EFCOG Best Practice #213 · NFPA 20, Standard for Installation of Stationary Pumps for Fire Protection 9. NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages 10

EFCOG Best Practice #213

Facility: DOE Complex

Best Practice Title: Adoption of NFPA 70 2017 in place of NFPA 70 2014

Point of Contact:

Michael Hicks NE-ID, 208-526-3724, [email protected]

John McAlhaney SRS, 803-557-9002, [email protected]

Andrew Drutel SRS, 803-952-9380, [email protected]

Brief Description of Best Practice: NFPA 70 2017 is recommended for approval across the

DOE Complex as an upgrade to NFPA 70 2014 in 10 CFR 851 Worker Safety and Health Plans

(WSHP).

Why the best practice was used: 10 CFR 851 lists safety and health consensus standards with

which the contractor must comply when applicable with site hazards (851.23). Only the versions

of consensus standards that were in effect on January 17, 2018 were promulgated pursuant to

rulemaking therefore only those specifically cited versions are required by the Rule. Contractors

may include successor versions of the consensus standards that provide equal or greater worker

protection if included in their DOE-approved worker safety and health program.

What are the benefits of the best practice: The use of NFPA 70 2017 is at least as protective

as the 2014 edition, and even more protective in some areas, such that the new edition should be

considered for DOE Complex wide acceptance. NFPA 70 2017 is recommended for approval

across the DOE Complex as an upgrade to NFPA 70 2014.

What problems/issues were associated with the best practice: There were no issues associated

with this gap analysis. Adoption of the 2017 Edition of NFPA 70 provides a level of protection

“As Safe or Safer” than the 2014 version.

How the success of the Best Practice was measured: N/A

Description of process experience using the Best Practice: At the time this analysis was

performed, process experience did not exist. .

Date: June 20, 2018 Code/Standard Title: NFPA 70® – National Electrical Code®

CODE/STANDARD EVALUATION

TITLE: Technical Evaluation of the Changes in NFPA 70 between 2014 and 2017 Editions Note: National Fire Protection Association ®, NFPA ®, NFPA 70®, National Electrical Code ®, NEC ®, National Electrical Safety Code®, NESC® are registered trademarks of the National Fire Protection Association, Quincy, MA.

NFPA 70 – 2014 edition vs 2017 edition

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1. DESCRIPTION

The purpose of this evaluation is to document the acceptability of the changes introduced in 2017 edition of NFPA 70 as compared to the 2014 edition and to identify and evaluate the impact of the changes to the safety and health of workers. The following revisions are not included in the Comparison Table (Attachment #3):

• the sections of the NEC that deal strictly with residential systems, health care installations, or systems not in use at industrial facilities,

• majority of editorial or usability changes, clarifications, relocations, additions of definitions, rearrangement of sections and related cross-reference revisions, or changes related to bringing the code into alignment with the NEC Style Manual,

• changes adding a requirement for a particular type of equipment or material to be listed,• changes to voltage level applicability from 600 V to 1000 V (consistent with the changes

introduced in 2014 edition of the NEC),• changes to cross-references to other Sections,• references to national consensus standards or updating edition dates.

Articles with no changes or with changes falling into one of the above categories are not listed. No Informational Notes and no Informative Annexes were evaluated as they are not part of the Code text and have no enforceable meaning.

2. TECHNICAL JUSTIFICATION

The attached comparison was prepared by Andrew Drutel and reviewed by Jackie McAlhaney. The review identified no detrimental impacts to worker safety and health and concluded that the use of the 2017 edition of NFPA 70 is as protective to the worker as the 2014 edition.

Attachment #3 to this document provides comparisons of changes that were made to 2014 edition of NEC in 2017 edition of the code. Each line item listed in the “Comparison Table” has been reviewed and rated for the impact on worker safety. A rating of “1” (editorial), “2” (technical improvement), or “3” (potential safety consequence) has been assigned for each item. Any item with a ranking of “3” requires additional justification. Examples of the three ratings are provided below.

1. Editorial Change – No impact to worker health or safetyExample: Adding a metrication reference.

2. Technical Improvement – Addition, enhancement, or change in methodology oracceptance criteria that does not degrade worker safety when compared to the previousedition.Example: Adding requirements for equipment grounding for lighting switches suppliedby a general-purpose branch circuit.


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3. Potential Safety Consequence – Changes or revisions that potentially make the electrical installation less robust and could affect personnel safety. A ranking of “3” requires additional justification or further action. Example: Change in an overcurrent protection of a conductor or equipment which could result in reduced margin of safety.

As demonstrated in Attachment #3, there have been no changes made to the NFPA 70, National Electrical Code in the 2017 Edition that could present adverse impact to worker health or safety (rated “3”, as described above). Furthermore, the provisions of the 2017 edition are at least as protective as the 2014 edition of the code.

3. REFERENCES

1. 10 CFR 851, Worker Safety and Health Program 2. ANSI/IEEE C2, National Electrical Safety Code 3. ANSI/UL 723, Standard for Safety Test for Surface Burning Characteristics of Building

Materials 4. ANSI/UL 1863, Standard for Safety Communications-Circuit Accessories 5. ASME A17.1/B44, Safety Code for Elevators and Escalators Includes Requirements for

Elevators, Escalators, Dumbwaiters, Moving Walks, Material Lifts, and Dumbwaiters with Automatic Transfer Devices

6. ASTM E84, Standard Test Method for Surface Burning Characteristics of Building Materials

7. IEEE 841, Premium- Efficiency, Severe-Duty, Totally Enclosed Fan-Cooled (TEFC) Squirrel Cage Induction Motors—Up to and Including 370 kW (500 hp)

8. NFPA 20, Standard for Installation of Stationary Pumps for Fire Protection 9. NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages 10. NFPA 70, National Electrical Code (2014 and 2017 editions) 11. NFPA 72, National Fire Alarm and Signaling Code 12. NFPA 75, Standard for the Fire Protection of Information Technology Equipment 13. NFPA 90A, Standard for the Installation of Air-Conditioning and Ventilating Systems 14. NFPA 262, Standard Method of Test for Flame Travel and Smoke of Wires and Cables

for Use in Air-Handling Spaces 15. NFPA 780, Standard for the Installation of Lightning Protection Systems 16. NEMA VE-1, Metal Cable Tray Systems 17. UL 67, Standard for Safety Panelboards 18. UL 797, Standard for Safety Electrical Metallic Tubing – Steel 19. UL 891, Standard for Safety Switchboards 20. UL 943C, Outline of Investigation for Special Purpose Ground-Fault Circuit-Interrupters

– Issue 2 21. UL 1008, Standard for Safety Transfer Switch Equipment 22. UL 1660, Standard for Safety Liquid-Tight Flexible Conduit


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4. GENERAL NOTES 1. The Comparison Table (Attachment #3) does not represent all changes potentially having

impact on future installations. Refer to the NEC - 2017 for the full extent of the changes introduced in this new edition of the code.

2. In some cases, text of a particular revised section was truncated, capturing only portion of the text relevant to a particular change. New Articles or Articles rearranged in their entirety are not copied in the Comparison Table.

3. The following Tentative Interim Amendments were considered in this evaluation: TIA 17-1, TIA 17-2, TIA 17-3, TIA 17-4, TIA 17-5, and TIA 17-6.

4. The following Errata were considered in this evaluation: Errata 70-17-1, Errata 70-17-2, Errata 70-17-3, and Errata 70-17-4.

5. ATTACHMENTS

1. Email, Freiter (NFPA) to Drutel, dated October 26, 2017 2. Letter, Berry (NFPA) to Drutel, dated October 26, 2017 3. Comparison Table


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Attachment #1


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Attachment #1 (cont.)


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Attachment #2


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NFPA 70 – 2014 edition vs 2017 editionAttachment #3 - Comparison Table

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2014 NEC 2017 NECChange Description and

Impact Rank

I. General110.3 Examination, Identification, Installation, and Useof Equipment.

Part I. General110.3 Examination, Identification, Installation, Use, and Listing (Product Certification) of Equipment.(C) Listing. Product testing, evaluation, and listing (product certification) shall be performed by recognized qualified electrical testing laboratories and shall be in accordance with applicable product standards recognized as achieving equivalent and effective safety for equipment installed to comply with this Code.

Change Description: The new section (C) Listing, provides clarification about requirements for listing (product certification) being accomplished by qualified electrical testing laboratories and that the product testing and certification process is in accordance with appropriate product standards. Product listing (certification) is the most common basis for AHJ approvals and the product listing must meet or exceed the minimum product safety requirements developed by recognized standards development organizations.

Impact(s):No negative impact.

2

I. General110.14 Electrical Connections.

Part I. General110.14 Electrical Connections.(D) Installation. Where a tightening torque is indicated as a numeric value on equipment or in installation instructions provided by the manufacturer, a calibrated torque tool shall be used to achieve the indicated torque value, unless the equipment manufacturer hasprovided installation instructions for an alternative method of achieving the required torque.

Change Description: Use of proper torque tools is essential to verify that terminations are properly made and the equipment will function properly throughout its life cycle. Testing has shown that installers use the wrong torque values in up to 75% of installations unless a torque measuring tool is used.

Impact(s):No negative impact

2

I. General110.16 Arc-Flash Hazard Warning.

Part I. General110.16 Arc-Flash Hazard Warning.(B) Service Equipment. In other than dwelling units, in addition to the requirements in (A), a permanent label shall be field or factory applied to service equipment rated 1200 amps or more. The label shall meet the requirements of 110.21(B) and contain the following information:(1) Nominal system voltage(2) Available fault current at the service overcurrent protective devices(3) The clearing time of service overcurrent protective devices based on the available fault current at the service equipment(4) The date the label was appliedException: Service equipment labeling shall not be required if an arc flash label is applied in accordance with acceptable industry practice.

Change Description: This revision recognizes the scope of both NEC and NFPA 70E and adds these installation-related requirements into a new 110.16(B) Service Equipment. This new section is limited to service equipment rather than a broader application.The information necessary to comply with the additional marking on service equipment is obtainable at or before the time of installation.


2

I. General110.21 Marking.(A) Manufacturer’s Markings.

Part I. General110.21 Marking.(A) Equipment Markings.(2) Reconditioned Equipment. Reconditioned equipment shall be marked with the name, trademark, or other descriptive marking by which the organization responsible for reconditioning the electrical equipment can be identified, along with the date of the reconditioning.Reconditioned equipment shall be identified as “reconditioned” and approval of the reconditioned equipment shall not be based solely on the equipment’s original listing.Exception: In industrial occupancies, where conditions of maintenance and supervision ensure that only qualified persons service the equipment, the markings indicated in 110.21(A)(2) shall not be required.

Change Description: The title of 110.21(A) was changed to Equipment Markings since the section is no longer limited to manufacturers marking.

New 110.21(A)(2) provides additional value to manufacturers, owners and authorities having jurisdiction. It provides traceability and information related to reconditioned equipment.


2

Note: Reprinted with the permission from NFPA 70 ®- 2014 and NFPA 70 ®-2014, National Electrical Code ®,Copyright © 2013 and 2016, respectively, National Fire Protection Association, Quincy, MA.

The material contained herein is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.

Article 110 Requirements For Electrical Installations


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Impact Rank

II. 600 Volts, Nominal, or Less.110.26 Spaces About Electrical Equipment.(A) Working Space. (3) Height of Working Space.

**Part II. 1000 Volts, Nominal, or Less.110.26 Spaces About Electrical Equipment.(A) Working Space.(3) Height of Working SpaceException No. 3: On Battery systems mounted on open racks, the top clearance shall comply with 480.10(D).(4) Limited Access. Where equipment operating at 1000 volts, nominal, or less to ground and likely to require examination, adjustment, servicing, or maintenance while energized is required by installation instructions or function to be located in a space with limitedaccess, all of the following shall apply: (a) Where equipment is installed above a lay-in ceiling, there shall be an opening not smaller than 559 mm × 559 mm (22 in. × 22 in.), or in a crawl space, there shall be an accessible opening not smaller than 559 mm × 762 mm (22 in. × 30 in.).(b) The width of the working space shall be the width of the equipment enclosure or a minimum of 762 mm (30 in.), whichever is greater.(c) All enclosure doors or hinged panels shall be capable of opening a minimum of 90 degrees.(d) The space in front of the enclosure shall comply with the depth requirements of Table 110.26(A)(1).The maximum height of the working space shall be the height necessary to install the equipment in the limited space. A horizontal ceiling structural member or access panel shall be permitted in this space.

Change Description:**Table 110.26(A)(1) Working Spaces omitted.

Revised Section and Table to upper level of circuit voltages covered (1000 V) and rounded numbers for the metric dimensions.

Added a new exception for batteries, refering Section 480.10(D).

Provided new criteria for installation of equipment in a space with limited access.


2

II. 600 Volts, Nominal, or Less.110.26 Spaces About Electrical Equipment.(A) Working Space (3) Height of Working Space. (Continued)

(continued)(5) Separation from High-Voltage Equipment. Where switches, cutouts, or other equipment operating at 1000 volts, nominal, or less are installed in a vault, room, or enclosure where there are exposed live parts or exposed wiring operating over 1000 volts, nominal, the high-voltage equipment shall be effectively separated from the space occupied by the low-voltage equipment by a suitable partition, fence, or screen.

Change Description:Added criteria for separation of equipment operating at voltages 1000 V or less from High-Voltage equipment.


2

III. Over 600 Volts, Nominal110.34 Work Space and Grounding

Part III. Over 1000 Volts, Nominal110.34 Work Space and Grounding

Change Description:Revised the voltage threshold from 600 V to 1000 V to correlate with the changes in section 110.26 and revisions introduced in 2014 edition of the code.


2

III. Over 600 Volts, Nominal Part III. Over 1000 Volts, Nominal110.41 Inspections and Tests.(A) Pre-energization and Operating Tests. Where required elsewhere in this Code, the complete electrical system design, including settings for protective, switching, and control circuits, shall be prepared in advance and made available on request to the authority having jurisdiction and shall be tested when first installed on-site.(B) Test Report. A test report covering the results of the tests required in 110.41(A) shall be available to the authority having jurisdiction prior to energization and made available to those authorized to install, operate, test, and maintain the system.

Change Description: A new section 110.41 requires pre-energization testing. The testing could include performance and safety testing. The new requirement is incorporated in Part III of Article 110 and correlates with the inspection and testing requirements contained in other NEC rules such as those in Article 225 and others.


2

I. General Provisions.210.5 Identification for Branch Circuits.(C) Identification of Ungrounded Conductors(1) Branch Circuits Supplied from More Than One Nominal Voltage System.(b) Posting of Identification Means.

I. General Provisions.210.5 Identification for Branch Circuits.(C) Identification of Ungrounded Conductors(1) Branch Circuits Supplied from More Than One Nominal Voltage System.(b) Posting of Identification Means. The label shall be of sufficient durability to withstand the environment involved and shall not be handwritten.Exception: In existing installations where a voltage system(s) already exists and a different voltage system is being added, it shall be permissible to mark only the new system voltage. Existing unidentified systems shall not be required to be identified at each termination, connection, and splice point in compliance with 210.5(C)(1)(a) and (b). Labeling shall be required at each voltage system distribution equipment to identify that only one voltage system has been marked for a new system(s). The new system label(s) shall include the words “other unidentified systems exist on the premises.”

Change Description:Added a new requirement that the labels identifying branch circuits on premises, fed from more than one nominal voltage system, shall be durable and shall not be handwritten. Included a new exception limiting the requirement for labeling systems with different voltages to the new systems being added.


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Article 210 Branch Circuits


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Impact Rank

I. General Provisions.210.5 Identification for Branch Circuits.(2) Branch Circuits Supplied from Direct-Current Systems.(a) Positive Polarity, Sizes 6 AWG or Smaller.

(b) Negative Polarity, Sizes 6 AWG or Smaller

Part I. General Provisions.210.5 Identification for Branch Circuits.(2) Branch Circuits Supplied from Direct-Current Systems.(a) Positive Polarity, Sizes 6 AWG or Smaller.(4) An approved permanent marking means such as sleeving or shrink-tubing that is suitable for the conductor size, at all termination, connection, and splice points, with imprinted plus signs (+) or the word POSITIVE or POS durably marked on insulation of a color other than green, white, gray, or black(b) Negative Polarity, Sizes 6 AWG or Smaller(4) An approved permanent marking means such as sleeving or shrink-tubing that is suitable for the conductor size, at all termination, connection, and splice points, with imprinted minus signs (–) or the word NEGATIVE or NEG durably marked on insulation of a color other than green, white, gray, or red.

Change Description:An additional list item is added to the identification means of positive and negative polarity conductors. This addition supports the re-use of branch conductors for dc applications.


1

210.8 Ground-Fault Circuit-Interrupter Protection for Personnel.(B) Other Than Dwelling Units.All 125-volt, singlephase, 15- and 20-ampere receptacles installed in the locations specified in 210.8(B)(1) through (8) shall have ground-fault circuit-interrupter protection for personnel.(1) Bathrooms(2) Kitchens(3) Rooftops(4) OutdoorsException No. 1 to (3): Receptacles on rooftops shall not be required to be readily accessible other than from the rooftop.Exception No. 2 to (3) and (4): Receptacles that are not readily accessible and are supplied by a branch circuit dedicated to electric snow-melting, deicing, or pipeline and vessel heating equipment shall be permitted to be installed in accordance with 426.28 or 427.22, as applicable.

210.8 Ground-Fault Circuit-Interrupter Protection for Personnel.(B) Other Than Dwelling Units.All single-phase receptacles rated 150 volts to ground or less, 50 amperes or less andthree- phase receptacles rated 150 volts to ground or less, 100 amperes or less installed in the following locations shall have ground-fault circuit-interrupter protection for personnel. (1) Bathrooms(2) Kitchens(3) RooftopsException: Receptacles on rooftops shall not be required to be readily accessible other than from the rooftop.(4) OutdoorsException No. 1 to (3) and (4): Receptacles that are notreadily accessible and are supplied by a branch circuit dedicated to electric snow- melting, deicing, or pipeline and vessel heating equipment shall be permitted to be installed in accordance with 426.28 or 427.22, as applicable.

Change Description:The requirements in this section have been expanded to recognize the fact that the shock hazard is not limited to 15 and 20 A single phase 125 V circuits, and expanded the requirement to 150 volt, 50 A or less single-phase and 150 V to ground, 100 A or less, three-phase.


2

210.8 Ground-Fault Circuit-Interrupter Protection for Personnel.(B) Other Than Dwelling Units (continued)(5) Sinks — where receptacles are installed within 1.8 m(6 ft) of the outside edge of the sink

(continued)(5) Sinks — where receptacles are installed within 1.8 m (6 ft) from the top inside edge of the bowl of the sink…(9) Crawl spaces — at or below grade level(10) Unfinished portions or areas of the basement not intended as habitable rooms.

Change Description:Provided more specific definition of the distance from the sink and added crawl spacesand basements to require GFCI type receptacles for personnel protection.


2

210.8 Ground-Fault Circuit-Interrupter Protection for Personnel.

210.8 Ground-Fault Circuit-Interrupter Protection for Personnel.(E) Crawl Space Lighting Outlets. GFCI protection shall be provided for lighting outlets not exceeding 120 volts installed in crawl spaces.

Change Description:Added GFCI protection requirement for crawl space lighting outlets.


2

215.2 Minimum Rating and Size.(A) Feeders Not More Than 600 Volts.(1) General.Feeder conductors shall have an ampacity not less than required to supply the load as calculated in Parts III, IV, and V of Article 220. Conductors shall be sized to carry not less than the larger of 215.2(A)(1)(a) or (b).(a) Where a feeder supplies continuous loads or any combination of continuous and noncontinuous loads, the minimum feeder conductor size shall have an allowable ampacity not less than the noncontinuous load plus 125 percent of the continuous load.(b) The minimum feeder conductor size shall have an allowable ampacity not less than the maximum load to be served after the application of any adjustment or correction factors.

215.2 Minimum Rating and Size.(A) Feeders Not More Than 600 Volts.(1) General. Exception No. 2: Where a portion of a feeder is connected at both its supply and load ends to separately installed pressure onnections as covered in 110.14(C)(2), it shall be permitted to have an allowable ampacity not less than the sum of the continuous load plus the noncon‐ tinuous load. No portion of a feeder installed under the provisions of this exception shall extend into an enclosure containing either the feeder supply or the feeder load terminations, as covered in 110.14(C)(1).

Change Description:A new Exception 2 is added that allows for intermediate feeder segments that are only limited by the ampacity parameters that apply over the length of the run and that do not involve usual termination limitations. This type of provision is technically appropriate and had been done in the past, but has been inadvertently prohibited due to the recent restructuring of the usual requirements. The exception also includes language excluding feeder segments that use this allowance from entering the source and destination enclosures. In this way the exception precludes the installation of the conductor length calculated under normal procedures that would otherwise evade the equipment termination requirements of the rule under the exception.


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Article 215 Feeders


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Impact Rank

215.12 Identification for Feeders.(C) Identification of Ungrounded Conductors.(2) Feeders Supplied from Direct-Current Systems.

215.12 Identification for Feeders.(C) Identification of Ungrounded Conductors.(2) Feeders Supplied from Direct-Current Systems.(4) An approved permanent marking means such as sleeving or shrink-tubing that is suitable for the conductor size, at all termination, connection, and splice points, withimprinted plus signs (+) or the word POSITIVE or POS durably marked on insulation of a color other than green, white, gray, or black.

Change Description:A list item has been added to the identification means of positive and negative polarity conductors. This addition supports the re-use of feeder conductors for DC applications.


2

IV. Optional Feeder and Service Load Calculations220.87 Determining Existing Loads.(1) The maximum demand data is available for a 1-year period.Exception: If the maximum demand data for a 1-year period is not available, the calculated load shall be permitted to be based on the maximum demand (measure of averagepower demand over a 15-minute period) continuously recorded over a minimum 30-day period using a recording ammeter or power meter connected to the highest loaded phaseof the feeder or service, based on the initial loading at the start of the recording. The recording shall reflect the maximum demand of the feeder or service by being takenwhen the building or space is occupied and shall include by measurement or calculation the larger of the heating or cooling equipment load, and other loads that may be periodic in nature due to seasonal or similar conditions.

Part IV. Optional Feeder and Service Load Calculations220.87 Determining Existing Loads(1) The maximum demand data is available for a 1-year period.Exception: If the maximum demand data for a 1-year period is not available, the calculated load shall be permitted to be based on the maximum demand (the highest average kilowatts reached and maintained for a 15-minute interval) continuously recorded over a minimum 30-day period using a recording ammeter or power meter connected to the highest loaded phase of the feeder or service, based on the initial loading at the start of the recording. The recording shall reflect the maximum demand of the feeder or service by being taken when the building or space is occupied and shall include by measure‐ ment or calculation the larger of the heating or cooling equipment load, and other loads that may be periodic in nature due to seasonal or similar conditions.

Change Description:The added text will improve clarity and understanding of the term “maximum demand”.


1

II. Overhead Service Conductors230.29 Supports over Buildings.Service conductors passing over a roof shall be securely supported by substantial structures. Where practicable, such supports shall be independent of the building.

Part II. Overhead Service Conductors230.29 Supports over Buildings.Service conductors passing over a roof shall be securely supported by substantial structures. For a grounded system, where the substantial structure is metal, it shall be bonded by means of a bonding jumper and listed connector to the grounded overhead service conductor. Where practicable, such supports shall be independent of the building.

Change Description:New wording adds requirement for metal structures that are mounted on or adjacent to buildings and that are used to support energized conductors to be adequately bonded to limit shock hazards.


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VII. Service Equipment — Overcurrent Protection.230.91 Location. The service overcurrent device shall be an integral part of the service disconnecting means or shall be located immediately adjacent thereto.

Part VII. Service Equipment — Overcurrent Protection.230.91 Location. The service overcurrent device shall be an integral part of the service disconnecting means or shall be located immediately adjacent thereto. Where fuses are used as the service overcurrent device, the disconnecting means shall be located ahead of the supply side of the fuses.

Change Description:This new requirement will enhance safety as it will allow the de-energizing of fuses or other overcurrent devices for testing and servicing.


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VII. Service Equipment — Overcurrent Protection.230.95 Ground-Fault Protection of Equipment.(C) Performance Testing. The ground-fault protection system shall be performance tested when first installed on site. The test shall be conducted in accordance with instructions that shall be provided with the equipment. A written record of this test shall be made and shall be available to the authority having jurisdiction.

Part VII. Service Equipment — Overcurrent Protection.230.95 Ground-Fault Protection of Equipment.(C) Performance Testing. The ground-fault protection system shall be performance tested when first installed on site. This testing shall be conducted by a qualified person(s) using a test process of primary current injection, in accordance with instructions that shall be provided with the equipment. A written record of this testing shall be made and shall be available to the authority having jurisdiction.

Change Description:This test system provides more adequate functionality testing of the GFPE device. This also clarifies that the testing must be conducted by qualified person(s).


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Part II. Location.240.24 Location in or on Premises.(A) Accessibility. Overcurrent devices shall be readily accessible and shall be installed so that the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than 2.0 m (6 ft 7 in.) above the floor or working platform, unless one of the following applies:(1) For busways, as provided in 368.17(C).(2) For supplementary overcurrent protection, as describedin 240.10.(3) For overcurrent devices, as described in 225.40 and230.92.(4) For overcurrent devices adjacent to utilization equipment that they supply, access shall be permitted to be by portable means.

Part II. Location.240.24 Location in or on Premises.(A) Accessibility. Switches containing fuses and circuit breakers shall be readily accessible and installed so that the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than 2.0 m (6 ft 7 in.) above the floor or working platform, unless one of the following applies:(1) For busways, as provided in 368.17(C).(2) For supplementary overcurrent protection, as described in 240.10.(3) For overcurrent devices, as described in 225.40 and 230.92.(4) For overcurrent devices adjacent to utilization equipment that they supply, access shall be permitted to be by portable means.Exception: The use of a tool shall be permitted to access overcurrent devices located within listed industrial control panels or similar enclosures.

Change Description:The first sentence has been revised and an exception added to clarify the requirement. This is necessary because of the change to the definition of “Accessible, Readily” in the 2014 NEC. The exception clarifies that a tool (e.g., a screwdriver) is permissible to be used to open the enclosure in order to gain access to the overcurrent device.


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Article 230 Services

Article 220 Branch-Circuit, Feeder, and Service Load Calculations

Article 240 Overcurrent Protection


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Impact Rank

VI. Cartridge Fuses and Fuseholders. Part VI. Cartridge Fuses and Fuseholders.240.67 Arc Energy Reduction.Where fuses rated 1200 A or higher are installed, 240.67(A) and (B) shall apply. This requirement shall become effective January 1, 2020.(A) Documentation. Documentation shall be available to those authorized to design, install, operate, or inspect the installation as to the location of the fuses.(B) Method to Reduce Clearing Time. A fuse shall have a clearing time of 0.07 seconds or less at the available arcing current, or one of the following shall be provided:(1) Differential relaying(2) Energy-reducing maintenance switching with local status indicator(3) Energy-reducing active arc flash mitigation system(4) An approved equivalent means

Change Description: A new requirement has been added (effective 1/1/2020) for fuses rated 1200 A and above to ensure reduction in arc flash incident energy. It is based on similar requirements for circuit breakers in Section 240.87. The delay in the effective date for this requirement is needed to ensure the electrical industry can respond with feasible solutions, available from multiple manufacturers, to meet this requirement.


2

VII. Circuit Breakers.240.87 Arc Energy Reduction.Where the highest continuous current trip setting for which the actual overcurrent device installed in a circuit breaker is rated or can be ad justed is 1200 A or higher, 240.87(A) and (B) shall apply.(A) Documentation. Documentation shall be available to those authorized to design, install, operate, or inspect the installation as to the location of the circuit breaker(s).(B) Method to Reduce Clearing Time. One of the following or approved equivalent means shall be provided:(1) Zone-selective interlocking(2) Differential relaying(3) Energy-reducing maintenance switching with local status indicator(4) Energy-reducing active arc flash mitigation system(5) An approved equivalent means

Part VII. Circuit Breakers.240.87 Arc Energy Reduction.(B) Method to Reduce Clearing Time. One of the following means shall be provided:(1) Zone-selective interlocking(2) Differential relaying(3) Energy-reducing maintenance switching with local status indicator(4) Energy-reducing active arc flash mitigation system(5) An instantaneous trip setting that is less than the available arcing current(6) An instantaneous override that is less than the available arcing current(7) An approved equivalent means

Change Description:This revision added new list items (5) and (6) for clarity and usability. These new list items will now clearly describe specific permitted methods of achieving the arc energy reduction required in this section.

Impact(s):No negative impact. 2

Part II. System Grounding.250.22 Circuits Not to Be Grounded.

Part II. System Grounding.250.22 Circuits Not to Be Grounded.(6) Class 2 load side circuits for suspended ceiling low-voltage power grid distribution systems as provided in 393.60(B)

Change Description:The change is made to align with Section 393.60.


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II. System Grounding.250.30 Grounding Separately Derived Alternating- Current Systems.(A) Grounded Systems.(1) System Bonding Jumper.Exception No. 2: If a building or structure is supplied by a feeder from an outdoor transformer, a system bonding jumper at both the source and the first disconnecting means shall be permitted if doing so does not establish a parallel path for the grounded conductor. If a grounded conductor is used in this manner, it shall not be smaller than the size specified for the system bonding jumper but shall not be required to be larger than the ungrounded conductor(s). For the purposes of this exception, connection through the earth shall not be considered as providing a parallel path.

Part II. System Grounding.250.30 Grounding Separately Derived Alternating-Current Systems.(A) Grounded Systems.(1) System Bonding JumperException No. 2: If a building or structure is supplied by a feeder from an outdoor separately derived system, a system bonding jumper at both the source and the first disconnect-ing means shall be permitted if doing so does not establish a parallel path for the grounded conductor. If a grounded conductor is used in this manner, it shall not be smaller than the size specified for the system bonding jumper but shall not be required to be larger than the ungrounded conductor(s). For the purposes of this exception, connection through the earth shall not be considered as providing a parallel path.

