EN 61232:1995

SLOVENSKI STANDARD
01-januar-1996
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Aluminium-clad steel wires for electrical purposes
Aluminium-ummantelte Stahldrähte für die Elektrotechnik
Fils d'acier revêtus d'aluminium pour usages électriques
Ta slovenski standard je istoveten z: EN 61232:1995
ICS:
29.060.10 Žice Wires
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEI
NORME
IEC
INTERNATIONALE
INTERNATIONAL
Première édition
STANDARD
First edition
1993-06
Fils d'acier revêtus d'aluminium
pour usages électriques
Aluminium-clad steel wires
for electrical purposes
de reproduction réservés — Copyright — all rights reserved
© CEI 1993 Droits
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1232 ©IEC:1993 – 3 –
CONTENTS
Page
FOREWORD 5
INTRODUCTION
Clause
1 Scope 9
2 Normative references 9
3 Definitions 9
4 Requirements 11
5 Sampling 13
6 Test methods 13
7 Packaging 19
8 Acceptance and rejection 19
Tables
Annexes
A Ratio of aluminium and steel cross-sectional areas 25
B Elongation 33
1232 ©IEC:1993 - 5 -
INTERNATIONAL ELECTROTECHNICAL COMMISSION
ALUMINIUM-CLAD STEEL WIRES
FOR ELECTRICAL PURPOSES
FOREWORD
The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
1)
comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to
promote international cooperation on all questions concerning standardization in the electrical and
electronic fields. To this end and in addition to other activities, the IEC publishes International Standards.
Their preparation is entrusted to technical committees; any IEC National Committee interested in
the subject dealt with may participate in this preparatory work. International, governmental and
non-governmental organizations liaising with the IEC also participate in this preparation. The IEC
collaborates closely with the International Organization for Standardization (ISO) in accordance with
conditions determined by agreement between the two organizations.
The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on
2)
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
3) They have the form of recommendations for international use published in the form of standards, technical
reports or guides and they are accepted by the National Committees in that sense.
In order to promote international unification, IEC National Committees undertake to apply IEC International
4)
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
This International Standard IEC 1232 has been prepared by IEC technical committee 7:
Bare aluminium conductors.
The text of this standard is based on the following documents:
DIS Report on Voting
7(CO)436
7(CO)434
rt
Full information on the voting for the approval of this standard can be found in the repo
on voting indicated in the above table.
Annexes A and B are for information only.

— 7 —
1232©IEC:1993
INTRODUCTION
Aluminium-clad steel wires have been used as all aluminium-clad steel stranded wires for
overhead ground wire purposes and as reinforcement of aluminium conductors for over-
head line conductor purposes. In some cases, they are also used as phase conductors.
Since various national standards exist in each country for the aluminium-clad steel wires,
this International Standard establishes the requirements for properties.
It should be noted that this standard has been prepared after consideration of the existing
IEC 888.
1232 ©IEC:1993 - 9 -
ALUMINIUM-CLAD STEEL WIRES
FOR ELECTRICAL PURPOSES
1 Scope
This International Standard applies to bare, hard-drawn, round, aluminium-clad steel wires
of different electrical and mechanical properties, in the diameter ranges shown in table 5,
for electrical purposes, before stranding.
It is intended to cover applications, for reinforcement in aluminium conductors and for all
aluminium-clad steel stranded conductors.
It does not cover the wires for redrawing purposes.
2 Normative references
The following normative document contains provisions which, through reference in this
text, constitute provisions of this International Standard. At the time of publication, the
edition indicated was valid. All normative documents are subject to revision, and parties to
agreements based on this International Standard are encouraged to investigate the possi-
bility of applying the most recent edition of the normative document indicated below.
Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 468: 1974, Method of measurement of resistivity of metallic materials.
3 Definitions
For the purpose of this International Standard, the following definitions apply:
3.1 aluminium-clad steel wire: Round wire consisting of a round steel core with a
uniform and continuous aluminium covering.
3.2 diameter: Mean of two measurements at right angles taken at the same cross-
section.
3.3 class: Aluminium-clad steel wires defined as "205K, "27SA", "30SA" and "40SA",
corresponding to their conductivity grades of 20,3 %, 27 %, 30 % and 40 % IACS*.
3.4 type: Aluminium-clad steel wires of class 20SA are divided into two types, A and B,
according to their tensile strength characteristics.
* IACS: International Annealed Copper Standard.

