indian standard for Hard-Drawn Copper Conductors for Over Head Power Transmission

lS:282-1982
(“Second Reoision )
Q C@Wight 1982
I::N:D 1 AN S T’U,N D A R D S I N S T I T U T I O,N
MANiK BHAVAN,. 9 BAHADUR SHAH ZAFAR MARG
‘,
NEW DELHI 110002
Gr 4 October 1982

IS : 282 - 1952
.lled~ers Representing
SHRI I<. ft. GUPTA Haryana State Electricity Board, Chandigarh
SHRI H. c. I<AUSHlK ( d/etYlUle )
SHRI 1’. JAYARASIAN Tamil Nadu Electricity Board, Madras
SHRI DEVADASAN EDWARD ( Alternate )
SHRI M. K. JHUNJIIUNWALA Cable and Conductor Manufacturers’ Association
of India, New Delhi
SHRI T. S. I’ADMANAI)HAN ( Alternate )
SHRI I. S. KALRA Bhakra Beas Management Board, Chandigarh
SHRI H. S. CHOPRA ( Alternare )
SHRI 0. P. MATHUR Electrical Manufacturina Co Ltd. Calcutta
DR P. BHATTACHARYA ( Alternute )
SHRI KAJ K. MITAL Delhi Electric Supply Undertaking, New Delhi
SHRI M. K. Ai-luJ~ ( Alternafe )
SHRI S. K. MIJKCIEIIJEE National Test House. Calcutta
SHIII U. S. VI-:I~MA ( A//ertra/e )
SHRI A. I(. RAMACIIANDI<:N National Thermal Power Corporation Ltd. New
Delhi
SHRI S. S. [LAO ( A/rrrrJrJre )
SHRI I-I. K. RA’I‘III Maharashtra State Electricity Board, Bombay
SHRI V. N. RIKII U.P. State Electricity Board, Luclcnow
SHRI V. K. AGARWAL ( Alternate )
SHRI V. K. SHARMA National Hydro-Electric Power Corporation Ltd.
New Delhi
SIIILI MAIIENDRA K~J~IAR ( Al~e~rrmrc )
SHRI i<. D. SHl3’li Electra-Metal Industries, Bombay
SIIRI G. .I. DI:~ASSYMIIT~Y ( Alrermre )
Slllll I>. Sl~,SUllllAblANl,aI Aluminium Industries Ltd. Kundara
SIII~I K. Al. JACOB ( /ll~euw!e )
PROt AI. ‘Ksuciol~AL Indian Institute of Technology, Madras
I’lLOl. Y. NAILAYASA Rho ( /llferrrcJle )
SHRI s. I’. SAcr~lxv, Director General, ISI (Ex-oJ%io Member )
Director f,Elcc Tech )
Secretcrry
SHRI SUKH BIR SINGH
Assistant Director (Elec Tech ), ISI

TO
IS:282-1582 SPECIFICATION FOR HARD-DRAh'N COPPER
COWJCTORS FOR OVERHEAD POWER TRANSMISSION
(SecondRevision)
(RzgeIO, Table 4) - Substititc the follovig
for the existing table:
TABLE 4 LIMITS OF LAY RATIOS OF DIFFERENT LAYERS
FJO. OF LAY RATIO FOR LAYER
ZiiTRAWS Wires in Prackcts)
if
(3 1 (6) (12)
/'MClX
(1) (2) (3) (4 1 (5) (6) (7)
3 16 11 - - - -
7 17 13 - -
19 22 13 16 12
Reprography Unit, XI, New Delhi, India

