IEC 62420:2008
(Main)Concentric lay stranded overhead electrical conductors containing one or more gap(s)
Concentric lay stranded overhead electrical conductors containing one or more gap(s)
IEC 62420:2008 specifies the electrical and mechanical characteristics of concentric lay stranded overhead electrical conductors, containing one or more self-supporting alumimium or aluminium alloy layer(s) made of combination of any of the following metal wires:
- Hand drawn aluminium as per IEC 60889, designated A1;
- aluminium alloy type A or B as per IEC 60104, designated A2 or A3;
- thermal resistant aluminium alloy as per IEC 62004, designated AT1, AT2, AT3, or AT4;
- regular strength steel as per IEC 60888, designated S1A or S1B;
- high strength steel as per IEC 60888, designated S2A or S2B;
- extra-high strength steel as per IEC 60888, designated S3A;
- aluminium-clad steel as per IEC 61232, designated 20SA, 27SA, 30SA or 40SA.
Conducteurs pour lignes électriques aériennes câblés en couches concentriques comprenant un ou plusieurs intervalles
La CEI 62420:2008 spécifie les caractéristiques électriques et mécaniques des conducteurs pour lignes électriques aériennes, câblés en couches concentriques comprenant une ou plusieurs couches d'aluminium ou d'alliage d'aluminium autoporteuses, constituées de combinaisons de l'un des câbles métalliques suivants:
- aluminium écroui dur selon la CEI 60889, désigné A1;
- alliage d'aluminium de type A ou B selon la CEI 60104, désigné A2 ou A3;
- type d'alliage d'aluminium résistant à la chaleur selon la CEI 62004, désigné AT1, AT2, AT3 ou AT4;
- acier à résistance normale selon la CEI 60888, désigné S1A ou S1B;
- acier à haute résistance selon la CEI 60888, désigné S2A ou S2B;
- acier à très haute résistance selon la CEI 60888, désigné S3A;
- acier revêtu d'aluminium selon la CEI 61232, désigné 20SA, 27SA, 30SA ou 40SA.
General Information
Standards Content (Sample)
IEC 62420
Edition 1.0 2008-04
INTERNATIONAL
STANDARD
Concentric lay stranded overhead electrical conductors containing one or more
gap(s)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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IEC 62420
Edition 1.0 2008-04
INTERNATIONAL
STANDARD
Concentric lay stranded overhead electrical conductors containing one or more
gap(s)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
U
ICS 29.240.20, 29.060.10 ISBN 2-8318-9721-1
– 2 – 62420 © IEC:2008(E)
CONTENTS
FOREWORD.4
1 Scope.6
2 Normative references .6
3 Terms and definitions .6
4 Designation system .8
5 Requirements for stranded conductors .8
5.1 Material .8
5.2 Conductor sizes .8
5.3 Surface .8
5.4 Stranding .8
5.4.1 General .8
5.4.2 Lay ratio for core wires .8
5.4.3 Lay ratio for aluminium layer(s) .9
5.4.4 Joints .9
5.4.5 Linear mass.9
5.4.6 Conductor strength .10
6 Tests .10
6.1 Classification of tests .10
6.2 Type Tests .10
6.2.1 Length of sample required .10
6.2.2 Joints in aluminium wires.10
6.2.3 Annular gap(s).10
6.2.4 Stress-strain curves.11
6.2.5 Breaking strength of conductor .11
6.2.6 Creep curves .11
6.3 Sample tests .11
6.3.1 Cross-sectional area.12
6.3.2 Overall diameter .12
6.3.3 Linear mass.12
6.3.4 Surface condition.12
6.3.5 Lay ratio and direction of lay.12
6.3.6 Breaking strength of wires after stranding (if requested) .13
6.3.7 Wire canting on the outside layer (if requested) .13
7 Inspection.13
7.1 Test location .13
7.2 Acceptance or rejection.13
8 Packaging and marking .14
8.1 Packaging .14
8.2 Marking and tare .14
8.3 Random lengths .14
Annex A (normative) Information to be supplied by purchaser.18
Annex B (normative) Stress-strain test method .19
Annex C (normative) Nominal mass of grease for stranded conductors .22
62420 © IEC:2008(E) – 3 –
Annex D (informative) Alternate method of measuring the gap(s) within the conductor.25
Annex E (informative) Recommended conductor sizes and tables of conductor
properties .26
Figure 1 – Examples of conductors containing one or more gaps .16
Figure 2 – Method of measuring wire canting.17
Figure C.1 – Illustration for calculation of mass of grease in round wire layer (s） .22
Figure C.2 – Illustration of calculation of mass of grease for core layer(s).23
Figure C.3 – Illustration of calculation of grease for annular gap(s).24
Table 1 – Metal combinations permitted.15
Table 2 – Number of joints permitted in aluminium wires.16
a
Table 3 – Standard increments due to stranding .16
Table E.1 – Properties of some A1G/S1A conductors with gaps.27
– 4 – 62420 © IEC:2008(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CONCENTRIC LAY STRANDED OVERHEAD ELECTRICAL
CONDUCTORS CONTAINING ONE OR MORE GAP(S)
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). 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. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
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expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62420 has been prepared by IEC technical committee 7:
Overhead electrical conductors.
