IEC 62420:2008

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

• Status: Published
• Publication Date: 24-Apr-2008
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.060.10 - Wires
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: TC 7 - Overhead electrical conductors
• Drafting Committee: MT 1 - TC 7/MT 1
• Current Stage: PPUB - Publication issued
• Start Date: 31-May-2008
• Completion Date: 25-Apr-2008

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

or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,

please contact the address below or your local IEC member National Committee for further information.

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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
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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
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.

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 conducto
...

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

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by
any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or
IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
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et les microfilms, sans l'accord écrit de la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: [e-mail]
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
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in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
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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, o
...