IEC 61089

SLOVENSKI STANDARD
SIST IEC 61089:1999
01-november-1999
Round wire concentric lay overhead electrical stranded conductors - Amendment
A1
Round wire concentric lay overhead electrical stranded conductors
Ta slovenski standard je istoveten z: IEC 61089
ICS:
29.060.10 Žice Wires
29.240.20 Daljnovodi Power transmission and
distribution lines
SIST IEC 61089:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEI
NORME
IEC
INTERNATIONALE
INTERNATIONAL
Première édition
STANDARD
First edition
1991-05
Conducteurs pour lignes aériennes
à brins circulaires, câblés en couches
concentriques
Round wire concentric lay overhead
electrical stranded conductors
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on
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1089©IEC – 3 –
CONTENTS
Page
5 FOREWORD
Clause
1 Scope
2 Normative references
3 Designation system
4 Definitions
5 Requirements for stranded conductors
5.1 Material
5.2 Conductor sizes
5.3 Surface
5.4 Stranding 13
5.5 Joints
5.6 Linear density – Mass per unit length
5.7 Conductor strength
6 Tests
6.1 Classification of tests 19
6.2 Test requirements
6.3 Sample size
6.4 Sample length
6.5 Type tests
6.6 Sample tests 23
6.7 Inspection
6.8 Acceptance or rejection
7 Packaging and marking
7.1 Packaging
7.2 Marking and tare
7.3 Random lengths
ANNEXES
A Information to be supplied by purchaser 29
B Stress-strain test method 31
C Nominal mass of grease for stranded conductors 39
D Recommended conductor sizes and tables of conductor properties 45

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1089©IEC
COMMISSION
INTERNATIONAL ELECTROTECHNICAL
ROUND WIRE CONCENTRIC LAY OVERHEAD
ELECTRICAL STRANDED CONDUCTORS
FOREWORD
1) The formal decisions or agreements of the IEC on technical matters, prepared by Technical Committees on
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.
They have the form of recommendations for international use and they are accepted by the National
2)
Committees in that sense.
In order to promote international unification, the IEC expresses the wish that all National Committees
3)
should adopt the text of the IEC recommendation for their national rules in so far as national conditions will
permit. Any divergence between the IEC recommendation and the corresponding national rules should, as
far as possible, be clearly indicated in the latter.
This standard has been prepared by IEC Technical Committee No. 7: Bare aluminium
conductors.
The text of this standard is based on the following documents:
Report on Voting
Six Months' Rule Report on Voting Two Months' Procedure
7(00)431 7(00)433
7(00)429 7(00)430
Full information on the voting for the approval of this standard can be found in the Voting
Reports indicated in the above table.
This standard replaces the following publications:
IEC 207: 1966,
Aluminium stranded conductors.
IEC 208: 1966, Aluminium alloy stranded conductors (aluminium-magnesium-silicon type).
IEC 209: 1966, Aluminium conductors, steel-reinforced.
IEC 210: 1966, Aluminium alloy conductors, steel-reinforced.
Annexes A, B and C form an integral pa rt of this International Standard.
Annex D is for information only.

1089©IEC - 7 -
ROUND WIRE CONCENTRIC LAY OVERHEAD
ELECTRICAL STRANDED CONDUCTORS
1 Scope
1.1 This International Standard specifies the electrical and mechanical characteristics of
round wire concentric lay overhead electrical stranded conductors made of combinations
of any of the following metal wires:
a) hard-drawn aluminium as per IEC 889 designated Al*;
b) aluminium alloy type B as per IEC 104 designated A2*;
c) aluminium alloy type A as per IEC 104 designated A3* (and when applicable to the
following cores, as per IEC 888);
d) regular strength steel, designated S1A or S1 B, where A and B are zinc coating
classes, corresponding respectively to classes 1 and 2;
e) high strength steel, designated S2A or S2B;
f) extra high strength steel, designated S3A.
1.2 The conductor designations included in this standard are:
Al, A2, A3,
Al/S1A, Al/S1B, Al/S2A, Al/S2B, Al/S3A, A2/S1A,
A2/S 1 B, A2/S3A, A3/S 1 A,
A3/S 1 B, A3/S3A, Al /A2, A1 /A3.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute
provisions of this International Standard. At the time of publication of this standard, the
editions indicated were valid. All standards are subject to revision, and parties to agree-
ments based on this International Standard are encouraged to investigate the possibility of
applying the most recent editions of the standards indicated below. Members of IEC and
ISO maintain registers of currently valid International Standards.
IEC 104: 1987, Aluminium-magnesium-silicon alloy wire for overhead line conductors.
IEC 888: 1987,
Zinc-coated steel wires for stranded conductors.
IEC 889: 1987,
Hard-drawn aluminium wire for overhead line conductors.
The resistivity of these metals is as follows (in increasing order):
Al: 28,264 nS1m (corresponding to 61% IACS),
A2: 32,530 nQm (corresponding to 53% IACS),
A3:
32,840 nam (corresponding to 52,5% IACS).