IS : 282 - 1982
Indian Standard
SPECIFICATION FOR
HARD-DRAWN COPPER CONDUCTORS
FOR OVERHEAD POWER TRANSMISSION
( Second Reoision )
Conductors and Accessories for Overhead Lines
Sectional Committee, ETDC 60
Chairman Representing
SHRI R. D. JAIN Rural Electrification Corporation Ltd, New Delhi
Members
SHR~ G. L. DUA ( AIternate to
Shri R. D. Jain )
ADDITIONAL GENERAL MANAGER Indian Posts & Telegraphs Department, New Delhi
( IT )
DIVISIONAL ENGINEER
( TELE )-E ( Alternate )
SHRI V. K. AGARWAL Tata Hydro-Electric Power Supply Co Ltd, Bombay
SHRI P. P. BHISEY ( Alternate )
SHR~ R. S. ARORA Directorate General of Supplies and Disposals,
New Delhi
SHRI J. S. PASSI ( Alternate )
SHRI S. BHA~TACHARYA Indian Cable Co Ltd, Calcutta
SHRI T. SINGH ( Alternate )
SHRI R. T. CHAKI Tag Corporation, Madras
SARI A. ARUNKUMAR ( Alternate )
SHRI S. D. DAND Kamani Engineering Corporation Ltd, Bombay
SHRI R. V. S. MANIAN ( Alternate )
DIRECTOR Central Power Research Institute, Bangalore
SHRI T. V. GOPALAN ( Alternate )
DIRECTOR ( TRANSMISSION ) Central Electricity Authority ( Transmission
Directorate ), New Delhi
DEPUTY DIRECTOR ( TRANS-
MISSION ) ( Alternate )
D ;;;Kvo; R ( TI ). RDSO, Ministry of Railways
JOINT DIRECTOR ( TI )-I,
RDSO, LUCKNOW ( Alternate )
( Continued on page 2 )
Q Copyright 1982
INDIAN STANDARDS INSTITUTION
This publicatron is protected under the Indian Copyright Acf ( XIV of 1957 ) and
reproduction in whole or in part by any means except with written permission of
the publisher shall be deemed to be an infringement of copyright under the said Act.

IS : 282 - 1982
Indian Standard
SPECIFICATION FOR
HARD-DRAWN COPPER CONDUCTORS
FOR OVERHEAD POWER TRANSMISSION
( Second Reoision )
0. F.OREWORD
0.1 This Indian Standard ( Second Revision ) was adopted by the Indian
Standards Institution on 20 May 1982, after the draft finalized by the
Conductors and Accessories for Overhead Lines Sectional Committee had
been approved by the Electrotechnical Division Council.
0.2 This standard, first published in 1951, was subsequently revised in 1963
to incorporate all quantities and dimensions in metric system. This
revision has been undertaken with a view to upgrade many of the essential
requirements and to bring it in line with the latest engineering practices
being followed in the country.
0.3 In the standard, values for constant-mass temperature coef&ient of
resistance and coefficient of linear expansion are given on the basis of IEC
Publication No. 28 ( 1925 ). International Standard of Resistance for
copper.
0.4 Hard-drawn copper wires covered by Telegraph Wires (Unlawful
possession ) Act No. LXXIV of 1950 as amended by Act No. LIII of 1953
have been dealt separately in 18:2532-1965*.
0.5 While preparing this standard, assistance has been derived from
BS 125: 1970 Hard-drawn Copper and Copper Cadmium Conductors for
Overhead Power Transmission Purposes, issued by the British Standards
Institution.
0.6 For the purpose of deciding whether a particular requirement of this
standard is complied with, the final value, observed or calculated, express-
ing the result of a test, shall be rounded off in accordance with IS :2-196Ot.
The number of significant places retained in the rounded off value should
be the same as that of the specified value in this standard.
*Specification for hard-drawn copper wire for telegraph and telephone purposes.
tRules for rounding off numerical values ( revised ).
3

1. SCOPE
1.1 This specification covers the requirements for hard-drawn solid and
stranded circular copper conductors for overhead power transmission
purposes.
2. TERMINOLOGY
2.0 For the purpose of this standard, the following definitions in addition
to those given in 1s : lS85 ( Part XXXII )-1971* shall apply.
2.1 Stranded Conductor - Conductor consisting of three or more copper
wires of the same nominal diameter twisted together in concentric layers.
When the conductor consists of more than one layer, successive layers are
twisted in opposite directions.
2.2 Diameter - The mean of two measurements at right angles taken at
the same crow section
2.3 Direction of Lay - The direction of lay is defined as right hand or left
hand. With right hand lay, the wires conform to the direction of the
central part of the letter 2 when the conductor is held vertically. With left
hand lay, the wires c:)nform to the direction of the central part of the
letter S when the conductor is held vertically.
2.4 Lay Ratio - Ratio of the axial length of a complete turn of the helix
formed by an individual wire in a stranded conductor to the external
diameter of the helix.
3. CONDUCTOR
3.1 Material -- The conductor shall consist of hard-drawn round copper
wire having the following properties.
3. I.l Physiml Co~~.r~nn~r,/or Hmi- Drnwn Copper
3.1.1.1 I/o/u/;re /z.sisliviry - The resistivity of hard-drawn high-con-
ductivity copper is 21function of the tensile strength. Within a range of
30 to 50 kg/mm2 tensile strength, the following formula has been found to
express suficiently closely the results obtained in practice, and has been
adopted in calculating the resistance given in this specification:
‘I‘
whew
P = percentage increase in resistivity of the hard-drawn copper
over its resistivity when annealed, and
T == tensile strength of the hard-drawn copper in kg/mm”.
*Electrotcchnical vocabulary: Part XXX11 Cables, conductors and accessories for
electricity supi>ly.

