283 Porcelain Insulator for Telephone Lines

8/6/2019 283 Porcelain Insulator for Telephone Lines

http://slidepdf.com/reader/full/283-porcelain-insulator-for-telephone-lines 1/21

© BIS 2004

B U R E A U O F I N D I A N S T A N D A R D SMANAK BHAVAN , 9 BAHADUR SHAH ZAFAR MARG

N E W D E L H I 110002

IS : 283 - 1976(R e a f fi r m e d 2 00 1)

E di t i on 4 .4(2003-09)

P r i ce Gr ou p 5

Ind ian S tandard SPE CIFICATION FOR

PORCELAIN INSULATORS FORTELEGRAPH AND TELEPH ONE LINES

( Th i rd Rev ision )

(Incorp ora tin g Amen dm ent Nos. 1, 2, 3 & 4)

UDC 621.315.62 : 621.315.612.2 : 621.39



IS : 283 - 1976

© BIS 2004

BUR EAU OF IND IAN STANDARDS

This publication is protected under the Indian Copyright Act (XIV of 1957) andrepr oduction in wh ole or in pa rt by any mea ns except with written permission of th epublisher sh all be deemed to be an infringement of copyright un der t he sa id Act.

Ind ian S tand ard

SPECIFICATION FORPORCELAIN INSULATORS FOR

TELEGRAPH AND TELEPHONE LINES

( Th ird Rev ision )

E lectr ical In su lat ors a nd Accessories Sectiona l Comm itt ee, ETDC 3

Chairm an R epresen ting

S H RI L. C. J AIN Ministry of Energy

Mem bersADDITIONAL C HIEF E NGINEER , P OSTS

AN D TELEGRAPHS , J ABALPURD IRECTOR OF T ELEGRAPHS (L)

( Alternate )D IVISIONAL E NGINEER ,

T ELEGRAPHS (C) ( Alternate )

Directorat e Genera l of Posts an d Telegra phs(Depart men t of Comm un icat ions),New Delh i

S H RI V. R. A NANTHANARAYANAN Bengal Potteries Limited, Calcut taS HRI C HANDER P ARKASH ( Alternate )

S H RI N. S. S. A ROKIASWAMY Tamil Nadu Electr icity Boar d, Madra sS HRI P. S. T HIRUNAVUKKARASU ( Alternate )

D R A. S. B HADURI Na tiona l Test House, CalcuttaS HRI S. K. M UKHERJEE ( Alternate )

S H RI B. N. B HAGATS HRI B. C. D AW ( Alternate )

All India Pottery Manufacturers’ Association,Calcutta

S H RI D. S. C HABHAL Directorate General of TechnicalDevelopment, New Delhi

S H RI A. K. C HOPRAS HRI N IRVAIR S INGH ( Alternate )

Pu njab Sta te Electr icity Boar d, Patia la

S H RI A. N. D EBS HRI A. C. B OS E ( Alternate )

Damodar Valley Corporat ion, Ca lcut ta

D IRECTOR OF R ESEARCH Maha rash tra Stat e Electricity Board, BombayD IRECTOR (T RACTION AN D

I NSTALLATION )D EPUTY D IRECTOR S TANDARDS

(OHE) ( Alternate )

Research, Designs a nd Sta ndar dsOrganization (Ministry of Railways),Lucknow

( Contin ued on page 2 )



IS : 283 - 1976

2

( Contin ued from page 1 )

M em bers R epresen tin g

D IRECTOR (T RANSMISSION )D EPUTY D IRECTOR

(T RANSMISSION ) ( Alternate )

Centr al E lectr icity Authority, New Delhi

S H RI H. M. S. L INGAIAH Karnataka Electricity Board, BangaloreS H RI G. S. M AHAGAONKAR Mysore P orcelains Ltd, Ban galoreS H RI M. L. M ITTAL

S H RI S. P. S INGH ( Alternate )Bha ra t H eavy Electr icals Ltd, Bhopal

D R G. M. P HADKE

S H RI K. N. J AYARAM ( Alternate )In dian Electr ical Man ufactu rer s’ Associat ion,

