sol~d partition or a solid nozzle boot but not completely surrounded' by a Division i area.

Within 18'inches horizontally in all directions from the Division i area located within the dispenser enclosure. Within 18 inches horizontally in all directions from the opening of a nozzle boot not isolated by a vapor-tight partit ion, except that the classified area need not be extended around a.9O degree or greater corner. SUBSTANTIATION: This change is needed so that 514-2 wil l agree with Tab|e 7-1 of Code 30. PANEL RECOMMENDATION:- Reject. PANEL COMMENT: See Panel action on Proposal No. 77 and send to NFPA 30 Committee. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-2(h)-(New): Reject CMP 14 SUBMITTER: Keith Bell amy, Canada, MN

79 Add new (h) as follows: Th~ The space above the Class I Division 1 locations set out

in Section 514-2(a) shall be classified as Class I Division 2 locations, which shall extend to a height of 18 inches above the Class I Division i locations. The space between 18 inches and 36 inches horizontally from the dispenser shall be classified as a Class I Division 2 location up to 5- feet 6-inches above the dispenser base. SUBSTANTIATION: Section 500-4(b)(3) defines a space adjacent to a Class I Division I location as a Class I Division 2 location.

Section 514-2(a) states that space within a dispenser, up to 4 feet above the base and a space within 18 inches horizontally of the dispenser up to 4 feet above the base shall be classified as Class I Division 1 locations. Section 514-2(b) states that any space beyond the Class I Division I location within 20 feet horizontally of the dispenser and up to 18 inches above the driveway shall be classified as a Class I Division 2 location. Nowhere in the Code does i t specify what the space directly above the dispenser or the space above the Class I Division I location surrounding the dispenser are to be classified. Nor does the Code specify what the space beyond the 18 inches horizontally from the dispenser shall be. In othe~words, there appears to be a void which the above proposal would look after. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 77 and send to NFPA 30 Committee. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-8: Reject CMP 14 SUBMITTER: H. F. van der.Voort, Cleveland, OH ~ 8 0 In f i r s t sentence delete: "where buried under not less than 2 feet of earth, i t shall be permitted in.", and in last sentence delete: "Exception No. 3 of." SUBSTANTIATION: This reflects intent of Section'3OO-5(a), which permits burial depths of 18 inches and exceptions thereto. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary because of normal heavy vehicular t ra f f ic . VOTE ON 'PANEL RECOMMENDATION: Unanimously Affirmative. ,

514-8: Accept CMP 14 SUBMITTER: Idaho Chapter IAEI PROPOSAL: 81 In the f i f t h line after the word "used," add ~t-f~ea-d-ed rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last two feet of the underground run to e~ergence;". The second sentence in Section 514-8 would then read: "Where rigid nonmetallic conduit is used, threaded rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last two feet of the underground run to emergence; or to the point of connection to the above ground raceways; an equipment grounding conductor shall be included to provide electrical continuity of the raceway system and for grounding of noncurrent-carrying metal parts." SUBSTANTIATION: As now written "where not buried under not less than two feet of earth," does not prevent the nonmetallic conduit from being extended directly into a nonhazardous area basement at this level. The nonmetallic conduit cannot be sealed. PANEL RECOMMENDATION: Acc%pt. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-8: Reject CMP 14 SUBMITTER: Idaho Chapter IAEI I~TOFO-S'7~-L-~.'82 Delete all the rest of the Section beyond "or where buried" in the second line which eliminates the use of nonmetallic conduit in a Class I Division I area. SUBSTANTIATION: There is no provision for the possibil i ty of extending the nonmetallic raceway out into a nonhazardous area where grade level is such that the include will permit this. Nonmetallic conduit cannot be sealed. Article 514 states "where

.buried under not less than two feet.etc" does not necessarily prohibit extending the NM conduit directly into a nonhazardous location in a basement frem this burial depth. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 81. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-8: Reject CMP 14 SUBMITTER: Idaho Chapter IAEI !~ITOI~}'S'AI-~. • 83 In the second sentence, add the words "threaded rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last two feet of the underground'run to emergence" after the words "nonmetallic conduit is used." SUBSTANTIATION~ As now written "where not buried under not less than two feet of earth," does not prevent the nonmetallic conduit from being extended directly into a nonhazardous area basement at this level. The nonmetallic conduit cannot be sealed. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 81. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-8: Reject CMP 14 SUBMITTER: Idaho Chapter IAEI ~ 8 4 Delete the remainder of the section after the ~ h r e a d e d steel intermediate metal conduit." SUBSTANTIATION: Delete all the rest of the section beyond "or where buried" in the second line which eliminates the use of nonmetallic conduit in a Class i Division I area.