1089©IEC - 9 -
3 Designation system
3.1 A designation system is used to identify stranded conductors made of aluminium,
with or without steel wires.
3.2 Homogeneous aluminium conductors are designated Ax, where x identifies the type
of aluminium.
3.3 Composite aluminium conductors are designated Ax/Ay, where Ax identifies external
wires (or the envelope) and Ay identifies internal wires (or the core).
3.4 Composite aluminium-steel conductors are designated Ax/Syz, where Ax identifies
the external aluminium wires (envelope), and Syz identifies the steel core. In the
designation of steel wires, y represents the type of steel (regular, high or extra high
strength) and z represents the class of zinc coating (A or B).
3.5 Conductors are identified as follows:
a) a code number giving the equivalent conductive section of Al aluminium expressed
in mm2;
b) a designation identifying the type of wires constituting the conductor. For composite
conductors the first designation applies to the envelope and the second to the core;
c) one or two numbers giving the stranding of the conductor. For composite conduc-
tors, the first number identifies the number of wires of the envelope and the second
identifies the number of wires of the core.
Examples:
500-Al-37: Conductor made of 37 wires of Al aluminium. Its area is 500 mm2.
500-A2-37: Conductor made of 37 wires of A2 aluminium with a total conductive area
equivalent to 500 mm 2 of Al aluminium. From the tables of annex D we find its actual
area is equal to 575 mm2.
500-A1 /S1 A-45/7: Conductor made of 45 wires of Al aluminium and 7 wires of regular
strength steel with class 1 zinc coating. The area of Al aluminium is 500 mm 2 and, from
the tables of annex D, the area of S1 A steel is 34,6 mm2.
500-A3/S3A-54/7: Conductor made of 54 wires of A3 aluminium and 7 wires of extra
high strength steel with class 1 zinc coating. The A3 aluminium area is equivalent in
conductivity to 500 mm 2 of Al aluminium (the actual area of A3 aluminium is 581 mm2
and of steel is 75,3 mm 2, which can be obtained from the tables of annex D).
4 Definitions
The following definitions apply in this International Standard:
aluminium: All types of aluminium and aluminium alloys listed.
conductor: A material intended to be used for carrying electric current consisting of a
plurality of uninsulated wires twisted together.

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1089 © IEC
concentric lay stranded conductor: A conductor composed of a central core surrounded
by one or more adjacent layers of wires being laid helically in opposite directions.
direction of lay: The direction of twist of a layer of wires as it moves away from the
viewer. A right-hand lay is a clockwise direction and a left-hand lay is an anti-clockwise
direction.
Alternative definition: 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 Z when the
conductor is held vertically. With left-hand lay, the wires conform to the direction of the
central part of the letter S when the conductor is held vertically.
lay length: The axial length of one complete turn of the helix formed by an individual wire
in a stranded conductor.
lay ratio: Means the ratio of the lay length to the external diameter of the corresponding
layer of wires in the stranded conductor.
lot: A group of conductors manufactured by the same manufacturer under similar condi-
tions of production. A lot may consist of part or all of the purchased quantity.
nominal: The name or identifying value of a measurable property by which a conductor or
component of a conductor is identified and to which tolerances are applied. Nominal
values should be target values.
steel ratio: The ratio of steel area to aluminium area as a percentage in Ax/Syz
conductors.
wire: A filament of drawn metal having a constant circular cross-section.
5 Requirements for stranded conductors
5.1 Material
Stranded conductors shall be made up of round aluminium wires and, when applicable, of
round zinc-coated steel wires. All wires shall have before stranding the properties speci-
fied in IEC 104, IEC 888 and IEC 889.
5.2 Conductor sizes
A list of conductor sizes is given as guidance in annex D and it is recommended that for
new designs of conductor sizes should be selected from those listed. Conductors for
existing or established designs of overhead lines as well as sizes and strandings not
included in this standard may be designed and supplied as agreed upon by the manu-
facturer and purchaser and the relevant requirements of this standard shall apply.