The text of this standard is based on the following documents:
FDIS Report on voting
7/587/FDIS 7/588/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
62420 © IEC:2008(E) – 5 –
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
– 6 – 62420 © IEC:2008(E)
CONCENTRIC LAY STRANDED OVERHEAD ELECTRICAL
CONDUCTORS CONTAINING ONE OR MORE GAP(S)
1 Scope
This International Standard specifies the electrical and mechanical characteristics of
concentric lay stranded overhead electrical conductors, containing one or more self-
supporting aluminium or aluminium alloy layer(s) as depicted in Figure 1, made of
combinations of any of the following metal wires:
a) hard-drawn aluminium as per IEC 60889, designated A1;
b) aluminium alloy type A or B as per IEC 60104, designated A2 or A3;
c) thermal resistant aluminium alloy type as per IEC 62004, designated AT1, AT2, AT3 or
AT4;
d) regular strength steel as per IEC 60888, designated S1A or S1B;
e) high strength steel as per IEC 60888, designated S2A or S2B;
f) extra-high strength steel as per IEC 60888, designated S3A;
g) aluminium-clad steel as per IEC 61232, designated 20SA, 27SA, 30SA or 40SA.
NOTE This standard covers the construction of self-damping conductors, as well as gap-type conductors.
Although both types of conductors share a common design feature and the presence of one or more gaps between
layers, they are intended for different purposes. Self-damping conductors (SDC) may have more than one gap to
provide increased self-damping, whereas gap-type conductors are so designed as to allow the aluminium layers to
slide freely over the core during installation, and therefore usually do not require more than one gap.
The various metal combinations permitted by this standard shall be in accordance with
Table 1.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60104:1987, Aluminium-magnesium-silicon alloy wire for overhead line conductors
IEC 60888:1987, Zinc-coated steel wires for stranded conductors
IEC 60889:1987, Hard-drawn aluminium wire for overhead line conductors
IEC 61232:1993, Aluminium-clad steel wires for electrical purposes
IEC 61395:1998, Creep test procedures for stranded conductors
IEC 62004:2007, Thermal resistant aluminium alloy wire for overhead line conductors
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
aluminium
all types of aluminium and aluminium alloys listed in Clause 1
3.2
annular gap
constant space, void of any material except for air or grease, between two layers of a
conductor
62420 © IEC:2008(E) – 7 –
3.3
canting
phenomena by which a formed wire is twisted relative to its own axis, thus producing a
protuberance outside the layer
3.4
conductor
material intended to be used for carrying electric current consisting of a plurality of
uninsulated wires twisted together
3.5
concentric lay stranded conductor
conductor composed of a central core surrounded by one or more adjacent layers of wires
being laid helically in opposite directions.
3.6
direction of lay
direction of twist of a layer of wires as it moves away from the viewer , with a right-hand lay
being a clockwise direction and a left-hand lay being an anti-clockwise direction
3.7
equivalent wire diameter
the diameter of a round wire which would have the same cross-sectional area as a given
formed wire
3.8
formed wire
filament of drawn or rolled metal having a constant, non-circular cross-section
3.9
layer
group of wires located at a constant radial distance from the centre of the conductor
3.10
lay length
axial length of one complete turn of the helix formed by an individual wire in a stranded
conductor
3.11
lay ratio
ratio of the lay length to the external diameter of the corresponding layer of wires in the
stranded conductor
3.12
lot
group of conductors manufactured by the same manufacturer under similar conditions of
production
NOTE A lot may consist of part or all of the purchased quantity.
3.13
nominal
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
NOTE Nominal values should be target values.
3.14
rated tensile strength
calculated maximum tensile load value at which a conductor may be subjected before one or
more of its constituent wires break
3.15
round wire
filament of drawn metal having a constant circular cross-section
– 8 – 62420 © IEC:2008(E)
3.16
self-supporting layer
layer made of formed wires which are designed in such a way as to not rely on the underlying
layer for support
4 Designation system
A designation system is used to identify stranded conductors containing one or more
gap(s).Conductors are designated AxGy/Syz or AxGy/SA where Ax identifies external wires
(or the envelope), Gy denotes the presence and the number of annular gap(s) between two or
more layers, and Syz and SA identify the steel core.In the designation of zinc coated wires, y
represents the type of steel (regular, high or extra high strength) and z represents the class of
zinc coating (A or B).
Conductors are identified as follows:
a) a code number giving the equivalent conductive section of A1 expressed in mm ;
b) a code number giving the section of the core material in mm ;
c) a designation identifying the type of wires constituting the conductor in accordance with
the second paragraph of this clause. The first designation (Ax) applies to the envelope,
the second designation (Gy) applies to the presence and number of annular gap(s), and
the third designation (Syz or SA) applies to the core;
d) a code number designating the outside diameter of the conductor.
2 2
Example: 400/66-A1G2/S1A-274: A conductor made of 400 mm A1 and 66 mm S1A (regular
strength steel), containing two annular gaps, with a nominal outside diameter of 27,4 mm
(274 x 0,1).
5 Requirements for stranded conductors
5.1 Material
Stranded conductors shall be made up of round and/or formed aluminium wires and of zinc-
coated steel or aluminium-clad wires. Before stranding all wires shall have the properties as
specified in the International Standards given in Clause 2.
5.2 Conductor sizes
A list of conductor sizes is given as guidance in Annex E. 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 manufacturer and purchaser
and the relevant requirements of this standard shall apply.