Change Description:The change clarified that the requirement applies not only to transformers but to all separately derived systems.


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(continued)(4) Grounding Electrode. The grounding electrode shallbe as near as practicable to, and preferably in the same area as, the grounding electrode conductor connection to the system. The grounding electrode shall be the nearest of one of the following:(1) Metal water pipe grounding electrode as specified in 250.52(A)(1)(2) Structural metal grounding electrode as specified in 250.52(A)(2)Exception No. 1: Any of the other electrodes identified in 250.52(A) shall be used if the electrodes specified by 250.30(A)(4) are not available.Exception No. 2 to (1) and (2): If a separately derived system originates in listed equipment suitable for use as service equipment, the grounding electrode used for the service or feeder equipment shall be permitted as thegrounding electrode for the separately derived system.

(continued)(4) Grounding Electrode. The building or structure grounding electrode system shall be used as the grounding electrodefor the separately derived system. If located outdoors, the grounding electrode shall be in accordance with 250.30(C) .Exception: If a separately derived system originates in equipment that is listed and identified as suitable for use as service equipment, the grounding electrode used for the service or feeder equipment shall be permitted to be used as the grounding electrode for the separately derivedsystem.

Change Description:These revisions better describe a grounding electrode and include the conductors that are suitable to extend the grounding electrode connection. The revisions to this section recognize the water pipe and the structural metal frame as covered in 250.68(C) that are being used are not grounding electrodes but rather are conductors extending the grounding electrode connection.The revised text allowed exception No. 1 to be deleted as those options are covered by the referenced sections. correct.


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Article 250 Grounding and Bonding


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III. Grounding Electrode System and Grounding Electrode Conductor250.64 Grounding Electrode Conductor Installation.(B) Securing and Protection Against Physical Damage.Where exposed, a grounding electrode conductor or its enclosure shall be securely fastened to the surface on which it is carried. Grounding electrode conductors shall be permitted to be installed on or through framing members.A 4 AWG or larger copper or aluminum grounding electrode conductor shall be protected if exposed to physical damage. A 6 AWG grounding electrode conductor that is free from exposure to physical damage shall be permitted to be run along the surface of the building construction without metal covering or protection if it is securely fastened to the construction; otherwise, it shall be protected in rigid metal conduit RMC, intermediate metal conduit (IMC), rigid polyvinyl chloride conduit (PVC), reinforced thermosettingresin conduit (RTRC), electrical metallic tubing EMT, or cable armor. Grounding electrode conductors smaller than 6 AWG shall be protected in (RMC), IMC, PVC, RTRC, (EMT), or cable armor. Grounding electrode conductors and grounding electrode bonding jumpers shall not be required to comply with 300.5.

Part III. Grounding Electrode System and Grounding Electrode Conductor250.64 Grounding Electrode Conductor Installation.(B) Securing and Protection Against Physical Damage.(3) Smaller Than 6 AWG. Grounding electrode conductors smaller than 6 AWG shall be protected in RMC, IMC, PVC, RTRC-XW, EMT, or cable armor.

(4) In Contact with the Earth. Grounding electrode conductors and grounding B46electrode bonding jumpers in contact with the earth shall not be required to comply with 300.5, but shall be buried or otherwise protected if subject to physical damage.

Change Description:The long paragraph was revised to list format for better usability. The statement in new list item (1) about being secured to the building surface was removed as it is redundant with the charging text. The protection methods that were provided for 6 AWG conductors were extended to include 6 AWG and larger conductors. Other editorial changes were made for clarity. Revised text was added to provide for burial of grounding electrode conductors.


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250.68 Grounding Electrode Conductor and Bonding Jumper Connection to Grounding Electrodes.(C) Grounding Electrode Connections.(1) Interior metal water piping located not more than 1.52 m (5 ft) from the point of entrance to the building shall be permitted to be used as a conductor to interconnect electrodes that are part of the grounding electrode system.

250.68 Grounding Electrode Conduct r and Bonding Jumper Connection to Grounding Electrodes.(C) Grounding Electrode Conductor Connections.(1) Interior metal water piping that is electrically continuous with a metal underground water pipe electrode and is located not more than 1.52 m (5 ft) from the point of entrance to the building shall be permitted to extend the connection to an electrode(s). Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a conductor to interconnect electrodes of the grounding electrode system.

Change Description: The revised text simplifies the statement of a location and the requirement that the connection for the grounding electrode conductor or the bonding jumpers used to interconnect electrodes shall be to interior metal water piping not extending more than five feet into the building.


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(continued)(2) The metal structural frame of a building shall be permitted to be used as a conductor to interconnect electrodes that are part of the grounding electrode system, or as a grounding electrode conductor.

(continued)(2) The metal structural frame of a building shall be permitted to be used as a conductor to interconnect electrodes that are part of the grounding electrode systemor as a grounding electrode conductor. Hold-down bolts securing the structural steel column that are connected to a concrete-encased electrode that complies with 250.52(A)(3) and is located in the support footing or foundation shall be permitted to connect the metal structural frame of a building or structure to the concrete encased grounding electrode. The hold-down bolts shall be connected to the concrete-encased electrode by weld‐ ing, exothermic welding, the usual steel tie wires, or other approved means.

Change Description:The text added to 250.68(C)(2) is being relocated from 250.52(A)(2) as it is no longer appropriate for that section but adds clarity to this section and should be preserved as a permitted connection method.


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(continued)(3) A concrete-encased electrode of either the conductor type, reinforcing rod or bar installed in accordance with 250.52(A)(3) extended from its location within the concrete to an accessible location above the concrete shall be permitted.

(continued)(3) A rebar-type concrete-encased electrode installed in accordance with 250.52(A)(3) with an additional rebar section extended from its location within the concrete to an accessible location that is not subject to corrosion shall be permitted for connection of grounding electrode conductors and bonding jumpers. The rebar extension shall not be exposed to contact with the earth without corrosion protection.

Change Description:Revised the text to remove redundant language already covered in 250.52(A)(3). The text was revised to apply to the rebar or rod type of concrete encased electrodes as intended and to provide additional requirements to be installed in such a manner to prevent any corrosion due to contact with the earth.


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IV. Enclosure, Raceway, and Service Cable Connections. 250.86 Other Conductor Enclosures and Raceways.Exception No. 3: A metal elbow shall not be required to be connected to the equipment grounding conductor where it is installed in a run of nonmetallic raceway and is isolated from possible contact by a minimum cover of 450 mm (18 in.) to any part of theelbow or is encased in not less than 50 mm (2 in.) of concrete.

Part IV. Enclosure, Raceway, and Service Cable Connections.250.86 Other Conductor Enclosures and Raceways.Exception No. 3: Metal components shall not be required to be connected to the equipment grounding conductor or supply-side bonding jumper where either of the following conditions exist:(1) The metal components are installed in a run of nonmetallic race‐ way(s) and isolated from possible contact by a minimum cover of 450 mm (18 in.) to any part of the metal components.(2) The metal components are part of an installation of nonmetallic raceway(s) and are isolated from possible contact to any part of the metal components by being encased in not less than 50 mm (2 in.) of concrete.

Change Description:The phrase "metal components" was added to each subdivision. Isolated sections of metal conduit that meet the requirements of this section are considered to be metal components.

The exception was converted to a list to improve usability.


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V. Bonding.250.94 Bonding for Communication Systems.

Part V. Bonding.250.94 Bonding for Communication Systems.(B) Other Means. Connections to an aluminum or copper busbar not less than 6 mm thick × 50 mm wide (1∕4 in. thick × 2 in. wide) and of sufficient length to accommodate at least three terminations for communication systems in addition to other connections. The busbar shall be securely fastened and shall be installed in an accessible location. Connections shall be made by a listed connector. If aluminum busbars are used, the installation shall also comply with 250.64(A).

Change Description:The alternate connection option allows connections to be made on a common bus bar with other bonding jumpers. This method is often used in commercial or multifamily mixeduse buildings.


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250.102 Grounded Conductor, Bonding Conductors, and Jumpers.(A) Material. Bonding jumpers shall be of copper or other corrosion-resistant material. A bonding jumper shall be a wire, bus, screw, or similar suitable conductor.

250.102 Grounded Conductor, Bonding Conductors, and Jumpers.(A) Material. Bonding jumpers shall be of copper, aluminum, copper-clad aluminum, or other corrosion-resistant material. A bonding jumper shall be a wire, bus, screw, or similar suitable conductor.

Change Description:Added aluminum, copper-clad aluminum to the list of material types acceptable for use as grounded and bonding conductors, and jumpers. This is consisten with other sections of this code which allow this type of material for GEC or EGC.


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VI. Equipment Grounding and Equipment Grounding Conductors.250.118 Types of Equipment Grounding Conductors.(5) Listed flexible metal conduit meeting all the following conditions:c. The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground-fault current path does not exceed 1.8 m (6 ft).

Part VI. Equipment Grounding and Equipment Grounding Conductors.250.118 Types of Equipment Grounding Conductors.(5) Listed flexible metal conduit meeting all the following conditions:c. The size of the conduit does not exceed metric designator 35 (trade size 1¼).

Change Description:Statement: The UL listing for equipment grounding of Flexible Metal Conduit and the associated fittings have only been listed up to the metric designator 35 (Trade size 1 1/4 ) for a number of years, see UL category code DXUZ.


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250.119 Identification of Equipment Grounding Conductors.(C) Flexible Cord. An uninsulated equipment grounding conductor shall be permitted, but, if individually covered, the covering shall have a continuous outer finish that is either green or green with one or more yellow stripes.

250.119 Identification of Equipment Grounding Conductors.(C) Flexible Cord. Equipment grounding conductors in flexible cords shall be insulated and shall have a continuous outer finish that is either green or green with one or more yellow stripes.

Change Description:The revision to 250.119(C) aligns the language to the lan-guage found in the standard for flexible cords, UL 62 paragraph 4.1.1.8.1.


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250.122 Size of Equipment Grounding Conductors(F) Conductors in Parallel. Where conductors are installed in parallel in multiple raceways or cables as permitted in 310.10(H), the equipment grounding conductors, whereused, shall be installed in parallel in each raceway or cable.Where conductors are installed in parallel in the same raceway, cable, or cable tray as permitted in 310.10(H), a single equipment grounding conductor shall be permitted. Equipment grounding conductors installed in cable tray shall meet the minimum requirements of 392.10(B)(1)(c).Each equipment grounding conductor shall be sized in compliance with 250.122.

250.122 Size of Equipment Grounding Conductors.(F) Conductors in Parallel.(1) Conductor Installations in Raceways, Auxiliary Gutters, or Cable Trays.(a) Single Raceway or Cable Tray. If conductors are installed in parallel in the same raceway or cable tray, a single wire- type conductor shall be permitted as the equipment grounding conductor. The wire-type equipment grounding conductor shall be sized in accordance with 250.122, based on the over‐ current protective device for the feeder or branch circuit. Wire- type equipment grounding conductors installed in cable trays shall meet the minimum requirements of 392.10(B)(1)(c). Metal raceways or auxiliary gutters in accordance with 250.118 or cable trays complying with 392.60(B) shall be permitted as the equipment grounding conductor.(b) Multiple Raceways. If conductors are installed in parallel in multiple raceways, wire-type equipment grounding conductors, where used, shall be installed in parallel in each raceway. The equipment grounding conductor installed in each raceway shall be sized in compliance with 250.122 based on the overcurrent protective device for the feeder or branch circuit. Metal raceways or auxiliary gutters in accordance with250.118 or cable trays complying with 392.60(B) shall be permitted as the equipment grounding conductor.

(Continued) (continued)(2) Multiconductor Cables.(a) If multiconductor cables are installed in parallel, the equipment grounding conductor(s) in each cable shall be connected in parallel.(b) If multiconductor cables are installed in parallel in the same raceway, auxiliary gutter, or cable tray, a single equipment grounding conductor that is sized in accordance with 250.122 shall be permitted in combination with the equipment grounding conductors provided within the multiconductor cables and shall all be connected together.(c) Equipment grounding conductors installed in cable trays shall meet the minimum requirements of 392.10(B)(1)(c). Cable trays complying with 392.60(B), metal raceways in accordance with 250.118, or auxiliary gutters shall be permitted as the equipment grounding conductor.(d) Except as provided in 250.122(F)(2)(b) for raceway or cable tray installations, the equipment grounding conductor in each multiconductor cable shall be sized in accordance with 250.122 based on the overcurrent protective device for the feeder or branch circuit.

Change Description:The revised text separates individual conductors installed in raceways or cable tray from multiconductor cables. The requirements are further separated for single or multiple raceways. The revisions also recognize where standard multiconductor cables are installed in a raceway or cable tray that is either suitable as the equipment grounding conductor or where a fully sized wire type equipment grounding conductor is provided in the raceway or cable tray, the standard multiconductor cable is to be permitted even though the internal equipment grounding conductors may be sized less than Table 250.122. Safety is maintained by the full sized equipment grounding conductor of the raceway orcable tray being present.

Impact(s):No negative entry.

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I. General Requirements.300.5 Underground Installations.(D) Protection from Damage. Direct-buried conductors and cables shall be protected from damage in accordance with 300.5(D)(1) through (D)(4).(4) Enclosure or Raceway Damage. Where the enclosure or raceway is subject to physical damage, the conductors shall be installed in rigid metal conduit, intermediate metal conduit, RTRC-XW, Schedule 80 PVC conduit, or equivalent.

Part I. General Requirements.300.5 Underground Installations.(D) Protection from Damage. Direct-buried conductors and cables shall be protected from damage in accordance with 300.5(D)(1) through (D)(4).(4) Enclosure or Raceway Damage. Where the enclosure or raceway is subject to physical damage, the conductors shall be installed in electrical metallic tubing, rigid metal conduit, intermediate metal conduit, RTRC-XW, Schedule 80 PVC conduit, or equivalent.

Change Description:Section 300.5(D)(4) is being revised to add electrical metallic tubing (EMT) since EMT is not restricted from underground applications and is commonly used under building slabs to connect electrical equipment. Corrosion protection is a requirement for listed EMT per UL 797 and in accordance with 300.6. In addition, Article 358 requires the use of listed fittings and 314.15 requires wet location fittings in this application. EMT is allowed to be used in locations where not subject to “severe” physical damage.


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300.5 Underground Installations.(G) Raceway Seals. Conduits or raceways through which moisture may contact live parts shall be sealed or plugged at either or both ends.

300.5 Underground Installations.(G) Raceway Seals. Conduits or raceways through which moisture may contact live parts shall be sealed or plugged at either or both ends. Spare or unused raceways shall also be sealed. Sealants shall be identified for use with the cable insulation, conductor insulation, bare conductor, shield, or other components.

Change Description:This new text is the same as used in 225.27, covering raceway seals for outside feeder and branch circuits, and similar to that of 230.8, covering raceway seals for service raceways. Any sealant used to seal a raceway containing conductors should not cause damage to cable insulation, the conductor, or any component of the cable.


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310.15 Ampacities for Conductors Rated 0–2000 Volts.(B) Tables(c) Raceways and Cables Exposed to Sunlight on Rooftops.Where raceways or cables are exposed to direct sunlight on or above rooftops, the djustments shown in Table 310.15(B)(3)(c) shall be added to the outdoor temperatureto determine the applicable ambient temperature for application of the correction factors in Table 310.15(B)(2)(a) or Table 310.15(B)(2)(b).Exception: Type XHHW-2 insulated conductors shall not be subject to this ampacity adjustment.

310.15 Ampacities for Conductors Rated 0–2000 Volts.(B) Tables(c) Raceways and Cables Exposed to Sunlight on Rooftops. Where raceways or cables are exposed to direct sunlight on or above rooftops, raceways or cables shall be installed a minimum distance above the roof to the bottom of the raceway or cable of 23 mm (7∕8 in.). Where the distance above the roof to the bottom of the raceway is less than 23 mm (7∕8 in.), a temperature adder of 33°C (60°F) shall be added to the outdoor temperature to determine the applicable ambient temperature for application of the correction factors in Table 310.15(B)(2)(a) or Table 310.15(B)(2)(b).Exception: Type XHHW-2 insulated conductors shall not be subject to this ampacity adjustment.

Change Description:Testing submitted indicates that wiring methods sized appropriately for the load and located on rooftops anywhere in the United States will not exceed their temperature rating, even without these adders. The submitted report also shows that even using the ambient temperature correction factors in Table 310.15(B)(2)(a) results in a conservative allowable ampacity. The test setup collected data from wiring methods that were not in direct contact with the roof surface. Modeling and testing was performed at a public university.


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300.22 Wiring in Ducts Not Used for Air Handling, Fabricated Ducts for Environment al Air, and Other Spaces for Environmental Air (Plenums).(B) Ducts Specifically Fabricated for Environmental Air.

300.22 Wiring in Ducts Not Used for Air Handling, Fabricated Ducts for Environment al Air, and Other Spaces for Environmental Air (Plenums).(B) Ducts Specifically Fabricated for Environmental Air.Exception: Wiring methods and cabling systems, listed foruse in other spaces used for environmental air (plenums), shall be permitted to be installed in ducts specifically fabri-cated for environmental air-handling purposes under the following conditions:(1) The wiring methods or cabling systems shall be permitted only if necessary to connect to equipment or devices associated with the direct action upon or sensing of the contained air, and(2) The total length of such wiring methods or cabling systems shall not exceed 1.2 m (4 ft).

Change Description:The new Exception provides the capability of wiring systems or cabling systems that are specifically listed as low smoke and flame spread, based on NFPA 262, to be installed in very limited lengths of a maximum of 4 feet to connect to electrical equipment or devices but only to equipment or devices that are associated with the direct action or sensing of the air contained within the fabricated duct. Similar text can be found in the NFPA 90A-2015 document in Section 4.3.4.2.


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I. Scope and Installation.312.8 Switch and Overcurrent Device Enclosures with Splices, Taps, and Feed-Through Conductors. The wiring space of enclosures for switches or overcurrent devicesshall be permitted for conductors feeding through, spliced, or tapping off to other enclosures, switches, or overcurrent devices where all of the following conditions are met:(1) The total of all conductors installed at any cross section of the wiring space does not exceed 40 percent of the cross-sectional area of that space.(2) The total area of all conductors, splices, and taps installed at any cross section of the wiring space does not exceed 75 percent of the cross-sectional area of that space.(3) A warning label complying with 110.21(B) is applied to the enclosure that identifies the closest disconnecting means for any feed-through conductors.

Part I. Scope and Installation.312.8 Switch and Overcurrent Device Enclosures.(B) Power Monitoring Equipment. The wiring space of enclosures for switches or overcurrent devices shall be permitted to contain power monitoring equipment where all of the following conditions are met:(1) The power monitoring equipment is identified as a field installable accessory as part of the listed equipment, or is a listed kit evaluated for field installation in switch or overcurrent device enclosures.(2) The total area of all conductors, splices, taps, and equipment at any cross section of the wiring space does not exceed 75 percent of the cross-sectional area of that space.

Change Description:This revision provides guidance as to when the addition of devices and/or equipment may be acceptable. The text limits the inclusion of devices and equipment in a wiring space to those that are identified as field installable accessories as part of the listed equipment, or as a listed kit evaluated for field installation in the specific equipment. This wording retainsthe limit on the amount of space occupied by all conductors, splices, taps, devices, and equipment to the same 75 percent fill requirement that is presently in 312.8(2). The wording also includes parent text in the section heading for clarity.


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Article 300 General Requirements for Wiring Methods and Materials

Article 312 Cabinets, Cutout Boxes, and Meter Socket Enclosures


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II. Installation.314.16 Number of Conductors in Outlet, Device, and Junction Boxes, and Conduit Bodies.(A) Box Volume Calculations. The volume of a wiring enclosure (box) shall be the total volume of the assembled sections and, where used, the space provided by plasterrings, domed covers, extension rings, and so forth, that are marked with their volume or are made from boxes the dimensions of which are listed in Table 314.16(A).(B) Box Fill Calculations The volumes in paragraphs 314.16(B)(1) through (B)(5), as applicable, shall be added together. No allowance shall be required for small fittingssuch as locknuts and bushings.

Part II. Installation.314.16 Number of Conductors in Outlet, Device, and Junction Boxes, and Conduit Bodies.(A) Box Volume Calculations. Where a box is provided with one or more securely installed barriers, the volume shall be apportioned to each of the resulting spaces. Each barrier, if not marked with its volume, shall be considered to take up 8.2 cm3 (1∕2 in3) if metal, and 16.4 cm3 (1.0 in3) if nonmetallic.(B) Box Fill Calculations. The volumes in paragraphs 314.16(B)(1) through (B)(5), as applicable, shall be added together. No allowance shall be required for small fittings such as locknuts and bushings. Each space within a box installed with a barrier shall be calculated separately.

Change Description:The change addresses the procedure for calculating the volume of the interior spaces of boxes divided by barriers installed in the field and clarifies that the required volume allowances for divided boxes are to be applied as applicable on the basis of the contents of each subdivided section.


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314.28 Pull and Junction Boxes and Conduit Bodies.(E) Power Distribution Blocks.(1) Installation. Power distribution blocks installed in boxes shall be listed.

314.28 Pull and Junction Boxes and Conduit Bodies.(E) Power Distribution Blocks.(1) Installation. Power distribution blocks installed in boxes shall be listed. Power distribution blocks installed on the line side of the service equipment shall be listed and marked “suitable for use on the line side of service equipment” or equivalent.

Change Description:This new wording adds a marking requirement so the suitability for use ahead of service equipment will beobvious to both installer and inspector. The label identifies the testing laboratory action, and the marking identifies the function.


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II. Installation. Part II. Installation.328.30 Support. Type MV cable terminated in equipment or installed in pull boxes or vaults shall be secured and supported by metallic or nonmetallic supports suitable to withstand the weight by cable ties listed and identified for securement and support, or other approved means, at intervals not exceeding 1.5 m (5 ft) from terminations or a maximum of 1.8 m (6 ft) between supports.

Change Description:New text provides guidance to installers, and code enforcement personnel, to better assure proper cable support for a safe, neat and workmanlike installation.


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II. Installation Part II. Installation330.15 Exposed Work. Exposed runs of cable, except as provided in 300.11(A), shall closely follow the surface of the building finish or of running boards. Exposed runs shall also be permitted to be installed on the underside of joists where supported at each joist and located so as not to be subject to physical damage.

Change Description:The added text provides requirements for exposed intallation of type MC cable consistent with other, similar wiring methods.


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II. Installation.336.10 Uses Permitted.(2) In cable trays.

Part II. Installation.336.10 Uses Permitted.(2) In cable trays, including those with mechanically discontinuous segments up to 300 mm (1 ft).

(10) Direct buried, where identified for such use.Informational Note: See 310.15(A)(3) for temperature limitation of conductors.

Change Description:(2) Cable trays are allowed to be installed with mechanically discontinuous segments in 392.18(A). If the discontinuous segment is 12 inches or less, the revised language will allow tray cable to be installed without additional support. 12 inches is the maximum support separation in cable tray allowed in NEMA VE-1.

(10) Rephrased the deleted Section 336.12(4)


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II. Installation.342.14 Dissimilar Metals.Where practicable, dissimilar metals in contact anywhere in the system shall be avoided to eliminate the possibility of galvanic action. Aluminum fittings and enclosures shall be permitted to be used with IMC.

Part II. Installation.342.14 Dissimilar Metals.Aluminum fittings and enclosures shall be permitted to be used with galvanized steel IMC where not subject to severe corrosive influences. Stainless steel IMC shall only be used with stainless steel fittings and approved accessories, outlet boxes, and enclosures.

Change Description:This revision clarifies the acceptable fittings that can be used with galvanized and stainless steel IMC, based on galvanic compatibility.


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Article 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Handhole Enclosures

Article 328 Medium Voltage Cable: Type MV

Article 330 Metal-Clad Cable: Type MC

Article 336 Power and Control Tray Cable: Type TC

Article 342 Intermediate Metal Conduit: Type IMC


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II. Installation.344.14 Dissimilar Metals. Where practicable, dissimilar metals in contact anywhere in the system shall be avoided to eliminate the possibility of galvanic action. Aluminumfittings and enclosures shall be permitted to be used with steel RMC, and steel fittings and enclosures shall be permitted to be used with aluminum RMC where not subject to severe corrosive influences.

Part II. Installation.344.14 Dissimilar Metals. Where practicable, dissimilar metals in contact anywhere in the system shall be avoided to eliminate the possibility of galvanic action. Aluminum fittings and enclosures shall be permitted to be used with galvanized steel RMC, and galvanized steel fittings and enclosures shall be permitted to be used with aluminum RMC where not subject to severe corrosive influences. Stainless steel RMC shall only be used with stainless steel fittings and approved accessories, outlet boxes, and enclosures.

Change Description:This revision clarifies the acceptable fittings that can be used with galvanized and stainless steel RMC, based on galvanic compatibility.


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II. Installation. Part II. Installation.350.28 Trimming. All cut ends of conduit shall be trimmed inside and outside to remove rough edges.

Change Description:Added for consistency with Articles 350 and 356. Properly trimming LFMC is necessary to ensure proper installation of the steel grounding ferrule which is important to maintain grounding continuity of the steel sheath.Impact(s):No negative impact.

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II. Installation358.10 Uses Permitted.(A) Exposed and Concealed. The use of EMT shall be permitted for both exposed and concealed work.

(B) Corrosion Protection. Ferrous or nonferrous EMT, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and approved as suitable for the condition.

(C) Wet Locations. All supports, bolts, straps, screws, and so forth shall be of corrosion-resistant materials or protected against corrosion by corrosion-resistant materials.

Part II. Installation358.10 Uses Permitted.(A) Exposed and Concealed. The use of EMT shall be permitted for both exposed and concealed work for the following:(1) In concrete, in direct contact with the earth or in areas subject to severe corrosive influences where installed in accordance with 358.10(B)(2) In dry, damp, and wet locations(3) In any hazardous (classified) location as permitted by other articles in this Code(B) Corrosive Environments. (1) Galvanized Steel and Stainless Steel EMT, Elbows, and Fittings. Galvanized steel and stainless steel EMT, elbows, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and approved as suitable for the condition.(2) Supplementary Protection of Aluminum EMT. Aluminum EMT shall be provided with approved supplementary corrosion protection where encased in concrete or in direct contact with the earth.(C) Cinder Fill. Galvanized steel and stainless steel EMT shall be permitted to be installed in cinder concrete or cinder fill where subject to permanent moisture when protected on allsides by a layer of noncinder concrete at least 50 mm (2 in.) thick or when the tubing is installed at least 450 mm (18 in.) under the fill.(D) Wet Locations. All supports, bolts, straps, screws, and so forth shall be of corrosion-resistant materials or protected against corrosion by corrosion-resistant materials.

Change Description:Section 358.10 was revised for consistency. Requirements were moved from 358.12 and reworded using positive language. Also included is Stainless Steel EMT which is listed to UL797.


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III. Construction Specifications358.100 Construction. Factory-threaded integral couplings shall be permitted. Where EMT with a threaded integral coupling is used, threads for both the tubing and coupling shall be factory-made. The coupling and EMT threads shall be designed so as to prevent bending of the tubing at any part of the thread.

Part III. Construction Specifications358.100 Construction. EMT shall be made of one of the following:(1) Steel with protective coatings(2) Aluminum(3) Stainless steel

Change Description:This revision clarifies the metal types used for the manufacture of EMT. Deleted statement about threading - EMT is not threaded.


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II. Installation Part II. Installation366.20 Conductors Connected in Parallel. Where single conductor cables comprising each phase, neutral, or grounded conductor of an alternating-current circuit are connected in parallel as permitted in 310.10(H), the conductors shall be installed in groups consisting of not more than one conductor per phase, neutral, or grounded conductor to prevent current imbalance in the paralleled conductors due to inductive reactance.

Change Description: There have been documented failures of parallel phase conductors due to inductive heating, where installed in wireways or auxiliary gutters. In addition to the requirement of each parallel phase conductor being the same length, the proper grouping of phases can reduce inductive heating and result in a more balanced load between each conductor of a parallel phase.


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Article 350 Liquidtight Flexible Metal Conduit: Type LFMC

Article 344 Rigid Metal Conduit: Type RMC

Article 358 Electrical Metallic Tubing: Type EMT

Article 366 Cable Trays


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Article 376 Metal WirewaysII. Installation Part II. Installation

376.20 Conductors Connected in Parallel. Where single conductor cables comprising each phase, neutral, or grounded conductor of an alternating-current circuit are connected in parallel as permitted in 310.10(H), the conductors shall be installed in groups consisting of not more than one conductor per phase, neutral, or grounded conductor to prevent current imbalance in the paralleled conductors due to inductive reactance.



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Article 378 Nonmetalic WirewaysII. Installation Part II. Installation

378.20 Conductors Connected in Parallel. Where single conductor cables comprising each phase, neutral, or grounded conductor of an alternating-current circuit are connected in parallel as permitted in 310.10(H), the conductors shall be installed in groups consisting of not more than one conductor per phase, neutral, or grounded conductor to prevent current imbalance in the paralleled conductors due to inductive reactance.



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II. Installation.392.22 Number of Conductors or Cables.(A) Number of Multiconductor Cables, Rated 2000 Volts or Less, in Cable Trays. The number of multiconductor cables, rated 2000 volts or less, permitted in a single cable tray shall not exceed the requirements of this section. The conductor sizes shall apply to both aluminum and copper conductors.

Part II. Installation.392.22 Number of Conductors or Cables.(A) Number of Multiconductor Cables, Rated 2000 Volts or Less, in Cable Trays. The number of multiconductor cables, rated 2000 volts or less, permitted in a single cable tray shall not exceed the requirements of this section. The conductor sizes shall apply to both aluminum and copper conductors. Where dividers are used, fill calculations shall apply to each divided section of the cable tray.

Change Description: Fill calculations must be applied to the width of each specifically divided section of the cable tray to appropriately manage the heat dissipation of the cables.