There is no provision for the possibil i ty of extending the nonmetallic raceway out into a nonhazardous area where grade level is such that the incline will permit this. Nonmetallic conduit cannot be sealed. Article 514 states "where buried under not less than two feet, etc." does not necessarily prohibit extending the NM conduit directly into a nonhazardous location in a basement from this burial depth. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 81. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 515 -- BULK-STORAGE PLANTS

515-1 and 515-2(h)-(New): Reject CMP 14 SUBMITTER: R. S. Pihkerton, Los Angeles, CA l PROPOSAL: 85 Add a new sentence to 515-1 as follows: ~ e s i g n a t i o n shall also include locations where ships carrying bulk cargos of gasoline or other volati le Flammable liquids are loaded or unloaded.

And add a new (h) as follows: (h) Loading and Unloading of Tanker Ships.

( i) The entire horizontal area of the loading dock and the horizontal area extending 35 feet in all directions from the tanker loading dock and continuing 15 feet inland measured from the mean high tide line shall be considered a Class I Division 2 location. The Class I Division 2 shall also extend, vert ical ly, below the dock to the water and upward to a level of 100 feet above the surface of the loading dock.

Exception: The hazardous location shall not be required to extend more than 18 inches above that portion of the grade, dock or ramp which is more than 35 feet from the ship side of the loading dock.

a. The Class I Division 2 location shall extend 25 feet in all directions from the surface of the loading hose manifgld.

b. The interior of a building, any portion which is located in a Class I Division 2 location, shall be classified as a Class I Division 2 location.

Exception: Buildings which are provided with satisfactory positive pressure ventilation, and safeguards, with air taken from a clean air source may be considered to be a nonhazardous location. SUBSTANTIATION: Following an explosion aboard an oil tanker

which destroyed the ship at its dock in the Los Angeles City harbor a Task Force was appointed to study the causes and recommend regulations which would minimize the chances of another such accident. The Task Force discovered that the Electrical Code requirements dealing with the installation of electric wiring on tanker loading docks were weak and inadequate, (Note: LA City Code requirements for hazardous locations are the same as NEC), and accordingly appointed an ad-hoc Electrical Code Advisory Committee to study the problem and propose appropriate changes to the Los Angeles City Electrical Code.

A survey of National Codes, standards or other publications

244

i

514-2(a): Reject CMP 14 SUBMITTER: Gene Mittermaier, Gasoline Pump Manufacturers Assn.

78 Revise as follows: --T~T--I~ispenser. The area within a dispenser e~closure ~p to 4 feet vert ical ly above the base and the area within a nozzle boot is a Class I , Division 1 location, except that area defined as Division 2.

The following areas are considered Division 2: Areas within a dispenser enclosure above the Division i area. Areas within a dispenser enclosure isolated from Division I by a sol~d partition or a solid nozzle boot but not completely surrounded' by a Division i area.

Within 18'inches horizontally in all directions from the Division i area located within the dispenser enclosure. Within 18 inches horizontally in all directions from the opening of a nozzle boot not isolated by a vapor-tight partit ion, except that the classified area need not be extended around a.9O degree or greater corner. SUBSTANTIATION: This change is needed so that 514-2 wil l agree with Tab|e 7-1 of Code 30. PANEL RECOMMENDATION:- Reject. PANEL COMMENT: See Panel action on Proposal No. 77 and send to NFPA 30 Committee. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-2(h)-(New): Reject CMP 14 SUBMITTER: Keith Bell amy, Canada, MN

79 Add new (h) as follows: Th~ The space above the Class I Division 1 locations set out

in Section 514-2(a) shall be classified as Class I Division 2 locations, which shall extend to a height of 18 inches above the Class I Division i locations. The space between 18 inches and 36 inches horizontally from the dispenser shall be classified as a Class I Division 2 location up to 5- feet 6-inches above the dispenser base. SUBSTANTIATION: Section 500-4(b)(3) defines a space adjacent to a Class I Division I location as a Class I Division 2 location.