BombayS H RI P. S. R AMAN

S H RI E. P. W ILFRED ( Alternate )New Governm ent Electr ic Fa ctory Ltd,

BangaloreS H RI M. K. S ANKARALINGAM

S H RI G. R. B HATIA ( Alternate )Directorat e Gener al of Supp lies an d Disposals,

New Delh iS H RI K. M. S ANKARAN

S H RI P . R AO ( Alternate )Rura l Electrificat ion Corporat ion Ltd,

New Delh iS H RI N. S. S EETHURAMON

S H RI V. S RINIVASAN ( Alternate )W. S. Insula tors of India Ltd, Mad ra s

D R U. S. S INGH

S H RI A. D. D U A ( Alternate )High Tension In sula tor Fa ctory, Ran chi

S H RI S URENDRA S INGH

S H RI T. B. L. S RIVASTAVA

( Alternate )

U. P. Governm ent Potter y Developmen tCentre, Khur ja

S H RI L. V ENKATASUBBU

S H RI R. V. A CHUTHAN ( Alternate )Seshasayee Industr ies Ltd, Vadalur P ost

(South Arcot Distr ict)S H RI S. P. S ACHDEV ,

Director (Elec tech)Director Gener al, ISI ( Ex-officio Mem ber )

S ecretaryS HRI R. C. J AIN

Deput y Director (Elec tech), ISI



IS : 283 - 1976

3

Ind ian S tandard SPE CIFICATION FOR

PORCELAIN INSULATORS FORTELEGRAPH AND TELEPH ONE LINES

( Th i rd Rev ision )0. F O R E W O R D

0.1 This Indian Sta nda rd (Third Revision) was a dopted by the In dianStan dards Inst i tut ion on 2 April 1976, after t he dra ft f ina lized by th eElectrical Insulators and Accessories Sectional Committee had beenap pr oved by th e Electr ot echn ica l Division Council.

0.2 This standard, originally published in 1951, was first revised in1959, when t he single-shed pot-head in sula tors a nd oil-cup ins ulat orswere excluded from its scope since the Posts and TelegraphsDepartment of the Government of India had decided to discontinuetheir use. Provision was also made for the inclusion of double-shedpot -hea d insu lat ors wh ich wer e foun d t o be sat isfactory.

0.2.1 The second revision was issued in 1966 with a view to aligning

this standard with other electrical insulator standards and effectingcomplete metricization. In that revision, which included all theam endm ents issued to-dat e to the first revision, a sta tistical sam plingplan for th e select ion of ins ula t ors for a ccepta nce test s h a d a lso beenincorporated.

0.3 The th ird r evision ha s been un derta ken with a view to simplifyingthe manufacture of large and small double-shed insulators bymodifying t he sh ape of the t op of th ese type of insu lat or s.

0.4 This standard has been prepared primarily to meet the

requirements of the Indian Posts and Telegraphs Department. Theinsulators covered by this standard should also be suitable fortelegraph and telephone lines of the Railways and other users. Thestandard does not, however, cover the insulators required for thecommunication circuits run solely for the operation and maintenanceof electr ic tr an sm ission system s a nd in close pr oximit y to such lines.

0.5 The stalks for use with these insulators are covered byIS : 1441-1966*.

*Specificat ion for insula tor st alks for telegraph s a nd telephone lines ( first revision ).



IS : 283 - 1976

4

0.6 In the preparation of this standard, assistance has been derivedfrom BS 16 : 1949 ‘Telegra ph m at erial insu lators, pole fittings, etc’issued by British Sta nda rds Inst itut ion.

0.7 This st an da rd is one of a series of In dian St an da rd specificat ion onporcelain elect rical insu lat ors.0.8 This edition 4.4 incorporates Amendment No. 1 (October 1983),Amen dment No. 2 (March 1989) Amendm ent No. 3 (October 1991) an dAmendment No. 4 (September 2003). Side bar indicates modification of th e text as t he r esult of incorporat ion of th e amen dment s.0.9 For th e pur pose of deciding wheth er a pa rt icular requir ement of th isstandard is complied with, the final value, observed or calculated,expressing the result of a test, shall be rounded off in accordance with

IS : 2-1960*. The num ber of significan t places r eta ined in t he r oun ded off value should be the sam e as th at of th e specified value in t his sta nda rd.