IS : 282 - 1982
The resistances given in the tables, are based on standard resistivjty
of annealed high-conductivity copper at 20°C modified in accordance with
the above formula.
At a temperature of 20°C the volume resistivity of standard annealed
copper is 0.017 241 ohm square millimetre per metre ( ohm mm3/m ).
Copper which has resistivity at 20°C of 0.017 241 ohm mm2/m is
said to have a conductivity of 100 percent.
3.1.1.2 Density - At a temperature of 20°C the density of hard-drawn
high conductivity copper has been taken as 8.89 g/cm3.
3.1.1.3 Coefficient of linear expansion - At a temperature of 20°C the
coefficient of linear expansion of hard-drawn high-conductivity copper has
been taken as 0’000 017 per Centigrade degree, This coefficient may be
used over a temperature range of 0°C to 150°C.
3.1.1.4 Constant-mass temperature coefficient of resistance - at a
temperature of 20°C the coefficient of variation of the resistance with
temperature of hard-drawn high-conductivity copper, measured between
two potential points rigidly fixed to the wire, the metal being allowed to
expand freely, has been taken as 0’003 81 per Centigrade degree, which is a
representative value for copper of 97 percent conductivity.
3.1.1.5 Freedom from defects - The wire shall be smooth and free
from al1 imperfections such as spills and spurns.
4. STANDARD RESISTANCE, WEIGHT AND SIZE OF SOLID
CONDUCTOR
4.1 After drawing, the wire shall have the resistance, weight and diameter
given in Table 1.
5. STANDARD RESISTANCE, WEIGHT AND SIZE OF STANDARD
CONDUCTOR
5.1 The size, weight and resistance of stranded circular conductor shall be
in accordance with the values given in Table 2.
5.2 In Table 2, the areas, weights and resistances of the stranded
conductors have been calculated by multiplying the corresponding values
for one of the single wires of which the stranded conductor is composed by
the constants set out in Table 3.
5.3 The calculated area in each case in Table 2 is given as obtained above,
and is that of a solid conductor of equal resistance assuming to same
specific conductivity.
5