Section 514-2(a) states that space within a dispenser, up to 4 feet above the base and a space within 18 inches horizontally of the dispenser up to 4 feet above the base shall be classified as Class I Division 1 locations. Section 514-2(b) states that any space beyond the Class I Division I location within 20 feet horizontally of the dispenser and up to 18 inches above the driveway shall be classified as a Class I Division 2 location. Nowhere in the Code does i t specify what the space directly above the dispenser or the space above the Class I Division I location surrounding the dispenser are to be classified. Nor does the Code specify what the space beyond the 18 inches horizontally from the dispenser shall be. In othe~words, there appears to be a void which the above proposal would look after. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 77 and send to NFPA 30 Committee. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-8: Reject CMP 14 SUBMITTER: H. F. van der.Voort, Cleveland, OH ~ 8 0 In f i r s t sentence delete: "where buried under not less than 2 feet of earth, i t shall be permitted in.", and in last sentence delete: "Exception No. 3 of." SUBSTANTIATION: This reflects intent of Section'3OO-5(a), which permits burial depths of 18 inches and exceptions thereto. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Present requirement is necessary because of normal heavy vehicular t ra f f ic . VOTE ON 'PANEL RECOMMENDATION: Unanimously Affirmative. ,

514-8: Accept CMP 14 SUBMITTER: Idaho Chapter IAEI PROPOSAL: 81 In the f i f t h line after the word "used," add ~t-f~ea-d-ed rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last two feet of the underground run to e~ergence;". The second sentence in Section 514-8 would then read: "Where rigid nonmetallic conduit is used, threaded rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last two feet of the underground run to emergence; or to the point of connection to the above ground raceways; an equipment grounding conductor shall be included to provide electrical continuity of the raceway system and for grounding of noncurrent-carrying metal parts." SUBSTANTIATION: As now written "where not buried under not less than two feet of earth," does not prevent the nonmetallic conduit from being extended directly into a nonhazardous area basement at this level. The nonmetallic conduit cannot be sealed. PANEL RECOMMENDATION: Acc%pt. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-8: Reject CMP 14 SUBMITTER: Idaho Chapter IAEI I~TOFO-S'7~-L-~.'82 Delete all the rest of the Section beyond "or where buried" in the second line which eliminates the use of nonmetallic conduit in a Class I Division I area. SUBSTANTIATION: There is no provision for the possibil i ty of extending the nonmetallic raceway out into a nonhazardous area where grade level is such that the include will permit this. Nonmetallic conduit cannot be sealed. Article 514 states "where

.buried under not less than two feet.etc" does not necessarily prohibit extending the NM conduit directly into a nonhazardous location in a basement frem this burial depth. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 81. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-8: Reject CMP 14 SUBMITTER: Idaho Chapter IAEI !~ITOI~}'S'AI-~. • 83 In the second sentence, add the words "threaded rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last two feet of the underground'run to emergence" after the words "nonmetallic conduit is used." SUBSTANTIATION~ As now written "where not buried under not less than two feet of earth," does not prevent the nonmetallic conduit from being extended directly into a nonhazardous area basement at this level. The nonmetallic conduit cannot be sealed. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 81. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

514-8: Reject CMP 14 SUBMITTER: Idaho Chapter IAEI ~ 8 4 Delete the remainder of the section after the ~ h r e a d e d steel intermediate metal conduit." SUBSTANTIATION: Delete all the rest of the section beyond "or where buried" in the second line which eliminates the use of nonmetallic conduit in a Class i Division I area.

There is no provision for the possibil i ty of extending the nonmetallic raceway out into a nonhazardous area where grade level is such that the incline will permit this. Nonmetallic conduit cannot be sealed. Article 514 states "where buried under not less than two feet, etc." does not necessarily prohibit extending the NM conduit directly into a nonhazardous location in a basement from this burial depth. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 81. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

ARTICLE 515 -- BULK-STORAGE PLANTS

515-1 and 515-2(h)-(New): Reject CMP 14 SUBMITTER: R. S. Pihkerton, Los Angeles, CA l PROPOSAL: 85 Add a new sentence to 515-1 as follows: ~ e s i g n a t i o n shall also include locations where ships carrying bulk cargos of gasoline or other volati le Flammable liquids are loaded or unloaded.

And add a new (h) as follows: (h) Loading and Unloading of Tanker Ships.

( i) The entire horizontal area of the loading dock and the horizontal area extending 35 feet in all directions from the tanker loading dock and continuing 15 feet inland measured from the mean high tide line shall be considered a Class I Division 2 location. The Class I Division 2 shall also extend, vert ical ly, below the dock to the water and upward to a level of 100 feet above the surface of the loading dock.