1 . SCOP E

1.1 This standard covers the pin type porcelain insulators intendedfor use in supporting telegra ph an d t elephone lines.

1.1.1 This st an dar d does not cover insu lat ors for comm un icat ion linesru nn ing in close proximity t o power t ra nsm ission lines.

2 . TER MINOLOGY

2.0 For t he pu rpose of this st an dar d, the following definit ions sha ll apply.2.1 P i n In s u l a t o r — A r igid insu lat or consist ing of single piece of porcelain or of two or more porcelain components permanentlyconn ected t ogeth er, an d inten ded to be mount ed rigidly on a support ingstructure by an insulator pin passing up inside the insulator. Unlessoth erwise sta ted, th is term excludes th e insulator pin.2.2 L o t o f I n s u l a t o r — All th e insu lators of th e same type an d designmanufactured under similar conditions of production, offered foracceptance; a lot may cons ist of th e whole or pa r t of th e quant ity ordered.

2.3 Ty p e Tes t s — Tests car ried out to prove conform ity with th especification. These are intended to prove the general qualities anddesign of a given t ype of insu lat or .

2.4 Ac c e p t a n c e Te st s — Tests car ried out on sam ples tak en from alot for th e pu rpose of a ccept an ce of the lot.

2.5 R o u t i n e Te st s — Tests car ried out on ea ch insulator t o check requ irem ent s which a re likely to var y durin g production.

*Rules for round ing off nu mer ical valu es ( revised ).



IS : 283 - 1976

5

3. G E N E R AL R E Q U I R E M E N T S

3.1 M a t e r i a l — The porcelain sha ll be soun d, free from defects (suchas cracks, chips, dots, specks, and other imperfections), thoroughlyvitrified and smoothly glazed.

3.2 The glaze sha ll cover a ll the porcelain par ts of t he in sula tor exceptth ose ar eas wh ich ser ve as su pport s dur ing firing or a re left u nglazedfor t he pur pose of a ssem bly.

3.3 C o lo u r — Un less specified otherwise by the pur cha ser, th e glazesha ll be whit e in colou r .

3.4 T h r e a d i n g — The th reads on t he insulat or sh all conform to th e

pr ofile shown in F ig. 1.

F IG . 1 P ROFILE OF I NSULATOR T HREADS



IS : 283 - 1976

6

3.4.1 In th e ca se of pot-hea d insu lat ors , no sealing com poun d sh all beapplied, but the threaded portion of the cap and the correspondingthreads on the insulator shall be lightly brushed with pure paraffinwax so as to enable the cap to be easily screwed on and off withoutdama ge to the th reads.

4 . DIME NSION S

4.1 The shapes and dimensions of insulators shall be in accordancewith th e figur es referred t o against each:

N OT E — Wherever dimensions are not given, the shape of the insulator shallconform to th e one indicated in t he r elevan t dr awing.

T ype Fig. N o.

Large, double-shed 2Small, double-shed 3

Pot -head, double-shed 4

F IG . 2 I NSULATOR , L ARGE , D OUBLE -S HE D



IS : 283 - 1976

7

5. MARKIN G

5.1 Each insulator shall be legibly and indelibly marked to show thefollowing:

a) Nam e or tr ade-ma rk of the ma nufactu rer,b) Month and year of man ufactu re,c) Coun tr y of ma nu facture, andd) Minimu m failing load in n ewtons.

5.1.1 Markings on porcelain shall be printed and shall be appliedbefore firing.

5.1.2 The insulators may also be marked with the ISI CertificationMark.

N OT E — The use of the ISI Certification Mark is governed by the provisions of theIndian Standards Insti tution (Certification Marks) Act and the Rules andRegulations made thereunder. The ISI Mark on products covered by an IndianStandard conveys the assurance that they have been produced to comply with therequirements of that standard under a well-defined system of inspection, testingand quality control which is devised and supervised by ISI and operated by theproducer. ISI marked products are also continuously checked by ISI for conformityto that standard as a further safeguard. Details of conditions under which a licence

for the use of the ISI Certification Mark may be granted to manufacturers orprocessors, ma y be obtain ed from the Indian Sta nda rds In stitu tion.