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I. General.400.8 Uses Not Permitted. Unless specifically permitted in 400.7, flexible cords and cables shall not be used for the following:(5) Where concealed by walls, floors, or ceilings or locatedabove suspended or dropped ceilings

Part I. General.400.12 Uses Not Permitted.

(5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings.Exception to (5): Flexible cord and flexible cable shall be permitted if contained within an enclosure for use in Other Spaces Used for Environmental Air as permitted by 300.22(C)(3).

Change Description: The added exception addresses an installation which is permitted elsewhere in the code and should be permitted in Article 400.


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I. Installation.404.2 Switch Connections.(C) Switches Controlling Lighting Loads .(5) Where multiple switch locations control the same lighting load such that the entire floor area of the room or space is visible from the single or combined switch locations.

Part I. Installation.404.2 Switch Connections.(C) Switches Controlling Lighting Loads.(5) Where a switch controls a receptacle loadThe grounded conductor shall be extended to any switch location as necessary and shall be connected to switching devices that require line-to-neutral voltage to operate the electronics of the switch in the standby mode and shall meet the requirements of 404.22.Exception: The connection requirement shall become effective on January 1, 2020. It shall not apply to replacement or retrofit switches installed in locations prior to local adoption of 404.2(C) and where the grounded conductor cannot be extended without removing finish materials. The number of electronic lighting control switches on a branch circuit shall not exceed five, and the number connected to any feeder on the load side of a system or main bonding jumper shall not exceed 25. For the purpose of this exception, a neutral busbar, in compliance with 200.2(B) and to which a main or system bonding jumper is connected shall not be limited as to the number of electronic lighting controlswitches connected.

Change Description: Section 404.2(C) Generally requires a grounded conductor to be installed to the lighting switch location. The purpose is to be able to connect the line-voltage operational circuit of switches with electronic circuitry such as occupancy sensors. The revisions to this section require the insulated grounded conductor to be installed and used with the proper listed electronic devices as described in the new 404.22. As currently written in the 2014 NEC, this rule only requires the grounded conductor to be provided at the lighting switch location, but does not address its use. These revisions clarify the intent of this section.


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Article 392 Cable Trays

Article 400 Flexible Cords and Flexible Cables

Article 404 Switches


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II. Construction Specifications. Part II. Construction Specifications.404.22 Electronic Lighting Control Switches.Electronic lighting control switches shall be listed. Electronic lighting control switches shall not introduce current on the equipment grounding conductor during normal operation. The requirement to not introduce current on the equipment grounding conductor shall take effect on January 1, 2020. Exception: Electronic lighting control switches that introduce current on the equipment grounding conductor shall be permitted for applications covered by 404.2(C), Exception. Electronic lighting control switches that introduce current on the equipment grounding conductor shall be listed and marked for use in replacement or retrofit applications only.

Change Description:This change introduces a requirement for the electronic lighting control switches to be designed in a manner preventing current flow on the equipment grounding conductor, with exceptions for existing installations.


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406.5 Receptacle Mounting.(E) Receptacles in Countertops and SimilarWork Surfaces.Receptacles, unless listed as receptacle assemblies for countertop applications, shall not be installed in a face-up position in countertops or similar work surfaces.Where receptacle assemblies for countertop applications are required to provide ground-fault circuit-interrupter protection for personnel in accordance with 210.8, such assemblies shall be permitted to be listed as GFCI receptacle assemblies for countertop applications.

406.5 Receptacle Mounting.(E) Receptacles in Countertops. Receptacle assemblies for installation in countertop surfaces shall be listed for countertop applications. Where receptacle assemblies for countertop applications are required to provide ground-fault circuit-interrupter protection for personnel in accordance with 210.8, such assemblies shall be permitted to be listed as GFCI receptacle assemblies for countertop applications.(F) Receptacles in Work Surfaces. Receptacle assemblies and GFCI receptacle assemblies listed for work surface or countertop applications shall be permitted to be installed in work surfaces.(G) Receptacle Orientation. Receptacles shall not be installed in a face-up position in or on countertop surfaces or work surfaces unless listed for countertop or work surface applications.

Change Description: This change addresses the need to differentiate suitable receptacle outlet assemblies for installation into kitchen and bathroom counters (subject to liquid spillage) from receptacle outlet assemblies intended for installation into work surfaces such as desks and tables.


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406.12 Tamper-Resistant Receptacles. Tamper-resistant receptacles shall be installed as specified in 406.12(A) through (C).(A) Dwelling Units. In all areas specified in 210.52, all nonlocking-type 125-volt, 15- and 20-ampere receptacles shall be listed tamper-resistant receptacles.(B) Guest Rooms and Guest Suites of Hotels and Motels. All nonlocking-type 125-volt, 15- and 20-ampere receptacles located in guest rooms and guest suites of hotels and motels shall be listed tamper-resistant receptacles.(C) Child Care Facilities. In all child care facilities, all nonlocking-type 125-volt, 15- and20-ampere receptacles shall be listed tamper-resistant receptacles.

406.12 Tamper-Resistant Receptacles. All 15- and 20-ampere, 125- and 250-volt nonlocking-type receptacles in the areas specified in 406.12(1) through (7) shall be listed tamperresistant receptacles.(1) Dwelling units in all areas specified in 210.52 and 550.13(2) Guest rooms and guest suites of hotels and motels(3) Child care facilities(4) Preschools and elementary education facilities(5) Business offices, corridors, waiting rooms and the like in clinics, medical and dental offices and outpatient facilities(6) Subset of assembly occupancies described in 518.2 to include places of waiting transportation, gymnasiums, skating rinks, and auditoriums(7) Dormitories

Change Description:This change expands the requirement for tamper-resistant receptacles to more locations where children might be present. The only applicable location would be a future assembly area for gathering of 100 or more persons.


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I. General.408.3 Support and Arrangement of Busbars and Conductors.(A) Conductors and Busbars on a Switchboard, Switchgear, or Panelboard.(2) Service Switchboards and Switchgear. Barriers shall be placed in all service switchboards and switchgear such that no uninsulated, ungrounded service busbar or service terminal is exposed to inadvertent contact by persons or maintenance equipment while servicing load terminations.

Part I. General.408.3 Support and Arrangement of Busbars and Conductors.(A) Conductors and Busbars on a Switchboard, Switchgear, or Panelboard.(2) Service Panelboards, Switchboards, and Switchgear. Barriers shall be placed in all service panelboards, switchboards, and switchgear such that no uninsulated, ungrounded service busbar or service terminal is exposed to inadvertent contact by persons or maintenance equipment while servicing load terminations.Exception: This requirement shall not apply to service panelboards with provisions for more than one service disconnect within a single enclosure as permitted in 408.36, Exceptions 1, 2, and 3.

Change Description:This change introduces a level of isolation from service-side uninsulated live parts in a manner similar to that afforded in switchboards (reference NEC 408.3(A)(3) and UL Standard for Switchboards, UL 891). Providing such protection is more practical for those panels designed for a single service disconnect, but less practical for panelboards designed for multiple service disconnects. Panelboards designed for a single service disconnect to be constructed such that, with the service disconnect in the off position, no ungrounded uninsulated live part is exposed to inadvertent contact by persons while servicing any load terminals. This proposal is intended to complement the new construction requirement in UL 67 and address the safety concern of access to ungrounded, uninsulated live parts


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II. Installation.409.22 Short-Circuit Current Rating

Part II. Installation.409.22 Short-Circuit Current Rating.(B) Documentation. If an industrial control panel is required to be marked with a short-circuit current rating in accordance with 409.110(4), the available short-circuit current at the industrial control panel and the date the short-circuit current calculation was performed shall be documented and made available to those authorized to inspect the installation.

Change Description:This added subsection will ensure that the industrial control panel is installed within its short-circuit current rating.


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Article 409 Industrial Control Panels

Article 406 Receptacles, Cord Connectors, and Attachement Plugs (Caps)

Article 408 Switchboards, Switchgear, and Panelboards


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III. Construction Specifications.409.110 Marking.(3) Industrial control panels supplied by more than one power source such that more than one disconnecting means is required to disconnect all power within the control panel shall be marked to indicate that more than one disconnecting means is required to de-energize the equipment.

Part III. Construction Specifications.409.110 Marking.(3) Industrial control panels supplied by more than one electrical source where more than one disconnecting means is required to disconnect all circuits 50-volts or more within the control panel shall be marked to indicate that more than one disconnecting means is required to deenergize the equipment. The location of the means necessary to disconnect all circuits 50-volts or more shall be documented and available.

Change Description:This change addresses a gap in worker safety for voltages over 50V. The current wording warns a service technician that multiple sources of power are present, but provides no guidance in how to locate those sources of power. If an emergency arises which necessitates disconnection of power but the technician is unfamiliar with the facility there could be a risk to both personnel and property.


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I. General.422.5 Ground-Fault Circuit-Interrupter (GFCI) Protection.The device providing GFCI protection required in this article shall be readily accessible.

Part I. General.422.5 Ground-Fault Circuit-Interrupter (GFCI) Protection for Personnel.(A) General. Appliances identified in 422.5(A)(1) through (5) rated 250 volts or less and60 amperes or less, single- or 3-phase, shall be provided with GFCI protection for personnel. Multiple GFCI protective devices shall be permitted but shall not be required.(1) Automotive vacuum machines provided for public use(2) Drinking water coolers(3) High-pressure spray washing machines — cord-and-plugconnected(4) Tire inflation machines provided for public use(5) Vending machines(B) Type. The GFCI shall be readily accessible, listed, and located in one or more of the following locations:(1) Within the branch circuit overcurrent device(2) A device or outlet within the supply circuit(3) An integral part of the attachment plug(4) Within the supply cord not more than 300 mm (12 in.) from the attachment plug(5) Factory installed within the appliance

Change Description: This revision incorporates concepts to collect GFCI requirements from 210.8 and throughout Article 422 related to personnel hazards from specific equipment (contact with equipment with excessive leakage current) and provide those requirements in a single location. Collection of GFCI requirements will increase clarity and usability. GFCI protection for general purpose outlets related to locations and environmental factors, not specific equipment, remain grouped in 210.8.

Impact(s):No negative impact. 2

III. Disconnecting Means.422.31 Disconnection of Permanently Connected Appliances.(A) Rated at Not over 300 Volt-Amperes or 1∕8 Horsepower. For permanently connected appliances rated at not over 300 volt-amperes or 1∕8 hp, the branch-circuit overcurrent device shall be permitted to serve as the disconnecting means.

(C) Motor-Operated Appliances Rated over 1∕8 Horsepower.The disconnecting means shall comply with 430.109 and 430.110. For permanently connected motoroperated appliances with motors rated over 1∕8 hp, the disconnecting means shall meet 422.31(C)(1) or (2).(1) The branch-circuit switch or circuit breaker shall be permitted to serve as the disconnecting means where the switch or circuit breaker is within sight from theappliance.(2) The disconnecting means shall be installed within sight of the appliance.

Part III. Disconnecting Means.422.31 Disconnection of Permanently Connected Appliances.(A) Rated at Not over 300 Volt-Amperes or 1∕8 Horsepower. For permanently connected appliances rated at not over 300 volt-amperes or 1∕8 hp, the branch-circuit overcurrent device shall be permitted to serve as the disconnecting means where the switch or circuit breaker is within sight from the appliance or is lockable in accordance with 110.25.

(C) Motor-Operated Appliances Rated over 1∕8 Horsepower.The disconnecting means shall comply with 430.109 and 430.110. For permanently connected motor-operated appliances with motors rated over 1∕8 hp, the disconnecting means shall be within sight from the appliance or be capable of being locked in the open position in compliance with 110.25.

Change Description:The disconnecting means needs to be within sight from the appliance or be lockable. The requirement was revised for consistency with 422.31(B) as the potential risk of electric shock would be the same for both circumstances.

Clarified the requirement by stating a general requirement followed by the exception.


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Part I. General.425.1 Scope.This article covers fixed industrial process heating employing electric resistance or electrode heating technology. For the purpose of this article, heating equipment shall include boilers, electrode boilers, duct heaters, strip heaters, immersion heaters, process air heaters, or other approved fixed electric equipment used for industrial process heating. This article shall not apply to heating and room air conditioning for personnel spaces covered by Article 424, fixed heating equipment for pipelines and vessels covered by Article 427, induction and dielectric heating equipment covered by Article 665,and industrial furnaces incorporating silicon carbide, molybdenum, or graphite process heating elements.

Change Description:New article covering fixed resistance and electrode industrial process heating equipment added. Note, only the Scope Section copied here.


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Article 422 Appliances

Article 425 Fixed Resistance and Electrode Industrial Process Heating Equipment


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IV. Impedance Heating.427.27 Voltage Limitations. Unless protected by groundfault circuit-interrupter protection for personnel, the secondary winding of the isolation transformer connected to the pipeline or vessel being heated shall not have an output voltage greater than 30 volts ac. Where ground-fault circuit-interrupter protection for personnel is provided, the voltage shall be permitted to be greater than 30 but not more than 80 volts.Exception: In industrial establishments, the isolation transformer connected to the pipeline or vessel being heated shall be permitted to have an output voltage not greater than 132 volts ac to ground where all of the following conditions apply:(1) Conditions of maintenance and supervision ensure thatonly qualified persons service the installed systems.(2) Ground-fault protection of equipment is provided.(3) The pipeline or vessel being heated is completely enclosed in a grounded metal enclosure.(4) The transformer secondary connections to the pipeline or vessel being heated are completely enclosed in a grounded metal mesh or metal enclosure.

Part IV. Impedance Heating.427.27 Voltage Limitations. The secondary winding of the isolation transformer connected to the pipeline or vessel being heated shall not have an output voltage greater than 30 volts ac.Exception No. 1: In industrial establishments, the isolation transformer connected to the pipeline or vessel being heated shall be permitted to have an output voltage greater than 30 but not more than 80 volts ac to ground where all of the following conditions apply:(1) Conditions of guarding, maintenance, and supervision ensure that only qualified persons have access to the installed systems.(2) Ground-fault protection of equipment is provided.

Change Description:The GFCI for personnel exception is being replaced by a combination of GFPE, guarding, and access control for operating voltages between 30 and 80 volts. Guarding has also been included in the existing exception for clarification. Ground fault protection for personnel (5 mA level) required for impedance heating operating at >30 V but ≤ 80V under previous edition of the Code could not function properly due to the normally occuring leakage current in such an installation.


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IV. Motor Branch-Circuit Short-Circuit and Ground-Fault Protection.430.53 Several Motors or Loads on One Branch Circuit.(D) Single Motor Taps

Part IV. Motor Branch-Circuit Short-Circuit and Ground-Fault Protection.430.53 Several Motors or Loads on One Branch Circuit.(D) Single Motor Taps.(4) Conductors from the point of the tap from the branch circuit to a listed manual motor controller additionally marked “Suitable for Tap Conductor Protection in Group Installations,” or to a branch-circuit protective device, shall be permitted to have an ampacity not less than onethird that of the branch-circuit conductors. The conductors from the controller to the motor shall have an ampacity in accordance with 430.22. The conductors from the point of the tap to the controller(s) shall (1) be suitably protected from physical damage and enclosed either by an enclosed controller or by a raceway and be not more than 7.5 m (25 ft) long or (2) have an ampacity not less than that of the branch-circuit conductors.

Change Description:The new subsection allows 25’ taps with the same conditions as is allowed in other areas of the NEC.


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VIII. Motor Control Centers. Part VIII. Motor Control Centers.430.99 Available Fault Current. The available short circuit current at the motor control center and the date the short circuit current calculation was performed shall be documented and made available to those authorized to inspect the installation.

Change Description:This change will ensure that the MCC is installed within its short-circuit current rating.


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X. Adjustable-Speed Drive Systems.430.130 Branch-Circuit Short-Circuit and Ground-Fault Protection for Single Motor Circuits Containing Power Conversion Equipment.(A) Circuits Containing Power Conversion Equipment.

Part X. Adjustable-Speed Drive Systems.430.130 Branch-Circuit Short-Circuit and Ground-Fault Protection for Single Motor Circuits Containing Power Conversion Equipment.(A) Circuits Containing Power Conversion Equipment.(4) Where an instantaneous trip circuit breaker or semiconductor fuses are permitted in accordance with the drive manufacturer’s instructions for use as the branch-circuit short-circuit and ground-fault protective device for listed power conversion equipment, they shall be provided as an integral part of a single listed assembly incorporating both the protective device and power conversion equipment.

Change Description:The inclusion of the short circuit ground fault device within the power conversion equipment from the Manufacturer will assure the proper devices are installed.


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I. General. Part I General.440.9 Grounding and Bonding. Where multimotor and combination-load equipment is installed outdoors on a roof, an equipment grounding conductor of the wire type shall be installed in outdoor portions of metallic raceway systemsthat use non-threaded fittings.

Change Description:Non-threaded conduit systems on rooftops supplying HVACR equipment are subject to movement and damage that results in separation of non threaded conduit or tubing resulting in loss of equipment grounding unless a wire type equipment ground is provided.


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Article 427 Fixed Electric Heating Equipment for Piplines and Vessels

Article 430 Motors, Motor Circuits, and Controllers

Article 440 Air Conditioning and Refrigerating Equipment


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I. General. 440.10 Short-Circuit Current Rating.(A) Installation. Motor controllers of multimotor and combination-load equipment shall not be installed where the available short-circuit current exceeds its short-circuit current rating as marked in accordance with 440.4(B).(B) Documentation. When motor controllers or industrial control panels of multimotor and combination load equipment are required to be marked with a short circuit current rating, the available short circuit current and the date the short circuit current calculation was performed shall be documented and made available to those authorized to inspect the installation.

Change Description:Section 440.4(B) requires that the equipment short-circuit current rating be marked on certain HVAC equipment. This new section specifically requires that the marked HVAC equipment not be installed where the available short-circuit current exceeds the marked short-circuit current rating. This requirement is similar to 670.5 (industrial machinery) and 409.22 (industrial control panels).


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445.11 Marking. Each generator shall be provided with anameplate giving the manufacturer’s name, the rated frequency, the number of phases if of ac, the rating in kilowatts or kilovolt-amperes, the normal volts and amperes corresponding to the rating, the rated revolutions per minute, and the rated ambient temperature or rated temperature rise.Nameplates for all stationary generators and portable generators rated more than 15 kW shall also give the power factor, the subtransient and transient impedances, the insulation system class, and the time rating.Marking shall be provided by the manufacturer to indicate whether or not the generator neutral is bonded to the generator frame. Where the bonding of a generator is modified in the field, additional marking shall be required to indicate whether the generator neutral is bonded to the generator frame.

445.11 Marking. Each generator shall be provided with a nameplate giving the manufacturer’s name, the rated frequency, the number of phases if ac, the rating in kilowatts or kilovolt-amperes, the power factor, the normal volts and amperes corresponding to the rating, the rated ambient temperature, and the rated temperature rise.Nameplates or manufacturer's instructions shall provide the following information for all stationary generators and portable generators rated more than 15 kW:(1) Subtransient, transient, synchronous, and zero sequence reactances(2) Power rating category(3) Insulation system class(4) Indication if the generator is protected against overload by inherent design, an overcurrent protective relay, circuit breaker, or fuse(5) Maximum short-circuit current for inverter-based generators, in lieu of the synchronous, subtransient, and transient reactances. Marking shall be provided by the manufacturer to indicate whether or not the generator neutral is bonded to its frame. Where the bonding is modified in the field, additional marking shall be required to indicate whether the neutral is bonded to the frame.

Change Description:The term “impedances” has been changed to “reactances” to provide the correct industry wording. The generator is now required to be marked with the maximum short-circuit current to assist in verifying application of proper overcurrent protection in the field. Newer generators are being manufactured with inverter based designs. Determining fault current ratings for these generators is difficult and is best marked on the generator by the manufacturer. Marking would also be now required to indicate whether the generator is inherently designed to prevent overload or whether an overcurrent protective relay is provided. This information will assist in determining compliance with 445.13.


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445.13 Ampacity of Conductors. 445.13 Ampacity of Conductors.(B) Overcurrent Protection Provided. Where the generator set is equipped with a listed overcurrent protective device or a combination of a current transformer and overcurrent relay, conductors shall be permitted to be tapped from the load side of the protected terminals in accordance with 240.21(B).Tapped conductors shall not be permitted for portable generators rated 15 kW or less where field wiring connection terminals are not accessible.

Change Description:445.13(B) has been added to clarify that feeder tap rules can be used if the generator is equipped with an overcurrent relay or other over overcurrent device.

Impact(s):Nonegative impact.

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445.14 Protection of Live Parts. Live parts of generators operated at more than 50 volts ac to ground shall not be exposed to accidental contact where accessible to unqualified persons.

445.14 Protection of Live Parts. Live parts of generators operated at more than 50 volts ac or 60 volts dc to ground shall not be exposed to accidental contact where accessible to unqualified persons.

Change Description:Expanded requirement to address DC live parts on the generator requiring protection from accidental contact.


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445.18 Disconnecting Means Required for Generators.Generators shall be equipped with a disconnect(s), lockable in the open position by means of which the generator and all protective devices and control apparatus are able to bedisconnected entirely from the circuits supplied by the generator except where the following conditions apply:(1) Portable generators are cord- and plug-connected, or(2) Both of the following conditions apply:a. The driving means for the generator can be readily shut down, is rendered incapable of restarting, and is lockable in the OFF position in accordance with 110.25.b. The generator is not arranged to operate in parallel with another generator or other source of voltage.

445.18 Disconnecting Means and Shutdown of Prime Mover.(B) Shutdown of Prime Mover. Generators shall have provisions to shut down the prime mover. The means of shutdown shall comply with all of the following:(1) Be equipped with provisions to disable all prime mover start control circuits to render the prime mover incapable of starting (2) Initiate a shutdown mechanism that requires a mechanical reset. The provisions to shut down the prime mover shall be permitted to satisfy the requirements of 445.18(A) where it is capable of being locked in the open position in accordance with 110.25.Generators with greater than 15 kW rating shall be provided with an additional requirement to shut down the prime mover. This additional shutdown means shall be located outside the equipment room or generator enclosure and shall also meet the requirements of 445.18(B)(1) and (B)(2).

Change Description:This revision clarifies that the general provisions to shut down the prime mover may satisfy the requirements in 445.18(A) under the given conditions. The additional means located outside the equipment room is modified to meet the requirements of 445.18(B)(1) and (B)(2).

Not all generator enclosures are weatherproof so this portion of the requirement has been removed.


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(continued) (continued)(C) Generators Installed in Parallel. Where a generator is installed in parallel with other generators, the provisions of 445.18(A) shall be capable of isolating the generator output terminals from the paralleling equipment. The disconnecting means shall not be required to be located at the generator.

Change Description:The revised text in 445.18(C) clarifies that where generators are installed in parallel it is not necessary to provide a disconnecting means at each generator and at the paralleling equipment.


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Article 445 Generators


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445.20 Ground-Fault Circuit-Interrupter Protection for Receptacles on 15-kW or Smaller Portable GeneratorsAll 125-volt, single-phase, 15- and 20-ampere receptacle outlets that are a part of a 15-kW or smaller portable generator either shall have ground-fault circuit-interrupter protection for personnel integral to the generator or receptacle or shall not be available for use when the 125/250-volt locking-type receptacle is in use. If the generator does not have a 125/250-volt locking-type receptacle, this requirement shall not apply.

445.20 Ground-Fault Circuit-Interrupter Protection for Receptacles on 15-kW or Smaller Portable GeneratorsReceptacle outlets that are a part of a 15-kW or smaller portable generator shall have listed ground-fault circuit-interrupter protection (GFCI) for personnel integral to the generator or receptacle as indicated in either (A) or (B):(A) Unbonded (Floating Neutral) Generators. Unbonded generators with both 125-volt and 125/250-volt receptacle outlets shall have listed GFCI protection for personnel integral to the generator or receptacle on all 125-volt, 15- and 20-ampere receptacle outlets.Exception: GFCI protection shall not be required where the 125-volt receptacle outlets(s) is interlocked such that it is not available for use when any 125/250-volt receptacle(s) is in use.(B) Bonded Neutral Generators. Bonded generators shall be provided with GFCI protection on all 125-volt, 15- and 20-ampere receptacle outlets.Informational Note: Refer to 590.6(A)(3) for GFCI requirements for 15-kW or smaller portable generators used for temporary electric power and lighting.Exception to (A) and (B): If the generator was manufactured or remanufactured prior to January 1, 2015, listed cord sets or devices incorporating listed GFCI protection for personnel identified for portable use shall be permitted.

Change Description:The change addresses differences between requirements for Ground Fault Circuit Interrupters for bonded and unbonded generators.


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450.5 Grounding Autotransformers.Exception: An auto transformer with a wye configuration on its line side and a zigzag configuration on its load side that does not permit neutral or ground-fault current to return over the line connection shall be permitted on the load side of a system grounding connection. This exception shall not apply to a connection made from a high-resistance grounded system applied in accordance with 250.36.

Part I. General Provisions.450.5 Grounding Autotransformers.

Change Description:Deleted exception added in 2014 to the section changes introduced in 2005 edition of the NEC. Based on further review of the exception, it was determined that the substantiation provided for 2014 change lacked merits.


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480.7 Insulation of Batteries Not Over 250 Volts. This section shall apply to storage batteries having cells connected so as to operate at a nominal battery voltage of not over 250 volts.(A) Vented Lead-Acid Batteries. Cells and multi-cell batteries with covers sealed to containers of nonconductive, heat-resistant material shall not require additional insulatingsupport.(B) Vented Alkaline-Type Batteries. Cells with covers sealed to containers of nonconductive, heat-resistant material shall require no additional insulation support. Cells in containers of conductive material shall be installed in trays of non-conductive material with not more than 20 cells (24 volts, nominal) in the series circuit in any one tray.(C) Rubber Containers. Cells in rubber or composition containers shall require no additional insulating support where the total nominal voltage of all cells in series does not exceed 150 volts. Where the total voltage exceeds 150 volts, batteries shall be sectionalized into groups of 150 volts or less, and each group shall have the individual cells installed in trays or on racks (D) Sealed Cells or Batteries. Sealed cells and multi-compartment sealed batteries constructed of nonconductive, heat-resistant material shall not require additional insulating support. Batteries constructed of a conducting container shall have insulating support if a voltage is present between the container and ground.

480.8 Insulation of Batteries. Batteries constructed of an electrically conductive container shall have insulating support if a voltage is present between the container and ground.

Change Description:This change eliminates discussion of design and technologies which are obsolete and no longer exist.


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480.8 Racks and Trays. Racks and trays shall comply with 480.8(A) and (B).(A) Racks. Racks, as required in this article, are rigid frames designed to support cells or trays. They shall be substantial and be made of one of the following:(1) Metal, treated so as to be resistant to deteriorating action by the electrolyte and provided with nonconducting members directly supporting the cells or with continuousinsulating material other than paint on conducting members (2) Other construction such as fiberglass or other suitable nonconductive materials(B) Trays. Trays are frames, such as crates or shallow boxes usually of wood or other nonconductive material, constructed or treated so as to be resistant to deteriorating action by the electrolyte.(C) Accessibility. The terminals of all cells or multi-cell units shall be readily accessible for readings, inspection, and cleaning where required by the equipment design. One side of transparent battery containers shall be readily accessible for inspection of the internal components.

480.9 Battery Support Systems. For battery chemistries with corrosive electrolyte, the structure that supports the battery shall be resistant to deteriorating action by the electrolyte. Metallic structures shall be provided with nonconducting support members for the cells, or shall be constructed with a continuous insulating material. Paint alone shall not be considered as an insulating material. The terminals of all cells or multi-cell units shall be readily accessible for readings, inspection, and cleaning where required by the equipment design. One side of transparentbattery containers shall be readily accessible for inspection of the internal components.

Change Description:The text is rewritten to use performance-based language versus prescriptive language.


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Article 450 Transformers and Transformer Vaults (Including Secondary Ties)

Article 480 Storage Batteries


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500.5 Classifications of Locations.(A) Classifications of Locations.Locations shall be classified depending on the properties of the flammable gas, flammable liquid–produced vapor, combustible liquid–produced vapors, combustible dusts, or fibers/flyings that may be present, and the likelihood that a flammable or combustible concentration or quantity is present. Each room, section, or area shall be considered individually in determining its classification. Where pyrophoric materials are the only materials used or handled, these locations are outside the scope of this article.

Rooms and areas containing ammonia refrigeration systems that are equipped with adequate mechanical ventilation may be classified as “unclassified” locations.

500.5 Classifications of Locations.(A) General. Locations shall be classified depending on the properties of the flammable gas, flammable liquid–produced vapor, combustible liquid–produced vapors, combustible dusts, or fibers/flyings that could be present, and the likelihood that a flammable or combustible concentration or quantity is present. Each room, section, or area shall be considered individually in determining its classification. Where pyrophoric materials are the only materials used or handled, these locations are outside the scope of this article.

Refrigerant machinery rooms that contain ammonia refrigeration systems and are equipped with adequate mechanical ventilation that operates continuously or is initiated by a detection system at a concentration not exceeding 150 ppm shall be permitted to be classified as “unclassified” locations.

Change Description:The revision clarifies that areas containing ammonia refrigeration may be classified as “unclassified” locations based on the use of gas detection and adequate ventilation, in order to harmonize with the American Society of Heating, Refrigerating and Air-Conditioning Engineers standards.


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500.8 Equipment.(E) Threading(2) Equipment Provided with Threaded Entries for Metric-Threaded Conduit or Fittings. For equipment with metric-threaded entries, listed conduit fittings or listed cable fittings shall be used. Such entries shall be identified as being metric, or listed adapters to permit connection to conduit or NPT-threaded fittings shall be provided with the equipment and shall be used for connection to conduit or NPT-threaded fittings.Metric-threaded entries into explosionproof equipment shall have a class of fit of at least 6g/6H and shall be made up with at least five threads fully engaged for Group C andGroup D, and at least eight threads fully engaged for Group A and Group B.