TABLE 1 STANDARD SOLID HARD-DRAWN COPPER CONDUCTORS tj
. .
(Clauses 4.1, 6.1, 6.2, 7.1, 11.3.2 curd 15.2)
SOhllNAL DIAMETEK STANDARD KESWANCI? AT MINlhlLJhl BIII:AK- MINlhlUhl
‘Stan- Masi-
dard Ill u Ill
12) (3)
mm 1nm
1.36: I.37
1.605 1.62
1.70; 1.72
2.12; 2.14
2.65: 2.6s
3.00: 3.03
3’25§$ 3.28
3.35: 3.38
3’55§: 3.59
3.65: 3.69
3.75:: 3’79
4.253: 4.29
4.504 4.54
4.75: 4’80
- S’OO$
25 5.305:
- S-60:
35 6.505
40 7’10§
SO 7.50s
65 9*sog
5'05 4.95 174.6 0.9014 0.9104 8.09 7.93 412.0 - 19’63
5.35 5.25 196.1 0.8019 0.8099 9.00 8.84 408.3 - 22.06
5.66 554 219-o 0.7181 0.7253 9.99 9.78 405.6 1.88 24.63
6’56 6.44 295.0 05327 0’5380 13.12 1288 395.5 1.98 33.18
7’17 7.03 352.0 0.4463 0.4508 15’38 15’07 388.5 2.07 39.59
7.58 7.42 392.7 0.3998 0.4038 16.94 1659 383.6 213 44.18
9’60 9.40 630’1 0.2488 0.2513 25.62 25.08 361.5 248 70.88
Mini-
“lull1
WEIGHT
PEU
km
(4, (5)
mm kg
1.35 12.91
1.58 17.87
1.68 20.18
2.10 31.38
2.62 49’03
291 62.84
3.22 73’75
3’32 78.36
3.51 87.99
3.61 93.02
3’71 98.10
4’21 126.1
4.46 141.4
4.70 157.5 0.9987 1*009
20°C PER km ING LOAV TENSILE
(--A-
-7 l------- *-------, STRENGTH
Stan-
dard
hstaxi-
mum
(6, 7)
ohm ohm
12.21 12.33
8.823 8.911
7.815 7.893
5.025 5.075
3-215 3.247
2.507 2532
2.136 2.157
2.010 2.030
1.790 1.808
1.693 1’710
1.604 1.620
1.248 I .265
1.113 1.124
On Stan-
dard Dia-
meter*
S)
kN
.667
.922
I.03
l-59
2’45
3.12
3.63
3.85
4.28
4.50
4.74
5.97
6.64
7.35
On Mini-
mum Dia-
meter’j
;‘)j
kN
.657
.892
1.01
I.56
2.40
3’05
3.56
3.77
4.18
4.40
4.64
5.87
6.52
7.19
(10)
MN/Ill’
458.6
456.6
455.9
450.9
445.4
440.7
437.0
435.1
432.1
4jo.7
429.2
421.3
417.6
4145
MINIMUM
ELONGA-
TION ON
2s cm
(II)
Percent
-
-
-
-
-
-
-
-
-
-
-
-
-
z
t3
CALCULI- ’
‘TEL) AUliA 5;
ON STAN- c
DAUV
DlhhlETEll
(12)
Ill 111”
1’453
2’011
2.270
3.530
5.515
7.069
8.296
S.814
9.898
IO.46
11.04
14.19
IS.90
17’72
NOTE 1 - The standard weight given in coi 5 is based on standard diameter and is for information only.
NOTE 2 - Minimum breaking loads after stranding shall be not less than 92.5 percent of the corresponding values
given in co1 8 and 9.
*The values specified in co1 8 are the basis from which the approximate breaking load of conductors specified in
Table 2 have been calculated.
tThe values specified in co1 9 are minima with which solid conductors and wires shall comply before stranding.
ZStandard sizes recommended for stranded conductors.
SStandard sizes recommended for use as solid conductors.

IS : 282 - 1982
TADLE 2 STANDARD STRANDED HARD-DRAWN
COPPER CONDUCTORS
( Clames 5.1, 5.2, 5.3, 6.1, 14.2 rind 15.2 )
STAND- NUMBER
ARD AND DI,-
NOMI- ~IEI‘I;II VI
NAL SSIIANIX
AKE.4
(1)
111111’~
10
14
16
2s
35
40
50
65
70
95
120
130
150
160
115
200
(2) (3) (4) (5)
mm mm m tm 2 kg
312.12 4.57 10.51 94.90
l/1,36 4.0s 10.0s 91.1 j
T/l.60 4.80 13.96 126.2
3/2%S 5.71 16.42 148.3
l/l’70 5.10 IS.76 142.4
313.25 7.00 24.70 223.0
712.12 6.36 24.50 221.5
313.75 sm 32.88 297.0
7l27.35 7.9s 38.29 346’1
713.00 9’00 49.07 443.5
19/2.12 10.6 66.24 604
713.5s IO.6 68.7 I 621.1
714’25 12,s 98.48 890. I
714.75 14.2 123’0 I 112
7/540 IS.0 136.3 1 232
19/3.00 15.0 132.7 1 209
715.30 15.9 153.2 1 384
1913’25 16.2 155.7 1419
115’60 16.S 171.0 1 545
19/3’35 16.8 165.4 1 508
19/3,SS 17,s 185.8 1 693
1913.65 lS.2 196.4 1 790
AP~ROXI- CALCULA- STAND-
MATE IED AREA ARD
o‘iil~il.L ON S.I.,N- WEIGIIT
I<ESISTAN~E AT 20°C APPROXI-
PER km WHEN CON- MATE
NECTFV TO STAN- BREAKING
VARV WElGHT
(6)
ohm
I.688
1.758
1.271
1.080
1.125
0.717 7
0.723 6
0.538 9
0.463 0
0.361 0
0.267 7
0.257 8
0.179 7
0.143 8
0.129 8
0.133 6
0.115 5
0.113 8
0.103 4
0,107 1
o-095 37
0*090 20
(7)
ohm
1‘JO.5
1,775
I.282
1.090
1.136
0.724 9
0.730 8
0.544 3
0.467 6
0.364 6
0.270 4
0.260 4
O*lSl 5
0.145 1
0.131 1
0’134 9
0.126 7
0.114 9
0.104 4
O*lOS 1
0’095 47
0.091 20
LOAD OF
CON-
DUCTOR
(8)
kN
4.38
4.30
5.93
6.77
6.63
IO.02
IO.23
13.08
15.79
20.09
27.17
27.55
38.47
47.32
52.12
53.35
58.00
62.07
64’31
65.76
73.14
77~00
Nore - The standard wight given in co1 5 is based on standard diameter and is
for information only.
8