F IG . 3 I NSULATOR , S MALL , D OUBLE -S H ED



IS : 283 - 1976

8

F IG . 4 I NSULATOR , P OT -H EAD , D OUBLE -S HED



IS : 283 - 1976

9

6. P ACKIN G

6.1 All insu lators sh all be packed in la yers in a wooden box with car dboard separators fitted with suitable cushion/grass packing on allinside walls of the box and also between layers if packing consists of more th an one layer for t he sa me box.

7 . TE STS

7.1 G e n e r a l

7.1.1 Type Tests — The following sha ll const itu te t he t ype tests :

a) Verificat ion of dimen sions ( 7.2 ),

b) Tempera tu re cycle test ( 7.3 ),

c) Insulation resistan ce test ( 7.4 ),

d) Mechan ical test ( 7.5 ),

e) Porosity test ( 7.6 ), an d

f) Visual exam inat ion ( 7.7 ).

7.1.2 Acceptan ce T ests — The following shall constitute theacceptance tests:

a) Verificat ion of dimen sions ( 7.2 ),

b) Tempera tu re cycle tests ( 7.3 ),

c) Insulation resistan ce test ( 7.4 ),

d) Mechan ical test ( 7.5 ); a nd

e) Porosity test ( 7.6 ).

7.1.2.1 Unless otherwise agreed, recommended sampling plan givenin Appen dix A sh a ll be followed.

N OT E — The sampling plan h as been prepared on the basis of IS : 2500 (Par t 1) 1973‘In spection by at tr ibut es a nd by coun t of defects ( first revision )’, shall provideuniform protection to the supplier of insulators either in small lots or bigger lots.This has been necessitated due to the fact that the earlier criteria of acceptance of lots give less protection to the supplier of smaller lots than the supplier of biggerlots.

7.1.3 The following sha ll be car ried out a s r out ine t ests:

a) Rout ine verificat ion of dimens ions ( 7.2.2 ),

b) Rout ine insulat ion resistan ce test ( 7.4.2 ), an d

c) Visual examina tion ( 7.7 ).



IS : 283 - 1976

10

7 .2 Ve r i fi c a t i on o f D ime n s ions

7.2.1 The gauges shall be of hardened tool steel and shall be inaccordance with Fig. 5 to 9. They shall he finished bright and allsur faces sh all be protected from oxidat ion by treat men t with neut ra lpetr oleum jelly

7.2.1.1 The insulators shall pass the gauge test as described inTable 1.

7.2.1.2 For dimen sions n ot covered by th e gauges a t oleran ce of ± 5percent sha ll be allowed. However, t he n egative tolera nce sha ll not beperm itt ed for t he t hickn ess of t he out er sh ed. The th ickn ess shown inthe figures shall be taken as the minimum permitted. In the case of unimportant dimensions for radii, the tolerances are given forguida nce only and m ay not be r igidly followed.

7.2.2 R outin e Verification of Dim ensions — In the case of routineverificat ion of dimen sions , th e insu lat ors sh all be test ed with th e ‘GO’screw ga uge ( see Fig. 5 ).

7.3 Te m p e r a t u r e C yc le Te s t

7.3.1 The insulators shall be quickly and completely immersed in a

water -bath ma inta ined at a temper at ur e of 70°C above tha t of th e coldwater and left submerged for a period of 15 minutes. They shall thenbe withdrawn and quickly and completely immersed, without beingplaced in an intermediate container, in a bath of cold water for thesam e period of 15 minu tes.

7.3.2 The complete test shall comprise five transfers; namely, hot tocold, cold t o hot , hot t o cold, cold t o hot and h ot to cold. The t ime t ak ento tra nsfer t he insulat ors from one bat h t o th e oth er sh all be as shortas possible an d sh all not exceed 30 seconds . The qua nt ity of wat er inthe test tanks shall be large enough not to cause a temperaturevariation of more than 5°C in the water, when the insulators areimmersed.

7.3.3 After the completion of the immersion, the insulator shall beexam ined to verify tha t it is not cra cked an d t he glaze is unda ma ged.