5.3 Surface
The surface of the conductor shall be free from all imperfections visible to the unaided eye
(normal corrective lenses accepted), such as nicks, indentations, etc., not consistent with
good commercial practice.
5.4 Stranding
5.4.1 General
All wires of the conductor shall be concentrically stranded. Before stranding, aluminium and
core wires shall have approximately uniform temperature.
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.
5.4.2 Lay ratio for core wires
The lay ratios for the zinc-coated (galvanised) steel or aluminium-clad wire layers shall be as
follows:
a) the lay ratio for the six-wire layer of the core shall be not less than 16 nor more than 26;
62420 © IEC:2008(E) – 9 –
b) the lay ratio for subsequent core layers shall be not less than 14 nor more than 22. The
lay ratio of subsequent layer(s) shall be not greater than the lay ratio of the core layer
immediately beneath it.
All core 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.
5.4.3 Lay ratio for aluminium layer(s)
The lay ratios for the aluminium layer(s) 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;
c) the lay ratio of any aluminium layer shall be not greater than the lay ratio of the aluminium
layer immediately beneath it.
Aluminium wires composing the outside layer of the conductor shall lie naturally in their
position, and where the conductor is cut, they shall remain in position or be readily replaced
by hand and then remain approximately in position.
5.4.4 Joints
There shall be no joints of any kind made in the core wire or wires during stranding.
There shall be no joints in the finished aluminium wire prior to stranding.
During stranding, no aluminium wire welds shall be made for the purpose of achieving the
required conductor length.
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 shape equal to that of the parent wires and shall not be kinked.
Joints in aluminium wires shall not exceed those specified in Table 2. 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 (see 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.
While the joints specified in this clause are not required to meet the requirements of unjointed
wires (see Note 2), they shall withstand a stress of not less than 75 MPa for annealed electric
butt welded joints and not less than 130 MPa for cold pressure and electric butt cold upset
welded joints. The manufacturer shall demonstrate that the proposed welding method is
capable of meeting the specified strength requirements.
NOTE 1 It is a practice in some countries to require the annealing of cold pressure joints made in A2 or A3
material.
NOTE 2 The behaviour of properly spaced wire joints in stranded conductors is related to both tensile strength
and elongation. Because of higher elongation properties, the lower strength annealed electric butt welded joint
gives a similar overall performance to that of a cold pressure or an electric butt cold upset welded joint.
5.4.5 Linear mass
The masses given in the Table E.1 of Annex E have been calculated for each size and
stranding of conductor using densities for the aluminium, aluminium-clad and zinc-coated
steel wires as given in the standards listed in Clause 2, the stranding increments given in
Table 3, and the cross-sectional areas for aluminium and core wires based on their theoretical
unrounded values.
– 10 – 62420 © IEC:2008(E)
The increments in per cent, for mass due to stranding, based on the mean lay ratios given in
5.4.2 and 5.4.3, shall be taken as given in Table 3. If greater accuracy is desired, actual lay
factors shall be used.
Whenever a conductor is to be greased, the nominal mass of grease shall be calculated
according to the method given in Annex C.
5.4.6 Conductor strength
The rated tensile strength at room temperature of composite conductors shall be the sum of
the tensile strength of the aluminium portion plus the strength of the core corresponding to an
elongation compatible with that of aluminium at rupture load. For the purpose of specification
and practicability, the strength of steel and aluminium-clad steel is conservatively established
as the stress corresponding to 1 % elongation in a 250 mm gauge length.
The tensile strength of any single wire is the product of its nominal area and the appropriate
minimum stress given in the standards listed in Clause 2.
6 Tests
6.1 Classification of tests
Type tests are intended to verify the main characteristics of a conductor which depend mainly
on its design. They are carried out once for a new design or manufacturing process of
conductor and then subsequently repeated only when the design or manufacturing process is
changed.
Sample tests are intended to guarantee the quality of conductors and compliance with the
requirements of this standard.
6.2 Type tests
Type tests shall be carried out only on a conductor which meets the requirements of all the
relevant sample tests.
Type tests consist of the following:
a) joints in aluminium wires;
b) annular gap(s);
c) stress-strain curves;
d) breaking strength of conductor;
e) creep curves.
6.2.1 Length of sample required
The sample length required for tensile and stress-strain tests shall be at least 400 times the
diameter of the conductor but not less than 10 m.
The length of samples in this subclause is the minimum required for a good accuracy of
stress-strain curves. In cases where the manufacturer can demonstrate to the satisfaction of
the purchaser with significant comparative test results that a shorter length can provide
equally accurate results then a short length of samples may be used.
6.2.2 Joints in aluminium wires
The manufacturer shall demonstrate to the purchaser that the method used for jointing
5.4.4 by supplying recent test results or
aluminium wires meets the strength requirements of
by performing the necessary tests.
6.2.3 Annular gap(s)
The method of measurement of the annular gap(s) shall be agreed upon between the
purchaser and the manufacturer. Measurements can be done directly on the outside and
inside diameters of the concerned layer or alternatively the method described in Annex D
shall be used.
62420 © IEC:2008(E) – 11 –
When measured in accordance with this subclause, the value of the annular gap shall not vary
by more than +0,15 mm and less than -0,25 mm from the value specified by the supplier.
6.2.4 Stress-strain curves
Stress-strain curves shall be supplied as a type test when requested by the purchaser and
shall represent the best knowledge of the behaviour of the purchased conductor under load.