Exception: The hazardous location shall not be required to extend more than 18 inches above that portion of the grade, dock or ramp which is more than 35 feet from the ship side of the loading dock.

a. The Class I Division 2 location shall extend 25 feet in all directions from the surface of the loading hose manifgld.

b. The interior of a building, any portion which is located in a Class I Division 2 location, shall be classified as a Class I Division 2 location.

Exception: Buildings which are provided with satisfactory positive pressure ventilation, and safeguards, with air taken from a clean air source may be considered to be a nonhazardous location. SUBSTANTIATION: Following an explosion aboard an oil tanker

which destroyed the ship at its dock in the Los Angeles City harbor a Task Force was appointed to study the causes and recommend regulations which would minimize the chances of another such accident. The Task Force discovered that the Electrical Code requirements dealing with the installation of electric wiring on tanker loading docks were weak and inadequate, (Note: LA City Code requirements for hazardous locations are the same as NEC), and accordingly appointed an ad-hoc Electrical Code Advisory Committee to study the problem and propose appropriate changes to the Los Angeles City Electrical Code.

A survey of National Codes, standards or other publications

244

i

dealing with the handling of flommable liquids or gases revealed that there are no existing standards for electrical systems which are located on tanker loading docks. One publication, The National Oil Tanker and" Terminal Safety Guide, did provide helpful background information which enabled the Con~ittee to develop valid, practical standards•

The developers of the safety guide had conducted wind tunnel tests to determine the extent of flammable vapors from the discharge point. These tests provided several different conditions which included various discharge rates of the vapor, various heights of the discharge opening, the number of exhaust vents and the effect of shipboard superstructures on the flow of vapors. The extent of the flommable vapors from the discharge point was well delineated and gavb the Committee a very real and practical guide in establishing the parameters of locations classified as hazardous.

The recommendations in the Oil Tanker and Terminal Safety Guide are consistent with NFPA Pamphlet No. 497-1975, • CLASSIFICATION OF CLASS I HAZARDOUS LOCATIONS FOR ELECTRICAL INSTALLATIONS IN CHEMICAL PLANTS. Although this pamphlet does not specify requirements on tanker loading docks, i t does

• classify certain areas as hazardous around similar operations such as bulk loading of tanker trucks, bulk loading of railway tank cars and areas around large storage tanks located adjacent to refineries.

The main source of the hazard, obviously, is aboard ship and to be completely accurate, the extent of a hazardous area must be delineated from the tanker vent. The Committee agreed that this would be impractical and unenforceable and so a study was made to determine the shortest distance from a ship vent to ship side of the dock and how far the vapors would extend from that point was determined by the results of the wind tunnel tests•

The proposed Code requirements are the results of this study. With the tremendous increase in the handling of petroleum products in the nations harbors, it. is imperative that the NEC be updated to provide for safe electrical systems installed adjacent to this extremely flammable material. PANEL RECOMMENDATION: Reject• PANEL COMMENT: The scope of Article 515 and the classification of areas is based on NFPA 30, the Panel believes NFPA 30 should be revised before Article 515. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

515-1/and 515-2(h)-(New): Reject CMP 14 SUBMITTER: Southwestern Section IAEI ~ 8 6 515-1 DEFINITIONS. Add the following to the

definition: This designation shall also include locations where ships

carrying bulk cargos of gasoline or other volati le flammable liquids are loaded or unloaded.

Add a Subparagraph to read: (h) Loading and Unloading of Tanker Ships.

I . The entire horizontal area of the loading dock and the. horizontal area extending 35 feet in all directions from the tanker loading dock and continuing 15 feet inland measured from the mean high tide line shall be considered a Class 1 Division 2 location. The Class I Division 2 location shall also extend,

• vert ical ly, below the dock to the water and upward to a level of 100 feet above the surface of the loading dock.

Exception: The hazardous location shall ndt be required to . extend more than 18 inches above that portion of the. grade, dock or romp which is more than 35 feet from the ship.side of the .loading dock.

2. The Class 1 Division 2 location shall extend 25 feet in all directions from the surface of the loading hose manifold.

3. The interior of a.building, any portion which is located in a Class 1 Division 2 location, shall be classified as a Class I Division 2 location. Exception: Buildings which are provided with satisfactory positive pressure ventilation, and safeguards, with air taken from a clean air source may.be considered to be a non-hazardous location. SUBSTANTIATION: Following an explosion aboard an oil tanker which destroyed the ship at its dock in the Los Angeles City harbor a Task Force was appointed to study the causes of another such accident. The Task Force discovered that the Electrical Code requirements dealing with the installation of electric wiring on tanker loading' docks were weak and inadequate (NOTE: L. A. City Code requirements for hazardous locations are the same as NEC), and accordingly appointed an ad-hoc Electrical Code Advisory Committee to study the problem and propose appropriate changes to the Los Angeles City Electrical Code.'