500.8 Equipment.(E) Threading(2) Equipment Provided with Threaded Entries for Metric- Threaded Fittings. For equipment with metric-threaded entries, listed conduit fittings or listed cable fittings shall be used. Such entries shall be identified as being metric, or listed adapters to permit connection to conduit or NPT-threaded fittings shall be provided with the equipment and shall be used for con-nection to conduit or NPT-threaded fittings.Metric-threaded fittings installed into explosionproof equipment shall have a class of fit of at least 6g/6H and shall be at least five threads fully engaged.

Change Description:Table 500.8(D)(2) and paragraph referencing the table is outdated by several code cycles as fixed limits do not apply anymore. The comparable table for gases and vapors has been removed now for several cycles.Section 500.9(E)(2) was not consistent with the equipment standards used to assess flame-proof equipment. The current standards require at least 5 full metric threads, regardless of gas group. Testing and field experience has demonstrated that 5 thread engagement is sufficient for all groups.


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(continued)(F) Optical Fiber Cables. Where an optical fiber cable contains conductors that are capable of carrying current (composite optical fiber cable), the optical fiber cable shallbe installed in accordance with the requirements of Article 500, 501, 502, or 503, as applicable.

(continued)(F) Optical Fiber Cables. An optical fiber cable, with or without current-carrying conductors (composite optical fiber cable), shall be installed to address the associated fire hazard and sealed to address the associated explosion hazard in accordance with the requirements of Article 500, 501, 502, or 503, as applicable.

Change Description:The revised text requires the cable to be sealed for explosion hazard and address the fire hazards, regardless if the cable contains current carrying conductors or not.


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II. Wiring.501.10 Wiring Methods.(B) Class I, Division 2.(1) General. In Class I, Division 2 locations, the following wiring methods shall be permitted:(1) All wiring methods permitted in 501.10(A).

Part II. Wiring.501.10 Wiring Methods.(B) Class I, Division 2.(1) General. In Class I, Division 2 locations, all wiring meth‐ ods permitted in 501.10(A) and the following wiring methods shall be permitted:(1) Rigid metal conduit (RMC) and intermediate metal conduit (IMC) with listed threadless fittings.

(8) Cablebus

Change Description:Threadless fittings for RMC and IMC provide an appropriate level of safety for a Class I, Division 2 location. Sealing with threaded connections at the Class I, Division 2 boundary is already addressed by 501.15(B)(2).

Cablebus per Article 370 provides a level of safety equivalent to the other wiring methods permitted for the identified locations.


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II. Wiring.501.15 Sealing and Drainage.(A) Conduit Seals, Class I, Division 1.(1) Entering Enclosures(2) The entry is metric designator 53 (trade size 2) or larger, and the enclosure contains terminals, splices, or taps.Factory-sealed enclosures shall not be considered to serve as a seal for another adjacent explosionproof enclosure that is required to have a conduit seal. Conduit seals shall be installed within 450 mm (18 in.) from the enclosure. Only explosionproof unions, couplings, reducers, elbows, capped elbows, and conduit bodies similar to L, T, and Cross types that are not larger than the trade size of the conduit shall be permitted between the sealing fitting and the explosionproof enclosure

Part II. Wiring501.15 Sealing and Drainage.(A) Conduit Seals, Class I, Division 1.(1) Entering Enclosures.(2) The entry is metric designator 53 (trade size 2) or larger,and the enclosure contains terminals, splices, or taps. ….Conduit seals shall be installed within 450 mm (18 in.) from the enclosure or as required by the enclosure marking. Only explosionproof unions, couplings, reducers, elbows, and capped elbows that are not larger than the trade size of the conduit shall be permitted between the sealing fitting and the explosionproof enclosure.

Change Description:This revision correlates with the revision to 501.15(D)(1). Some explosionproof enclosures must have the seal located less than 18 in. away and are so marked. It was not the intent of this section to override those restrictions. Conduit bodies were removed from the list in (2) because they should not be allowed in this application due to the increased volume in the raceway system.


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Article 500 Hazardous (Classifed) Locations, Classes, I, II and III Divisions 1 and 2

Article 501 Class I Locations


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(continued)501.15 Sealing and Drainage (continued)(D) Cable Seals, Class I, Division 1.(1) At Terminations.

(continued)501.15 Sealing and Drainage.(D) Cable Seals, Class I, Division 1.(1) At Terminations.Seals for cables entering enclosures shall be installed within 450 mm (18 in.) of the enclosure or as required by the enclo‐ sure marking. Only explosionproof unions, couplings, reduc‐ ers, elbows, and capped elbows that are not larger than the trade size of the enclosure entry shall be permitted between the sealing fitting and the enclosure.

Change Description:The revised text addresses the need for other types of explosionproof fittings that can be safely utilized between a cable seal and an enclosure. Some explosionproof enclosures must have the seal located less than 18 in. away and are so marked.


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III. Equipment.501.105 Meters, Instruments, and Relays.(B) Class I, Division 2. In Class I, Division 2 locations, meters, instruments, and relays shall comply with 501.105(B)(1) through (B)(6).(4) General-Purpose Assemblies. Where an assembly is made up of components for which general-purpose enclosures are acceptable as provided in 501.105(B)(1),(B)(2), and (B)(3), a single general-purpose enclosure shall be acceptable for the assembly. Where such an assembly includes any of the equipment described in 501.105(B)(2),the maximum obtainable surface temperature of any component of the assembly shall be clearly and permanently indicated on the outside of the enclosure. Alternatively,equipment shall be permitted to be marked to indicate the temperature class for which it is suitable, using the temperature class (T Code) of Table 500.8(C).

Part III. Equipment.501.105 Meters, Instruments, and Relays(B) Class I, Division 2. In Class I, Division 2 locations, meters, instruments, and relays shall comply with 501.105(B)(2) through (B)(6).(1) General-Purpose Assemblies. Where an assembly is made up of components for which general-purpose enclosures are acceptable as provided in 501.105(B)(1), (B)(2), and (B)(3), a single general-purpose enclosure shall be acceptable for the assembly. Where such an assembly includes any of the equipment described in 501.105(B)(1), 501.105(B)(2), and 501.105(B)(3), the maximum obtainable surface temperature of any component of the assembly that exceeds 100°C shall be clearly and permanently indicated on the outside of the enclosure. Alternatively, equipment shall be permitted to be marked to indicate the temperature class for which it is suitable, using the temperature class (T Code) of Table 500.8(C).

Change Description:The requirement for marking the maximum attainable surface temperature of any component should also apply to enclosures that contain switches, circuit breakers, and make-and-break contacts or where transformer windings, impedance coils, solenoids, and other windings are con-tained within the enclosure. The section was further revised to clarify when the 80% rule of the AIT applies and when the Temperature Classification can be used. Also added was the exclusion to the marking requirement for surface temperatures that are 100°C or less.


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(continued)(B) Class I, Division 2. (continued)(6) Connections. To facilitate replacements, process control instruments shall be permitted to be connected through flexible cord, attachment plug, and receptacle, provided all of the following conditions apply:(1) A switch complying with 501.105(B)(1) is provided so that the attachment plug is not depended on to interrupt current.Exception: The switch is not required if the circuit is non-incendive field wiring.(2) The current does not exceed 3 amperes at 120 volts,nominal

(continued)(B) Class I, Division 2 (continued)(6) Connections. To facilitate replacements, process control instruments shall be permitted to be connected through flexible cord by means of attachment plug and receptacle, provided that all of the following conditions apply:(1) The attachment plug and receptacle are listed for use in Class I, Division 2 locations and for use with flexible cords and shall be of the locking and grounding type.Exception: A Class I, Division 2 listing shall not be required if the circuit is nonincendive field wiring.(2) Unless the attachment plug and receptacle are inter‐ locked mechanically or electrically, or otherwise designed so that they cannot be separated when the contacts are energized and the contacts cannot be energized when the plug and socket outlet are separated, a switch complying with 501.105(B)(2) is provided so that the attachment plug or receptacle is not depended on to interrupt current.

(5) The circuit has a maximum current of 3 amps.

Change Description:The requirements for flexible cords are clarified.


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501.125 Motors and Generators.(A) Class I, Division 1.(4) Of a type designed to be submerged in a liquid that is flammable only when vapor-ized and mixed with air, or in a gas or vapor at a pressure greater than atmos-pheric and that is flammable only when mixed with air; and the machine isso arranged to prevent energizing it until it has been purged with the liquid or gas to exclude air, and also arranged to auto-matically de-energize the equipment when the supply of liquid or gas or vapor fails or the pressure is reduced to atmospheric

501.125 Motors and Generators.(A) Class I, Division 1.(4) For machines that are for use only in industrial establishments with restricted public access, where the conditions of maintenance and supervision ensure that only qualified persons service the installation, the machine is permitted to be of a type designed to be submerged in a liquid that is flammable only when vapor-ized and mixed with air, or in a gas or vapor at a pressure greater than atmospheric and that is flammable only when mixed with air; and the machine is so arranged to prevent energizing it until it has been purged with the liquid or gas to exclude air, and also arranged to automatically de-energize the equipment when the supply of liquid or gas or vapor fails or the pressure is reduced to atmospheric

Change Description: Submersible machines and those protected by a flammable atmosphere maintained above the UFL require operation and maintenance by trained persons, and therefore should only be used in industrial establishments with restricted public access.


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501.125 Motors and Generators. (B) Class I, Division 2.

501.125 Motors and Generators(B) Class I, Division 2.(5) A sliding contact shaft bonding device used for the purpose of maintaining the rotor at ground potential, shall be permitted where the potential discharge energy is determined to be nonincendive for the application. The shaft bonding device shall be permitted to be installed on the inside or the outside of the motor.

Change Description:The new item 5) permits a shaft bonding device to be usedon inverter-fed motors for the purpose of maintaining the rotor at ground potential to reduce bearing failure due to arcing. Informational note no. 5 was added to provide guidance on application of shaft bonding devices.


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II. Wiring.502.10 Wiring Methods.(A) Class II, Division 1..(1) General.

Part II. Wiring.502.10 Wiring Methods.(A) Class II, Division 1.(1) General.(5) In industrial establishments with restricted public access, where the conditions of maintenance and supervision ensure that only qualified persons service the installation, listed Type ITC-HL cable with a gas/vaportight continuous corrugated metallic sheath and an overall jacket of suitable polymeric material, and terminated with fittings listed for the application, and installed in accordancewith the provisions of Article 727.

Change Description:Based on the UL testing and listing, ITC-HL cable provides an appropriate level of safety for a Class II, Division 1 location and was added to the acceptable wiring methods in theCode.


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502.10 Wiring Methods .(continued)(B) Class II, Division 2.(1) General.

502.10 Wiring Methods .(continued)(B) Class II, Division 2.(1) General.(6) Type MC, MI, MV, TC, or TC-ER cable installed in ladder, ventilated trough, or ventilated channel cable trays in a single layer, with a space not less than the larger cablediameter between the two adjacent cables, shall be the wiring method employed.(9) Cablebus.

Change Description:Based on the UL testing and listing, MV and TC-ER provide an appropriate level of safety for a Class II, Division 2 location. Cablebus per Article 370 provides a level of safety equivalent to the other wiring methods permitted for the identified locations.


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III. Equipment.502.125 Motors and Generators.(B) Class II, Division 2.

Part III. Equipment.502.125 Motors and Generators.(B) Class II, Division 2.(4) Machines with sealed bearings, bearing isolators, and seals

Change Description:Motor manufacturers are changing bearing designs because the standard bearings being used on IEEE 841 motors present an "external opening". As a result, the standard available motors aren't being sold for use in areas classified for dust, even though they meet the temperature code and are TEFC design. These IEEE 841 motors have bearings with seals, or bearing isolators, and are not an "external opening" that would credibly allow dust inside the motor in any significant way such that the motor internals would be an ignition source.


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II. Wiring.503.10 Wiring Method.(A) Class III, Division 1.(1) General.(4) Type MC, MI, TC, or TC-ER cable installed in ladder, ventilated trough, or ventilated channel cable trays in a single layer, with a space not less than the larger cablediameter between the two adjacent cables, shall be the wiring method employed. The cable shall be terminated with listed fittings.

Part II. Wiring.503.10 Wiring Methods.(A) Class III, Division 1.(1) General.(4) Type MC, MI, MV, TC, or TC-ER cable installed in ladder, ventilated trough, or ventilated channel cable trays in a single layer, with a space not less than the larger cablediameter between the two adjacent cables, shall be the wiring method employed. The cable shall be terminated with listed fittings.(5) Cablebus.

Change Description:Based on the UL testing and listing, MV provides an appropriate level of safety for a Class III, Division 1 location. Cablebus per Article 370 provides a level of safety equivalent to the other wiring methods permitted for the identified locations.


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505.5 Classifications of Locations.(A) Classification of Locations.

505.5 Classifications of Locations.(A) General.Refrigerant machinery rooms that contain ammonia refrigeration systems and are equipped with adequate mechanical ventilation that operates continuously or is initiated by a detection system at a concentration not exceeding 150 ppm shall be permitted to be classified as “unclassified” locations.

Change Description:The revision clarifies that areas containing ammonia refrigeration may be classified as “unclassified” locations based on the use of gas detection and adequate ventilation, in order to harmonize with the ASHRAE standard.

Impact(s):No negative imapct.

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505.7 Special Precaution.(F) Available Short-Circuit Current for Type of Protection “e”.The available short-circuit current for electrical equipment using type of protection “e” for the field wiring connections in Zone 1 locations shall be limited to 10,000 rms symmetrical amperes to reduce the likelihood of ignition of a flammable atmosphere by an arc during a short-circuit event.

505.7 Special Precaution.(F) Available Short-Circuit Current for Type of Protection “e”.Unless listed and marked for connection to circuits with higher available short-circuit current, the available short-circuit current for electrical equipment using type of protection “e” for the field wiring connections in Zone 1 locations shall be limited to 10,000 rms symmetrical amperes to reduce the likelihood of ignition of a flammable atmosphere by an arc during a short-circuit event.

Change Description:Where listed and marked, equipment evaluated for a higher available short circuit current could be applied in a hazardous (classified) location.


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Article 503 Class III Locations

Article 505 Zone 0, 1, and 2 Locations

Article 502 Class II Locations


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505.15 Wiring Methods.(A) Class I, Zone 0. In Class I, Zone 0 locations, onlyintrinsically safe wiring methods in accordance with Article 504 shall be permitted.

505.15 Wiring Methods.(A) Class I, Zone 0. In Class I, Zone 0 locations, equipment protected by intrinsic safety “ia” and equipment protected by encapsulation “ma” shall be connected using intrinsically safe “ia” circuits with wiring methods in accordance with Article 504.

Change Description:The current text permits any wiring method as referenced to Article 504.20 wiring methods, which thus permits any unclassified wiring method, which would permit the connection of “ma” equipment to any wiring method, as well as any equipment suitable for Zone 1 and Zone 2 to use any wiring method, as referenced by 501.15(B)(1)(a) and 501.15(C)(1)(a). The new text correctly limits wiring methods for Zone 0 to intrinsically safe circuits only.


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505.15 Wiring Methods. (continued)(C) Class I, Zone 2.(1) General.

505.15 Wiring Methods.(continued)(C) Class I, Zone 2.(1) General.(9) Cablebus.

Change Description:Cablebus per Article 370 provides a level of safety equivalent to the other wiring methods permitted for the identified locations.


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506.15 Wiring Methods.(C) Zone 22.

506.15 Wiring Methods.(C) Zone 22.(10) Cablebus.

Change Description:Cablebus per Article 370 provides a level of safety equivalent to the other wiring methods permitted for the identified locations.


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511.3 Area Classification, General.(C) Major Repair Garages. Where flammable liquidshaving a flash point below 38°C (100°F) such as gas-oline, or gaseous fuels such as natural gas, hydrogen, or LPG, will not be dispensed, but repair activities that involve the transfer of such fluids or gases are performed, the classification rules in (1), (2), and (3) shall apply. (1) Floor Areas.(a) Ventilation Provided. The floor area shall be unclassified where there is mechanical ventilation providing a minimum of four air changes per hour or 0.3 m3/min/m2 (1 cfm/ft2) of exchanged air for each square meter (foot) of floor area. Ventilation shall provide for air exchange across the entire floor area, and exhaust air shall be taken at a point within 0.3 m (12 in.) of the floor.(b) Ventilation Not Provided. The entire floor area up to a level of 450 mm (18 in.) above the floor shall be classified as Class I, Division 2 if the ventilation does not comply with 511.3(C)(1)(a).(2) Ceiling Areas. Where lighter-than-air gaseous fueled vehicles, such as vehicles fueled by natural gas or hydrogen, are repaired or stored, the area within 450 mm (18 in.) of the ceiling shall be con-sidered for classification in accordance with (a) and (b). (a) Ventilation Provided. The ceiling area shall be unclassi-fied where ventilation is provided, from a point not more than 450 mm (18 in.) from the highest point in the ceiling, to exhaust the ceiling area at a rate of not less than 0.3 m3/min/m2 (1 cfm/ft2) of ceiling area at all times that the building is occupied or when vehicles using lighter-than- air gaseous fuels are parked below this area.

511.3 Area Classification, General.(C) Repair Garages, Major and Minor. Where vehicles using Class I liquids or heavier-than-air gaseous fuels (such as LPG) are repaired, hazardous area classification guidance is found in Table 511.3(C).

Change Description: In order to align with NFPA 30A-2015, 511.3(C) is replaced in its entirety with a new 511.3(C) covering both major and minor repair garages where heavier than air gaseous Class I liquids are transferred or dispensed. The new Table 511.3(C) is a replica of the corresponding portion of Table 8.3.2 of NFPA 30A in order to comply with the NEC Style Manual with regards to internal references that exist within the NFPA 30A table. An informational note was added to refer back to the original table in NFPA 30A.


Article 506 Zone 20, 21, and 22 Locations for Combustible Dusts or Ignitable Fibers/Flyings

Article 511 Commercial Garages, Repair and Storage


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(continued)(b) Ventilation Not Provided. Ceiling areas that are not ventilated in accordance with 511.3(C)(2)(a) shall be classified as Class I, Division 2.(3) Pit Areas in Lubrication or Service Room. Any pit, belowgrade work area, or subfloor work area shall be classified as provided in (a) or (b).(a) Ventilation Provided. The pit area shall be a Class I, Division 2 location where there is mechanical ventilation providing a minimum of six air changes per hour.(b) Ventilation Not Provided. Where ventilation is not provided in accordance with 511.3(C)(3)(a), any pit or depression below floor level shall be a Class I, Division 1 location that extends up to the floor level.(D) Minor Repair Garages. Where flammable liquids having a flash point below 38°C (100°F) such as gasoline, or gaseous fuels such as natural gas or hydrogen, will not be dispensed or transferred, the classification rules in (D)(1), (D)(2), and (D)(3) shall apply to the lubrication and service rooms.(1) Floor Areas. Floor areas in minor repair garages without pits, belowgrade work areas, or subfloor work areas shall be unclassified. Where floor areas include pits, belowgrade work areas, or subfloor work areas in lubrication or service rooms, the classification rules in (a) or (b) shall apply.

(continued)

(D) Repair Garages, Major. Where vehicles using lighter-than-air gaseous fuels (such as hydrogen and natural gas) are repaired or stored, hazardous area classification guidance is found in Table 511.3(D).

(continued)(a) Ventilation Provided. The entire floor area shall be unclassified where there is mechanical ventilation providing a minimum of four air changes per hour or 0.3 m3/min/m2 (1 cfm/ft2) of exchanged air for each square meter (foot) of floor area. Ventilation shall provide for air exchange across the entire floor area, and exhaust air shall be taken at a point within 0.3 m (12 in.) of the floor.(b) Ventilation Not Provided. The floor area up to a level of 450 mm (18 in.) above any unventilated pit, belowgrade work area, or subfloor work area and extending a distance of 900 mm (3 ft) horizontally from the edge of any such pit, belowgrade work area, or subfloor work area, shall be classified as Class I, Division 2.

(continued)

514.3 Classification of Locations.(B) Classified Locations.(2) Compressed Natural Gas, Liquefied Natural Gas,and Liquefied Petroleum Gas Areas. Table 514.3(B)(2) shall be used to delineate and classify areas where compressed natural gas (CNG), liquefied natural gas (LNG), or liquefied petroleum gas (LPG) is stored, handled, or dispensed. Where CNG or LNG dispensers are installed beneath a canopy or enclosure, either the canopy or the enclosure shall be designed to prevent accumulation or entrapment of ignitible vapors, or all electrical equipment installed beneath the canopy or enclosure shall be suitable for Class I, Division 2 hazardous (classified) locations. Dispensing devices for liquefied petroleum gas shall be located not less than 1.5 m (5 ft) from any dispensingdevice for Class I liquids. [30A:12.1, 12.4, 12.5]

514.3 Classification of Locations.(B) Classified Locations.(2) Compressed Natural Gas, Liquefied Natural Gas, and Liquefied Petroleum Gas Areas. Table 514.3(B)(2) shall be used to delineate and classify areas where CNG, LNG, compressed or liquefied hydrogen, LP-Gas, or combinations of these, are dispensed as motor vehicle fuels along with Class I or Class II liquids that are also dispensed as motor vehicle fuels. [30A:12.1] Where CNG or LNG dispensers are installed beneath a canopy or enclosure, either the canopy or enclosure shall be designed to prevent accumulation or entrapment of ignitible vapors or all electrical equipment installed beneath the canopy or enclosure shall be suitable for Class I, Division 2 hazardous (classified) locations. [30A:12.4]Dispensing devices for LP-Gas shall be located as follows:(1) At least 3 m (10 ft) from any dispensing device for Class I liquids (2) At least 1.5 m (5 ft) from any dispensing device for Class I liquids where the following conditions exist:a. The LP-Gas deliver nozzle and filler valve release no more than 4 cm3 (0.1 oz) of liquid upon disconnection.b. The fixed maximum liquid level gauge remains closed during the entire refueling process. [30A:12.5.2]

(continued)Table 514.3(B)(2) Electrical Equipment Classified Areas for Dispensing Devices.Class I, Division 2 (column).From 1.5 m to 3.0 m (5 ft to 10 ft) in all directions from the dispenser enclosure

(continued)Table 514.3(B)(2) Electrical Equipment Classified Areas for Dispensing Devices.Class I, Division 2 (column).3 m (10 ft) in all directions from the dispenser enclosure.

Article 514 Motor Fuel Dispensing Facilities

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Change Description:In order to align with NFPA 30A-2015, 511.3(D) is replaced in its entirety with a new 511.3(D) covering major repair garages where vehicles using lighter than air gaseous fuels are repaired or stored. The new Table 511.3(D) is a replica of the corresponding portion of Table 8.3.2 of NFPA 30A in order to comply with the NEC Style Manual with regards to internal references that exist within the NFPA 30A table. An informational note was added to refer back to the original table in NFPA 30A. Notes were added to the table to apply the correct groups for hydrogen applications.


Change Description:To align with NFPA 30A-2015, 514.3(B)(2) is replaced in its entirety with a new 514.3(B)(2).


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514.11 Circuit Disconnects.(A) General. Each circuit leading to or through dispensing equipment, including all associated power, communications, data, and video circuits, and equipment for remotepumping systems, shall be provided with a clearly identified and readily accessible switch or other approved means, located remote from the dispensing devices, to disconnectsimultaneously from the source of supply, all conductors of the circuits, including the grounded conductor, if any. Single-pole breakers utilizing handle ties shall not bepermitted.(B) Attended Self-Service Motor Fuel Dispensing Facilities.Emergency controls as specified in 514.11(A) shall be installed at a location acceptable to the authority having jurisdiction, but controls shall not be more than 30 m (100 ft) from dispensers. [30A:6.7.1](C) Unattended Self-Service Motor Fuel Dispensing Facilities.Emergency controls as specified in 514.11(A) shall be installed at a location acceptable to the authority having jurisdiction, but the control shall be more than 6 m (20 ft) but less than 30 m (100 ft) from the dispensers. Additional emergency controls shall be installed on each group of dispensers or the outdoor equipment used to control the dispensers. Emergency controls shall shut off all power to all dispensing equipment at the station. Controls shall be manually reset only in a manner approved by the authority having jurisdiction. [30A:6.7.2]

514.11 Circuit Disconnects.(A) Emergency Electrical Disconnects. Fuel dispensing systems shall be provided with one or more clearly identified emergency shutoff devices or electrical disconnects. Such devices or disconnects shall be installed in approved locations but not less than 6 m (20 ft) or more than 30 m (100 ft) from the fuel dispensing devices that they serve. Emergency shutoff devices or electrical disconnects shall disconnect power to all dispensing devices; to all remote pumps serving the dispensing devices; to all associated power, control, and signal circuits; and to all other electrical equipment in the hazardous (classified) locations surrounding the fuel dispensing devices. When more than one emergency shutoff device or electrical disconnect is provided, all devices shall be interconnected. Resettingfrom an emergency shutoff condition shall require manual intervention and the manner of resetting shall be approved by the authority having jurisdiction. [30A:6.7] Exception: Intrinsically safe electrical equipment need not meet this requirement. [30A:6.7](B) Attended Self-Service Motor Fuel Dispensing Facilities. At attended motor fuel dispensing facilities, the devices or disconnects shall be readily accessible to the attendant. [30A:6.7.1](C) Unattended Self-Service Motor Fuel Dispensing Facilities.At unattended motor fuel dispensing facilities, the devices or disconnects shall be readily accessible to patrons and at leastone additional device or disconnect shall be readily accessible to each group of dispensing devices on an individual island. [30A:6.7.2]

Change Description:Changes made to align this section with NFPA 30A.


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515.3 Class I LocationsTable 515.3 Electrical Area Classifications

515.3 Class I Locations.Table 515.3 Electrical Area Classifications.Location: Tank vault — interior Division:1 Zone:1 Extent of Classified Area: Entire interior volume, if Class I liquids are stored within

Change Description:Changes made to align this section with NFPA 30A.


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II. Mobile and Manufactured Homes.550.13 Receptacle Outlets. (B) Ground-Fault Circuit Interrupters (GFCI). All 125-volt, single-phase, 15- and 20-ampere receptacle outlets installed outdoors, in compartments accessible from outside the unit, or in bathrooms, including receptacles in luminaires, shall have GFCI protection. GFCI protection shall be provided for receptacle outlets serving countertops in kitchens and receptacle outlets located within 1.8 m (6 ft) of a wet bar sink. The exceptions in 210.8(A) shall be permitted.Feeders supplying branch circuits shall be permitted to be protected by a ground-fault circuit-interrupter in lieu of the provision for such interrupters specified herein.

Part II. Mobile and Manufactured Homes.550.13 Receptacle Outlets.(B) Ground-Fault Circuit Interrupters (GFCI). All 125-volt, single-phase, 15- and 20-ampere receptacle outlets installed in the locations specified in 550.13(B)(1) through (5) shall have GFCI protection for personnel.(1) Outdoors, including compartments accessible from outside the unit(2) Bathrooms, including receptacles in luminaires(3) Kitchens, where receptacles are installed to serve countertop surfaces(4) Sinks, where receptacles are installed within 1.8 m (6 ft) of the outer edge of the sink(5) Dishwashers Informational Note: For information on protection of dishwashers, see 422.5.

Change Description:Alligned GFI requirements for receptacle outlets installed in mobile homes with the requirements found in Section 210.8.


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590.4 General.(B) Feeders. Overcurrent protection shall be provided in accordance with 240.4, 240.5, 240.100, and 240.101. Conductors shall be permitted within cable assemblies or within multiconductor cords or cables of a type identified in Table 400.4 for hard usage or extra-hard usage. For the purpose of this section, Type NM and Type NMC cables shall be permitted to be used in any dwelling, building, or structure without any height limitation or limitation by building construction type and without concealment within walls, floors, or ceilings. (C) Branch Circuits. All branch circuits shall originate in an approved power outlet, switchgear, switchboard or panelboard, motor control center, or fused switch enclosure.Conductors shall be permitted within cable assemblies or within multiconductor cord or cable of a type identified in Table 400.4 for hard usage or extra-hard usage. Conductorsshall be protected from overcurrent as provided in 240.4, 240.5, and 240.100. For the purposes of this section, Type NM and Type NMC cables shall be permitted to be used inany dwelling, building, or structure without any height limitation or limitation by building construction type and without concealment within walls, floors, or ceilings.

590.4 General.(B) Feeders. Overcurrent protection shall be provided in accordance with 240.4, 240.5, 240.100, and 240.101. Conductors shall be permitted within cable assemblies or within multiconductor cords or cables of a type identified in Table 400.4 for hard usage or extra-hard usage. For the purpose of this section, the following wiring methods shall be permitted:(1) Type NM, Type NMC, and Type SE cables shall be permitted to be used in any dwelling, building, or structure without any height limitation or limitation by building construction type and without concealment within walls, floors, or ceilings.(2) Type SE cable shall be permitted to be installed in a raceway in an underground installation.(C) Branch Circuits. For the purposes of this section, the following wiring methods shall be permitted:(1) Type NM, Type NMC, and Type SE cables shall be permitted to be used in any dwelling, building, or structure without any height limitation or limitation by building construction type and without concealment within walls, floors, or ceilings.(2) Type SE cable shall be permitted to be installed in a raceway in an underground installation.

Change Description:Type SE cable is commonly used for temporary power installations during construction activity and the installation limitations involving SE cables in a temporary installation is being modified in Article 590 in the same manner as Type NM and Type NMC cables. Type SE cables have proven themselves to be more than adequate for an underground installation in a raceway in temporary installations. However, it remains prohibited for permanent installations (338.12(A)(2)).


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Article 590 Temporary Installations

Article 515 Bulk Storage Plants

Article 550 Mobile Homes, Manufactured Homes, and Mobile Home Parks


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(continued)(G) Splices. On construction sites, a box shall not be required for splices or junction connections where the circuit conductors are multiconductor cord or cable assemblies,provided that the equipment grounding continuity is maintained with or without the box. See 110.14(B) and 400.9. A box, conduit body, or terminal fitting having a separatelybushed hole for each conductor shall be used wherever a change is made to a conduit or tubing system or a metal-sheathed cable system.