If agreed between purchaser and supplier when placing an order, stress-strain tests shall be
performed on the conductor and on the core, in accordance with the method given in Annex B.
6.2.5 Breaking strength of conductor
The breaking strength of conductors shall be determined by pulling a conductor in a suitable
tensile testing machine having an accuracy of at least
...
IEC 62420 ®
Edition 1.0 2008-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Concentric lay stranded overhead electrical conductors containing one or more
gap(s)
Conducteurs pour lignes électriques aériennes câblés en couches
concentriques comprenant un ou plusieurs intervalles
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International Standards for all electrical, electronic and related technologies.
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IEC 62420 ®
Edition 1.0 2008-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Concentric lay stranded overhead electrical conductors containing one or more
gap(s)
Conducteurs pour lignes électriques aériennes câblés en couches
concentriques comprenant un ou plusieurs intervalles
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
U
CODE PRIX
ICS 29.060.10; 29.240.20 ISBN 978-2-88910-699-8
– 2 – 62420 © IEC:2008
CONTENTS
FOREWORD.4
1 Scope.6
2 Normative references .6
3 Terms and definitions .6
4 Designation system .8
5 Requirements for stranded conductors .8
5.1 Material .8
5.2 Conductor sizes .8
5.3 Surface .9
5.4 Stranding .9
5.4.1 General .9
5.4.2 Lay ratio for core wires .9
5.4.3 Lay ratio for aluminium layer(s) .9
5.4.4 Joints .9
5.4.5 Linear mass.10
5.4.6 Conductor strength .10
6 Tests .10
6.1 Classification of tests .10
6.2 Type Tests .11
6.2.1 Length of sample required .11
6.2.2 Joints in aluminium wires.11
6.2.3 Annular gap(s).11
6.2.4 Stress-strain curves.11
6.2.5 Breaking strength of conductor .11
6.2.6 Creep curves .12
6.3 Sample tests .12
6.3.1 Cross-sectional area.12
6.3.2 Overall diameter .13
6.3.3 Linear mass.13
6.3.4 Surface condition.13
6.3.5 Lay ratio and direction of lay.13
6.3.6 Breaking strength of wires after stranding (if requested) .14
6.3.7 Wire canting on the outside layer (if requested) .14
7 Inspection.14
7.1 Test location .14
7.2 Acceptance or rejection.14
8 Packaging and marking .15
8.1 Packaging .15
8.2 Marking and tare .15
8.3 Random lengths .15
Annex A (normative) Information to be supplied by purchaser.19
Annex B (normative) Stress-strain test method .20
Annex C (normative) Nominal mass of grease for stranded conductors .23
Annex D (informative) Alternate method of measuring the gap(s) within the conductor.27
62420 © IEC:2008 – 3 –
Annex E (informative) Recommended conductor sizes and tables of conductor
properties .28
Figure 1 – Examples of conductors containing one or more gaps .17
Figure 2 – Method of measuring wire canting.18
Figure C.1 – Illustration for calculation of mass of grease in round wire layer (s） .23
Figure C.2 – Illustration of calculation of mass of grease for core layer(s).24
Figure C.3 – Illustration of calculation of grease for annular gap(s).25
Table 1 – Metal combinations permitted.16
Table 2 – Number of joints permitted in aluminium wires.17
Table 3 – Standard increments due to stranding .17
Table E.1 – Properties of some A1G/S1A conductors with gaps.29
– 4 – 62420 © IEC:2008
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CONCENTRIC LAY STRANDED OVERHEAD ELECTRICAL
CONDUCTORS CONTAINING ONE OR MORE GAP(S)
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). 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. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62420 has been prepared by IEC technical committee 7:
Overhead electrical conductors.
This bilingual version (2009-04) replaces the English version.
The text of this standard is based on the following documents:
FDIS Report on voting
7/587/FDIS 7/588/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
62420 © IEC:2008 – 5 –
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – 62420 © IEC:2008
CONCENTRIC LAY STRANDED OVERHEAD ELECTRICAL
CONDUCTORS CONTAINING ONE OR MORE GAP(S)
1 Scope
This International Standard specifies the electrical and mechanical characteristics of
concentric lay stranded overhead electrical conductors, containing one or more self-
supporting aluminium or aluminium alloy layer(s) as depicted in Figure 1, made of
combinations of any of the following metal wires:
a) hard-drawn aluminium as per IEC 60889, designated A1;
b) aluminium alloy type A or B as per IEC 60104, designated A2 or A3;
c) thermal resistant aluminium alloy type as per IEC 62004, designated AT1, AT2, AT3 or
AT4;
d) regular strength steel as per IEC 60888, designated S1A or S1B;
e) high strength steel as per IEC 60888, designated S2A or S2B;
f) extra-high strength steel as per IEC 60888, designated S3A;
g) aluminium-clad steel as per IEC 61232, designated 20SA, 27SA, 30SA or 40SA.
NOTE This standard covers the construction of self-damping conductors, as well as gap-type conductors.
Although both types of conductors share a common design feature and the presence of one or more gaps between
layers, they are intended for different purposes. Self-damping conductors (SDC) may have more than one gap to
provide increased self-damping, whereas gap-type conductors are so designed as to allow the aluminium layers to
slide freely over the core during installation, and therefore usually do not require more than one gap.