IS : 283 - 1976

11

F IG . 5 ‘G O ’ G AUGE



IS : 283 - 1976

12

F IG . 6 T ELL -T ALE G AUGE



1 3

F IG . 7 G AUGES FOR P OT -H EAD I NSULATOR C AP



IS : 283 - 1976

14

7 .4 I n s u l a t i o n R e s i s t a n c e Te s t

7.4.1 The insulators shall be kept immersed, as described below,inside an air-conditioned cha mber m aint ained at a const an t h um idityof 80 ± 2 percent and a temperatu re of 27 ± 1°C for a t leas t hal f anhour:

a ) Large and sm all d ouble-shed in sulators

1) M eth od of setting u p for test — Level of wat er in t he t an k a ndin th e space between sheds sha ll be 25 mm from th e edge of th e out er sh ed. Level of wat er in t he screw-thr ead cavity sha llbe 25 mm below th e edge of th e inn er sh ed.

F IG . 8 G AUGES FOR P OT -H E AD INSULATOR B OD Y T OP



IS : 283 - 1976

15

2) T est Cond ition — Insu lation to be measu red:

i) between wat er in th e int er-shed cavity an d th e screw-th readcavity, an d

ii) between wa ter in t he inter-shed cavity an d th e tan k.

F IG . 9 ‘GO’ AND ‘NOT GO’G AUGES



IS : 283 - 1976

16

b) Pot-head, d ouble-shed in sula tors:1) Meth od of setting u p for test — Covers sha ll be rem oved before

immersion. Level of water in the tank and in the spacebetween sh eds shall be 25 mm from th e edge of th e out er shed.

Level of wat er in t he screw-th read cavity shall be 25 mmbelow th e edge of t he inn er s hed.2) T est cond ition — Insu lation to be measu red between water in

th e inter -shed cavity a nd th e screw-th read cavity.

Under the same humidity and temperature conditions, the insulatorsshall be subjected to an insulation resistance test at a dc potential of not less tha n 250 V and n ot m ore tha n 500 V, measur ed by a sensit ivereflectin g galvanometer of D’Arsonval t ype with a m inimu msensitivity of 600 mm per microampere a t one metre.

The insulat ion r esista nce obtained sh all be at least 50 000 megaohm s.7.4.2 R out ine Insu lation R esistance T est — In the case of routineinsulation resistance test, the insulators shall be completelyimmer sed in t he invert ed position in wat er for n ot less tha n 12 hour s.They shall then be kept imm ersed in th e inverted position in wa ter t othe depths mentioned in 7.4.1 for a period of 4 hours before theinsulation resistan ce test s a re condu cted.

7.4.2.1 The insulation resistance shall be measured between pointmentioned in 7.4.1 with a 500-volt, 100 megaohms range insulationtester , and sha ll not be below th e infinity mar k, th e relative hum iditybeing not m ore t ha n 80 percent .

TAB LE 1 G AU GE S F O R I NS UL AT OR S( Clause 7.2.1.1 )

G AUGE W HERE U SED F IG . N O .(1) (2) (3)

‘GO’ screw‘TELL-TALE’

For a ll typesdo

56

‘GO’ plug For cap of pot -hea d in su la tordouble-shed

7‘NOT GO’ plug‘THREAD’

dodo

‘GO’ r in g

‘NOT GO’ r ing

For top of body of pot-headinsu lat or double-shed

do8

‘GO’ tool

‘NOT GO’ tool

For checking the diam eter of LS wir e-leadin g in-hole

do9



IS : 283 - 1976

17

7.5 M e ch a n i c a l Te s t — The insulators sha ll be moun ted on a testpin with a head identical to the one which is used in actual service.The pin shall be fixed upright to a metal bracket on the testingma chin e. A flexible wire rope, about 6 m m in diam eter , sha ll be loopedround the tie-wire groove and shall be pulled at right angles to theaxis of th e insula tor. The pull sha ll be increas ed grad ua lly and evenlyto the value shown in Ta ble 2 and m aint ained for one minut e. Theresha ll be no fra ctu re of th e ins ula tor.