A survey of National Cedes, standards or other publications dealing with the handling of flammaWle liquids or gases revealed that there are no existing standards for electrical systems which are located on tanker loading docks. One publication, The National Oil Tanker and Terminal Safety Guide, did provide helpful background information which enabled the Committee to develop valid, practical standards.

The developers of the safety guide had conducted wind tunnel tests to determine the extent ef flammable vapors from the discharge point. These tests provided several different conditions which included various discharge rates of the vapor, various heights of the discharge opening, the number of exhaust vents and the effect of shipboard superstructures on the flow of vapors. The extent of the flammable vapors from the discharge

245

point was well delineated and gave the Committee a very real and practical guide in establishing the parameters of locations classified as hazardous.

The recommendations in the Oil Tanker and Terminal Safety Guide are consistent withNFPA Pamphlet No. 497-1975, CLASSIFICATION OF CLASS 1 HAZARDOUS LOCATIONS FOR ELECTRICAL INSTALLATIONS IN CHEMICAL PLANTS. Although this pamphlet does not specify requirements on tanker loading docks, i t does classify certain areas as hazardous around similar operations such as bulk, loading of tanker trucks, bulk loading of railway tank cars and areas around large storage tanks located adjacent to refineries.

The main source of the hazard, obviously, is aboard ship and to be completely accurate, the extent of a hazardous area must be delineated from the tanker vent. The Committee agreed that this would be impractical and unenforceable and so a study was made to determine the shortest distance from a ship vent to ship side of the dock and how far the vapors would extend from that point was _determined by the results of the wind tunnel tests•

The proposed Code requirements are the results of this study. With the tremendous increase in the handling of petroleum products in the nations harbors, i t is imperative that the NEC be updated to provide for safe electrical- systems installed adjacent to th is extremely flammable mater ia l . PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel Comment on Proposal 85. VOTE ONP~NEL RECOMMENDATION:

AFFIRM#ITIVE: 15. NEGATIVE: Joriman.

EXPLANATION OF VOTE: JORIMAN: The IAEI concurred with the Task Force studies that

the National Electrical Code requirements dealing with the installation of electrical wiring on tanker loading docks are weak and inadequate. Therefore, Proposal No. 86 should not have been rejected.

515-2: Accept CMP 14 SUBMITTER: Edward C. Semmer, NFPA No. 30 S/C General Storage rl~---~--C-omb. Liquids PROPOSAL: 87 Delete Section 515-2(a) through (g) and replace w~-Tt-FF-Th-6 fo l lowing:

The fo l lowing table shall be applied where Class I l iqu ids are stored, handled or dispensed and shall be used to del ineate and c lass i f y bulk storage plant areas for the purpose of e lec t r i ca l equipment under normal'circumstances. I t is based on the premise that the i ns ta l l a t i on meets a l l requirements of NFPA No. 30. Should th is not be the case, the inspector shall have the author i ty to determine the extent of the c lass i f ied area. A c lass i f ied area shall not extend beyond an unpierced wal l , roof or other sol id pa r t i t i on . SUBSTANTIATION: NFPA No. 30 S/C General Storage and Handling of Flammable and Combustible Liquids has the basic respons ib i l i t y for c lass i f i ca t ion of e lec t r i ca l areas in bulk plants. The present text in No. 70 is not in complete agreement with No. 30 and thus presents a conflict. This conflict can be eliminated by:

(1) revision of the existing text in No. 70, or (2) by dropping requirements contained in these articles and referencing No. 30, or (3) by incorporating the table contained in No. 30 into 515-~ of No. 70.

Of the three approaches, number 3 is probably the most attractive since i t elimin#tes the confl ict and provides information to the inspector without the need for an additional reference code. Updating as changes may be made in No. 30 is not a significant problem since both codes are close in cycles. There is a further advantage since the table proposed for inclusion in No. 70 is more complete and covers classified areas not presently covered in No. 70. PANEL RECOMMENDATION: Accept as Revised:

"The following Table shall be applied where Class I liquids are stored, handled or dispensed and shall be used to delineate and classify bulk storage plants. The'Class I location shall not extend beyond an unpierced wall, roof or other solid • part i t ion."