The various metal combinations permitted by this standard shall be in accordance with
Table 1.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60104:1987, Aluminium-magnesium-silicon alloy wire for overhead line conductors
IEC 60888:1987, Zinc-coated steel wires for stranded conductors
IEC 60889:1987, Hard-drawn aluminium wire for overhead line conductors
IEC 61232:1993, Aluminium-clad steel wires for electrical purposes
IEC 61395:1998, Creep test procedures for stranded conductors
IEC 62004:2007, Thermal resistant aluminium alloy wire for overhead line conductors
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
62420 © IEC:2008 – 7 –
3.1
aluminium
all types of aluminium and aluminium alloys listed in Clause 1
3.2
annular gap
constant space, void of any material except for air or grease, between two layers of a
conductor
3.3
canting
phenomena by which a formed wire is twisted relative to its own axis, thus producing a
protuberance outside the layer
3.4
conductor
material intended to be used for carrying electric current consisting of a plurality of
uninsulated wires twisted together
3.5
concentric lay stranded conductor
conductor composed of a central core surrounded by one or more adjacent layers of wires
being laid helically in opposite directions
3.6
direction of lay
direction of twist of a layer of wires as it moves away from the viewer , with a right-hand lay
being a clockwise direction and a left-hand lay being an anti-clockwise direction
3.7
equivalent wire diameter
the diameter of a round wire which would have the same cross-sectional area as a given
formed wire
3.8
formed wire
filament of drawn or rolled metal having a constant, non-circular cross-section
3.9
layer
group of wires located at a constant radial distance from the centre of the conductor
3.10
lay length
axial length of one complete turn of the helix formed by an individual wire in a stranded
conductor
3.11
lay ratio
ratio of the lay length to the external diameter of the corresponding layer of wires in the
stranded conductor
3.12
lot
group of conductors manufactured by the same manufacturer under similar conditions of
production
NOTE A lot may consist of part or all of the purchased quantity.
– 8 – 62420 © IEC:2008
3.13
nominal
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
NOTE Nominal values should be target values.
3.14
rated tensile strength
calculated maximum tensile load value at which a conductor may be subjected before one or
more of its constituent wires break
3.15
round wire
filament of drawn metal having a constant circular cross-section
3.16
self-supporting layer
layer made of formed wires which are designed in such a way as to not rely on the underlying
layer for support
4 Designation system
A designation system is used to identify stranded conductors containing one or more
gap(s).Conductors are designated AxGy/Syz or AxGy/SA where Ax identifies external wires
(or the envelope), Gy denotes the presence and the number of annular gap(s) between two or
more layers, and Syz and SA identify the steel core. In the designation of zinc coated wires, y
represents the type of steel (regular, high or extra high strength) and z represents the class of
zinc coating (A or B).
Conductors are identified as follows:
a) a code number giving the equivalent conductive section of A1 expressed in mm ;
b) a code number giving the section of the core material in mm ;
c) a designation identifying the type of wires constituting the conductor in accordance with
the second paragraph of this clause. The first designation (Ax) applies to the envelope,
the second designation (Gy) applies to the presence and number of annular gap(s), and
the third designation (Syz or SA) applies to the core;
d) a code number designating the outside diameter of the conductor.
2 2
Example: 400/66-A1G2/S1A-274: A conductor made of 400 mm A1 and 66 mm S1A (regular
strength steel), containing two annular gaps, with a nominal outside diameter of 27,4 mm
(274 × 0,1).
5 Requirements for stranded conductors
5.1 Material
Stranded conductors shall be made up of round and/or formed aluminium wires and of zinc-
coated steel or aluminium-clad wires. Before stranding all wires shall have the properties as
specified in the International Standards given in Clause 2.
5.2 Conductor sizes
A list of conductor sizes is given as guidance in Annex E. Conductors for existing or
established designs of overhead lines as well as sizes and strandings not included in this
62420 © IEC:2008 – 9 –
standard may be designed and supplied as agreed upon by the manufacturer and purchaser
and the relevant requirements of this standard shall apply.
5.3 Surface
The surface of the conductor shall be free from all imperfections visible to the unaided eye
(normal corrective lenses accepted), such as nicks, indentations, etc., not consistent with
good commercial practice.
5.4 Stranding
5.4.1 General
All wires of the conductor shall be concentrically stranded. Before stranding, aluminium and
core wires shall have approximately uniform temperature.
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.
5.4.2 Lay ratio for core wires
The lay ratios for the zinc-coated (galvanised) steel or aluminium-clad wire layers shall be as
follows:
a) the lay ratio for the six-wire layer of the core shall be not less than 16 nor more than 26;
b) the lay ratio for subsequent core layers shall be not less than 14 nor more than 22. The
lay ratio of subsequent layer(s) shall be not greater than the lay ratio of the core layer
immediately beneath it.
All core 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.
5.4.3 Lay ratio for aluminium layer(s)
The lay ratios for the aluminium layer(s) 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;
c) the lay ratio of any aluminium layer shall be not greater than the lay ratio of the aluminium
layer immediately beneath it.
Aluminium wires composing the outside layer of the conductor shall lie naturally in their
position, and where the conductor is cut, they shall remain in position or be readily replaced
by hand and then remain approximately in position.
5.4.4 Joints
There shall be no joints of any kind made in the core wire or wires during stranding.
There shall be no joints in the finished aluminium wire prior to stranding.
During stranding, no aluminium wire welds shall be made for the purpose of achieving the
required conductor length.