7 .6 P o r os i t y Tes t

7.6.1 Porcelain fragments from the insulators shall be immersed inone per cent a lcoholic solut ion of fuchsin (1 g fuchsin in 100 g of meth ylat ed spirit) un der a pressur e of not less tha n 15 MN/m 2 for aperiod such t ha t t he product of th e test dur at ion in h our s an d th e test

pressur e in MN/m2

is not less th an 180.7.6.2 The fragment s sha ll then be removed from t he solut ion, wash ed,dried and broken. Examination with naked eye of the freshly brokensurface shall not reveal any dye penetration. Penetration into smallcra cks form ed dur ing the init ial break ing sha ll be neglected.

7.7 Vi su a l E x a m i n a t i o n

7.7.1 A visual examination of the insulator shall be made. Theinsulator shall be free from physical distortion of shape and thevitr ified glaze sha ll be ha rd an d sm ooth , free from cra cks or a ny otherdefect likely to be pr ejudicial t o sa t isfa ctory per formance in ser vice.

7.7.2 With the exception of screw threads and those areas [as shownon the drawings ( see Fig. 2 to 4 )] which serve as supports du ringfiring, th e a rea of un glazed or d efectively glazed pa rt s sh all not exceed0.25 cm 2 per insu lator.

7.7.3 The colour of the insulators shall approximate the colourspecified ( see 3.3 ). Some variation in the colour shade is permittedan d sh all not just ify rejection of th e insu lat ors .

TAB LE 2 T E ST LO AD ON IN SU LAT OR S

T YPE T E ST L OAD TO BE APPLIED

(1) (2)kN

Large, double-shed 9Small, double-shed 4.5P ot -head, double-shed 9



IS : 283 - 1976

18

A P P E N D I X A

( Clause 7.1.2.1 )

S AM P L I N G P R O C E D U R E F O R P O R C E L AI N I N S U LAT O R SF O R T E L E G R AP H AN D T E L E P H O N E L I NE S

A-1 . SCALE OF SAMP LING

A-1.1 Lot — In a consignm ent, all th e insu lators of th e sam e type an ddesign manufactured from the same material in the same factoryunder similar conditions of production shall be grouped together toconst itu te a lot.

A-1.2 The number of insulators to be selected from each lot shalldepend upon the size of the lot and shall be in accordance with col 1an d 2 of Table 3.

A-1.2.1 These insulators shall be selected from the lot at random. Inorder to ensure the randomness of selection, procedure given inIS : 4905-1968*, may be followed.

A-2 . NUMBER OF TE STS AND CR ITER IA F OR CONF ORMITY

A-2.1 All the insu lat ors selected at ra ndom a ccordin g to col 1 an d 2 of Table 3 shall be subjected to dimensions, temperature cycle andinsulation resistance tests. The insulators failing to satisfy either of the requirements shall be termed as defectives. The lot shall beconsidered as conforming to these requirements if the number of

TAB LE 3 S AMP L E S IZE AN D AC CE P TAN CE N U MB E R( Clauses A-1.2, A-2.1, A-2.2 and A-2.3 )

LOT S IZE F OR D IMENSIONS , T EMPERATURE C YCLE

AND INSULATION R ESISTANCE T EST

F OR M ECHANICAL

T E ST AND P OROSITY T EST

FirstSample

Size

SecondSample

Size

AcceptanceNumber

FirstRejection

( r 1 )

SecondRejection

( r 2 )

FirstSample

Size

SecondSample

Size(1) (2) (3) (4) (5) (6) (7) (8)

Up to 1 000 8 8 0 2 2 5 5

1 001 to 3 000 13 13 0 2 2 8 8

3 001 to 10 000 20 20 0 2 2 13 13

*Methods for r an dom s am pling.



IS : 283 - 1976

19

defectives found in the sample is less than or equal to correspondingaccept ance nu m ber given in col 4 of Table 3. Th e lot sh all be r ejected if the number of defectives in the same is greater than or equal to thefirst rejection number ( r

1) given in col 5. If th e n umber of defect ives

is between the acceptance number and the first rejection number, asecond sample of the same size ( see col 3 of Table 3 ) sh all be select edfrom the lot at random and subjected to these tests. The number of defectives in t he firs t sam ple an d second sam ple sha ll be combined. If the combined number of defectives is less than the second rejectionnumber ( r 2 ) given in col 6 of Ta ble 3, th e lot shall be considered a sconforming to these requirements. Otherwise the lot shall be rejectedwith out furth er testing.