1232 © IEC:1993
4 Requirements
4.1 Materials
4.1.1 The base metal shall be steel produced by the open-hearth, electric-furnace, or
basic-oxygen process and shall be of such composition that the finished clad wire shall
have the properties and characteristics given in this standard.
4.1.2 The aluminium used for covering shall have a minimum purity of 99,5 % and
quality sufficient to meet thickness and electrical resistance requirements of this standard.
4.2 Freedom from defects
The wires shall be smooth and free from all impe rfections such as fissures, roughness,
rformance of the product.
grooves, inclusions or other defects which may endanger the pe
4.3 Density
For the purpose of calculating the nominal mass of the wires, the density of the aluminium-
clad steel wire shall be taken as shown in table 1.
4.4 Tolerances on nominal diameter of wires
Aluminium-clad steel wires shall not depart from the nominal diameter by more than the
amounts given in table 2.
4.5 Minimum thickness of aluminium
The minimum aluminium thickness of wires at any point shall comply with the requirements
given in table 3.
4.6 Tensile stress
The wire shall comply with the requirements given in table 5. In computing breaking load
of a single wire from tensile stress, the actual diameter of the finished wire shall be used.
4.7 Elongation
The wire shall comply with either the requirement of 1 % minimum elongation after
fracture, or 1,5 % minimum total elongation at fracture, for, in both cases, a gauge length
of 250 mm. Measurement shall be made either under no load after fracture or at the time
of fracture by the use of a suitable extensometer.
Unless otherwise agreed upon between the manufacturer and purchaser at the time of
purchase, it is at the option of the manufacturer to select the measurement method.
The test shall be made by only one of the two methods prescribed in 6.3.2.
4.8 Resistivity
The maximum resistivity of wires shall conform to the requirements prescribed in table 5 at
the temperature of 20 °C.
1232 ©IEC:1993 –13 –
4.9 Torsion test
The wire shall withstand, without fracture, not less than 20 twists in a length equivalent to
100 times the nominal diameter of the wire.
The specimen, after twisting to destruction, shall show no separation of the aluminium
from the steel when examined with the naked eye or with normal corrective glasses.
4.10 Stress at 1 % extension
The wire shall conform to the requirement of stress at 1 % extension given in table 5. The
test shall be made on straight undeformed wires.
4.11
Joints
4.11.1 There shall be no joints of any kind made in the finished wire. Joints may be
made in the wire rods prior to drawing to the finished wire.
The finished wire at such joints shall meet the requirements of 4.5.
such that it can be demonstrated that
4.11.2 Jointing equipment and procedure shall be
be not
the tensile stress of a finished wire specimen containing the jointed section shall
, and also greater than 90 % of minimum specified value in
less than 80 % of normal pa rt
table 5.
4.11.3 Elongation, torsion and stress at 1 % extension tests are not required for jointed
sections in a finished wire.
5 Sampling
Samples for tests shall be taken by the manufacturer from 10 % of the individual lengths
of finished wire.
In case of wire supply in large quantities and where the manufacturer has demonstrated
capability of meeting or exceeding the requirements, the number of samples may be
reduced, by agreement between the purchaser and the manufacturer, to a level which
ensures that each production lot of wire is given an adequate monitoring.
6 Test methods
6.1 Place of testing
All tests shall be made at the manufacturer's plant unless mutually agreed between the
manufacturer and purchaser.
6.2 Tests
The following tests numbers 1 to 9 shall be made on each of the samples before strand-
ing. When the wires are to be used for products consisting of only aluminium-clad steel
wires, it may be agreed between the manufacturer and the purchaser not to carry out
test 9.
1232 ©IEC:1993 - 15 -
1) Appearance;
2) finish;
3) diameter;
4) tensile stress;
5) elongation;
6) torsion;
7) resistivity;
minimum aluminium thickness;
8)
9) stress at 1 % extension.
6.3 Test method
6.3.1 Tensile test
The breaking load of the specimen shall be determined by means of a suitable tensile test-
ing machine. The load shall be applied gradually and the rate of separation of the jaws of
the testing machine shall be not less than 25 mm per minute and not greater than 100 mm
per minute.
In calculating the tensile stress from the measured breaking load, the diameter of the
finished wire before stressing shall be used.
6.3.2 Elongation tests
The elongation tests may be made on the same samples in the same operation as the
tensile test described in 6.3.1.
a) Percentage elongation after fracture
The ultimate elongation measured under no load shall be determined on the specimen.
The specimen shall be straightened by hand and an original gauge length of 250 mm
marked on the wire and loaded as described in the tensile test. After the wire is broken
the specimen ends shall be carefully placed together and the distance between the
gauge marks measured.
The elongation is the increase in gauge length expressed as a percentage of the
original gauge length.
If the fracture occurs outside the gauge marks, or within 25 mm of either mark, and the
required elongation is not obtained, another test shall be made.
Percentage total elongation at fracture
b)
The specimen shall be gripped in the jaws of a tensile testing machine. A load
corresponding to the appropriate tensile stress given in table 4 shall be applied and an
extensometer applied on a 250 mm gauge length and adjusted to the appropriate initial
setting given in table 4.
A tensile load shall be applied as described in the tensile test and the reading at the
time of fracture shall be taken as the elongation of specimen.
If the fracture occurs outside the gauge marks, or within 25 mm of either mark, and the
required elongation is not obtained, another test shall be made.

1232 © IEC:1993 – 17 –
6.3.3 Torsion test
One specimen shall be gripped at its ends in two vices with the distance between vices
equivalent to 100 times the nominal wire diameter, one of which shall be free to move
2 % of the breaking
longitudinally during the test. A small tensile load, not exceeding
strength of the wire, shall be applied to the sample during testing.
The specimen shall be twisted by causing one of the vices to revolve until fracture occurs
and the number of twists shall be indicated by a counter or other suitable device.
The rate of twisting shall not exceed 60 rev/min.
6.3.4 Thickness of aluminium
The thickness of aluminium of the specimen shall be determined by using suitable electrical
indicating instruments operating on the permeameter principle, or direct measurement.
Measurements shall be read to three decimal places, and number rounded to two decimal
places is considered as measured thickness. For reference purposes, direct measurement
shall be used to determine aluminium thickness on specimens taken from the end of the
coils.
6.3.5 Resistivity test
The electrical resistance of the specimen shall be measured by the method specified in
IEC 468 at a temperature which shall be not less than 10 °C or more than 30 °C. The
measured resistance shall be corrected to the value at 20 °C by means of the formula:
RT
R20 1+ a (T – 20) )
where
T is th
...