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
– 10 – 62420 © IEC:2008
of aluminium wires. Joints shall conform to the geometry of original wire, i.e. joints shall be
dressed smoothly with a shape equal to that of the parent wires and shall not be kinked.
Joints in aluminium wires shall not exceed those specified in Table 2. 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 (see 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.
While the joints specified in this clause are not required to meet the requirements of unjointed
wires (see Note 2), they shall withstand a stress of not less than 75 MPa for annealed electric
butt welded joints and not less than 130 MPa for cold pressure and electric butt cold upset
welded joints. The manufacturer shall demonstrate that the proposed welding method is
capable of meeting the specified strength requirements.
NOTE 1 It is a practice in some countries to require the annealing of cold pressure joints made in A2 or A3
material.
NOTE 2 The behaviour of properly spaced wire joints in stranded conductors is related to both tensile strength
and elongation. Because of higher elongation properties, the lower strength annealed electric butt welded joint
gives a similar overall performance to that of a cold pressure or an electric butt cold upset welded joint.
5.4.5 Linear mass
The masses given in the Table E.1 of Annex E have been calculated for each size and
stranding of conductor using densities for the aluminium, aluminium-clad and zinc-coated
steel wires as given in the standards listed in Clause 2, the stranding increments given in
Table 3, and the cross-sectional areas for aluminium and core wires based on their theoretical
unrounded values.
The increments in per cent, for mass due to stranding, based on the mean lay ratios given in
5. 4. 2 a nd 5.4.3, shall be taken as given in Table 3. If greater accuracy is desired, actual lay
factors shall be used.
Whenever a conductor is to be greased, the nominal mass of grease shall be calculated
according to the method given in Annex C.
5.4.6 Conductor strength
The rated tensile strength at room temperature of composite conductors shall be the sum of
the tensile strength of the aluminium portion plus the strength of the core corresponding to an
elongation compatible with that of aluminium at rupture load. For the purpose of specification
and practicability, the strength of steel and aluminium-clad steel is conservatively established
as the stress corresponding to 1 % elongation in a 250 mm gauge length.
The tensile strength of any single wire is the product of its nominal area and the appropriate
minimum stress given in the standards listed in Clause 2.
6 Tests
6.1 Classification of tests
Type tests are intended to verify the main characteristics of a conductor which depend mainly
on its design. They are carried out once for a new design or manufacturing process of
conductor and then subsequently repeated only when the design or manufacturing process is
changed.
62420 © IEC:2008 – 11 –
Sample tests are intended to guarantee the quality of conductors and compliance with the
requirements of this standard.
6.2 Type tests
Type tests shall be carried out only on a conductor which meets the requirements of all the
relevant sample tests.
Type tests consist of the following:
a) joints in aluminium wires;
b) annular gap(s);
c) stress-strain curves;
d) breaking strength of conductor;
e) creep curves.
6.2.1 Length of sample required
The sample length required for tensile and stress-strain tests shall be at least 400 times the
diameter of the conductor but not less than 10 m.
The length of samples in this subclause is the minimum required for a good accuracy of
stress-strain curves. In cases where the manufacturer can demonstrate to the satisfaction of
the purchaser with significant comparative test results that a shorter length can provide
equally accurate results then a short length of samples may be used.
6.2.2 Joints in aluminium wires
The manufacturer shall demonstrate to the purchaser that the method used for jointing
aluminium wires meets the strength requirements of 5.4.4 by supplying recent test results or
by performing the necessary tests.
6.2.3 Annular gap(s)
The method of measurement of the annular gap(s) shall be agreed upon between the
purchaser and the manufacturer. Measurements can be done directly on the outside and
inside diameters of the concerned layer or alternatively the method described in Annex D
shall be used.
When measured in accordance with this subclause, the value of the annular gap shall not vary
by more than +0,15 mm and less than -0,25 mm from the value specified by the supplier.
6.2.4 Stress-strain curves
Stress-strain curves shall be supplied as a type test when requested by the purchaser and
shall represent the best knowledge of the behaviour of the purchased conductor under load.
If agreed between purchaser and supplier when placing an order, stress-strain tests shall be
performed on the conductor and on the core, in accordance with the method given in Annex B.
6.2.5 Breaking strength of conductor
The breaking strength of conductors shall be determined by pulling a conductor in a suitable
tensile testing machine having an accuracy of at least ±1 %. It is recommended that the rate
of increase of load should be as in B.6. For the purposes of this test, appropriate fittings shall
be installed on the ends of the conductor samples. During this test, the breaking strength of
the conductor shall be determined by the load attained at which one or more wires of the
conductor are fractured.A retest, up to a total of three tests, may be made if wire fracture
– 12 – 62420 © IEC:2008
occurs within 10 mm of the end fittings and the tensile strength falls below the specified
breaking strength requirements.
When tests for breaking strength of conductors are required, these shall withstand, without
the fracture of any wire not less than 95 % of their rated tensile strength calculated according
to 5. 4. 6.
When required, the breaking strength of the core shall be determined in accordance with this
subclause.
6.2.6 Creep curves
Creep curves shall be supplied as a type test when requested by the purchaser and shall
represent the best knowledge of the behaviour of the purchased conductor under load.
If agreed between purchaser and supplier when placing an order, creep tests shall be
performed on the conductor, in accordance with IEC 61395.