(continued)(G) Splices. A box, conduit body, or other enclosure, with a cover installed, shall be required for all splices.Exception: On construction sites, a box, conduit body, or other enclosure shall not be required for either of the following conditions:(1) The circuit conductors being spliced are all from nonmetallic multiconductor cord or cable assemblies, provided that the equipment grounding continuity is maintained with or without the box.(2) The circuit conductors being spliced are all from metal sheathed cable assemblies terminated in listed fittings that mechanically secure the cable sheath to maintain effective electrical continuity.

Change Description:The revision provides a general rule that all splices be made in a junction box with a "cover". Adding "cover" to this requirement is necessary because the present modification does not require a cover. It also removes "on construction sites", making this rule applicable to all temporary installations. (Incorporated TIA 17-4)Impact(s):No negative impact.

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590.6 Ground-Fault Protection for Personnel.(B) Use of Other Outlets.

590.6 Ground-Fault Protection for Personnel.(B) Use of Other Outlets.(2) SPGFCI Protection. Special purpose ground-fault circuit interrupter protection for personnel.

Change Description:The changes to 590.6(B) involving special purpose ground-fault circuit-interrupter protection (SPGFCI) for personnel are accepted since code making panel has accepted a new definition of SPGFCI. SPGFCIs work in 208, 240, 480V circuits (listed under UL 943C), making personnel protection possible in applications where in the past ground fault protection was not available.


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II. Conductors620.11 Insulation of Conductors.(A) Hoistway Door Interlock Wiring. The conductors to the hoistway door interlocks from the hoistway riser shall be flame retardant and suitable for a temperature of not less than 200°C (392°F). Conductors shall be Type SF or equivalent.

Part II. Conductors620.11 Insulation of Conductors.(A) Hoistway Door Interlock Wiring. The conductors to the hoistway door interlocks from the hoistway riser shall be one of the following:(1) Flame retardant and suitable for a temperature of not less than 200°C (392°F). Conductors shall be Type SF or equivalent.(2) Physically protected using an approved method, such that the conductor assembly is flame retardant and suitable for a temperature of not less than 200°C (392°F).

Change Description:ASME A17.1/B44 Code allows the use of alternative technologies for elevator hoistway door interlocks. These technologies may require cables that are not available with high temperature ratings. Alternative methods and materials exist to achieve equivalent performance in temperature and flame ratings.


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II. Conductors Part II. Conductors620.16 Short-Circuit Current Rating.(A) Marking. Where an elevator control panel is installed, it shall be marked with its short-circuit current rating, based on one of the following:(1) Short-circuit current rating of a listed assembly(2) Short-circuit current rating established utilizing an approved method.(B) Installation. The elevator control panel shall not be installed where the available short-circuit current exceeds its short-circuit current rating, as marked in accordance with 620.16(A).

Change Description: (A) This part of the requirement, which is similar to 409.110(4), 440.4(B), and 670.3(A)(4), helps in verification that equipment with adequate short-circuit current rating is installed.

(B) Marking the equipment with its short-circuit current rating alone is not enough. It must also be applied within that rating. This part of the requirement, which is similar to 409.22 and 670.5, increases safety by assuring that the equipment is installed within its short-circuit current rating.


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VI. Disconnecting Means and Control620.51 Disconnecting Means.(D) Identification and Signs. Where there is more than one driving machine in a machine room, the disconnecting means shall be numbered to correspond to the identifying number of the driving machine that they control.The disconnecting means shall be provided with a sign to identify the location of the supply side overcurrent protective device.

Part VI. Disconnecting Means and Control620.51 Disconnecting Means.(D) Identification and Signs.(2) Available Short-Circuit Current Field Marking. Where an elevator control panel is used, it shall be legibly marked in the field with the maximum available short-circuit current at its line terminals. The field marking(s) shall include the date the short-circuit current calculation was performed and be of sufficient durability to withstand the environment involved. When modifications to the electrical installation occur that affect the maximum available short-circuit current at the elevator control panel, the maximum available short-circuit current shall be verified or recalculated as ne-cessary to ensure the elevator control panel’s short-circuit current rating is sufficient for the maximum available short-circuit current at the line terminals of the equipment. The required field marking(s) shall be adjusted to reflect the new level of maximum available short-circuit current.(E) Surge Protection. Where any of the disconnecting means in 620.51 has been designated as supplying an emergency system load, surge protection shall be provided.

Change Description:The addition of the field marking of the available short circuit current will increase safety for field personnel.The addition of surge protection for equipment designatedas emergency equipment will add to reliability and safety.


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Article 620 Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts


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IX. Grounding620.85 Ground-Fault Circuit-Interrupter Protection for Personnel. Each 125-volt, single-phase, 15- and 20-ampere receptacle installed in pits, in hoistways, on elevator cartops, and in escalator and moving walk wellways shall be of the ground-fault circuit-interrupter type.

Part IX. Grounding620.85 Ground-Fault Circuit-Interrupter Protection for Personnel. Each 125-volt, single-phase, 15- and 20-ampere receptacle installed in pits, in hoistways, on the cars of elevators and dumbwaiters associated with wind turbine tower elevators, on the platforms or in the runways and machinery spaces of platform lifts and stairway chairlifts, and in escalator and moving walk wellways shall be of theground-fault circuitinterrupter type.

Change Description:The GFCI Requirement will make these installations safer.


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625.18 Interlock. Electric vehicle supply equipment shall be provided with an interlock that de-energizes the electric vehicle connector whenever the electrical connector is uncoupled from the electric vehicle. An interlock shall not be required for portable cord-and-plug-connected electric vehicle supply equipment intended for connection to receptacle outlets rated at 125 volts, single phase, 15 and 20 amperes. An interlock shall not be required for dc supplies less than 50 volts dc.

625.18 Interlock. Electric vehicle supply equipment shall be provided with an interlock that de-energizes the electric vehicle connector whenever the electrical connector is uncoupled from the electric vehicle. An interlock shall not be required for portable cord-and-plug-connected electric vehicle supply equipment intended for connection to receptacle outlets rated at 125 volts, single phase, 15 and 20 amperes. An interlock shall not be required for dc supplies less than 60 volts dc.

Change Description:Revised the requirements to 60V to cover charging of DC systems where float voltages can exceed 50V.


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625.44 Electric Vehicle Supply Equipment Connection.Electric vehicle supply equipment shall be permitted to be cord-and plug-connected to the premises wiring system in accordance with one of the following:(A) Connections to 125-Volt, Single-Phase, 15-and 20-Ampere Receptacle Outlets. Electric vehicle supply equipment intended for connection to nonlocking, 2-pole, 3-wire grounding-type receptacle outlets rated at 125 V, single phase, 15 and 20 amperes or from a supply of less than 50 volts dc.(B) Connections to Other Receptacle Outlets. Electric vehicle supply equipment that is rated 250 V maximum and complying with all of the following:(1) It is intended for connection to nonlocking, 2-pole, 3-wire and 3-pole, 4-wire, grounding-type receptacle outlets rated not more than 50 amperes.(2) EVSE is fastened in place to facilitate any of the following:a. Ready removal for interchange b. Facilitation of maintenance and repairc. Repositioning of portable, movable, or EVSE fastened in place(3) Power-supply cord length for electric vehicle supply equipment fastened in place is limited to 1.8 m (6 ft).(4) Receptacles are located to avoid physical damage to the flexible cord.All other electric vehicle supply equipment shall be permanently wired and fastened in place to the supporting surface, a wall, a pole, or other structure. The electric vehiclesupply equipment shall have no exposed live parts.

625.44 Equipment Connection. Equipment shall be connected to the premises wiring system in accordance with one of the following:(A) Portable Equipment. Portable equipment shall be connected to the premises wiring systems by one or more of the following methods: (1) A onlocking, 2-pole, 3-wire grounding-type receptacle outlet rated at 125 volts, single phase, 15 or 20 amperes (2) A nonlocking, 2-pole, 3-wire grounding-type receptacle outlet rated at 250 volts, single phase, 15 or 20 amperes (3) A nonlocking, 2-pole, 3-wire or 3-pole, 4-wire grounding-type receptacle outlet rated at 250 volts, single phase, 30 or 50 amperes (4) A nonlocking, 2-pole, 3-wire grounding-type receptacle outlet rated at 60 volts dc maximum, 15 or 20 amperesThe length of the power supply cord, if provided, between the receptacle outlet and the equipment shall be in accordance with 625.17(A) (3).(B) Stationary Equipment. Stationary equip-ment intended to be fastened in place in such a way as to permit ready removal for interchange, facilitation of maintenance or repair, or repositioning shall be connected to the premises wiring system by one of the following methods:(1) A nonlocking, 2-pole, 3-wire grounding-type receptacle outlet rated 125 volt or 250 volt, single phase, up to 50 amperes(2) A nonlocking, 3-pole, 4-wire grounding-type receptacle outlet rated 250 volt, three phase, up to 50 amperes(3) Any of the receptacle outlets in 625.44(A)(1) or (2) The length of the power supply cord, if pro-vided, between the receptacle outlet and the equipment shall be in accordance with 625.17(A)(3).(C) Fixed Equipment. All other equipment shall be permanently wired and fixed in place to the supporting surface.

Change Description:Revised to correlate with new definition of portable, stationary and fixed. Revised the requirements to 60V to cover charging of DC systems where float voltages can exceed 50V.(TIA 17-2 incorporated)


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625.47 Multiple Feeder or Branch Circuits. Where equipment is identified for the application, more than one feeder or branch circuit shall be permitted to supply equipment.

Change Description:Currently there is electric vehicle supply equipment that is listed and identified to be fed by more than one branch circuit or feeder. Without this new section added to Article 625, the requirements of sections 225.30 would prevent this listed equipment from being installedas it would be a violation if fed on the load side of a service disconnecting means by more than one feeder or branch circuit.


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Article 625 Electric Vehicle Charging System


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625.48 Interactive Systems. Electric vehicle supply equipmentand other parts of a system, either on board or off board the vehicle, that are intended to be interconnected to a vehicle and also serve as an optional standby system or an electric power production source or provide for bidirectional power feed shall be listed and marked as suitable for that purpose. When used as an optional standby system, the requirements of Article 702 shall apply, and when used as an electric power production source, the requirements of Article 705 shall apply.

625.48 Interactive Systems. Electric vehicle supply equipment that is part of an interactive system that serves as an optional standby system, an electric power production source, or a bidirectional power feed shall be listed, evaluated for use with the specific electric vehicles, and marked as suitable for that purpose. When used as an optional standby system, the requirements of Article 702 shall apply; when used as an electric power production source, the requirements ofArticle 705 shall apply.

Change Description: Because of technology that is emerging and/or currently being deployed, this section was clarified and the reference to on board systems was removed. Listing the interface device and requiring a specific compatibility evaluation will address the fundamental concerns, without requiring AHJ to impractically impose listing requirements on EVs. The revision provides a clearer path for the authority to enforce the installation of interactive systems for this technology.


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625.50 Location. The electric vehicle supply equipment shall be located for direct electrical coupling of the EV connector (conductive or inductive) to the electric vehicle. Unless specifically listed and marked for the location, the coupling means of the electric vehicle supply equipment shall be stored or located at a height of not less than 450 mm (18 in.) above the floor level for indoor locations and 600 mm (24 in.) above the grade level for outdoor locations.

625.50 Location. The electric vehicle supply equipment shall be located for direct electrical coupling of the EV connector (conductive or inductive) to the electric vehicle. Unless specifically listed and marked for the location, the coupling means of the electric vehicle supply equipment shall be stored or located at a height of not less than 450 mm (18 in.) above the floor level for indoor locations or 600 mm (24 in.) above the grade level for outdoor locations. This requirement does not apply to portable electric vehicle supply equipment constructed in accordance with 625.44(A).

Change Description:Revised to exclude portable EVSE from mounting location requirements.


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625.54 Ground-Fault Circuit-Interrupter Protection for Personnel. All single-phase receptacles installed for the connection of electric vehicle charging that are rated 150 volts to ground or less, and 50 amperes or less shall have ground-fault circuit-interrupter protection for personnel.

Change Description:Added new requirements for ground-fault protection for personnel for electric vehicle charging stations.


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625.56 Receptacle Enclosures. All receptacles installed in a wet location for electric vehicle charging shall have an enclosure that is weatherproof with the attachment plug cap inserted or removed.

Change Description:Added new requirements for electric vehicle charging stations located in wet locations.


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Part IV. Wireless Power Transfer Equipment(New in 2017)

Change Description:A new Part IV for Wireless Power Transfer Equipment was added. This new part includes additional requirements for grounding and constructional features to be provided during the installation of wireless power transfer equipment. Additional changes to Section 625.52 were made to remove the reference to electric vehicle supply equipment thereby allowing the requirement to apply to both electric vehicle supply and wireless charging equipment. This change is linked to other changes on wireless charging throughout the Article.


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IV. Transport Refrigerated Units (TRUs)626.31 Disconnecting Means and Receptacles.(C) Receptacles. All receptacles shall be listed and of the grounding type. Every electrified truck parking space intended to provide an electrical supply for transport refrigerated units shall be equipped with one or both of the following:(1) A 30-ampere, 480-volt, 3-phase, 3-pole, 4-wire receptacle(2) A 60-ampere, 208-volt, 3-phase, 3-pole, 4-wire receptacle

Part IV. Transport Refrigerated Units (TRUs)626.31 Disconnecting Means and Receptacles.(C) Receptacles. All receptacles shall be listed and of the grounding type. Every electrified truck parking space intended to provide an electrical supply for transport refrigerated unitsshall be equipped with one or more of the following:(1) A 30-ampere, 480-volt, 3-phase, 3-pole, 4-wire receptacle(2) A 60-ampere, 208-volt, 3-phase, 3-pole, 4-wire receptacle(3) A 20-ampere, 1000-volt, 3-phase, 3-pole, 4-wire receptacle, pin and sleeve type.

Change Description:This change is adding the use of 1000 volt receptacles to address the increase in operating voltages in the Code.


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626.32 Separable Power Supply Cable Assembly.(A) Rating(s). The power supply cable assembly shall be listed and be rated in accordance with (1) or (2).(1) 30 ampere, 480-volt, 3-phase(2) 60 ampere, 208-volt, 3-phase

626.32 Separable Power Supply Cable Assembly.(A) Rating(s). The power supply cable assembly shall be listed and be rated in accordance with one of the following:(1) 30 ampere, 480-volt, 3-phase(2) 60 ampere, 208-volt, 3-phase(3) A 20-ampere, 1000-volt, 3-phase

Change Description:This change is adding the use of 1000 volt receptacles to address the increase in operating voltages in the Code.


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Article 626 Electrified Truck Parking Spaces


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645.3 Other Articles.(E) Fire Alarm Equipment. Parts I, II, and III of Article 760 shall apply to fire alarm systems equipment installed in an information technology equipment room.

645.3 Other Articles.(E) Fire Alarm Cables and Equipment. Parts I, II, and III of Article 760 shall apply to fire alarm systems cables and equipment installed in an information technology equipment room. Only fire alarm cables listed in accordance with Part IV of Article 760 and listed fire alarm equipment shall be permitted to be installed in an information technology equipment room.

Change Description:This revision will prevent use of equipment and cabling that has not been listed and evaluated for fire alarm use. This correlates with NFPA 72.


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(continued)(F) Communications Equipment. Parts I, II, III, IV, and V of Article 800 shall apply to communications equipment installed in an information technology equipment room. Article 645 shall apply to the powering of communications equipment in an information technology equipment room.

(G) Community Antenna Television and Radio DistributionSystems Equipment. Parts I, II, III, IV, and V of Article 820 shall apply to community antenna television and radio distribution systems equipment installed in an information technology equipment room. Article 645 shall apply to the powering of community antenna television and radio distribution systems equipment installed in an information technology equipment room.

(continued)(F) Cable Routing Assemblies, Communications Wires, Cables, Raceways, and Equipment. Parts I, II, III, IV, and V of Article 800 shall apply to cable routing assemblies, communications wires, cables, raceways, and equipment installed in an information technology equipment room. Only communications wires and cables listed in accordance with 800.179, cable routing assemblies and communications raceways listed in accordance with 800.182, and communications equipment listed in accordance with 800.170 shall be permitted to be installed in an information technology equipment room. Article 645 shall apply to the powering of communications equipment in an information technology equipment room. (G) Community Antenna Television and Radio Distribution Systems Cables and Equipment. Parts I, II, III, IV, and V of Article 820 shall apply to community antenna television and radio distribution systems cables and equipment installed in an information technology equipment room. Only community antenna television and radio distribution cables listed in accordance with 820.179 and listed CATV equipment shall be permitted to be installed in an information technology equipment room. Article 645 shall apply to the powering of community antenna television and radio distribution systems equipment installed in an information technology equipment room.N (H) Optical Fiber Cables. Only optical fiber cables listed in accordance with 770.179 shall be permitted to be installed in an information technology equipment room.

Change Description:This revision correlates with 645.4(3) which requires listed communications and IT equipment as a condition for using Article 645. Only listed cables are permitted in a data center. Sections 770.48, 800.48 and 820.48 permit 50 feet of unlisted (outside plant) cables to enter a building. These cables are highly combustible and should never be installed in a data center unless they are enclosed in IMC or RMC.

This revision clarifies that in addition to listed communications equipment, only listed cable routing assemblies and listed communications wires, cables and raceways are permitted to be installed in an information technology room.


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645.4 Special Requirements for Information Technology Equipment Room.This article shall be permitted to provide alternate wiring methods to the provisions of Chapter 3 and Article 708 for power wiring, Parts I and III of Article 725 for signaling wiring, and Parts I and V of Article Article 770 for optical fiber cabling where all of the followingconditions are met:

645.4 Special Requirements for Information Technology Equipment Room. The alternative wiring methods to Chapter 3 and Parts I and III of Article 725 for signaling wiring andParts I and V of Article 770 for optical fiber cabling shall be permitted where all of the following conditions are met:

Change Description:This revision refers to the latest edition of NFPA 75.Removed reference to Article 708. Section 708.14 has requirements for signaling wiring in a critical operations power system that would be extremely onerous if applied to a data center. Article 645 provides permissive alternative wiring methods.


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Article 645 Information Technology Equipment


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645.5 Supply Circuits and Interconnecting Cables.(E) Under Raised Floors. Power cables, communications cables, connecting cables, interconnecting cables, cord-and-plug connections, and receptacles associated with the infor-mation technology equipment shall be permitted under a raised floor, provided the following conditions are met:(1) The raised floor is of approved construction, and the area under the floor is accessible.(2) The branch-circuit supply conductors to receptacles or field-wired equipment are in rigid metal conduit, rigid non-metallic conduit, intermediate metal conduit, electricalmetallic tubing, electrical nonmetallic tubing, metal wireway, nonmetallic wireway, surface metal raceway with metal cover, surface nonmetallic raceway, flexible metal conduit, liquidtight flexible metal conduit, or liquidtight flexible nonmetallic conduit, Type MI cable, Type MC cable, or Type AC cable and associated metallic and nonmetallic boxes or enclosures. These supply conductors shall be installed in accordance with the requirements of 300.11.(3) Supply cords of listed information technology equipment are in accordance with 645.5(B).(4) Ventilation in the underfloor area is used for the information technology equipment room only, except as provided in 645.4(2).(5) Openings in raised floors for cords and cables protect cords and cables against abrasion and minimize the entrance of debris beneath the floor.(6) Cables, other than those covered in 645.5(E)(2) and (E)(3), are one of the following:a. Listed Type DP cable having adequate fire-resistantcharacteristics suitable for use under raised floors ofan information technology equipment roomb. Interconnecting cables enclosed in a racewayc. Cable type designations shown in Table 645.5(E)(6)d. Equipment grounding conductors

645.5 Supply Circuits and Interconnecting Cables.(E) Under Raised Floors. Where the area under the floor is accessible and openings minimize the entrance of debris beneath the floor, power cables, communication cables, connecting cables, interconnecting cables, cord-and-plug connections, and receptacles associated with the information technology equipment shall be permitted under a raised floor of approved construction. The installation requirement shall comply with 645.5(E)(1) through (3). N (1) Installation Requirements for Branch Circuit Supply Conductors Under a Raised Floor.(a) The supply conductors shall be installed in accordance with the requirements of 300.11.(b) In addition to the wiring methods of 300.22(C), the following wiring methods shall also be permitted:(1) Rigid metal conduit(2) Rigid nonmetallic conduit(3) Intermediate metal conduit(4) Electrical metallic tubing(5) Electrical nonmetallic tubing(6) Metal wireway(7) Nonmetallic wireway(8) Surface metal raceway with metal cover(9) Surface nonmetallic raceway(10) Flexible metal conduit(11) Liquidtight flexible metal conduit(12) Liquidtight flexible nonmetallic conduit(13) Type MI cable(14) Type MC cable(15) Type AC cable(16) Associated metallic and nonmetallic boxes or enclosures(17) Type TC power and control tray cable

(2) Installation Requirements for Electrical Supply Cords, Data Cables, Interconnecting Cables, and Grounding Conductors Under a Raised Floor. The following cords, cables,and conductors shall be permitted to be installed under a raised floor:(1) Supply cords of listed information technology equipment in accordance with 645.5(B)(2) Interconnecting cables enclosed in a raceway(3) Equipment grounding conductors(4) In addition to wiring installed in compliance with 725.135(C), Types CL2R, CL3R, CL2, and CL3 and substitute cables including CMP, CMR, CM, and CMG installed in accordance with 725.154(A), shall be permitted under raised floors.(5) Listed Type DP cable having adequate fire-resistant characteristics suitable for use under raised floors of an information technology equipment room(3) Installation Requirements for Optical Fiber Cables Under a Raised Floor. In addition to optical fiber cables installed in accordance with 770.113(C), Types OFNR, OFCR, OFN, and OFC shall be permitted under raised floors.

(continued)(F) Securing in Place. Power cables; communications cables; connecting cables; interconnecting cables; and associated boxes, connectors, plugs, and receptacles thatare listed as part of, or for, information technology equipment shall not be required to be secured in place.

(continued)(F) Securing in Place. Power cables; communications cables, connecting cables, interconnecting cables, and associated boxes, connectors, plugs, and receptacles that are listed as part of, or for, information technology equipment shall not be required to be secured in place where installed under raised floors.

Change Description:Installations can be subject to physical damage if not secured in place above the floor. By not including installations above raised floor, it is understood that Chapters 1-4 apply.


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645.18 Surge Protection for Critical Operations Data Systems.Surge protection shall be provided for critical operations data systems.

Change Description: This change correlates with 708.20(D) for Critical Operations Power Systems. Critical Operations Data Systems serve operations that deal with public safety, emergency management, national security, and business continuity. It is important that protection is provided to ensure reliable power.


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Change Description: Articles 760, 800 and 820 permissions have been removed.

The format of this section has been revised to use lists. These requirements are unchanged with the exception that NPLFR, FPLR, NPLF, FPL, CATVR, and CATV are no longer permitted under raised floors because Section 645.3(G) refers to Article 820. Section 645.3(E) refers to Article 760 for installation of fire alarm cables.

CMP, CMR, CM, and CMG are approved substitute cables for type CL2 in Article 725.

Added Table 645.10(B)(5)


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I. General646.3 Other Articles.(B) Plenums. Sections 300.22(C)(1), 725.154(A), 760.53(B)(2), 760.154(A), 770.113(C), 800.113(C), and Table 725.154, Table 760.154, Table 770.154(a), Table 800.154(a),and Table 820.154(a) shall apply to wiring and cabling in other spaces used for environmental air (plenums).

Part I. General646.3 Other Articles.(B) Wiring and Cabling in Other Spaces Used for Environmental Air (Plenums). The following sections and tables shall apply to wiring and cabling in other spaces used for environmental air (plenums) within a modular datacenter space:(1) Wiring methods: 300.22(C)(1)(2) Class 2, Class 3, and PLTC cables: 725.135(C) and Table 725.154(3) Fire alarm systems: 760.53(B)(2), 760.135(C) and Table 760.154(4) Optical fiber cables: 770.113(C) and Table 770.154(a)(5) Communications circuits: 800.113(C) and Table 800.154(a), (b), and (c)(6) CATV and radio distribution systems: 820.113(C) and Table 820.154(a)

Change Description: This change clarifies that 646.3(B) applies to all environmental air spaces (plenums) within the Modular Data Center. Other editorial changes and corrections of errors were made as well.Impact(s):No negative impact.

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(continued)(E) Fire Alarm Equipment. The provisions of Parts I, II, and III of Article 760 shall apply to fire alarm system equipment installed in an MDC, where provided.

(F) Communications Equipment. Parts I, II, III, IV, and V of Article 800 shall apply to communications equipment installed in an MDC

(G) Community Antenna Television and Radio Distribution Systems Equipment. Parts I, II, III, IV, and V of Article 820 shall apply to community antenna television and radio distribution systems equipment installed in an MDC.

(continued)(E) Fire Alarm Equipment. Parts I, II, and III of Article 760 shall apply to fire alarm systems, cables, and equipment installed in an MDC, where provided. Only fire alarm cables listed in accordance with Part IV of Article 760 and listed fire alarm equipment shall be permitted to be installed in an MDC.(F) Cable Routing Assemblies and Communications Wires, Cables, Raceways, and Equipment. Parts I, II, III, IV, and V of Article 800 shall apply to cable routing assemblies, communications wires, cables, raceways, and equipment installed in an MDC. Only communications wires and cables listed in accordance with 800.179, cable routing assemblies and communications raceways listed in accordance with 800.182, and communications equipment listed in accordance with 800.170 shall be permitted to be installed in an MDC.(G) Community Antenna Television and Radio Distribution Systems Cables and Equipment. Parts I, II, III, IV, and V of Article 820 shall apply to community antenna television and radio distribution systems equipment installed in an MDC. Only community antenna television and radio distribution cables listed in accordance with 820.179 and listed CATV equipment shall be permitted to be installed in an MDC.

Change Description:Revision clarifies that only listed fire alarm equipment and cables, listed cable routing assemblies and listed communications wires, cables and raceways, listed CATV cables are permitted to be installed in an MDC.


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646.7 Short-Circuit Current Rating.(B) MDCs Connected to Branch Circuits and Feeders. Modular data centers that connect to a branch circuit or a feeder circuit shall have a short-circuit current rating notless than the available fault current of the branch circuit or feeder. The short-circuit current rating of the MDC shall be based on the short-circuit current rating of a listed andlabeled MDC or the short-circuit current rating established utilizing an approved method.Informational Note No. 1: UL 508A-2001, Standard for Industrial Control Panels, Supplement SB, is an example of an approved method.Informational Note No. 2: This requirement does not apply to listed and labeled equipment connected to branch circuits located inside of the MDC equipment enclosure.

646.7 Short-Circuit Current Rating.(B) MDCs Connected to Branch Circuits and Feeders. Modular data centers that connect to a branch circuit or a feeder circuit shall have a short-circuit current rating not less than the available fault current of the branch circuit or feeder. The short-circuit current rating of the MDC shall be based on the short-circuit current rating of a listed and labeled MDC or the short-circuit current rating established utilizing an approved method.Exception: This requirement shall not apply to listed and labeled equipment connected to branch circuits located inside of the MDC equipment enclosure.Informational Note: UL 508A-2013, Standard for Industrial Control Panels, Supplement SB, is an example of an approved method.

Change Description:Changed Informational Note No. 2 to an exception.


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647.3 General. Use of a separately derived 120-volt single-phase 3-wire system with 60 volts on each of two ungrounded conductors to a grounded neutral conductor shall be permitted for the purpose of reducing objectionable noise in sensitive electronic equipment locations, provided the following conditions apply:(1) The system is installed only in commercial or industrial occupancies.(2) The system’s use is restricted to areas under close supervision by qualified personnel.(3) All of the requirements in 647.4 through 647.8 are met.

647.3 General. Use of a separately derived 120-volt singlephase 3-wire system with 60 volts on each of two ungrounded conductors to an equipment grounding conductor shall be permitted for the purpose of reducing objectionable noise in sensitive electronic equipment locations, provided the following conditions apply:(1) The system is installed only in commercial or industrial occupancies.(2) The system’s use is restricted to areas under close supervision by qualified personnel.(3) All of the requirements in 647.4 through 647.8 are met.

Change Description:The use of the term grounded neutral conductor is incorrect. The conductor is grounded, but is never intended to carry current so it is not a neutral. The equipment grounding conductors connect to this point on this type of separately derived system.


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Article 646 Modular Data Centers

Article 647 Sensitive Electronic Equipment


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I. General660.5 Disconnecting Means. A disconnecting means of adequate capacity for at least 50 percent of the input required for the momentary rating, or 100 percent of the inputrequired for the long-time rating, of the X-ray equipment, whichever is greater, shall be provided in the supply circuit. The disconnecting means shall be operable from a location readily accessible from the X-ray control. For equipment connected to a 120-volt, nominal, branch circuit of 30 amperes or less, a grounding-type attachment plug cap and receptacle of proper rating shall be permitted to serve as a disconnecting means.

Part I. General660.5 Disconnecting Means. A disconnecting means of adequate capacity for at least 50 percent of the input required for the momentary rating, or 100 percent of the input required for the long-time rating, of the X-ray equipment, whichever is greater, shall be provided in the supply circuit. The disconnecting means shall be located within sight from the X-ray control and readily accessible.Exception: The disconnecting means for the X-ray equipment shall not be required under either of the following conditions, provided that the controller disconnecting means is lockable in accordance with 110.25:(1) Where such a location of the disconnecting means for the X-ray equipment is impracticable or introduces additional or increased hazards to persons or property(2) In industrial installations, with written safety procedures, where conditions of maintenance and supervision ensure that only qualified persons service the equipment.

Change Description:This revision will ensure the proper location of the disconnecting means, with the use of a defined term “within sight”, and ensure the disconnecting means is readily accessible. The exceptions were added due to the industrial applications that sometimes are encountered with this equipment.