Incorporate Table 6-1 of NFPA 30 into Section 515-2 labeling i t Table 515-2. (See attached editorial modiffcations to Table.) VOTE ON PANEL RECOMMENDATION:


COMMENT ON VOTE: EWERS:. In the Panel Recommendation "Table 515-2" should be

substituted for "The following.table" to agree with Proposal No. 77.

SCHRAM: I suggest "the following table" be revised to: "Table 515-2" to be consistent with Panel Action on Proposal No. 77. EXPLANATION OF VOTE:

ADAMS: Some as comment on Proposal No. 77.

Table 515-2. Class I Locations - - Bulk Plants

\

Location

Class I, Group D

~ v 1 ~ C l a s s I Location Division

TANK Vl~ HICI..E~"~ AND TANK C A R ~ Loading Through 1 Within 3 feet of edge of dome,

Open Dome. extending in all directions.

%' 2 ~ e t w e e n 3 feet and 15 feet from f edge of dome, extending in all

directions.

I 'S'pace~

Loading Through Bottom 1 Connections With Atmo-

spheric Venting

2

Loading Through Closed 1 Dome ' With Atmospheric

Venting 2

Loading Through Closed Dome With Vapor Recovery

Bottom Loading With Vapor Recovery or Any Bottom

Unloading

Within 3 feet of point of venting to atmosphere extending in all directions.

~sd~r.between!3 feet and 15 feet from point of venting to atmosphere, extending in all directions. ALso up to 18 inches above grade within a horizontal radius o f 10 feet from point of loading connection.

Within 3 feet of open end of vent, extending in all directions.

-¢~m[ between 3 feet and 15 feet from open end of vent, extending in aU

directions. Also within 3 feet of edge of dome, extending in all directions.

Within ,3 feet of point of connection of both fill and vapor lines, extending in all directions.

/ Within 3 feet of point of connections extending in all directions. Aho up to 18 inches above grade withi~ a horizontal radius of 10 feet from point of connection.

~ e ace ' " nt o ~ , consideration shall be given to fact that tank

[ cars or tank vehicles may be spotted at. varying points. Therefore, the ex- [ t rerm' t ies of the loading or unloading positions shall be used. L p

246

Tab le 515-2 - con t i nued

Location

Class I, Group D Division Cl ass I

PUMPS, B r.v-~nl~s, WITHDRAWAL FITTINGS s METERS AND SIMILAR Dsvtc~s

Indoors 2

Outdoors

Within 5 feet of an~ edge of such devices, extending in all directions. Also up to 3 feet above floor or grade level within 25 feet horizontally from any edge of such devices.

Within 3 feet of any edge of such devices, extending in all directions. Also up to 18 inches

.above grade level within 10 feet horizontally f rom any edge of such devices.

STORAGE AND REPAIR GARAGE FOR TANK VEHICLES

All pits or spaces below floor level.

• 4 ~ ' ~ u p to 18 inches above floor or grade level for entire storage or repair garage.

DRAINAGE DITCHES n SEPARATORS, IMPOUNDING BASINS

u ~ ~ p to 18 inches above ~tch, separator or basin. Also up to 18 inches above grade within 15 feet horizontally from any edge.

GARAGES FOR OTHER THAN TANK VEHICLES

Ord inary I f there is 'any opening to these rooms within the extent of an outdoor ~' . . . . __" . . . . . the entire room shall be cl~sified the same as the area classification at the point of the opening.

//OUTDOOR .DRUM STORAGE Ord ina ry

Locat ion

F a ej [SpaceJ

v i s i o n 1 o r , l o c a t i o n ,

INrOOR WAREHOUSING WHERE THERE Is No FLAMMABLE LIQUID TRANSFER

Ord inary I f there is any opening to these rooms within the extent of an indoor ~ ' 1 7 h e room shall be classified the same as if the wall, curb or partition did not exist.

D i v i s i o n 1 o r 2J l o c a t i o n ,

OFFICE AND REST ROOMS Ord inary

247

1

Table 515-2 - continued

- - -- ....;:,,--'.2 /

Location

C l a s s I, G r o u p D D i v i m o n Cl ass

DRUM AND C O N T ~ Fn~Lmo

Outdoors, or Indoors With Adequate Ventilation

Within 3 feet of vent and fill opening, extending in all directions.

~m~-between 3 feet and 5 feet from vent or fill opening, extending in all directions. Also up to 18 inches above floor or grade level within a horizontal radius of 10 feet from vent o r flU opening.