1089 ©IEC - 13 -
5.3 Surface
rf rfections visible to the unaided eye
The su ace of the conductor shall be free from all impe
(normal corrective lenses accepted), such as nicks, indentations, etc., not consistent with
good commercial practice.
5.4 Stranding
5.4.1 All wires of the conductor shall be concentrically stranded.
5.4.2 Adjacent wire layers shall be stranded with reverse lay directions. The direction of
lay of the external layer shall be "right-hand" except when specifically indicated in the
purchase order.
5.4.3 The wires in each layer shall be evenly and closely stranded around the underlying
wire or wires.
5.4.4 The lay ratios for the zinc-coated steel wire layers shall be as follows:
the lay ratio for the six-wire layer of 7 and 19-wire steel cores shall be not less than
a)
16 nor more than 26;
b) the lay ratio for the 12-wire layer of 19-wire steel core shall be not less than 14 nor
more than 22.
5.4.5 The lay ratios for the aluminium layers of all types of conductor shall be as follows:
a) the lay ratio for the outside layer of aluminium wires shall be not less than 10 nor
more than 14;
b) the lay ratios for the inner layers of aluminium wires shall be not less than 10 nor
more than 16.
5.4.6 In a 19-wire steel core, the lay ratio of the 12-wire layer shall be not greater than
the lay ratio of the 6-wire layer. Similarly, in a conductor having multiple layers of alu-
minium wires, the lay ratio of any aluminium layer shall be not greater than the lay ratio of
the aluminium layer immediately beneath it.
5.4.7 All steel wires shall lie naturally in their position in the stranded core, and where
the core is cut, the wire ends shall remain in position or be readily replaced by hand and
then remain approximately in position. This requirement also applies to the outer layer of
aluminium wires of a conductor.
5.4.8 Before stranding, aluminium and steel wires shall have approximately uniform
temperatures.
5.5
Joints
5.5.1 There shall be no joints of any kind made in the zinc-coated steel core wire or wires
during stranding.
5.5.2 No more than one jointed aluminium finished wire as permitted in the references of
5.1 shall be used per length of conductor.

1089©IEC – 15 –
5.5.3 During stranding, no aluminium wire welds shall be made for the purpose of achiev-
ing the required conductor length.
5.5.4 Joints are permitted in aluminium wires unavoidably broken during stranding,
provided such breaks are not associated with either inherently defective wire or with the
use of short lengths of aluminium wires. Joints shall conform to the geometry of original
wire, i.e. joints shall be dressed smoothly with a diameter equal to that of the parent wires
and shall not be kinked.
Joints in aluminium wires shall not exceed those specified in table 1. These joints shall
not be closer than 15 m from a joint in the same wire or in any other aluminium wire of the
completed conductor.
Joints shall be made by electric butt welding, electric butt cold upset welding or cold
pressure welding (note 1) and other approved methods. These joints shall be made in
accordance with good commercial practice. The first type of joints shall be electrically
annealed for approximately 250 mm on both sides of the weld.
Table 1 – Number of joints permitted
in aluminium conductors
Number of aluminium Joints permitted per
layers conductor length
1 2
3 4
4 5
5.5.5 While the joints specified in 5.5.4 are not required to meet the requirements of un-
jointed wires (note 2), they shall withstand a stress of not les
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