6.3 Sample tests
Sample tests consist of the following:
a) on wire before stranding as per applicable wire standards;
b) on the completed conductor:
– cross-sectional area
– overall diameter
– linear mass
– surface condition
– lay ratio and direction of lay
– breaking strength of wires after stranding (if requested)
– wire canting on the outside layer (if requested).
Samples for tests specified in a) shall be taken before stranding and tested in accordance
with the standards listed in Clause 2.
Samples for the tests specified in b) shall be taken at random from the outer end of 10 % of
the drums of conductor. However, the inspection of the surface condition of the conductor
shall be carried out on every drum prior to lagging.
Samples for tests of individual wires after stranding, when requested, shall consist of a 1,5 m
length cut from the outer end of the drums of conductors.
6.3.1 Cross-sectional area
The cross-sectional area of the conductor shall be taken as the sum of the areas of the wires
composing the conductor. The area of round wires shall be based on the measurements made
in accordance with 6.3.1.1. The area of formed wires shall be based on the method in
accordance with 6.3.1.2.
6.3.1.1 Round wires
The diameter of a round wire shall include the metallic coating, where applicable and shall be
measured using a micrometer calliper having flat surfaces on both the anvil and the end of the
spindle and graduated to be read in micrometers.The diameter shall be the average of three
diameter measurements, each of which is the average of the maximum and minimum readings
at a point taken near each end and in the centre of the sample.
62420 © IEC:2008 – 13 –
When measured in accordance with this subclause, the area shall not vary from the nominal
value by more than ±2 % in any sample and by more than ±1,5 % for the average of any four
measured values at locations selected at random with a minimum spacing of 200 mm.
6.3.1.2 Formed wires
The equivalent diameter of a formed wire shall be obtained from the weight measurements
made on a sample not less than 1 m in length, and its density as defined in the appropriate
standard listed in Clause 2.
When determined in accordance with this subclause, the area shall not vary from the nominal
value by more than ±2 % in any sample and by more than ±1,5 % for the average of any four
samples selected at random on the bobbins after drawing.
6.3.2 Overall diameter
The conductor diameter shall be measured half-way between the closing die and the capstan
while still under tension on the stranding machine. Measurements shall be made with a
calliper graduated to be read in 0,01 mm. The diameter shall be the average of two readings,
rounded to two decimals of a millimetre, taken at right angles to each other at the same
location.
When measured in accordance with this subclause, the diameter of the conductor shall not
vary by more than ±1 % for diameters larger than or equal to 10 mm and ±0,1 mm for
diameters smaller than 10 mm.
NOTE The purpose of measuring under tension is to ensure that all layers are resting on the layer underneath.
Thus, other means of measurement, such as on a cut sample, are possible.
6.3.3 Linear mass
The linear mass of the conductor shall be determined by using apparatus capable of
achieving an accuracy of ± 0,1 %.
The mass of grease in a conductor shall be determined from the difference between the mass
of the conductor with grease and its mass after removing all the grease. The mass of grease
shall correspond at least to the minimum values specified in Annex C. In case of non-
compliance with the values of Annex C, the manufacturer shall demonstrate that the weight of
grease is adequate to achieve its intended purpose.
When measured in accordance with this subclause, the mass of the conductor per unit length
without grease shall not vary from its nominal value by more than ±2 %. In case of non
compliance with nominal values, the actual lay factors shall be used.
6.3.4 Surface condition
The surface of the conductor shall comply with the requirements of 5. 3 .
6.3.5 Lay ratio and direction of lay
The lay ratio of each layer of the conductor shall be obtained through the ratio of the
measured lay length to the external diameter of the applicable layer.
When measured in accordance with this subclause, the obtained values shall comply with the
requirements of 5.4. In addition, the direction of each layer shall be noted and shall also
comply with the requirements of 5. 4.
– 14 – 62420 © IEC:2008
6.3.6 Breaking strength of wires after stranding (if requested)
When required, breaking strength tests shall be made on wires obtained from conductors after
stranding. The specimen of wire shall be taken from the conductor sample and shall be
removed from its position and straightened, care being taken not to stretch it in so doing.
The cross-sectional area of the wire is determined from the diameter measurements indicated
in 6.3.1.1 and 6.3.1.2. The straightened wire shall be installed in a suitable tensile testing
machine. The load shall be applied gradually with a rate of separation of the jaws not less
than 25 mm/min and not greater than 100 mm/min.
When tested in accordance with this subclause, the load at failure divided by the cross-
sectional area of the wire shall be not less than 95 % of the applicable stress requirements
prior to stranding (the 5 % reduction accounts for handling and twisting of wires during
stranding.).
6.3.7 Wire canting on the outside layer (if requested)
This test is intended for conductors that are to be used for the reduction of aeolian vibrations
and for which the outside layer is composed of formed wires.
Wire canting shall be measured on the outside layer of the conductor (as shown in
Figure 2).The magnitude of wire canting shall be measured while the conductor is in the
stranding equipment, under tension, half-way between the capstan and the closing die.
Canting shall be measured on each wire with a feeler gauge and recorded.
When measured in accordance with this subclause, the maximum canting for any wire shall
not be more than 0,5 mm.
7 Inspection
7.1 Test location
All tests and inspection shall be made at the manufacturer’s plant prior to shipment unless
mutually agreed between the manufacturer and the purchaser at the time of purchase and
shall be conducted in such a way as not to interfere unnecessarily with the manufacturer’s
operations. The manufacturer shall afford the inspector, representing the purchaser, all
necessary and sufficient testing facilities in order to satisfy purchaser that the material is
being furnished in accordance with this standard.