TANK - - ABOVF.f.~OU ND*

Shell, Ends, or Roof and Dike Area

Vent

2

Floating Roof 1

Within !0 feet from shell, ends, or roof of tank. ~ tnsme dikes to level of top of dike.

Within 5 feet of open end of vent, extending in all directions.

.A,s~ between 5 feet and 10 feet from open end of vent, extending in all directions.

~ v e the roof and within the shell.

I Location

PITS

Without Mechanical Ventilation

With Mechanical 2 Ventilation

Containing Valves, Fit- tings or Piping, and Not

_ _ Within a Division 1 or 2 -~-~,,~-~-~-r Loca t i on.

Entire w a d ~i th in pit if any part is within a Division 1 or 2 ~

Entire ~ w i t h i n pit i f any part is within a Division 1 or 2 ~ ! ~ : ~ : ~ ~--~=__

Entire pit.

~kspace

Cloca t i on -I

ocatio

*For Tanks - - Underground, -,.-c -t ~ ~.~ . . . . . . s e e A r t i c l e 5 1 4 - 2 .

248

515-5: Reject CMP 14 SUBMITTER: H. F. van der Voort, Cleveland, OH I~TOIR)-S'A-L-T.'88 In f i r s t sentence delete: "where buried under not less than 2 feet of earth, i t shall be permitted in." After second sentence add: "Refer to Section 300-5(a)." SUBSTANTIATION: This reflects intent of Article 300-5(a), which permits bu r i~ depths of 18 inches and all the exceptions thereto. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present requirement is necessary because of normal heavy vehicular t ra f f ic . VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

515-5(a): Accept , CMP 14 SUBMITTER: TSC~Approved for the Purpose

89 See the Technical Subcommittee "Reco~endations" un--6-de-r--~e definition of "Approved for the Purpose" in Article I00. SUBSTANTIATION: See the TSC "findings" under the definition of "Approved for the Purpose" in Article 100. PANEL RECOMMENDATION: Accept as Revised: : ~ - l - { n - e ~ to "conduit or an approved cable." 'V_OTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

515-5(a): Accept CMP 14 SUBMITTER: Idaho Chapter IAEI PROPOSAL: 90 In the 5th line of Section 515-5(a), after the

~ r p o s e , " add the following senteh~e: "Where rigid nonmetallic conduit is used, threaded rigid metal conduit or threaded steel intermediated metal conduit shall be used for the last two feet of the conduit run to emergence or to the point of connection to the above ground ~aceway." The rest of the section to remain unchanged. ' SUBSTANTIATION: Section 515-5, as" i t is now written, misleadingl~ermits rigid nonmetallic conduit to emerge from its minimum required buried depth of two feet by directly requiring cable to be enclosed in threaded rigid or threaded steel intermediate conduit from point of lowest buried cable level. PANEL RECOMMENDATION: Accept. VOTE ON PANEL RECOMMENDATION: Unanimously AFfirmative.

515-5(a): Reject CMP 14 SUBMITTER: Idaho Chapter IAEI !~-O-gb-~-A-C-~.' 91 Add a sentence before the last sentence as

Where rigid nonmetallic conduit is used, threaded rigid metal conduit or threaded steel intermediated metal condGit shall be used for the last two feet of the conduit run to emergence or to the point of connection to the above ground raceway. SUBSTANTIATION: Section 515-5, as i t ,is now written, misleadingl~ermits rigid nonmetalIic conduit to emerge from its minimum required buried depth of two feet by directly requiring cable to be enclosed in threaded rigid or threaded steel intermediate conduit from point of lowest buried cable level. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 90. ~TE ON PANEL RECOMMENDATION: Unanimously Affirmative.

515-5(c): Reject CMP 14 SUBMITTER: Idaho Chapter IAEI

92 Delete "with a nonmetallic sheath" from the ~ i n e . After "cable" in the f i r s t line, add "approved for the purpose." I t wil l then read: "Where rigid nonmetallic conduit or'cable approved for the purpose is used . . . . " (Rest of Section to remain unchanged.) SUBSTANTIATION: The phrase "cable with a nonmetallic sheath" can be misle~ing to include UF cable. PANEL RECOMMENDATION: Reject. PANEL COMMENT: The present wording adequately reflects the Panel's intent. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

515-5(c): Reject CMP 14 SUBMITTER: Idaho Chapter IAEI ~OSAL: 93 Revise as follows:

"Where rigid nommetallic conduit or cable approved for the purpose is used . . . . " (Rest of Section to remain unchanged.) SUBSTANTIATION: The phrase "cable with a nonmetallic sheath" can be misleading to include UF cable. PANEL RECOMMENDATION: Reject. PANEL COMMENT: See Panel action on Proposal No. 92. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

249

ARTICLE 516 -- FINISHING PROCESSES

Article 516 (HOD 1978 NEC): Reject CMP 14 SUBMITTER: Chet Noyes, AIJen KnicKrehm

94 Revise Article 616 as follows: ~ e v i s e scope (definition) by addiqg second sentence: "This Article also covers electroplating and electrolytic finishing processes."