IS : 282 - 1982
TABLE 3 CONVERSION CONSTANTS FOR
STRANDED CONDUCTORS
( Clatrse 5.2 )
No. OF WIRES CONSTANT
STRANDED r----.-.e--h--- ---l
Area Weight Resistance
(1) (2) (3) (4)
3 2.977 3’024 0.336 0
I 6.942 7.058 0.144 0
19 18.77 19.24 0.053 28
5.4 The resistances have been corrected in accordance with the formula
given in 3.1.1.1.
6. TOLERANCES ON THE STANDARD DIAMETER AND
RESISTANCE OF CONDUCTORS
6.1 Tolerances as given below shall be permitted on the standard diameter
and resistances of all conductors:
a) Tolerance on standard diameter f I percent, and
b) Tolerance on resistance + 1 percent when corrected to standard
weight.
When corrected to standard weight and temperature, the resistance of
the conductor shall not exceed the appropriate maximum resistance given
in Tables 1 and 2.
6.2 The mean diameter of the conductor shall fall within the appropriate
maximum and.minimum values given in Table 1.
6.3 The cross-section bf any conductor shall not depart from circuiarity by
more than an amount corresponding to a tolerance of 2 percent on the
standard diameter.
7. MECHANICAL PROPERTIES
7.1 The mechanical properties of the wire shall be such that the tensile
strength and elongation when tested in accordance with 14.3 and 14.4 shall
be as shown in Table 1.
7.2 Wires smaller than 5.60 mm diameter shall also comply with the
requirements of the wrapping test as specified in 14.2.
NOTE -For purposes of calculation, the modulus of elasticity of hard-drawn
copper shall be taken as 1.27 x loo kg/cm’J.
9

IS : 282 - 1982
8. JOINTS IN WIRES, EXCEPT DlJRING STRANDING
8.1 The wires shall be drawn in continuous lengths, without joints, except
those made in the soft rod or wire before final drawing.
9. JOINTS IN STRANDED CONDUCTORS
9.1 Conductors Containing Seven Wires or Less -Joints in wires, other
than those permitted under 8, shall not be permitted in any wire of a
stranded conductor containing 7 wires or less.
9.2 Conductors Coutairiiug More than Seven Wires - In the case of
stranded conductor containin g more than 7 wires, a joint in any wire shall
be permitted provided that no two joints ( other than those in wires before
stranding. permitted under 8 ) occur at points in the stranded conductor
nearer than 15 m. Joints shdl be hard-soldered or welded.
9.3 The breaking strength of the joint permitted under 9.2, shall be in no
case be less than 220 MN/mr?.
10.1 The wire entering, into the construction of stranded conductors shall,
before stranding, satlsty all the requirements of this specification for solid
wires.
10.2 The lay ratios of different layers shall be within the limits given in
Table 4.
TABLE 4 LIMITS OF LAY RATIOS OF DIFFERENT LAYERS
No. OF
STRANDS
(1)
3
I
19
LAY RATIO FOR LAYER
( WITH NUMBER OF WIRES IN BRACKETS )
f-------- --- ,
1st 2nd
!3) (6) (12)
,----h -7 f---------*-~
Max Min M NX Mire
f-----*--l
Max Min
(2) (3) (4) (5) (6) (7)
30 20 - - - -
- -- 25 20 - -
.._. - 32 20 20 15