A-2.2 The lot which has been found as conforming to the aboverequirements shall then be divided into two parts, as shown in col 7an d 8 of Table 3. The n um ber of insu lat ors t o be test ed for m echa nicalan d porosit y test s sh all be in accordance with col 7 of Ta ble 3. The lotshall be considered as conforming to these requirements if nodefective is foun d in t he sa m ple an d sh all be rejected if th ere a re t woor more defectives. If there is one defective, a second sample of samesize ( see col 8 of Table 3 ) sha ll be selected a t r an dom an d subjected t othe tests. The lot shall be considered as conforming to theserequ iremen t s if no defective is foun d in th e second sam ple; oth erwise

th e lot sha ll be rejected without fur th er t esting.A-2.3 The lot sh all be considered a s conform ing to the r equirem ent s of accept ance test s if cond itions in A-2.1 , and A-2.2 ar e sat isfied.



B u r e a u o f I n d i a n S t a n d a r d sBIS is a statutory insti tution established under the Bureau of Indian Standards Act , 1986 topromote harmonious development of the activities of standardization, marking and qualitycertificat ion of goods a nd a tt ending to conne cted m at ters in th e coun tr y.

C o p y r i g h tBIS ha s th e copyright of all its pu blicat ions. No par t of these publicat ions m ay be repr oduced in a nyform without the prior permission in writing of BIS. This does not preclude the free use, in thecours e of implement ing the st an dar d, of necessar y details, such as symbols and sizes, type or gra dedesignations. En quiries rela ting t o copyright be addr essed to th e Director (Pu blications), BIS.

R e v ie w o f I n d i a n S t a n d a r d sAmendments are issued to standards as the need arises on the basis of comments. Standards arealso reviewed periodically; a standard along with amendments is reaffirmed when such reviewindicates t hat no chan ges ar e needed; if the r eview indicat es tha t chan ges ar e needed, it is t aken upfor revision. Users of Indian Standards should ascertain that they are in possession of the latestam endm ents or edition by referrin g to th e latest issu e of ‘BIS Cata logue’ an d ‘Sta nda rds : MonthlyAdditions’.This Indian Stan dard ha s been developed by Technical Comm ittee : ETDC 3 and a mended byE TDC 6

Am e n d m e n t s I s s u e d S in c e P u b l ic a t i o nAm e n d N o. Da t e o f I s su e

Am d. No. 1 Oct ober 1983

Am d. No. 2 Mar ch 1989

Am d. No. 3 Oct ober 1991

Am d. No. 4 Sept em ber 2003

B UR E AU O F I ND IAN S TAN DAR DSHeadquar ters :

Manak Bhavan, 9 Baha dur Sh ah Zafar Marg, New Delhi 110002.Telephones: 323 01 31, 323 33 75, 323 94 02

Telegrams: Manaksanstha(Common to all offices)

Regiona l Offices: Telephon e

C en t r a l : M an a k Bh a va n , 9 B a ha d u r S h ah Za fa r Ma rg

NEW DELH I 110002

323 76 17

323 38 41East ern : 1/14 C. I . T. Scheme VII M, V. I . P. Road, Kankurgachi

KOLKATA 700054337 84 99, 337 85 61337 86 26 , 33 7 91 2 0

Nort hern : SCO 335-336, Sector 34-A, CH ANDIGARH 160022 60 38 4360 20 25

Sout hern : C. I . T. Cam pus, IV Cross Roa d, CHENNAI 600113 235 02 16, 235 04 42235 15 19 , 23 5 23 1 5

Wes tern : Manaka laya , E9 MIDC, Marol , Andher i (Eas t )MUMBAI 400093

832 92 95 , 83 2 78 58832 78 91 , 83 2 78 92

Branches : AHMEDABAD. BANGALORE. BHOP AL. BHUBANESHWAR. COIMBATORE.

FARIDABAD. GHAZIABAD. GUWAHATI. H YDERABAD. J AIPUR. KANPUR. LUCKNOW.NAGPUR. NALAGARH. PATNA. PUNE. RAJKOT. THIRUVANANTHAPURAM.VISHAKHAPATNAM

Documents

283 Porcelain Insulator for Telephone Lines