Cord and plug for disconnect means is already defined elsewhere in the Code (Chapter 4). The permission is redundant so it has been removed.


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670.5 Short-Circuit Current Rating. Industrial machineryshall not be installed where the available fault current exceeds its short-circuit current rating as marked in accordance with 670.3(A)(4).

670.5 Short-Circuit Current Rating.(1) Industrial machinery shall not be installed where the available short-circuit current exceeds its short-circuit current rating as marked in accordance with 670.3(A)(4).(2) Industrial machinery shall be legibly marked in the field with the maximum available short-circuit current. The field marking(s) shall include the date the short-circuit current calculation was performed and be of sufficient durability to withstand the environment involved.

Change Description:This revision adds requirements to ensure that industrial machinery is properly installed and eases enforcement. Requiring a field marking of the available fault current, at the industrial machinery, ensures the equipment is installed where fault currents do not exceed the equipment’s short circuit current rating as required in 670.5 (1).


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670.6 Surge Protection. Industrial machinery with safety interlock shall have surge protection installed.

Change Description:The study, “Data Assessment for Electrical Surge Protective Devices” commissioned by the Fire Protection Research Foundation, 1 Batterymarch Park, Quincy, MA 02169-7471, provides results of a 2013 and 2014 survey of facility managers concerning surge damage. It shows that 26% had damage to safety interlocking systems on machines due to surges. These safety interlocking systems are in place to protect workers from interactions with the machinery.


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2014 Text not included due to the extent of the changes - see Change Description. 2017 Text not included due to the extent of the changes - see Change Description. Change Description:Article 690 has been rearranged and revised practically in its entirety to reflect rapidly changing technology and many permutations of PV systems available on the market. Review of the changes did not identify any revisions which would have an adverse effect on safety.


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New Article in 2017. Change Description:New Article added to address large-scale PV power production facilities.


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Article 691 Large-Scale Photovoltaic (PV) Electric Power Production Facility

Article 690 Solar Photovoltaic (PV) Systems

Article 660 X-Ray Equipment

Article 670 Industrial Machinery


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I. General694.7 Installation.(B) Equipment. Wind electric systems shall be listed and labeled for the application.

(F) Metal or Nonmetallic Poles or Towers Supporting Wind Turbines Used as a Raceway. A metallic or nonmetallicpole or tower shall be permitted to be used as araceway if evaluated as part of the listing for the windturbine or otherwise shall be listed or evaluated for thepurpose.

Part I. General694.7 Installation.(B) Equipment. Wind electric systems shall be listed and labeled or field labeled for the application. Wind electric systems undergoing evaluation for type certification and listing shall be permitted to be operated in a controlled location with access limited to qualified personnel.

(F) Poles or Towers Supporting Wind Turbines Used as a Raceway. A pole or tower shall be permitted to be used as a raceway if evaluated as part of the listing for the windturbine or otherwise shall be listed or field labeled for the purpose.

Change Description:(B) Field labeling is a common activity for large wind turbines, as they are often build as a batch using common components, but with some variation from batch to batch. It is impractical to type test or fully fix the design of large-scale wind turbines (this applies to listing of the overall assembly - in general, individual components are certified for the application). Field-labeling is sometimes also used for intermediate and small wind turbines, but they are more generally type-tested and listed. Questions regarding appropriate wording for listing and labeling were raised across the board for all articles in this code cycle. Wind turbines are a special case where the either listing and labeling OR field labeling is appropriate and necessary.

The additional sentence regarding turbines under development is also important as a wind turbine cannot be listed or certified without several months of operating at a wide range of wind speeds. This certification testing is performed under in an access-limited environment. Provision for such testing is necessary as turbines need to feed the power grid during testing, and so are subject to inspection and the NEC. Utility Interactive inverters are required to be listed to applicable ANSI standards and interconnection must comply with Article 705. (F) It is necessary to require both listing and labeling of devices as AHJs depend upon this information. Some installations will require field evaluation as an alternate method to listing and labeling.


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(continued)(G) Working Clearances. Working space shall be provided for electrical cabinets and other electrical equipment in accordance with 110.26(A).For large wind turbines where service personnel enter the equipment, where conditions of maintenance and supervision ensure that only qualified persons perform the work, working clearances shall be permitted to comply with Table 694.7 for systems up to 1000 V nominal.

Change Description:Revised Table 110.26(A)(1) to reflect the change throughout the Code from 600 to 1000 V. A third line was added to the table:601–1000 V: 900 mm (3 ft) 1.2 m (4 ft) 1.5 m (5 ft)Many wind turbines operate at 690 Vac and in the past took spacings requirements from the 2014 Table 110.26(A)(1) line 2. The new requirements for greater than 600 V use the 2014 values from Table 110.34(A) line 1 (601-2500V).Requirements for 2500 V are a major change for systems that may operate at 690 V, and 30 cm of additional space is very difficult to implement in existing designs, and especially for wind turbine nacelles.Access using reduced spacings is limited to qualified personnel.


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VIII. Systems over 1000 Volts694.80 General. Wind electric systems with a maximum system voltage exceeding 1000 volts ac or dc shall comply with Article 490 and other requirements applicable to installations rated over 1000 V.

694.85 Cable and Equipment Ratings. For the purposes of Part IX of this article, the voltages used to determine cable and equipment ratings shall be as specified in 694.85(A) and (B).(A) Battery Circuits. In battery circuits, the voltage used shall be the highest voltage experienced under charging or equalizing conditions.(B) Other Circuits. In other circuits, the voltage used shall be the maximum voltage experienced in normal operation.

Change Description:The entire Part VIII was removed as it was unnecessary and provided no guidance or clarity to the user.


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Article 694 Wind Electric Systems


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695.4 Continuity of Power.(B) Connection Through Disconnecting Means and Overcurrent Device.(1) Number of Disconnecting Means.(a) General. A single disconnecting means and associated overcurrent protective device(s) shall be permitted to be installed between the fire pump power source(s) and one of the following: [20:9.1.2](1) A listed fire pump controller(2) A listed fire pump power transfer switch(3) A listed combination fire pump controller and power transfer switch(b) Feeder Sources. For systems installed under the provisions of 695.3(C) only, additional disconnecting means and the associated over-current protective device(s) shall be permitted as required to comply with other provisions of this Code.(c) On-Site Standby Generator. Where an on-site standby generator is used to supply a fire pump, an additional disconnecting means and an associated overcurrent protective device(s) shall be permitted.

695.4 Continuity of Power.(B) Connection Through Disconnecting Means and Overcurrent Device.(2) Overcurrent Device Selection.The requirement to carry the locked rotor currents indefinitely shall not apply to feeder overcurrent protective devices installed in accordance with 695.3(C).(3) Disconnecting Means.Exception to 695.4(B)(3)(a): For a multibuilding campus-style complex(s) installed under the provisions of 695.3(C), only the requirements in 695.4(B)(3)(a)(2) shall apply for normal power source disconnects.

Change Description:The deleted text in 695.4(B)(1)(b) along with the new text in 695.4(B)(2)(a)(1) provides significant clarity for overcurrent protection requirements of feeders installed in multibuilding campus installations in accordance with 695.3(C).

Feeders installed in multibuilding campus installations in accordance with 695.3(C) are not required to carry indefinitely the sum of the locked-rotor current of the largest fire pump motor and the pressure maintenance pump motor(s) and the full-load current of all of the other pump motors and associated fire pump accessory equipment.

The new exception in 695.4(B)(3)(a) clarifies that the disconnect requirements in 695.4(B)(3)(a) need only comply with requirements for the disconnect to be capable of being locked in the closed position.


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695.6 Power Wiring.(A) Supply Conductors.(2) Feeders. Fire pump supply conductors on the load side of the final disconnecting means and overcurrent device(s) permitted by 695.4(B), or conductors that connect directly to an on-site standby generator, shall comply with all of the following:(a) Independent Routing. The conductors shall be kept entirely independent of all other wiring.(b) Associated Fire Pump Loads. The conductors shall supply only loads that are directly associated with the fire pump system.(c) Protection from Potential Damage. The conductors shall be protected from potential damage by fire, structural failure, or operational accident.(d) Inside of a Building. Where routed through a building, the conductors shall be installed using one of the following methods:(1) Be encased in a minimum 50 mm (2 in.) of concrete (2) Be protected by a fire-rated assembly listed to achieve a minimum fire rating of 2 hours and dedicated to thefire pump circuit(s) (3) Be a listed electrical circuit protective system with aminimum 2-hour fire rating.

(G) Ground-Fault Protection of Equipment. Groundfault protection of equipment shall not be permitted for fire pumps.

695.6 Power Wiring.(A) Supply Conductors.(2) Feeders.(d) Inside of a Building. Where routed through a building, the conductors shall be protected from fire for 2 hours using one of the following methods:(1) The cable or raceway is encased in a minimum 50 mm (2 in.) of concrete.(2) The cable or raceway is a listed fire-resistive cable system.

(G) Ground-Fault Protection of Equipment. Ground-fault protection of equipment shall not be installed in any fire pump power circuit. [20:9.1.8.1]

Change Description:(A)(2)(d)The revisions to this section clarify the protection requirements for fire pump conductors routed through a building.

(G) This revision clarifies that ground-fault protection of equipment is not permitted for the fire pump power circuit. This revision is limited to the fire pump power circuit as 695.6 is titled “Power Wiring”. This change is necessary to clarify that multi building campus style distribution systems may include upstream ground fault protection.See NFPA 20: 9.1.8.1 for the NFPA 20 requirement.


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695.14 Control Wiring.(E) Electric Fire Pump Control Wiring Methods. All electric motor–driven fire pump control wiring shall be in rigid metal conduit, intermediate metal conduit, liquidtightflexible metal conduit, liquidtight flexible nonmetallic conduit Type B (LFNC-B), listed Type MC cable with an impervious covering, or Type MI cable.

(F) Generator Control Wiring Methods. Control conductors installed between the fire pump power transfer switch and the standby generator supplying the fire pump during normal power loss shall be kept entirely independent of all other wiring. They shall be protected to resist potential damage by fire or structural failure. They shall be permitted to be routed through a building(s) using one of the following methods:(1) Be encased in a minimum 50 mm (2 in.) of concrete.(2) Be protected by a fire-rated assembly listed to achievea minimum fire rating of 2 hours and dedicated to the fire pump circuits.(3) Be a listed electrical circuit protective system with a minimum 2-hour fire rating. The installation shall comply with any restrictions provided in the listing of the electrical circuit protective system used.

695.14 Control Wiring.(E) Electric Fire Pump Control Wiring Methods. All electric motor–driven fire pump control wiring shall be in rigid metal conduit, inter-mediate metal conduit, liquidtight flexible metal conduit, electrical metallic tubing, liquidtight flexible nonmetallic conduit, listed Type MC cable with an imper-vious covering, or Type MI cable.

(F) Generator Control Wiring Methods. The integrity of the generator control wiring shall be continuously monitored. Loss of integrity of the remote start circuit(s) shall initiate visual and audible annunciation ofgenerator malfunction at the generator local and remote annunciator(s) and start the generator(s).

Change Description:(E) The three Types of Liquidtight Flexible Nonmetallic Conduit that are described in 356.2 are required to be Listed to UL 1660 Liquidtight Flexible Nonmetallic Conduit. All three Types of LFNC are required to meet the same physical performance testing, such as cold temperature impact, vertical flame, tension, deformation, etc, per UL 1660. Each Type of LFNC is equivalent and are acceptable wiring methods for Fire Pump Control Wiring.

(F) The addition of requirements for the generator start circuit will ensure that there will be power to the terminals of the fire pump controller in the event of failure to the start circuit. It will also supervise the start circuit under normal conditions, such that an open/failure of the start circuit will start the generator and alert the occupants in the event of a normal power loss that the fire pump will not be available.


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Article 695 Fire Pumps


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695.15 Surge Protection. A listed surge protection device shall be installed in or on the fire pump controller.

Change Description:Added a new section. The surge protection device is necessary to provide protection for the fire pump controller. The location and type of surge protection device is a design issue and should remain with the designer and/or installer. These devices are already required to be listed by 285.5.


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I. General700.3 Tests and Maintenance(C) Battery Systems Maintenance. Where battery systems or unit equipments are involved, including batteries used for starting, control, or ignition in auxiliary engines, theauthority having jurisdiction shall require periodic maintenance.

Part I. General700.3 Tests and Maintenance(C) Maintenance. Emergency system equipment shall be maintained in accordance with manufacturer instructions and industry standards.

Change Description:Section 700.3 provides requirements for tests and maintenance. Requirements for testing are adequately covered in 700.3(A), (B) and (E). The previous requirementfor maintenance, which was limited to batteries, is expanded to include all emergency equipment.

As battery chemistries other than lead-acid or nickel-cadmium are used in back-up emergency power systems, the NEC needs to evolve to consider their maintenance requirements and to mandate that such maintenance be performed in accordance with manufacturer instructions and industry standards.

All parts of the emergency system will not need regular or periodic maintenance. However, generators, transfer switches, some types of circuit breakers and other equipment are required to have maintenance performed. The required maintenance is outlined by the equipment manufacturer and applicable industry standards.

Impact(s):No negative impact. However, current maintenance and periodic testing procedures will need to be evaluated and revised to implement this requirement.

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(continued) (continued)(F) Temporary Source of Power for Maintenance or Repair of the Alternate Source of Power. If the emergency system relies on a single alternate source of power, which will be disabled for maintenance or repair, the emergency system shall include permanent switching means to connect a portable or temporary alternate source of power, which shall be available for the duration of the maintenance or repair. The permanent switching means to connect a portable or temporary alternate source of power shall comply with the following:(1) Connection to the portable or temporary alternate source of power shall not require modification of the permanent system wiring.(2) Transfer of power between the normal power source and the emergency power source shall be in accordance with 700.12.(3) The connection point for the portable or temporary alternate source shall be marked with the phase rotation and system bonding requirements.(4) Mechanical or electrical interlocking shall prevent inadvertent interconnection of power sources.

Change Description:The existing last paragraph in 700.4(B) provides a performance based requirements for a portable or temporary alternate source to be available whenever the emergency generator is out of service for maintenance or repair. No prescriptive requirements exist.

This new first level subdivision provides a prescriptive requirement along with an exception that recognizes where a permanent switching means to temporarily connect an alternate source of power is not required.

This revision provides necessary clarity to the maintenance requirements of emergency systems.


Article 700 Emergency Systems


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(continued) (5) The switching means shall include a contact point that shall annunciate at a location remote from the generator or at another facility monitoring system to indicate thatthe permanent emergency source is disconnected from the emergency system.It shall be permissible to utilize manual switching to switch from the permanent source of power to the portable or temporary alternate source of power and to utilize the switching means for connection of a load bank.Informational Note: There are many possible methods to achieve the requirements of 700.3(F). See Figure 700.3(F) for one example.Exception: The permanent switching means to connect a portable or temporary alternate source of power, for the duration of the maintenance or repair, shall not be required where any of the following conditions exists:(1) All processes that rely on the emergency system source are capable of being disabled during maintenance or repair of the emergency source of power.(2) The building or structure is unoccupied and fire suppression systems are fully functional and do not require an alternate power source.(3) Other temporary means can be substituted for the emergency system.(4) A permanent alternate emergency source, such as, but not limited to, a second on-site standby generator or separate electric utility service connection, capable of supporting the emergency system, exists.

700.5 Transfer Equipment. 700.5 Transfer Equipment.(E) Documentation. The short-circuit current rating of the transfer equipment, based on the specific overcurrent protective device type and settings protecting the transfer equipment, shall be field marked on the exterior of the transfer equipment.

Change Description:New section added. Transfer equipment is required to be marked per UL 1008 with the short-circuit withstand/closing or short-time current rating (short-circuit current rating). UL 1008 for Transfer Switch Equipment has many options for short-circuit protection. Typically a transfer switch is usually marked by the manufacturer with several different options resulting in many short-circuit current rating values. These marked short-circuit current rating values can vary based upon the overcurrent protective device type, ampere rating and settings. For an actual specific installation, this can be confusing for an inspector because it is not obvious which short-circuit current rating is being utilized: that is the short-circuit current rating value with specific installed type overcurrent protective device, ampere rating, and settings. Therefore, the short-circuit current rating of the transfer switch, which is based on the specific overcurrent protection provided, should be additionally field marked on the equipment. The available fault current must be documented to verify compliance with NEC 110.3(B) and 110.10. In this requirement the term “short-circuit current rating” includes all the various options by which UL 1008 evaluates transfer switches for fault currents, such as “short-circuit withstand and closing rating”, “short-time current rating” and the common industry term “withstand/close-on rating.”


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700.6 Signals.(D) Ground Fault. To indicate a ground fault in solidly grounded wye emergency systems of more than 150 volts to ground and circuit-protective devices rated 1000 amperesor more. The sensor for the ground-fault signal devices shall be located at, or ahead of, the main system disconnecting means for the emergency source, and the maximum setting of the signal devices shall be for a ground-fault current of 1200 amperes. Instructions on thecourse of action to be taken in event of indicated ground fault shall be located at or near the sensor location.

700.6 Signals.(D) Ground Fault. To indicate a ground fault in solidly grounded wye emergency systems of more than 150 volts to ground and circuit-protective devices rated 1000 amperes or more. The sensor for the ground-fault signal devices shall be located at, or ahead of, the main system disconnecting means for the emergency source, and the maximum setting of the signal devices shall be for a ground-fault current of 1200 amperes. Instructions on the course of action to be taken in event of indicated ground fault shall be located ator near the sensor location. For systems with multiple emergency sources connected to aparalleling bus, the ground fault sensor shall be permitted tobe at an alternative location.

Change Description:The additional text is added to recognize that systems with multiple sources connected to a paralleling bus may bond the neutral in the paralleling switchgear, and the ground fault sensing means cannot be located at or ahead of the main system (usually a generator) disconnecting means.

For multiple emergency sources ground fault sensing may be determined by zero sequence sensing, differential relaying of the paralleling bus in conjunction with residual ground fault sensing device of the feeders, or other equivalent means.

Revised sections 700.6 (D) and 701.6 (D) to clarify the location for the ground fault sensor for systems with multiple emergency sources connected to a paralleling bus.


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II. Circuit Wiring700.10 Wiring, Emergency System.(A) Identification. All boxes and enclosures (including transfer switches, generators, and power panels) for emergency circuits shall be permanently marked so they will be readily identified as a component of an emergency circuit or system.

Part II. Circuit Wiring700.10 Wiring, Emergency System.(A) Identification. Emergency circuits shall be permanently marked so they will be readily identified as a component of an emergency circuit or system by the following methods:(1) All boxes and enclosures (including transfer switches, generators, and power panels) for emergency circuits shall be permanently marked as a component of an emergencycircuit or system.(2) Where boxes or enclosures are not encountered, exposed cable or raceway systems shall be permanently marked to be identified as a component of an emergency circuit or system, at intervals not to exceed 7.6 m (25 ft).Receptacles supplied from the emergency system shall have a distinctive color or marking on the receptacle cover plates or the receptacles.

Change Description:Marking of receptacles supplied from an emergency systemis necessary for the end user to identify emergency supplied devices for connection to equipment needed where there is a loss of normal power.


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(continued)(D) Fire Protection.(3) Generator Control Wiring. Control conductors installed between the transfer equipment and the emergency generator shall be kept entirely independent of all otherwiring and shall meet the conditions of 700.10(D)(1).

(continued)(D) Fire Protection.(3) Generator Control Wiring. Control conductors installed between the transfer equipment and the emergency generator shall be kept entirely independent of all otherwiring and shall meet the conditions of 700.10(D)(1).The integrity of the generator control wiring shall be continuously monitored. Loss of integrity of the remote start circuit(s) shall initiate visual and audible annunciation of generator malfunction at the generator local and remote annunciator(s) and start the generator(s).

Change Description:Adding this requirement will insure that there will be power to the emergency terminals of the transfer equipment in the event of failure of the generator start circuit. It will also serve to supervise the start circuit under normal conditions, in that an open or failure of the start circuit will start the generator and alert the occupants that a problem exists.


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III. Sources of Power700.12 General Requirements.(A) Storage Battery. Storage batteries used as a source of power for emergency systems shall be of suitable rating and capacity to supply and maintain the total load for a minimumperiod of 11∕2 hours, without the voltage applied to the load falling below 871∕2 percent of normal. Batteries, whether of the acid or alkali type, shall be designed and constructed to meet the requirements of emergency service and shall be compatible with the charger for that particular installation.For a sealed battery, the container shall not be required to be transparent. However, for the lead acid battery that requires water additions, transparent or translucent containers shall be furnished. Automotive-type batteries shall not be used. An automatic battery charging means shall be provided.

Part III. Sources of Power700.12 General Requirements.(A) Storage Battery. Storage batteries shall be of suitable rating and capacity to supply and maintain the total load for a minimum period of 11∕2 hours, without the voltage applied to the load falling below 871∕2 percent of normal. Automotive-type batteries shall not be used.An automatic battery charging means shall be provided.

Change Description:This revision recognizes there are many battery types that now can be used. The critical voltage criterion is that the voltage does not drop below the load equipment’s minimum voltage specification value.


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V. Control — Emergency Lighting Circuits700.25 Automatic Load Control Relay. If an emergency lighting load is automatically energized upon loss of the normal supply, a listed automatic load control relay shall bepermitted to energize the load. The load control relay shall not be used as transfer equipment.

Part V. Control — Emergency Lighting Circuits700.25 Branch Circuit Emergency Lighting Transfer Switch. Emergency lighting loads supplied by branch circuits rated at not greater than 20 amperes shall be permitted to be transferred from the normal branch circuit to an emergency branch circuit using a listed branch circuit emergency lighting transfer switch. The mechanically held requirement of 700.5(C) shall not apply to listed branch circuit emergency lighting transfer switches.

Change Description:New section added. This addition addresses a new class of transfer switching devices intended for operation of individual branch circuits in an emergency lighting system. The design requirements are in UL 1008.


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I. General701.3 Tests and Maintenance(C) Battery Systems Maintenance. Where batteries are used for control, starting, or ignition of prime movers, the authority having jurisdiction shall require periodic maintenance.

Part I. General701.3 Tests and Maintenance(C) Maintenance. Legally required standby system equipment shall be maintained in accordance with manufacturer instructions and industry standards.

Change Description:Section 701.3 provides requirements for tests and maintenance. Requirements for testing are adequately covered in 701.3(A), (B) and (E). The previous requirement for maintenance, which was limited to batteries, is expanded to include all emergency equipment.

As battery chemistries other than lead-acid or nickel-cadmium are used in back-up emergency power systems, the NEC needs to evolve to consider their maintenance requirements and to mandate that such maintenance be performed in accordance with manufacturer instructions and industry standards.

All parts of the legally required standby systems will not need regular or periodic maintenance. However, generators, transfer switches, some types of circuit breakers and other equipment are required to have maintenance performed. The required maintenance is outlined by the equipment manufacturer and applicable industry standards.

Impact(s):No negative impact. However, current maintenance and periodic testing procedures will need to be evaluated and revised to implement this requirement.

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701.5 Transfer Equipment. 701.5 Transfer Equipment.(D) Documentation. The short-circuit current rating of the transfer equipment, based on the specific overcurrent protective device type and settings protecting the transfer equipment, shall be field marked on the exterior of the transfer equipment.

Change Description: New section added. Transfer equipment is required to be marked per UL 1008 with the short-circuit withstand/closing or short-time current rating (short-circuit current rating). UL 1008 for Transfer Switch Equipment has many options for short-circuit protection. Typically a transfer switch is usually marked by the manufacturer with several different options resulting in many short-circuit current rating values. These marked short-circuit current rating values can vary based upon the overcurrent protective device type, ampere rating and settings. For an actual specific installation, this can be confusing for an inspector because it is not obvious which short-circuit current rating is being utilized: that is the short-circuit current rating value with specific installed type overcurrent protective device, ampere rating, and settings. Therefore, the short-circuit current rating of the transfer switch, which is based on the specific overcurrent protection provided, should be additionally field marked on the equipment. The available fault current must be documented to verify compliance with NEC 110.3(B) and 110.10. In this requirement the term “short-circuit current rating” includes all the various options by which UL 1008 evaluates transfer switches for fault currents, such as “short-circuit withstand and closing rating”, “short-time current rating” and the common industry term “withstand/close-on rating.”


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701.6 Signals.(D) Ground Fault. To indicate a ground fault in solidly grounded wye, legally required standby systems of more than 150 volts to ground and circuit-protective devicesrated 1000 amperes or more. The sensor for the groundfault signal devices shall be located at, or ahead of, the main system disconnecting means for the legally requiredstandby source, and the maximum setting of the signal devices shall be for a ground-fault current of 1200 amperes.Instructions on the course of action to be taken in event of indicated ground fault shall be located at or near the sensor location.

701.6 Signals.(D) Ground Fault. To indicate a ground fault in solidly grounded wye, legally required standby systems of more than 150 volts to ground and circuit-protective devices rated1000 amperes or more. The sensor for the ground-fault signal devices shall be located at, or ahead of, the main system disconnecting means for the legally required standby source, and the maximum setting of the signal devices shall be for a groundfault current of 1200 amperes. Instructions on the course of action to be taken in event of indicated ground fault shall be located at or near the sensor location. For systems with multiple emergency sources connected to a paralleling bus, the ground fault sensor shall be permitted at an alternate location.

Change Description:701.6(D) is revised to correlate with the revision made in section 700.6. The additional text is added to recognize that systems with multiple sources connected to a paralleling bus may bond the neutral in the paralleling switchgear, and the ground fault sensing means cannot be located at or ahead of the main system (usually a generator) disconnecting means.


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Article 701 Legally Required Standby Systems


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III. Sources of Power701.12 General Requirements.(A) Storage Battery. A storage battery shall be of suitable rating and capacity to supply and maintain at not less than 87½ percent of system voltage the total load of the circuitssupplying legally required standby power for a period of at least 1½ hours.Batteries, whether of the acid or alkali type, shall be designed and constructed to meet the service requirements of emergency service and shall be compatible with thecharger for that particular installation.For a sealed battery, the container shall not be required to be transparent. However, for the lead acid battery that requires water additions, transparent or translucent containers shall be furnished. Automotive-type batteries shall not be used. An automatic battery charging means shall be provided.

Part III. Sources of Power701.12 General Requirements.(A) Storage Battery. Storage batteries shall be of suitable rating and capacity to supply and maintain the total load for a minimum period of 1½ hours without the voltage applied tothe load falling below 87½ percent of normal. Automotive type batteries shall not be used. An automatic battery charging means shall be provided.

Change Description:This revision recognizes there are many battery types that now can be used. The critical voltage criterion is that the voltage does not drop below the load equipment’s minimum voltage specification value. This revision correlates with the revised 700.12(A).

Impact(s):No negative impact 2

701.6 Signals.(D) Ground Fault. To indicate a ground fault in solidly grounded wye emergency systems of more than 150 volts to ground and circuit-protective devices rated 1000 amperesor more. The sensor for the ground-fault signal devices shall be located at, or ahead of, the main system disconnecting means for the emergency source, and the maximum setting of the signal devices shall be for a ground-fault current of 1200 amperes. Instructions on thecourse of action to be taken in event of indicated ground fault shall be located at or near the sensor location.

701.6 Signals.(D) Ground Fault. To indicate a ground fault in solidly grounded wye emergency systems of more than 150 volts to ground and circuit-protective devices rated 1000 amperes or more. The sensor for the ground-fault signal devices shall be located at, or ahead of, the main system disconnecting means for the emergency source, and the maximum setting of the signal devices shall be for a ground-fault current of 1200 amperes. Instructions on the course of action to be taken in event of indicated ground fault shall be located ator near the sensor location. For systems with multiple emergency sources connected to aparalleling bus, the ground fault sensor shall be permitted to be at an alternate location.

Change Description:The additional text is added to recognize that systems with multiple sources connected to a paralleling bus may bond the neutral in the paralleling switchgear, and the ground fault sensing means cannot be located at or ahead of the main system (usually a generator) disconnecting means.

For multiple emergency sources ground fault sensing may be determined by zero sequence sensing, differential relaying of the paralleling bus in conjunction with residual ground fault sensing device of the feeders, or other equivalent means.

Revised sections 700.6 (D) and 701.6 (D) to clarify the location for the ground fault sensor for systems with multiple emergency sources connected to a paralleling bus.


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I. General702.5 Transfer Equipment. Transfer equipment shall be suitable for the intended use and designed and installed so as to prevent the inadvertent interconnection of normal andalternate sources of supply in any operation of the transfer equipment. Transfer equipment and electric power production systems installed to permit operation in parallel with the normal source shall meet the requirements of Article 705. Transfer equipment, located on the load side of branch circuit protection, shall be permitted to contain supplemental overcurrent protection having an interrupting rating sufficient for the available fault current that the generator can deliver. The supplementary overcurrent protection devices shall be part of a listed transfer equipment. Transfer equipment shall be required for all standby systems subject to the provisions of this article and for which an electric utility supply is either the normal or standby source.

Part I. General702.5 Transfer Equipment. Transfer equipment shall be suitable for the intended use and designed and installed so as to prevent the inadvertent interconnection of normal and alternate sources of supply in any operation of the transfer equipment. Transfer equipment and electric power production systems installed to permit operation in parallel with the normal source shall meet the requirements of Article 705.Transfer equipment, located on the load side of branch circuit protection, shall be permitted to contain supplemental overcurrent protection having an interrupting rating sufficient for the available fault current that the generator can deliver. The supplementary overcurrent protection devices shall be part of a listed transfer equipment.Transfer equipment shall be required for all standby systems subject to the provisions of this article and for which an electric utility supply is either the normal or standby source.The short-circuit current rating of the transfer equipment, based on the specific overcurrent protective device type and settings protecting the transfer equipment, shall be field marked on the exterior of the transfer equipment.