When inspection is to be made by the purchaser before shipment, the tests shall all be made
within 10 days after receipt of a notice by the purchaser that the material is ready to test, and
the material shall be accepted or rejected at the manufacturer's plant. If the purchaser does
not have a representative present at the manufacturer's plant to test the material at the
expiration of the said 10 days, the manufacturer shall make the tests herein provided for and
furnish to the purchaser, when requested, official copies of the results of these tests. The
purchaser shall accept or reject the material in accordance with the results of these tests.
Alternatively, the manufacturer may provide relevant test results if these have already been
carried out in production.
7.2 Acceptance or rejection
Failure of a test specimen to comply with any one of the requirements of this standard shall
constitute grounds for rejection of the lot represented by the specimen.
If any lot is rejected in this manner, the manufacturer shall have the right to test, only once, all
individual drums of conductors in the lot and submit those which meet the requirements for
acceptance.
62420 © IEC:2008 – 15 –
8 Packaging and marking
8.1 Packaging
The conductor shall be suitably protected against damage which could occur in ordinary
handling and shipping.
NOTE The following should be agreed upon between the manufacturer and the purchaser when placing the order or
at the earliest possible time:
– the type and size of package and method of packing;
– the packaging size and drum bore requirements and also the availability of the inner end of the conductor for
grounding purposes, where conductors’ stringing practices require special considerations.
If required in order to prevent differential movement of the layers during subsequent handling,
the trailing end of the conductor on the drum shall be properly secured by an adequate
method.
8.2 Marking and tare
The gross, net and tare weight, length (or length and number of pieces, if more than one
length is agreed upon to be supplied on the same drum), designation, and any other
necessary identification shall be suitably marked inside the package. This same information,
together with the purchase order number, the manufacturer's serial number (if any) and all
shipping marks and other information shall appear on the outside of each package.
8.3 Random lengths
Random lengths of conductors unavoidably obtained during production shall not exceed 5 %
of the length provided that no piece is less than 50 % of the contractual length.
– 16 – 62420 © IEC:2008
Table 1 – Metal combinations permitted
Core (internal wires)
Envelope
(external wires)
20SA, 27SA 30SA,
S1A, S1B S2A, S2B S3A
40SA
A1G/20SA,
A1G/S1A, A1G/S2A,
A1G/27SA,
A1 A1G/S3A
A1G/S1B A1G/S2B
A1G/30SA,
A1G/40SA
A2G/20SA,
A2G/S1A, A2G/S2A,
A2G/27SA,
A2 A2G/S3A
A2G/S1B A2G/S2B
A2G/30SA,
A2G/40SA
A3G/20SA,
A3G/S1A, A3G/S2A,
A3G/27SA,
A3 A3G/S3A
A3G/S1B A3G/S2B
A3G/30SA,
A3G/40SA
AT1G/20SA,
AT1G/S1A, AT1G/S2A,
AT1G/27SA,
AT1 AT1G/S3A
AT1G/S1B AT1G/S2B
AT1G/30SA,
AT1G/40SA
AT2G/20SA,
AT2G/S1A, AT2G/S2A,
AT2G/27SA,
AT2 AT2G/S3A
AT2G/S1B AT2G/S2B
AT2G/30SA,
AT2G/40SA
AT3G/20SA,
AT3G/S1A, AT3G/S2A,
AT3G/27SA,
AT3 AT3G/S3A
AT3G/S1B AT3G/S2B
AT3G/30SA,
AT3G/40SA
AT4G/20SA,
AT4G/S1A, AT4G/S2A,
AT4G/27SA,
AT4 AT4G/S3A
AT4G/S1B AT4G/S2B
AT4G/30SA,
AT4G/40SA
62420 © IEC:2008 – 17 –
Table 2 – Number of joints permitted in aluminium wires
Number of aluminium Joints permitted per
layers conductor length
1 2
2 3
3 4
4 5
a
Table 3 – Standard increments due to stranding
Conductor stranding Increment (%)
No of layer(s) in Number of wire(s) Mass and electrical
Mass of core
envelope in the core resistance of envelope
1 1 1,5 ---
2 1 2,0 ---
3 1 2,5 ---
1 7 1,5 0,43
2 7 2,0 0,43
3 7 2,5 0,43
1 19 1,5 0,77
2 19 2,0 0,77
3 19 2,5 0,77
a
These increments have been calculated using average lay ratios for each applicable layer of core or
envelope.
IEC 533/08
Figure 1 – Examples of conductors containing one or more gaps
– 18 – 62420 © IEC:2008
Feeler gauge
IEC 534/08
Figure 2 – Method of measuring wire canting
62420 © IEC:2008 – 19 –
Annex A
(normative)
Information to be supplied by purchaser
When making an enquiry or placing an order the purchaser shall furnish the following
information:
a) quantity of conductors;
b) cross-sectional area and designation;
c) length of conductor per drum, its tolerance and where applicable, matching of conductor
lengths;
d) type and size of package and method of packing;
e) special packaging requirements, if any;
f) lagging requirements, if any;
g) if inspection is required and the place of inspection;
h) whether tests on wires after stranding are required;
i) whether tests on wire canting are required;
j) whether conductor breaking strength tests are required;
k) whether conductor stress-strain tests are required;
l) whether creep
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