IS : 282 - 1982
10.3 For all constructions successive layers shall have opposite directions of
lay, the outer layer being right handed.
11. LENGTHS AND VARIATIONS IN LENGTHS
11.1 Unless otherwise agreed between the manufacturer and purchaser,
hard-drawn copper conductors shall be supplied in the manufacturer’s
usual production lengths with a permitted variation of & 5 percent in the
length of any one length.
11.2 Unless otherwise agreed between manufacturer and purchaser, it shall
be permissible to supply not more than 10% of the lengths on any one
order in random lengths, none, of them shall be shorter than 1/3rd of the
nominal lengths.
12. PACKING AND MARKING
12.1 The conductor shall be supplied in coils or on drums* and one drum
or coil shall carry only one continuous length of conductor. Each coil or
drum shall be marked with the following information:
a) Trade-name, if any;
b) Manufacturer’s name;
c) Size of conductor;
d) Length of conductor;
e) Weight of the conductor;
f) Drum number; and
g) Any other particulars as specified by the purchaser.
12.1.1 The conductor may also be marked with the ISI Certification
Mark.
NOTE - The use of the ISI Certification Mark is governed by the provisions of
the Indian Standards Institution ( Certification Marks) Act and. the Rules and
Regulations made thereunder. The IS1 Mark on products covered by an Indian
Standard conveys the assurance that they have been produced to comply with
the requirements of that standard under a well-defined system of inspection, testing
and quality control which is devised and supervised by ISI and operated by the
producer. ISI marked products are also continuously checked by IS1 for conformity
to that standard as a further safeeguard. Details of conditions under which a
licence for the use of the IS1 Certification Mark may be granted to manufacturers or
processors, may be obtained from the Indian Standards Institution.
*It is recommended that the drums for bare conductors should comply with
IS: 1778-1980 Specification for reels and drums for bare wire ( /irsr revision ).
11

IS : 282 - 1982
13. TEST SAMPLES
13.1 Solid Conductors - Samples for the tests specified in 14 and 15 shall
be taken from approximately 10 percent of the drums included in any one
consignment.
One sample, sulbcient to provide one specimen for each test, shall be
taken from each of the selected drums.
13.2 Stranded Conductors
13.2.1 Tests Before Strnnding - Samples for the tests specified in 14
and 15 shall be taken by the manufacturer before stranding from not less
than 10 percent of the individual lengths of wire which will be included in
any one consignment of stranded conductor. One sample, sufficient to
provide one test specimen for each test, shall be taken from each of the
selected lengths of wire.
1X2.2 Test A.fter Strcmling - Alternatively, when the purchaser states
at the time of ordering that he desires tests to be made in the presence of
his representatives, samples of wire shall be taken from lengths of stranded
conductor selected from approximately 10 percent of the drums included in
any one consignment. One sample, sufficient to provide one specimen for
each test, shall be taken from each of the selected drums.
14. MECHANICAL TESTS
14.1 General - In the case of both solid and stranded conductors, the
mechanical tests shall be carried out on single wires only.
14.2 Wrapping Test
14.2.1 This test shall be carried out only on wires of less than 5.60 mm
diameter.
14.2.2 The wire shall not break when tested in the following manner,
14.2.2.1 The wire shall be wrapped round a wire of its own diameter
to form a close helix of eight turns. Six turns shall then be unwrapped
and again closely rcwrappcd in the same direction as the first wrapping.
14.3 Tensile Test
14.3.1 This test shall apply to solid conductors and to the component
wires of stranded conductors. Wherever practicable, tests of wires shall be
made before stranding.
14.3.2 II’ it is not l)ossible to test the component wires of a stranded
conductor before stranding, the test may be made on wires taken from the
strandctl co:jductor. Tn such cases, the tensile strength of any of the wires
shall be not less tha:1 92.5 percent of the values given in Table 1 and the
average tensile strcrl~rh of the wires in a stranded conductor shall be not
less than 9-3pcrccnt of the values specified in Table 1.

IS : 282 - 1982
14.3.3 A tensile testing machine shall be used the accuracy of which can
be easily checked and the machine adjusted, if necessary. The test samples
being placed in the machine shall be straightened, if necessary, in such a
way as to cause the minimum alteration in the physical properties.
14.3.3.1 When an automatic tensile testing machine is used, the load
shall be applied gradually and the rate of separation of the jaws of the
testing machine shall not be greater than 10 cm per minute and shall be so
adjusted that the total time of testing from the moment of application of
the load till fracture is between 15 to 60 seconds.
14.3.3.2 When a hand-operated lever testing machine is used 90 percent
of the breaking load shall be applied quickly and the load shall then be
increased steadily until the specimen breaks. The time taken to apply the
balance 10 percent of the load shall be approximately 15 seconds and the
total time from the application of the load to the break shall be approxi-
mately 20 seconds.
NOTE - The strength of a stranded conductor in terms of the sum of the strength
of the individual component wires may be assumed to be not less than the values
given in Table 5.
TABLE 5 STRENGTH OF STRANDED CONDUCTOR
No. OF WIRES PERCENTAGE STRENGTH BASED PERCENTAGE STRENGTH BASED
IN STRANDED ON THE SUM OF THE STRENGTHS ON THE SUM OF THE STRENGTHS
CONDUUOR OF THE WIRES WHEN TAKEN OF THE COMPONENT WIRES
FROM THE STRANDED BEFORE STKANDING
CONDUCTOR AND ( THAT IS IN
TESTED THE COIL )
(1) (2) (3)
3 96 92
7 95 92
19 93 90
14.4 Elongation Test
14.4.1 This test shall be performed only on wires of 5.60 mm diameter
and over.
14.4.2 The load shall be applied on straightened lengths of wire having
an original gauge-length of 25 cm. The extension shall be measured on
the gauge-length after the fractured ends have been fitted together, provided
13