(2) Make the present wording "Article 516 Part A-Liquid Finish Processes."

(3) Make new "Part B-Electrolytic Finish Processes." (4) Add:

516-xx. General. Equipment for use in electrolytic finishing process shall be of a type intended for such service. 516-xx. Branch-Circult Conductor. The branch-circuit conductor supplying one or more units of equipment to a source of supply shall have an ampacity of not less than 125 percent of the total connected load. 516-xx. Secondary Wiring. The conductor connecting the electrolite tank equipment to the regulating or conversion equipment shall be permitted to run as open wiring not on insulator, provided:

(a) they are protected from physical damage; (b) they operate at 25 volts or less.

516-xx. Busbars. Open noninsulated busbaFs shall be permitted to be installed over or adjacent to electrolite containers, provided:

(a) signs are posted to indicate open electric conductors are present;

(b) the busbars occur only in the areas where electrical connection is required. 516-xx. Overcurrent Protection. Secondary and busbars shall be protected fgom overcurrent by one or more of the following:

(a) fuses or circu!t breakers; (b) a current sensing device which operates a disconnecting

means (c) an inherently current limiting equipment or apparatus

which by its design and construction, wil l l imit overcurrent to 120% of normal--reduce output voltage--de-energize the secondary conductors i f an overcurrent continues for a set length of time of not more than five seconds. SUBSTANTIATION: The present NEC rules do not cover the electroplating industry. When inspectors apply the NEC rules open conductors necessary are not permitted. This, of course, cannot be permitted. This proposal is an attempt to correct this situation. See attached letter for further supporting comment. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Outside the scope of CMP 14. VOTE ON PANEL RECOMMENDATION: Unanimously Affirmative.

516-2(b)(5): Reject CMP 14 Secretary's Note: I t was the action of the Correlating

Committee that further consideration be given to the comments expressed in Mr. Schram's voting. SUBMITTER: Nicholas J. Talbot, NFPA Finishing Processes

PROPOSAL: 95 Change 20 feet horizontal dimension to 25 feet. SUBSTANTIATION: Conflict with the intent of NFPA 34. Correction of Error.

Figure 6-1 of NFPA 34-1974 indicates the dimension is 25 feet, but the text of Section 6-2.4 of NFPA 34-1974 indicates the dimension is 20 feet. The text of Section 516-2(b)(5) of the National Electrical Code is based on the text of NFPA 34-1974 rather than the dimension shown in the figure in NFPA 34-1974 (see Proposal No. 112 in the "Preprint" for the 1978 NEC). The text of Section 6-2.4 of NFPA 34 is now in the process of being corrected by the Finishing Processes Committee to agree with the Figure 6-I. PANEL RECOMMENDATION: Reject. PANEL COMMENT: Pending f inal action on NFPA 34. VOTE ON PANEL RECOMMENDATION:

AFFIRMATIVE: 14. NEGATIVE: Conaway, Schram.

EXPLANATION OF VOTE: CONAWAY: Correct distance to 2B f t . in 516-2(b)(5). There

should be no inconsistencies between NFPA 34 and NEC. Figures i , 2, and 3 should also track NFPA 33. Figure 1 in

the NFC does not do this as powder coating that requires Class I I installations is not covered. For that matter, Article 516 does not indicate that certain powder coating operations need Class I I , Division 1 or Division 2 installations.

SCHRAM: There were no comments on this Proposal during the period of public review of revised NFPA No. 34 as noted in TEC-79-F. I believe the Panel should have voted affirmative with the same Panel Comment.

Table 6-I Electrical Equipment Classified Areas--Bulk Plants

TANK VEHICLE AND TANK CAR* Loading Through 1 Within 3 feet of edge of dome, Open Dome extending in all directions.

* Loading Through Bottom

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conduit, it shall be contained in the conduit with the ... - NFPA