Change Description: New section added. Transfer equipment is required to be marked per UL 1008 with the short-circuit withstand/closing or short-time current rating (short-circuit current rating). UL 1008 for Transfer Switch Equipment has many options for short-circuit protection. Typically a transfer switch is usually marked by the manufacturer with several different options resulting in many short-circuit current rating values. These marked short-circuit current rating values can vary based upon the overcurrent protective device type, ampere rating and settings. For an actual specific installation, this can be confusing for an inspector because it is not obvious which short-circuit current rating is being utilized: that is the short-circuit current rating value with specific installed type overcurrent protective device, ampere rating, and settings. Therefore, the short-circuit current rating of the transfer switch, which is based on the specific overcurrent protection provided, should be additionally field marked on the equipment. The available fault current must be documented to verify compliance with NEC 110.3(B) and 110.10. In this requirement the term “short-circuit current rating” includes all the various options by which UL 1008 evaluatestransfer switches for fault currents, such as “short-circuit withstand and closing rating”, “short-time current rating” and the common industry term “withstand/close-on rating.”


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II. Wiring702.12 Outdoor Generator Sets.

Part II. Wiring702.12 Outdoor Generator Sets.(C) Power Inlets Rated at 100 Amperes or Greater, for Portable Generators. Equipment containing power inlets for the connection of a generator source shall be listed for theintended use. Systems with power inlets shall be equipped with an interlocked disconnecting means.Exception No. 1: If the inlet device is rated as a disconnecting meansException No. 2: Supervised industrial installations where permanent space is identified for the portable generator located within line of sight of the power inlets shall not be required to have interlocked disconnecting means nor inlets rated as disconnects.

Change Description:New section added. This revision provides prescriptive requirements for power inlets used with portable generators rated at 100 amps or more. This requirement provides a necessary means to ensure that disconnection of the power inlet does not occur under load.


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Article 702 Optional Standby Systems


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II. Utility-Interactive Inverters705.65 Overcurrent Protection.

Part II. Interactive Inverters705.65 Overcurrent Protection.(C) Conductor Ampacity. Power source output circuit conductors that are connected to a feeder, if smaller than the feeder conductors, shall be sized to carry not less than the larger of the current as calculated in 705.60(B) or as calculated in accordance with 240.21(B) based on the over-current device protecting the feeder.

Change Description:New section added. This revision properly locates the requirements for overcurrent protection of an inverter output circuit connected to a feeder.


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New Article in 2017. Change Description:New Article added addressing energy storage systems.

Impact(s): No negative impact.

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II. Circuit Wiring and Equipment708.10 Feeder and Branch Circuit Wiring.(A) Identification.(2) Receptacle Identification. In a building in whichCOPS are present with other types of power systems described in other sections in this article, the cover plates for the receptacles or the receptacles themselves supplied fromthe COPS shall have a distinctive color or marking so as to be readily identifiable.

Part II. Circuit Wiring and Equipment708.10 Feeder and Branch Circuit Wiring.(A) Identification.(2) Receptacle Identification. Nonlocking-type, 125-volt, 15- and 20-ampere receptacles supplied from the COPS shall have an illuminated face or an indicator light to indicate that there is power to the receptacle.

Change Description:This revision provides for ready and continuous ability to identify devices that are part of the COPS. This performance based requirement is essential in a COPS facility.


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III. Power Sources and Connection708.24 Transfer Equipment.

Part III. Power Sources and Connection708.24 Transfer Equipment.(E) Documentation. The short-circuit current rating of the transfer equipment, based on the specific overcurrent protective device type and settings protecting the transfer equipment, shall be field marked on the exterior of the transfer equipment.

Change Description:New section added. Transfer equipment is required to be marked per UL 1008 with the short-circuit withstand/closing or short-time current rating (short-circuit current rating). UL 1008 for Transfer Switch Equipment has many options for short-circuit protection. Typically a transfer switch is usually marked by the manufacturer with several different options resulting in many short-circuit current rating values. These marked short-circuit current rating values can vary based upon the overcurrent protective device type, ampere rating and settings. For an actual specific installation, this can be confusing for an inspector because it is not obvious which short-circuit current rating is being utilized: that is the short-circuit current rating value with specific installed type overcurrent protective device, ampere rating, and settings. Therefore, the short-circuit current rating of the transfer switch, which is based on the specific overcurrent protection provided, should be additionally field marked on the equipment. The available fault current must be documented to verify compliance with NEC 110.3(B) and 110.10. In this requirement the term “short-circuit current rating” includes all the various options by which UL 1008 evaluates transfer switches for fault currents, such as “short-circuit withstand and closing rating”, “short-time current rating” and the common industry term “withstand/close-on rating.”


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Article 705 Interconnected Electric Power Production Sources

Article 706 Energy Storage Systems

Article 708 Critical Operations Power Systems (COPS)


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710.1 Scope. This article covers electric power production sources operating in stand-alone mode.710.6 Equipment Approval. All equipment shall be listed or field labeled for the intended use.710.15 General. Premises wiring systems shall be adequate to meet the requirements of this Code for similar installations supplied by a feeder or service. The wiring on the supply side of the building or structure disconnecting means shall comply with the requirements of this Code, except as modified by 710.15(A) through (F).(A) Supply Output. Power supply to premises wiring systems shall be permitted to have less capacity than the calculated load. The capacity of the stand-alone supply shall be equal to or greater than the load posed by the largest single utilization equipment connected to the system. Calculated general lighting loads shall not be considered as a single load. (B) Sizing and Protection. The circuit conductors between a stand-alone source and a building or structure disconnecting means shall be sized based on the sum of the output ratings of the stand-alone sources.

(C) Single 120-Volt Supply. Stand-alone systems shall be permitted to supply 120 volts to single-phase, 3-wire, 120/240-volt service equipment or distribution panels where there are no 240-volt outlets and where there are no multiwire branch circuits. In all installations, the sum of the ratings of the power sources shall be less than the rating of the neutral bus in the service equipment. This equipment shall be marked with the following words or equivalent:WARNING: SINGLE 120-VOLT SUPPLY. DO NOT CONNECT MULTIWIRE BRANCH CIRCUITS!The warning sign(s) or label(s) shall comply with 110.21(B).(D) Energy Storage or Backup Power System Requirements. Energy storage or backup power supplies are not required. (E) Back-Fed Circuit Breakers. Plug-in type back-fed circuit breakers connected to an interconnected supply shall be secured in accordance with 408.36(D). Circuit breakers marked “line” and “load” shall not be back-fed.(F) Voltage and Frequency Control. The stand-alone supply shall be controlled so that voltage and frequency remain within suitable limits for the connected loads.

New Article in 2017. Change Description:New Article covering Direct Current microgrids added.


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I. General725.3 Other Articles.(C) Ducts, Plenums, and Other Air-Handling Spaces. Class 1, Class 2, and Class 3 circuits installed in ducts, plenums, or other space used for environmental air shall comply with 300.22. Exception: As permitted in Table 725.154.

Part I. General725.3 Other Articles.(C) Ducts, Plenums, and Other Air-Handling Spaces. Class 1, Class 2, and Class 3 circuits installed in ducts, plenums, or other space used for environmental air shall comply with 300.22.Exception No. 1: Class 2 and Class 3 cables selected in accordance with Table 725.154 and installed in accordance with 725.135(B) and 300.22(B), Exception shall be permitted to be installed in ducts specifically fabricated for environmental air.Exception No. 2: Class 2 and Class 3 cables selected in accordance with Table 725.154 and installed in accordance with 725.135(C) shall be permitted to be installed in other spaces used for environmental air (plenums).

Change Description:This revision aligns this section with changes to Section 300.22(B). The modified 300.22(B) added a new Exception indicating Class 2 and Class 3 cables are permitted in ducts specifically fabricated for environmental air with two conditions (a) The wiring methods or cabling systems shall be permitted only if necessary to connect to equipment or devices associated with the direct action upon, or sensing of the contained air and (b) The total length of such wiring methods or cabling systems shall not exceed 1.2 m (4 ft). These two conditions correspond to Section 4.3.4.2 in NFPA 90A—2015. Class 2 or Class 3 plenum rated cable is acceptable in ducts specifically fabricated for environmental air but only where connecting to equipment used to sense or has direction action on the contained air and limited to a maximum of 4foot length based on NFPA 90A.


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Article 725 Class 1, Class 2, and Class 3 Remote-Control, Signaling and Power-Limited Circuits

Article 712 Direct Current Microgrids

Article 710 Stand-Alone SystemsChange Description:This new Article addresses requirements for power supply systems which are independent (stand-alone) and not connected to the power distribution grid (e.g. signs fed from photovoltaic panels with storage batteries).


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(continued) (continued)(M) Cable Routing Assemblies. Class 2, Class 3, and Type PLTC cables shall be permitted to be installed in plenum cable routing assemblies, riser cable routing assemblies, and general purpose cable routing assemblies selected in accordance with Table 800.154(c), listed in accordance with the provisions of 800.182, and installed in accordance with 800.110(C) and 800.113.(N) Communications Raceways. Class 2, Class 3, and Type PLTC cables shall be permitted to be installed in plenum communications raceways, riser communications raceways, and general-purpose communications raceways selected in accordance with the provisions of Table 800.154(b), listed in accordance with 800.182, and installed in accordance with 800.113 and 362.24 through 362.56, where the requirements applicable to electrical nonmetallic tubing (ENT) apply.

Change Description:This revision added a new sections 725.3(M) and (N) to provide consistency in the selection, listing and installation requirements for cable routing assemblies and communications raceways.


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III. Class 2 and Class 3 Circuits725.121 Power Sources for Class 2 and Class 3 Circuits.

Part III. Class 2 and Class 3 Circuits725.121 Power Sources for Class 2 and Class 3 Circuits.(C) Marking. The power sources for limited power circuits in 725.121(A)(3) and limited power circuits for listed audio/video information technology (equipment) and listed industrial equipment in 725.121(A)(4) shall have a label indicating the maximum voltage and current output for each connection point. The effective date shall be January 1, 2018.

Change Description:This new section addresses labeling of limited power circuit output connection points on listed IT equipment and listed industrial control panels and equipment. Bundling of large numbers of Class 2 conductors from IT servers and other similar IT and industrial equipment can create safety issues with very small current levels so having the output ports identified with the current and voltage rating is critical so the installer can connect the proper cable types. Labeling the output connections will permit the installer to have ready access to the current and voltage levels at the point of connection at the equipment, rather than internally within the equipment. The effective date was inserted to allow the manufacturers to comply with this requirement.


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725.135 Installation of Conductors and Equipment in Cables, Compartments, Cable Trays, Enclosures, Manholes, Outlet Boxes, Device Boxes, Raceways, and Cable Routing Assemblies for Class 2 and Class 3 Circuits.(J) Industrial Establishments.

(K) Other Building Locations.

725.135 Installation of Conductors and Equipment in Cables, Compartments, Cable Trays, Enclosures, Manholes, OutletBoxes, Device Boxes, Raceways, and Cable Routing Assemblies for Class 2 and Class 3 Circuits.(J) Industrial Establishments. Where not subject to physical damage, Type PLTC-ER cable shall be permitted to transition between cable trays and between cable trays and utilization equipment or devices for a distance not to exceed 1.8 m (6 ft) without continuous support. The cable shallbe mechanically supported where exiting the cable tray to ensure that the minimum bending radius is not exceeded.

(K) Other Building Locations.(6) Type CMUC undercarpet communications wires and cables installed under carpet, modular flooring, and planks

Change Description:Added new text to (J) - An exception for TC-ER cable exists in Article 336.10 (7) which permits the cable “to transition between cable trays and between cable trays and utilization equipment or devices for a distance not to exceed 1.8 m (6 ft) without continuous support.” The same allowance is being permitted for PLTC-ER cables since the construction of these cables are the similar to TC-ER cables.

Added new text to (K) - The revised text introduces the useof floor coverings other than carpet. Based on the Fact Finding investigation, there were no additional heating effects caused by the alternate flooring when tested using type FCC cables. Type FCC cables carry more power than CMUC. Therefore the results of the fact finding report should also be applicable to CMUC. Based on testing, the type of flooring does not have an impact on the performance of the cables.


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(continued) 725.144 Transmission of Power and Data. The requirements of 725.144(A) and (B) shall apply to Class 2 and Class 3 circuits that transmit power and data to a powered device. The requirements of Parts I and III of Article 725 and 300.11 shall apply to Class 2 and Class 3 circuits that transmit power and data. The conductors that carry power for the data circuits shall be copper. The current in the power circuit shall not exceed the current limitation of the connectors.(A) Use of Class 2 or Class 3 Cables to Transmit Power and Data. Where Types CL3P, CL2P, CL3R, CL2R, CL3, or CL2 transmit power and data, the following shall apply, as applicable:(1) The ampacity ratings in Table 725.144 shall apply at an ambient temperature of 30°C (86°F).(2) For ambient temperatures above 30°C (86°F), the correction factors of 310.15(B)(2) shall apply.

Change Description:New section added addressing concerns related to bundling of power/data cables. The results of the testing and the UL Fact Finding Report clearly indicate a potential hazard when bundling these cables together. If bundling of cables does not occur or is limited to small bundles, the current limitations in the ampacity table are well above anything the industries are currently using or even anticipating for the foreseeable future and the alternative, optional, LP cables would not need to be considered. Where bundling does occur, the ampacity table or optional use of LP cables can be used to mitigate the potential hazard. The UL Fact Finding Report provides information on introducing power and data on the same cable and possible hazards relating to cable overheating when bundling large quantities of powered LAN cables together. The evolving power over LAN cable schemes introduce, on a broad scale, issues such as relatively small wire gauges and very large, tightly packed bundles of cable that result in significant cable heating. Previous Class 2 and Class 3 power sources, voltage, and current levels provided in the listing requirements in 725.121 and Tables 11(A) and (B) were never intended to


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(continued) (continued)(B) Use of Class 2-LP or Class 3-LP Cables to Transmit Power and Data. Types CL3P-LP, CL2P-LP, CL3R-LP, CL2R-LP, CL3-LP, or CL2-LP shall be permitted to supply power to equipment at a current level up to the marked ampere limit located immediately following the suffix LP and shall be permitted to transmit data to the equipment. The Class 2-LP and Class 3-LP cables shall comply with the following, as applicable:Informational Note 1: The “(xxA)” following the suffix -LP indicates the ampacity of each conductor in a cable.Informational Note 2: An example of a limited power (LP) cable is a cable marked Type CL2-LP(0.5A), 23 AWG. A Type CL2-LP(0.5), 23 AWG could be used in any location where a Type CL2 could be used; however, the LP cable would be suitable for carrying up to 0.5 A per conductor, regardless of the number of cables in a bundle. If used in a 7-cable bundle, the same cable could carry up to 1.2 amperes per conductor.(1) Cables with the suffix “-LP” shall be permit-ted to be installed in bundles, raceways, cable trays, communications raceways, and cable routing assemblies.(2) Cables with the suffix “-LP” and a marked ampere level shall follow the substitution hierarchy of Table 725.154 and Figure 725.154(A) for the cable type without thesuffix “LP” and without the marked ampere level.(3) System design shall be permitted by qualified persons under engineering supervision.

725.154 Applications of Listed Class 2, Class 3, and PLTC Cables. 725.154 Applications of Listed Class 2, Class 3, and PLTC Cables.Table 725.154 Applications of Listed Class 2, Class 3, CMUC, and PLTC Cables in Buildings.In other spaces used for environmental air as described in 300.22(C) CL2P & CL3P cables are allowed in plemum cable routing assemblies - subject to limitations described in 725.130 through 725.143

Change Description:Revised the title to Table 725.154 to include CMUC that is covered in the table and revised the table to include the permitted use of cable routing assemblies as permitted by NFPA 90A.


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IV. Listing Requirements Part IV. Listing Requirements725.170 Listing and Marking of Equipment for Power and Data Transmission. The listed power source for circuits intended to provide power and data over Class 2 cables to remote equipment shall be as specified in 725.121(A)(1), (A)(2), (A)(3), or (A)(4). In accordance with 725.121(B), the power sources shall not have the output connections paralleled or otherwise interconnected, unless listed for such interconnection. Powered devices connected to a circuit supplying data and power shall be listed. Marking of equipment output connections shall be in accordance with 725.121(C).

Change Description:This new section provides appropriate references to other Sections within Article 725 that apply to Power and Data Transmission equipment. Marking of the output connections was referred back to 725.121(C) where the marking requirement originates.


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727.4 Uses Permitted. 727.4 Uses Permitted.Exception to (5): Where not subject to physical damage, Type ITC-ER shall be permitted to transition between cable trays and between cable trays and utilization equipment or devices for a distance not to exceed 1.8 m (6 ft) without continuous support. The cable shall be mechanically supported where exiting the cable tray to ensure that the minimum bending radius is not exceeded.

Change Description:An exception for TC-ER cable exists in Article 336.10 (7) which permits the cable “to transition between cable trays and between cable trays and utilization equipment or devices for a distance not to exceed 1.8 m (6 ft) without continuous support.” The same allowance is being permitted for ITC-ER cables since the construction of these cables is similar to TC-ER cables.


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I. General760.3 Other Articles.(B) Ducts, Plenums, and Other Air-Handling Spaces. Section 300.22, where installed in ducts or plenums or other spaces used for environmental air.Exception: As permitted in 760.53(B)(1) and (B)(2) andTable 760.154.

Part I. General760.3 Other Articles.(B) Ducts, Plenums, and Other Air-Handling Spaces. Powerlimited and non-power-limited fire alarm cables installed in ducts, plenums, or other spaces used for environmental air shall comply with 300.22.Exception No. 1: Power-limited fire alarm cables selected in accordance with Table 760.154 and installed in accordance with 760.135(B) and 300.22(B), Exception shall be permitted to be installed in ducts specifically fabricated for environmental air. Exception No. 2: Power-limited fire alarm cables selected in accordance with Table 760.154 and installed in accordance with 760.135(C) shall be permitted to be installed in other spaces used for environmental air (plenums).

Change Description:The second exception was inserted to deal with power-limited fire alarm cables installed in other spaces used for environmental air (plenums). The reference to 300.22(B), Exception was inserted to ensure correlation with the requirements in NFPA 90A.


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Article 760 Fire Alarm Systems

Article 727 Instrumentation Tray Cable: Type ITC

t e st g equ e e ts 7 5. a d ab es ( ) a d ( ) we e eve te ded to

apply to power over LAN cable applications. The data from the fact-finding investigation indicates that under various, reasonable installation conditions (i.e. installation methods commonly used for LAN cable), currents well below the limits permitted by the existing NEC Class 2 tables resulted in the overheating and/or melting of the cables. In a number of cases, a current of only 1 ampere per conductor resulted in measured temperatures within the bundle reaching 140°C in open air and exceeding 185°C in a cable routing assembly and in PVC conduit. The data clearly shows that for many common installation scenarios, overheating of cables is a safety concern that is being addressed in this new section.


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(continued) (continued)(L) Cable Routing Assemblies. Power-limited fire alarmcables shall be permitted to be installed in plenum cable routing assemblies, riser cable routing assemblies, andgeneral-purpose cable routing assemblies selected in accordance with Table 800.154(c), listed in accordance with the provisions of 800.182, and installed in accordance with 800.110(C) and 800.113.(M) Communications Raceways. Power-limited fire alarm cables shall be permitted to be installed in plenum communications raceways, riser communications raceways, and generalpurpose communications raceways selected in accordance with Table 800.154(b), listed in accordance with the provisions of 800.182, and installed in accordance with 800.113 and 362.24 through 362.56, where the requirements applicable to electrical non-metallic tubing apply.

Change Description:The new text clarifies the installation requirements for power-limited fire alarm cables by inserting new subsections covering cable routing assemblies and communications raceways.


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III. Power-Limited Fire Alarm (PLFA) Circuits760.135 Installation of PLFA Cables in Buildings.(C) Other Spaces Used For Environmental Air (Plenums).(3) Types FPLP and FPLP-CI cables supported by open metallic cable trays or cable tray systems

Part III. Power-Limited Fire Alarm (PLFA) Circuits760.135 Installation of PLFA Cables in Buildings.(C) Other Spaces Used For Environmental Air (Plenums)(3) Type FPLP cables installed in plenum routing assemblies

Change Description:The general requirements for materials in plenums in NFPA 90A-2015 implicitly include plenum cable routing assemblies. The text was revised to include plenum cable routing assemblies. NFPA 90A-2015 has expanded its requirements for materials exposed to the airflow in ceiling cavity plenums and raised floor plenums to include a “general rule” of either 1) noncombustible or 2) exhibiting a maximum flame spread index of 25 and a maximum smoke developed index of 50 when tested in accordance with ASTM E84, Standard Test Method for Surface Burning Characteristics of Building Materials, or ANSI/UL 723, Standard Test Method for Surface Burning Characteristics of Building Materials.


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760.154 Applications of Listed PLFA Cables. 760.154 Applications of Listed PLFA Cables.Table 760.154 Applications of Listed PLFA Cables in Buildings.FPLP & FPLP-CT cables are allowed in plemum cable routing assemblies - subject to limitations described in 760.130 through 760.145

Change Description:Cable routing assemblies has been revised from “not permitted” to one application of permitted for FPLP and not permitted for FPLR and FPL.


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IV. Listing Requirements760.176 Listing and Marking of NPLFA Cables.

(G) NPLFA Cable Markings.

Part IV. Listing Requirements760.176 Listing and Marking of NPLFA Cables. Non-power-limited fire alarm cables shall have a temperature rating of not less than 60°C (140°F).(G) NPLFA Cable Markings. Temperature rating shall be marked on the jacket of NPLFA cables that have a temperature rating exceeding 60°C (140°F).The jacket of NPLFA cables shall be marked with the conductor size.

Change Description:(C) The temperature rating of these cables is required to provide pertinent information so the installer is aware of the temperature limitation of the conductors.(G) Added temperature marking requirements to 760.176(G). The Panel maintains that 60°C is established and is a listing requirement.


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760.179 Listing and Marking of PLFA Cables and Insulated Continuous Line-Type Fire Detectors.(C) Ratings.

760.179 Listing and Marking of PLFA Cables and Insulated Continuous Line-Type Fire Detectors.(C) Ratings. The cable shall have a voltage rating of not less than 300 volts. The cable shall have a temperature rating of not less than 60°C (140°F).

Change Description:The temperature rating of these cables is required to provide pertinent information so the installer is aware of the temperature limitation of the conductors.


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II. Cables Outside and Entering Buildings Part II. Cables Outside and Entering Buildings770.44 Overhead (Aerial) Optical Fiber Cables. Overhead optical fiber cables containing a non–current-carrying metallic member entering buildings shall comply with 840.44(A) and (B).(A) On Poles and In-Span. Where outside plant optical fiber cables and electric light or power conductors are supported by the same pole or are run parallel to each other in-span, the conditions described in 770.44(A)(1) through (A)(4) shall be met.(1) Relative Location. Where practicable, the outside plant optical fiber cables shall be located below the electric light or power conductors.(2) Attachment to Cross-Arms. Attachment of outside plant optical fiber cables to a cross-arm that carries electric light or power conductors shall not be permitted.(3) Climbing Space. The climbing space through outside plant optical fiber cables shall comply with the requirements of 225.14(D).(4) Clearance. Supply service drops and sets of overhead service conductors of 0 to 750 volts running above and parallel to optical fiber cable service drops shall have a minimum separation of 300 mm (12 in.) at any point in the span, including the point of their attachment to the building. Clearance of not less than 1.0 m (40 in.) shall be maintained between the two services at the pole.

(continued)(B) Above Roofs. Outside plant optical fiber cables shall have a vertical clearance of not less than 2.5 m (8 ft) from all points of roofs above which they pass.Exception No. 1: The requirement of 770.44(B) shall not apply to auxiliary buildings such as garages and the like.Exception No. 2: A reduction in clearance above only the overhanging portion of the roof to not less than 450 mm (18 in.) shall be permitted if (a) not more than 1.2 m (4 ft) of optical fiber cable service drop cable passes above the roof overhang, and (b) the cable is terminated at a through-or above-the-roof raceway or approved support.Exception No. 3: Where the roof has a slope of not less than 100 mm in 300 mm (4 in. in 12 in.), a reduction in clearance to not less than 900 mm (3 ft) shall be permitted.Informational Note: For additional information regarding overhead wires and cables, see ANSI/IEEE C2-2012 , National Electric Safety Code, Part 2, Safety Rules for Overhead Lines.

770.48 Unlisted Cables and Raceways Entering Buildings.(A) Conductive and Nonconductive Cables. Unlisted conductive and nonconductive outside plant optical fiber cables shall be permitted to be installed in building spaces,other than risers, ducts used for environmental air, plenums used for environmental air, and other spaces used for environmental air, where the length of the cable within thebuilding, measured from its point of entrance, does not exceed 15 m (50 ft) and the cable enters the building from the outside and is terminated in an enclosure.(B) Nonconductive Cables in Raceway. Unlisted nonconductive outside plant optical fiber cables shall be permitted to enter the building from the outside and shall be permittedto be installed in any of the following raceways:(1) Intermediate metal conduit (IMC)(2) Rigid metal conduit (RMC)(3) Rigid polyvinyl chloride conduit (PVC)(4) Electrical metallic tubing (EMT)

770.48 Unlisted Cables Entering Buildings.(A) Conductive and Nonconductive Cables.The point of entrance shall be permitted to be extended from the penetration of the external wall or floor slab by continuously enclosing the entrance optical fiber cables in rigid metal conduit (RMC) or intermediate metal conduit (IMC) to the point of emergence.(B) Nonconductive Cables in Raceway.Unlisted nonconductive outside plant cables installed in rigid polyvinyl chloride conduit (PVC) or electrical metallic tubing (EMT) shall not be permitted to be installed in risers, ducts used for environmental air, plenums used for environmental air, and other spaces used for environmental air.

Change Description:This revision clarifies the intent of 770.48(A) and 770.48(B) and addresses the use of RMC and IMC to extend the point of entry. The additional text for 770.48(B) clarifies that rigid polyvinyl chloride conduit and electrical metallic tubing containing unlisted outside plant cable are not permitted to be installed in risers, air ducts or plenums. The last paragraph was added to provide clarity permitting the use of rigid polyvinyl chloride conduit (PVC) or electrical metallic tubing (EMT).


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IV. Grounding Methods770.100 Entrance Cable Bonding and Grounding.(B) Electrode.(3) In Buildings or Structures Without Intersystem Bonding Termination or Grounding Means.

Part IV. Grounding Methods770.100 Entrance Cable Bonding and Grounding.(B) Electrode.(3) In Buildings or Structures Without Intersystem Bonding Termination or Grounding Means....not less than 1.5 m (5 ft) in length and 12.7 mm (1∕2 in.) in diameter, driven, where practicable, into permanently damp earth and separated from lightning protection system conductors as covered in 800.53 and at least 1.8 m (6 ft) from electrodes of other systems. Steam, hot water pipes, or lightning protection system conductors shall not be employed as electrodes for non–current-carrying metallic members

Change Description:This revision edits the text to clarify that lightning protection system conductors, not just air terminals, are not be used as a part of the grounding electrode conductor or as a grounding electrode and removes redundant text regarding bonding, covered in Article 250.


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Article 770 Optical Fiber CablesChange Description:A section dealing with overhead outside plant optical fiber cables exists in Article 840 but not in Article 770. This revision fixes that omission.


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V. Installation Methods Within Buildings770.110 Raceways and Cable Routing Assemblies for Optical Fiber Cables.(A) Types of Raceways.(2) Communications Raceways. Optical fiber cables shall be permitted to be installed in listed plenum communications raceways, listed riser communications raceways, and listed general-purpose communications raceways selected in accordance with the provisions of 770.113, 800.110, and 800.113, and installed in accordance with 362.24 through 362.56, where the requirements applicable to electrical nonmetallic tubing (ENT) apply.

Part V. Installation Methods Within Buildings770.110 Raceways and Cable Routing Assemblies for Optical Fiber Cables.(A) Types of Raceways.(2) Communications Raceways. Optical fiber cables shall be permitted to be installed in plenum communications raceways, riser communications raceways, and general-purpose communications raceways selected in accordance with Table 800.154(b), listed in accordance with 800.182, and installed in accordance with 800.113 and 362.24 through 362.56, where the requirements applicable to electrical nonmetallic tubing (ENT) apply.

Change Description:Section 770.110(A)(2), communications raceways, is revised to include the applications requirements of Table 800.154(b), the listing requirements of 800.182, and for correlation and consistency with similar revisions to 770.110(C), cable routing assemblies. (Incorporated TIA 17-3)


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770.113 Installation of Optical Fiber Cables.(C) Other Spaces Used For Environmental Air (Plenums). The following cables shall be permitted in other spaces used for environmental air as described in 300.22(C):(1) Types OFNP and OFCP cables(2) Types OFNP and OFCP cables installed in plenum communications raceways(3) Types OFNP and OFCP cables supported by open metallic cable trays or cable tray systems(4) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC cables installedin raceways that are installed in compliance with 300.22(C)(5) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC cables supported by solid bottom metal cable trays with solid metal covers in other spaces used for environmental air (plenums), as described in 300.22(C)(6) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC cables installed in plenum communications raceways, riser communications raceways, or general-purpose communications raceways supported by solid bottom metal cable trays with solid metal covers in other spaces used for environmental air (plenums), as described in 300.22(C)

770.113 Installation of Optical Fiber Cables.(C) Other Spaces Used for Environmental Air (Plenums). The following cables shall be permitted in other spaces used for environmental air as described in 300.22(C):(1) Types OFNP and OFCP(2) Types OFNP and OFCP installed in plenum communications raceways listed in accordance with 800.182(3) Types OFNP and OFCP installed in plenum cable routing assemblies listed in accordance with 800.182(4) Types OFNP and OFCP supported by open metallic cable trays or cable tray systems(5) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC installed in raceways that are installed in compliance with 300.22(C)(6) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC supported by solid bottom metal cable trays with solid metal covers in other spaces used for environmental air (plenums), as described in 300.22(C)(7) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC installed in plenum communications raceways, riser communications raceways, or general-purpose commun-ications raceways listed in accordance with 800.182 or supported by solid bottom metal cable trays with solid metal covers in other spaces used for environmental air (plenums), as described in 300.22(C)

Change Description:The revised states that the only types of communications raceways and cable routing assemblies permitted must be listed as required in 800.182.