IS : 282 - 1952
that the fracture occurs between the gauge marks and not closer than
25 mm to either mark. If the fracture occurs outside these limits and if the
required elongation is not obtained, the test shall be discarded and another
test made.
15. RESISTANCE TEST
15.1 The dc resistance of the conductor shall be measured at room
temperature. The conductor shall be in the test room which shall be at a
reasonably constant temperature for sufficient time to ensure that the
conductor temperature is equal to the ambient temperature.
15.2 The electrical resistance as measured shall be converted to resistance
per kilometre which when multiplied by
K = standard weight per km,
W = weight per km of test sample, and
C = multiplier constant for correction to 20°C;
shall not exceed the maximum values given in Tables 1 and 2.
15.2.1 The multiplier constant shall be in accordance with Table 6.
15.3 The measurement of resistance shall be carried out to an accuracy of
one part in a thousand. The length of the sample selected for the test of
electrical resistance shall be suficient to give the accuracy required and
shall be suitable for the method of testing employed. Certificates as to the
accuracy of the apparatus shall be provided, and either party concerned
shall have the right to satisfy itself that the apparatus and the method of
testing are correct.
16. REJECTION AND RETESTS
16.1 Should any one of the test pieces first selected fail to pass the test,
three further samples from the same batch shall be selected, one of which
shall be from the length from which the original test sample was taken,
unless that length has been withdrawn by the supplier.
16.2 Should all of the three test pieces from these additional samples
satisfy the rec~uirements of the tests, the batch represented by these samples
shall bc deemed to comply with the standard. Should the test pieces from
any of the three additional samples fail, the batch represented shall be
deemed not to comply with the standard.
14

IS : 282 - 1982
TABLE 6 MULTIPLIER CONSTANTS
( Clause 14.2.1 )
Factors for converting resistances at various temperatures, of hard-drawn high
conductivity copper of 97 percent conductivity, to the standard reference temperature
of 20°C and reciprocals of the factors, for converting resistances at 20°C to other
temperatures.
TEMPERA- MULTIPLIER
TURE"C CONSTANT
RECIPRO-
CALOF
CONSTANT
(3)
0.94i 9
0.944 8
0.946 7
0.948 6
TEMPERA- MULTIPLIER
TURE "C CONSTANT.
(1) (2)
5 1.060 6
5’5 1.058 5
6 1.056 3
6.5 1.054 2
(1) (2)
10 1’039 6
lo;5 1.037 6
11 1.035 5
11.5 1.033 5
RECIPRO-
CALOF
CONSTANT
(31
0.961 9
0.963 8
O-965 7
0.967 6
7 1.052 1 0.950 5 12 I.031 4 O-969 5
7.5 1.050 0 0,952 4 12.5 I.029 4 0.971 4
8 1.047 9 0.954 3 13 I.027 4 0.973 3
8.5 1.045 8 0.956 2 13.5 1.025 4 0.975 2
9 1.043 7 0.958 1
9.5 l-041 7 O-960 0
14 1.023 4 o-977 1
14.5 1.021 4 0.979 0
15 1.019 4 0.981 0
155 1.017 4 0.982 9
16 l-015 5 0.984 8
16.5 I.013 5 0.986 7
25.5 0’979 5 1.021 0
26 o-977 7 1’022 9
26.5 0.975 8 l-024 8
17 l-011 6 0.988 6
17.5 1.009 6 0.990 5
18 1.007 7 0.992 4
18.5 1’005 7 0.994 3
27 0.974 0 I.026 7
27.5 0.972 2 I.028 6
28 0.970 4 1.030 5
28.5 0.968 6 1.032 4
19 1.003 8 0.996 2
19.5 1’001 9 0.998 1
20 1.000 0 I*000 0
20.5 o-998 1 I-001 9
29 0.966 8 1.034 3
29.5 0’965 1 I.036 2
30 0.963 3 1.038 1
35 0’945 9 I.057 1
( Continued )
15