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(continued)(E) Risers — Cables in Metal Raceways. The following cables shall be permitted in metal raceways in a riser having firestops at each floor:(1) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC cables (2) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC cables installed in:a. Plenum communications racewaysb. Riser communications racewaysc. General-purpose communications racewaysInformational Note: See 770.26 for firestop requirementsfor floor penetrations.(F) Risers — Cables in Fireproof Shafts. The following cables shall be permitted to be installed in fireproof riser shafts having firestops at each floor:(1) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC cables(2) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC cables installed in:a. Plenum communications racewaysb. Plenum cable routing assembliesc. Riser communications racewaysd. Riser cable routing assembliese. General-purpose communications racewaysf. General-purpose cable routing assemblies

(H) Cable Trays. The following cables shall be permitted to be supported by cable trays:(1) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC cables

(continued)(E) Risers — Cables and Innerducts in Metal Raceways. The following cables and innerducts shall be permitted in metal raceways in a riser having firestops at each floor:(1) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC(2) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC installed in:a. Plenum communications raceways (innerduct)b. Riser communications raceways (innerduct)c. General-purpose communications raceways (inner‐ duct) Informational Note: See 770.26 for firestop requirements for floor penetrations.(F) Risers — Cables in Fireproof Shafts. The following cables shall be permitted to be installed in fireproof riser shafts having firestops at each floor:(1) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC(2) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC installed in:a. Plenum communications racewaysb. Plenum cable routing assembliesc. Riser communications racewaysd. Riser cable routing assembliese. General-purpose communications racewaysf. General-purpose cable routing assembliesInformational Note: See 770.26 for firestop requirements for floor penetrations.

(H) Cable Trays. The following cables shall be permitted to be supported by cable trays:(1) Types OFNP, OFCP, OFNR, OFCR, OFNG, OFCG, OFN, and OFC

Change Description: Installation of a communications raceway inside a metal raceway is an example of the use of a communications raceway as an innerduct. This change revises the title to reflect the use of raceways with innerduct as covered in 770.113(E)(2). Added innerduct in parenthesis after each of the list items to clarify that raceways can be used as innerduct.

The provisions of Section 770.110 cover listing requirements for optical fiber cables installed in communications raceways and cable routing assemblies.


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770.154 Applications of Listed Optical Fiber Cables.Table 770.154(a) Applications of Listed Optical Fiber Cables in BuildingsIn other spaces used for environmental air (plenums) as described in 300.22(c) OFNP & OFCP cables installed in plenum cable routing assemblies are not permitted.

770.154 Applications of Listed Optical Fiber Cables.Table 770.154(a) Applications of Listed Optical Fiber Cables in Buildings.In other spaces used for environmental air (plenums) as described in 300.22(c) OFNP & OFCP cables are permitted in plenum cable routing assemblies to the limitations described in 770.10 and 770.113.

Change Description:Changes made for consistency with the changes to Section 770.113, allowing use of OFNP and OFCP in plenum cable routing assemblies to be used in other spaces used for environmental air (plenums), as described in 300.22(c).


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VI. Listing Requirements770.179 Optical Fiber Cables. Optical fiber cables shall be listed in accordance with 770.179(A) through (F) and shall be marked in accordance with Table 770.179. Optical fiber cables shall have a temperature rating of not less than 60°C (140°F).

Part VI. Listing Requirements770.179 Optical Fiber Cables. Optical fiber cables shall be listed and identified in accordance with 770.179(A) through (F) and shall be marked in accordance with Table 770.179. Optical fiber cables shall have a temperature rating of not less than 60°C (140°F). Temperature rating shall be marked on the jacket of optical fiber cables that have a temperature rating exceeding 60°C (140°F).

Change Description:Temperature marking on all high temperature rated cables will enable their appropriate application.


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IV. Grounding Methods800.100 Cable and Primary Protector Bonding and Grounding(B) Electrode.(3) In Buildings or Structures Without an Intersystem Bonding Termination or Grounding Means. If the building or structure served has no intersystem bonding termination or has no grounding means, as described in 800.100(B)(2) or (B)(3)(1), to any one of the individual grounding electrodes described in 250.52(A)(7) and (A)(8) or to a ground rod or pipe not less than 1.5 m (5 ft) in length and 12.7 mm (1∕2 in.) in diameter, driven, where practicable, into permanently damp earth and separated from lightning conductors as covered in 800.53 and at least 1.8 m (6 ft) from electrodes of other systems. Steam or hot water pipes or air terminal conductors (lightning-rod conductors) shall not be employed as electrodes for protectors and grounded metallic members.

Part IV. Grounding Methods800.100 Cable and Primary Protector Bonding and Grounding.(B) Electrode.(3) In Buildings or Structures Without an Intersystem Bonding Termination or Grounding Means....damp earth and separated from lightning protection system conductors as covered in 800.53 and at least 1.8 m (6 ft) from electrodes of other systems. Steam, hot water pipes, or lightning protection system conductors shall not be employed as electrodes for protectors and grounded metallic members.

Change Description:This revision clarifies that lightning protection system conductors, not just air terminals, shall not be used as a part of the grounding electrode conductor or as a grounding electrode.


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V. Installation Methods Within Buildings800.113 Installation of Communications Wires, Cables and Raceways, and Cable Routing Assemblies.(C) Other Spaces Used for Environmental Air (Plenums).(3) Type CMP cables installed in plenum communications raceways(4) Type CMP cables and plenum communications raceways supported by open metallic cable trays or cable tray systems(5) Types CMP, CMR, CMG, CM, and CMX cables and communications wires installed in raceways that are installed in compliance with 300.22(C)(J) Other Building Locations.(8) Type CMUC under-carpet communications wires and cables installed under carpet

Part V. Installation Methods Within Buildings800.113 Installation of Communications Wires, Cables and Raceways, and Cable Routing Assemblies.(C) Other Spaces Used for Environmental Air (Plenums). (3) Plenum cable routing assemblies(4) Type CMP cables installed in plenum communications raceways(5) Type CMP cables installed in plenum cable routing assemblies

(J) Other Building Locations.(8) Type CMUC under-carpet communications wires and cables installed under carpet, modular tiles, and planks

Change Description:This revision adds “cable routing assemblies” to coordinate with the requirements of NFPA 90A.Also, the revision allows installation of CMUC under-carpet wires under modular tiles and planks.


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800.154 Applications of Listed Communications Wires, Cables and Raceways, and Listed Cable Routing Assemblies.Table 800.154(a) Applications of Listed Communications Wires and Cables in BuildingsIn other spaces used for environmental air as described in 300.22(C)CMP cables are not allowed In plenum cable routing assemblies....NOT PERMITTED

Table 800.154(b) Applications of Listed Communications Raceways in BuildingsApplications: In specifically fabricated ducts as described in 300.22(B)---In metal raceway that complies with 300.22(B):::: Plenum Communications Raceways (Y), Riser Communications Raceways (Y), General-Purpose Communications Raceways (Y)Applications: In other spaces, used for environmental air as described in 300.22(C):::::In plenum cable routing assemblies: NOT PERMITTED

Table 800.154(c) Applications of Listed Cable Routing Assemblies in BuildingsApplications: In other spaces used for environmental airListed cable :::Plenum Cable Routing Assembly(N)

800.154 Applications of Listed Communications Wires, Cables, and Raceways, and Listed Cable Routing Assemblies.Table 800.154(a) Applications of Listed Communications Wires and Cables in Buildings.In other spaces used for environmental air as (plenums) described in 300.22(C).CMP cables are allowed in plenum cable routing assemblies - subject to the limitations described in 800.113.

Table 800.154(b) Applications of Listed Communications Raceways in Buildings.Application: In ducts specifically fabricated for environmental air as described in 300.22(B)----In Metal raceway that complies with 300.22B----- Plenum (N), Riser (N) and General Purposes (N),

Applications -In orther spaces used for environmental air (plenums) as described in 300-22(C):::: In plenum cable routing assemblies - Plenum (N)

Table 800.154(c) Applications of Listed Cable Routing Assemblies in Buildings.Applications: In other spaces used for environmental air - Listed Cable Routing Assembly Plenums (Y)

Change Description:

The revisions to Table 800.154(a), (b), and (c) correlate the tables with the revisions to 800.113.


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Article 800 Communications Circuits


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800.179 Communications Wires and Cables. Communications wires and cables shall be listed in accordance with 800.179(A) through (I) and marked in accordance with Table 800.179. Conductors in communications cables, other than in a coaxial cable, shall be copper. Communications wires and cables shall have a voltage rating of not less than 300 volts. The insulation for the individual conductors, other than the outer conductor of a coaxial cable, shall be rated for 300 volts minimum. The cable voltage rating shall not be marked on the cable or on the undercarpet communications wire. Communications wires and cables shall have a temperature rating of not less than 60°C.

800.179 Communications Wires and Cables. Communications wires and cables shall be listed in accordance with 800.179(A) through (I) and marked in accordance with Table 800.179. Conductors in communications cables, other than in a coaxial cable, shall be copper. Communications wires and cables shall have a voltage rating of not less than 300 volts. The insulation for the individual conductors, other than the outer conductor of a coaxial cable, shall be rated for 300 volts minimum. The cable voltage ratingshall not be marked on the cable or on the undercarpet communications wire. Communications wires and cables shall have a temperature rating of not less than 60°C (140°F). The temperature rating shall be marked on the jacket of communications cables that have a temperature rating exceeding 60°C (140°F).

Change Description:Temperature marking on all high temperature rated cables enable their appropriate application. 60°C (140°F) is the minimum temperature required and therefore marking on the cable is not necessary.


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800.182 Communications Raceways and Cable Routing Assemblies.Communications raceways and cable routing assemblies shall be listed in accordance with 800.182(A) through (C).

(A) Plenum Communications Raceways and Plenum Cable Routing Assemblies. Plenum communications raceways and plenum cable routing assemblies shall be listed ashaving adequate fire-resistant and low-smoke producing characteristics.

800.182 Cable Routing Assemblies and Communications Raceways.Cable routing assemblies and communications raceways shall be listed in accordance with 800.182(A) through (C). Cable routing assemblies shall be marked in accordance with Table 800.182(a). Communi-cations raceways shall be marked in accordance with Table 800.182(b).(A) Plenum Cable Routing Assemblies and Plenum Communications Raceways. Plenum cable routing assemblies and plenum communications raceways shall be listed as having adequate fire-resistant and low-smoke-producing characteristics.

Change Description:This revision correlates the NEC with the NFPA 90A-2015 requirements for cable routing assemblies (general rule only) and communications raceways (general rule or the specific rule which is equivalent to the long-standing rule for testing cables). NFPA 90A-2015 has expanded its requirements for materials exposed to the airflow in ceiling cavity plenums and raised floor plenums to include a“general rule” of either 1) noncombustible or 2) exhibiting a maximum flame spread index of 25 and a maximum smoke developed index of 50 when tested in accordance with ASTM E84, Standard Test Method for Surface Burning Characteristics of Building Materials, or ANSI/UL 723, Standard Test Method for Surface Burning Characteristics of Building Materials.


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II. Receiving Equipment — Antenna Systems810.15 Grounding. Masts and metal structures supporting antennas shall be grounded in accordance with 810.21.

Part II. Receiving Equipment — Antenna Systems810.15 Grounding. Masts and metal structures supporting antennas shall be grounded in accordance with 810.21, unless the antenna and its related supporting mast or structure are within a zone of protection defined by a 46 m (150 ft) radius rolling sphere.

Change Description:The revision acknowledges the zone of protection afforded by surrounding taller structures as determined by the 300-foot diameter rolling sphere theory of lightning protection, consistent with NFPA 780.


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I. General820.3 Other Articles.(J) Cable Routing Assemblies. The definition in Article 100, the applications in Table 800.154(c), and the installation requirements in 800.110 shall apply to Article 820 and 800.113.

Part I. General820.3 Other Articles.

Change Description:Keeping this deleted text would make it redundant as it is now covered by the action taken on first revision text of 820.110. This revision provides consistency throughout 770, 800 820, 830 and 840.


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II. Coaxial Cables Outside and Entering Buildings820.47 Underground Coaxial Cables Entering Buildings.(B) Direct-buried coaxial cable shall be separated at least 300 mm (12 in.) from conductors of any light or power or Class 1 circuit.

Part II. Coaxial Cables Outside and Entering Buildings820.47 Underground Coaxial Cables Entering Buildings.(B) Direct-Buried Cables and Raceways. Direct-buried coaxial cable shall be separated at least 300 mm (12 in.) from conductors of any light or power, non–power-limited fire alarm circuit conductors, or Class 1 circuit.

Change Description:Non–power-limited fire alarm cables were added to correct an omission. Exception Nos. 1 and 2 are rewritten to comply with Section 3.1.4.1 of the NEC Style Manual that requires exceptions to be written in complete sentences.


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820.48 Unlisted Cables Entering Buildings. Unlistedoutside plant coaxial cables shall be permitted to be installed in building spaces other than risers, ducts used for environmental air, plenums used for environmental air, and other spaces used for environmental air, where the length of the cable within the building, measured from its point of entrance, does not exceed 15 m (50 ft) and the cable enters the building from the outside and is terminated at a grounding block.

820.48 Unlisted Cables Entering Buildings. Unlisted outside plant coaxial cables shall be permitted to be installed in building spaces other than risers, ducts used for environmental air, plenums used for environmental air, and other spaces used for environmental air, where the length of the cable within the building, measured from its point of entrance, does not exceed 15 m (50 ft) and the cable enters the building from the outside and is terminated at a grounding block. The point of entrance shall be permitted to be extended from the penetration of the external wall or floor slab by continuously enclosing the entrance cables in rigid metal conduit (RMC) or intermediate metal conduit (IMC) to the point of emergence.

Change Description:This revision inserts the text into the body of 820.48 rather than in an informational note to allow only RMC and IMC to be used to extend the point of entry.


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820.49 Metallic Entrance Conduit Grounding. Rigid metal conduit (RMC) or intermediate metal conduit (IMC) containing entrance coaxial cable shall be connected by a bonding conductor or grounding electrode conductor to a grounding electrode in accordance with 820.100(B).

820.49 Metallic Entrance Conduit Grounding. Metallic conduit containing entrance coaxial cable shall be connected by a bonding conductor or grounding electrode conductor to a grounding electrode in accordance with 820.100(B).

Change Description:Revised to require that all metallic entrance conduit needs to be grounded, not just RMC and IMC.


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Article 810 Radio and Television Equipment

Article 820 Community Antenna Television and Radio Distribution Systems


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IV. Grounding Methods820.100 Cable Bonding and Grounding.For communications systems using coaxial cable confined within the premises and isolated from out-side cable plant, the shield shall be permitted to be grounded by a connection to an equipment grounding conductor as described in 250.118. Connecting to an equipment grounding conductor through a grounded receptacle using a dedicated bonding jumper and a permanently connected listed device shall be permitted. Use of a cord and plug for the connection to an equipment grounding conductor shall not be permitted.(B) Electrode.(3) In Buildings or Structures Without an Intersystem Bonding Termination or Grounding Means.(2) If the building or structure served has no intersystem bonding termination or grounding means, as described in 820.100(B)(2) or B)(3)(1), to any one of the individual grounding elec-trodes described in 250.52(A)(5), (A)(7), and (A)(8). Steam or hot water pipes or air terminal conductors (lightning-rod conductors) shall not be employed as grounding electrodes for bonding conductors or grounding electrode conductors.

Part IV. Grounding Methods820.100 Cable Bonding and Grounding.Exception: For communications systems using coaxial cable completely contained within the building (i.e., they do not exit the building) or the exterior zone of protection defined by a 46 m (150 ft) radius rolling sphere and isolated from outside cable plant, the shield shall be permitted to be grounded by a connection to an equipment grounding conductor as described in 250.118.

(B) Electrode.(3) In Buildings or Structures Without an Intersystem Bonding Termination or Grounding Means.(2)...Steam, hot water pipes, or lightning protection system conductors shall not be employed as grounding electrodes for bonding conductors or grounding electrode conductors.

Change Description:The revisions to the “exception” provide clear direction that it applies only to cable contained completely within the building or exterior within a zone of protection. The term “premises” has been deleted as it may include locations outside the building per the definition in 820.2 and leaving the zone of protection which could make them more susceptible to induced or direct surges.

(B) This revision clarifies that lightning protection system conductors, not just air terminals, shall not be used as a part of the grounding electrode conductor or as a grounding electrode. It is unnecessary to add text reinforcing bonding together of separate grounding electrodes and intersystem bonding. These concepts are adequately covered in 250.50, 250.60 Informational Note No.2 and 820.100(D).


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V. Installation Methods Within Buildings820.110 Raceways and Cable Routing Assemblies for Coaxial Cables.(A) Types of Raceways.

Part V. Installation Methods Within Buildings820.110 Raceways and Cable Routing Assemblies for Coaxial Cables.(A) Types of Raceways.(3) Innerduct for Coaxial Cables. Listed plenum communications raceways, listed riser communications raceways, and listed general-purpose communications raceways selected in accordance with Table 800.154(b) shall be permitted to be installed as innerduct in any type of listed raceway permitted in Chapter 3.

Change Description:Table 800.154(c) covers the applications of cable routing assemblies and listing requirements are covered in 800.182. Both are now referenced in this section. Installation requirements are covered in 800.110(C), Hence, 820.110(C)(1) and (C)(2) are superfluous and are deleted. The reference to 800.113 is relocated within the text as it applies to instal-lation requirements rather than selection requirements. These revisions provide consistency and correlation with revisions to 725.3(M), 760.3(L), 770.110(C), 820.110(C) and 830.110(C).


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820.133 Installation of Coaxial Cables and Equipment.(A) Separation from Other Conductors.(1) In Raceways, Cable Trays, Boxes, Enclosures, and Cable Routing Assemblies. (a) Optical Fiber and Communications Cables. Coaxial cables shall be permitted in the same raceway, cable tray, box, enclosure, or cable routing assembly with jacketed cables of any of the following:(1) Nonconductive and conductive optical fiber cables in compliance with Parts I and V of Article 770(2) Communications circuits in compliance with Parts I and V of Article 800(3) Low-power network-powered broadband communications circuits in compliance with Parts I and V of Article 830 (b) Other Circuits. Coaxial cables shall be permitted in the same raceway, cable tray, box, enclosure, or cable routing assembly with jacketed cables of any of the following:(1) Class 2 and Class 3 remote-control, signaling, and power-limited circuits in compliance with Article 645 or Parts I and III of Article 725(2) Power-limited fire alarm systems in compliance with Parts I and III of Article 760(c) Electric Light, Power, Class 1, Non–Power-Limited Fire Alarm, and Medium-Power Network-Powered Broadband Communications Circuits. Coaxial cable shall not be placed in any raceway, compartment, outlet box, junction box, or other enclosures with conduc-tors of electric light, power, Class 1, non-power-limited fire alarm, or medium -power network-powered broadband communications circuits.

820.133 Installation of Coaxial Cables and Equipment.Beyond the point of grounding, as defined in 820.93, the coaxial cable installation shall comply with 820.133(A) and(B).(A) Separation from Other Conductors.(1) In Raceways, Cable Trays, Boxes, Enclosures, and Cable Routing Assemblies.(a) Other Circuits. Coaxial cables shall be permitted in the same raceway, cable tray, box, enclosure, or cable routing assembly with jacketed cables of any of the following:(1) Class 2 and Class 3 remote control, signaling, and powerlimited circuits in compliance with Article 645 or Parts I and III of Article 725(2) Power-limited fire alarm systems in compliance with Parts I and III of Article 760(3) Nonconductive and conductive optical fiber cables in compliance with Parts I and V of Article 770(4) Communications circuits in compliance with Parts I and V of Article 800(5) Low-power network-powered broadband communi-cations circuits in compliance with Parts I and V of Article 830 (b) Electric Light, Power, Class 1, Non–Power-Limited Fire Alarm, and Medium-Power Network-Powered Broadband Communications Circuits. Coaxial cable shall not be placed in any raceway, compartment, outlet box, junction box, or other enclosures with conductors of electric light, power, Class 1, non–powerlimited fire alarm, or medium-power network-powered broadband communications circuits.(2) Other Applications. Coaxial cable shall be separated at least 50 mm (2 in.) from conductors of any electric light, power, Class 1, non–power-limited fire alarm, or medium-power network-powered broadband communications circuits.

Change Description: This section was separated into two parts in the 2011 NEC because cable routing assemblies were not recognized in Articles 725 and 760. Now that there are consistent provisions for cable routing assemblies in Articles 725, 760, 800, 820 & 830, it is no longer necessary to subdivide the section. Exception Nos. 1 and 2 are revised to be full sentences in compliance with Section 3.1.4.1 of the NEC Style Manual.


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820.154 Applications of Listed CATV Cables.Table 820.154(a) Applications of Listed Coaxial Cables in BuildingsApplications::In other spaces used for environmental air as described in 300.22(C)In plenum communications raceways- Cable Type is NOT PERMITTED

820.154 Applications of Listed CATV Cables.Table 820.154(a) Applications of Listed Coaxial Cables in BuildingsApplications: In other spaces used for environmental air (plenums) as described in 300.2 (C)In Plenum communications raceways the Listed Coaxial Cable Type CATVP is (Y) - subject to the limitations described in 820.113.

Change Description:The revisions to Table 820.154(a) correlate the table with the revisions to 820.113.


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VI. Listing Requirements820.179 Coaxial Cables.

Part VI. Listing Requirements820.179 Coaxial Cables. ...Coaxial cables shall have a temperature rating of not less than 60°C (140°F). The temperature rating shall be marked on the jacket of coaxial cables that have a temperature rating exceeding 60°C (140°F).

Change Description:Requiring a minimum 60°C temperature rating is consistent with the UL standard for listing of these cables. Temperature marking on all high temperature rated cables will enable their appropriate application.


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V. Installation Methods Within Buildings830.110 Raceways and Cable Routing Assemblies for Network-Powered Broadband Communications Cables.(A) Types of Raceways.

Part V. Installation Methods Within Buildings830.110 Raceways and Cable Routing Assemblies for Network-Powered Broadband Communications Cables.(A) Types of Raceways.(3) Innerduct for Low-Power Network-Powered Broadband Communications Cables. Listed plenum communications raceways, listed riser communications raceways, and listed general-purpose communications raceways selected in accordance with Table 800.154(b) shall be permitted to be installed as innerducts in any type of listed raceway permitted in Chapter 3.

Change Description:In order to achieve consistency and parallelism, an innerduct section is added to Article 830.


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830.154 Applications of Network-Powered Broadband Communications System Cables.Table 830.154(a) Applications of Network-Powered Broadband Cables in BuildingsApplications:::In other spaces used for environmental air as described in 300.22(C)In plenum cable routing assemblies the Cable Type is NOT PERMITTED

830.154 Applications of Network-Powered Broadband Communications System Cables.Table 830.154(a) Applications of Listed Network-Powered Broadband Cables in BuildingsApplications:::In other spaces used for environmental air (plenums) as described in 300.2 (C)In plenum cable routing assemblies the Listed Network Powered Broadband Cable Type BLP is (Y) - subject to the limitations described in 830.113.

Change Description: The revisions to Table 830.154(a) correlate the table with the revisions to 830.113.


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VI. Listing Requirements830.179 Network-Powered Broadband CommunicationsEquipment and Cables

Part VI. Listing Requirements830.179 Network-Powered Broadband Communications Equipment and Cables. Network-powered broadband communications equipment and cables shall be listed and marked in accordance with 830.179(A) or (B). Network-powered broadband communications cables shall have a temperature rating of not less than 60°C (140°F). Temperature rating shall be marked on the jacket of network-powered broadband communications cables that have a temperature rating exceeding 60°C (140°F).

Change Description:Requiring a minimum 60°C temperature rating is consistent with the UL standard for listing of these cables. Temperature marking on all high temperature rated cables will enable their appropriate application.


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I. General840.3 Other Articles.

Part I. General840.3 Other Articles.(F) Other Communications Systems. As appropriate for the system involved, traditional communications systems shall comply with the requirements of the following:(1) Communications Circuits — Article 800(2) Radio and Television Equipment — Article 810(3) Community Antenna Television and Radio Distribution Systems — Article 820(4) Network-Powered Broadband Communications Systems — Article 830(G) Electrical Classification of Data Circuits and Cables. Sections 725.139(D)(1) and 800.133(A)(1)(b+A163) shall apply to the electrical classification of Class 2 and Class 3 circuits in the same cable with communications circuits.

Change Description:(F) This revision adds a new section to 840.3 to make it clear that article 840 is not intended to supersede or replace other chapter 8 articles that cover traditional communications systems. (G) Added new section. Sections 725.139(D)(1) and 800.133(A)(1)(c) permit class 2 and class 3 circuits to be run in the same cable as communications circuits but requires the class 2 and class 3 circuits to be reclassified as communications circuits and be installed in accordance with the requirements for communications circuits in Chapter 8.


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II. Cables Outside and Entering Buildings Part II. Cables Outside and Entering Buildings840.45 Overhead (Aerial) Communications Wires and Cables. Section 800.44 shall apply to overhead (aerial) communications wires and multipair communications cables.

840.46 Overhead (Aerial) Coaxial Cables. Section 820.44 shall apply to overhead (aerial) coaxial cables.

Change Description:Added new Sections 840.45 and 46. In order to expand the coverage of Article 840, a series of revisions recognize twisted pair and coaxial cable based systems in addition to optical fiber based systems.


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(continued) 840.47 Underground Wires and Cables Entering Buildings.(B) Communications Wires and Cables. Installations of communications wires and multipair communications cables shall comply with 800.47.(C) Coaxial Cables. Installations of coaxial cables shall comply with 820.47.

Change Description:In order to expand the coverage of Article 840, a series of revisions recognize twisted pair and coaxial cable based systems in addition to optical fiber based systems.


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Article 840 Premises-Powered Broadband Communications Systems

Article 830 Network-Powered Broadband Communications Systems


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840.48 Unlisted Cables and Raceways Entering Buildings.The requirements of 770.48 shall apply.

840.48 Unlisted Wires and Cables Entering Buildings. Installations of unlisted cables entering buildings shall comply with 840.48(A), (B), or (C), as applicable.(A) Optical Fiber Cables. Installations of unlisted optical fiber cables entering buildings shall comply with 770.48.(B) Communications Wires and Cables. Installations of unlisted communications wires and unlisted multipair communications cables entering buildings shall comply with 800.48.(C) Coaxial Cables. Installations of unlisted coaxial cables entering buildings shall comply with 820.48.

Change Description:This revision edits the section to accommodate the addition of unlisted twisted pair-based and coaxial cable-based systems to Article 840.


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V. Installation Methods Within Buildings840.110 Raceways for Premises-Powered Broadband Communications Optical Fiber Cables.

Part V. Installation Methods Within Buildings840.110 Raceways and Cable Routing Assemblies.(A) Optical Fiber Cables. The requirements of 770.110 shall apply.(B) Multipair Communications Cables. The requirements of 800.110 shall apply.(C) Coaxial Cables. The requirements of 820.110 shall apply.

Change Description:This revision edits the section to accommodate the addition of twisted pair-based and coaxial cable-based systems to Article 840. Cable routing assemblies are added to correlate with 770.110, 800.110 and 820.110.


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VI. Listing Requirements840.170 Equipment and Cables.

Part VII. Listing Requirements840.170 Equipment and Cables.(D) Cable Routing Assemblies and Communications Raceways. Cable routing assemblies and communications raceways shall be listed in accordance with 800.182.(E) Premises Communications Wires and Cables. Communications wires and cable shall be listed and marked in accordance with 800.179(G) Power Source. The power source for circuits intended to provide power over communications cables to remote equipment shall be limited in accordance with Table 11(B) in Chapter 9 for voltage sources up to 60 V dc and be listed as specified in either of the following:(1) A power source shall be listed as specified in 725.121(A) (1), (A)(2), (A)(3), or (A)(4). The power sources shall not have the output connections paralleled or otherwiseinterconnected unless listed for such interconnection.(2) A power source shall be listed as communications equipment for limited-power circuits.(H) Accessory Equipment. Communications accessory equipment and/or assemblies shall be listed for application with premises-powered communications systems.Informational Note: One way to determine applicable requirements is to refer to ANSI/UL 1863-2004, Communications-Circuit Accessories.

Change Description:The expanded coverage of Article 840 to cover PoE requires that the article recognize twisted pair-based and coaxial cable-based systems in addition to optical fiber-based systems. Instead of “optical network terminal” which applies only to optical fiber-based systems, the recommended text simply calls the interface a “network terminal”.Added sections (D) and (E) to address listing requirements for cable routing assemblies, communication raceways, and premises communications wires and cables.New sections (G) and (H) are added to address power sources and to cover listing requirements for these power sources.


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Notes to Tables(9) A multiconductor cable, optical fiber cable, or flexible cord of two or more conductors shall be treated as a single conductor for calculating percentage conduit fill area. For cables that have elliptical cross sections, the cross-sectional area calculation shall be based on using the major diameter of the ellipse as a circle diameter.

Notes to Tables(9) A multiconductor cable, optical fiber cable, or flexible cord of two or more conductors shall be treated as a single conductor for calculating percentage conduit or tubing fill area. For cables that have elliptical cross sections, the cross-sectional area calculation shall be based on using the major diameter of the ellipse as a circle diameter. Assemblies of single insulated conductors without an overall covering shall not be considered a cable when determining conduit or tubing fill area.The conduit or tubing fill for the assemblies shall be calculated based upon the individual conductors.

Change Description:Assembled conductors shall not be considered a cable and are required to be treated as individual conductors. The expanded Note 9 to Table 1 clarifies the requirements for wire fill calculation.


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Chapter 9 - Tables

Documents

EFCOG Best Practice #213 · NFPA 20, Standard for Installation of Stationary Pumps for Fire Protection 9. NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages 10