IS : 282 - 1982
TABLE 6 MULTIPLIER CONSTANTS - Conrd
Factors for converting resistances at various temperatures, of hard-drawn high
conductivity copper of 97 percent conductivity, to the standard reference temperature
of 2O”C, and reciprocals of the factors, for converting resistances at 20°C to other
temperatures.
TEMPERA- MULTIPLIER
TURE°C CONSTANT
RECIPRO-
CALOF
CONSTANT
(1) (2) (3)
21 0.996 2 I.003 8
21.5 0.994 3 1.005 I
22 0.992 4 I.007 6
22.5 0.990 6 I.009 5
23
23.5
24
24.5
o-9%3 I
0.956 8
0.985 0
0*9s3 1
l-011 4
1.013 3
1*015 2
1.017 1
25 O.OSl 3 I.019 1
TEMPERA- MULTIPLIER
TURE "c CONSTANT
(1)
40
45
50
55
60 0.867 8 I.152 4
65 0.863 6 1.171 4
70 0.840 0 1.190 5
75 0.826 8 1’209 5
so 0.813 9 1.228 6
85 0.801 5 1.247 8
(2)
o-929 2
0.913 0
0497 4
OS32 3
CALOF
CONSTANT
(3)
I.076 2
I.095 2
1.114 3
I.133 3
NOTE - The temperature coefficient of resistance of copper varies slightly from
sample to sample according to its exact conductivity. The figures given in Table 6
are based on a value of the temperatures coefficient of resistance of 0.003 81 per
Centigrade degree at 2O”C, which is an average value for copper of 97 percent
conductivity.
The primary purpose of this table is to enable a resistance measured at a tempera-
ture other than 20°C to be converted to the resistance at 20°C in order to determine
whether the conductor under test complies with the requirements of the standard.
For this purpose, the factors have been given at half-degree intervals from 5°C to
30°C. and the error in using the table between these limits for copper within the
range of conductivity. 96 percent lo 98 percent will not exceed 0.06 percent.
The factors and their reciprocals have also been found of value for other purposes,
such as calculation of voltage drop on heated conductors. For these purposes only,
values have been given at five-degree intervals from 30°C to 85°C. It should be
realized, however, that their use may lead to errors of up to 0.2 percent at the upper
end of the range.

INDIAN STANDARDS
ON
CONDUCTORS AND ACCESSORIES FOR OVERHEAD .LINES
IS:
282-1982 Hard-drawn copper conductors for overheciQ power, tra%%UiS%QU,
( second revision )
398 Aluminium conductors for overhead transmission l?urPoses:
(Part I)-1976 Aluminium stranded conductors (secoridrevision)
(Part II)-1976 Aluminium conductors, galvanized steel reinforced Lseconu
revision )
(Part III)-1976 Aluminium conductors, aluminized steel reinforced ( second
revision )
(Part IV)-1979 Aluminium alloy stranded conductors ~,alurninium;mnag~es~~~~
silicon type) ( secondrevision )
(Part V)-1982 Aluminium conductors, galvanized steel reinforced F&&tr$&g
voltage ( 400 kV and above )
177S-19SO Reels and drums for bare wire ( firsf revision )
1% (Part XxX11)-1971 Electrotechnical vocabulary: Part XXX11 Cables;conductors
and accessories [or electricity supply
2121 Conductors and earth wire accessories for overhead power lines:
(Part Q-1981 Armour rods, binding wires and tapes for cF$uctors ($&&i&%)
- -’:?3w~~~~~,*~
(Part II)-1981 Mid span joints and repair sleeves for conduc[ors (fi~~~;@r~~&$
2532.1965 Hard-drawn copper wire for telegraph and t&ph$~k.purpo$$.$
2665-1964 Cadmium copper wire for telegraph and.telephoa~f;u~~os~~
3402-1965 Cadmium copper conductors for overhead r&ibaj?~&& ..,, I. ^.
3476-1967 Trolley and contact wire for electric traction
9708-1980 Stock bridge vibration dampers for overheid pow& l@s
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