IEC 62067:2011

IEC 62067 ®
Edition 2.0 2011-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Power cables with extruded insulation and their accessories for rated voltages
above 150 kV (U = 170 kV) up to 500 kV (U = 550 kV) – Test methods and
m m
requirements
Câbles d'énergie à isolation extrudée et leurs accessoires pour des tensions
assignées supérieures à 150 kV (U = 170 kV) et jusqu'à 500 kV (U = 550 kV) –
m m
Méthodes et exigences d'essai
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
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
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: inmail@iec.ch
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.
 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It also gives information on projects, withdrawn and replaced publications.
 IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
 Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
 Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: csc@iec.ch
Tel.: +41 22 919 02 11
Fax: +41 22 919 03 00
A propos de la CEI
La Commission Electrotechnique Internationale (CEI) est la première organisation mondiale qui élabore et publie des
normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.
 Catalogue des publications de la CEI: www.iec.ch/searchpub/cur_fut-f.htm
Le Catalogue en-ligne de la CEI vous permet d’effectuer des recherches en utilisant différents critères (numéro de référence,
texte, comité d’études,…). Il donne aussi des informations sur les projets et les publications retirées ou remplacées.
 Just Published CEI: www.iec.ch/online_news/justpub
Restez informé sur les nouvelles publications de la CEI. Just Published détaille deux fois par mois les nouvelles
publications parues. Disponible en-ligne et aussi par email.
 Electropedia: www.electropedia.org
Le premier dictionnaire en ligne au monde de termes électroniques et électriques. Il contient plus de 20 000 termes et
définitions en anglais et en français, ainsi que les termes équivalents dans les langues additionnelles. Egalement appelé
Vocabulaire Electrotechnique International en ligne.
 Service Clients: www.iec.ch/webstore/custserv/custserv_entry-f.htm
Si vous désirez nous donner des commentaires sur cette publication ou si vous avez des questions, visitez le FAQ du
Service clients ou contactez-nous:
Email: csc@iec.ch
Tél.: +41 22 919 02 11
Fax: +41 22 919 03 00
IEC 62067 ®
Edition 2.0 2011-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Power cables with extruded insulation and their accessories for rated voltages
above 150 kV (U = 170 kV) up to 500 kV (U = 550 kV) – Test methods and
m m
requirements
Câbles d'énergie à isolation extrudée et leurs accessoires pour des tensions
assignées supérieures à 150 kV (U = 170 kV) et jusqu'à 500 kV (U = 550 kV) –
m m
Méthodes et exigences d'essai
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XB
ICS 29.060.20 ISBN 978-2-88912-779-5

– 2 – 62067 © IEC:2011
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references. 9
3 Terms and definitions . 10
3.1 Definitions of dimensional values (thicknesses, cross-sections, etc.) . 10
3.2 Definitions concerning tests . 11
3.3 Other definitions . 11
4 Voltage designations and materials . 12
4.1 Rated voltages . 12
4.2 Cable insulating materials . 12
4.3 Cable metal screens/sheaths . 12
4.4 Cable oversheathing materials . 12
5 Precautions against water penetration in cables . 12
6 Cable characteristics . 13
7 Accessory characteristics. 13
8 Test conditions . 14
8.1 Ambient temperature . 14
8.2 Frequency and waveform of power frequency test voltages . 14
8.3 Wave form of impulse test voltages . 14
8.3.1 Lightning impulse voltage . 14
8.3.2 Switching impulse voltage . 14
8.4 Relationship of test voltages to rated voltages . 14
8.5 Determination of the cable conductor temperature . 14
9 Routine tests on cables and on the main insulation of prefabricated accessories . 15
9.1 General . 15
9.2 Partial discharge test . 15
9.3 Voltage test . 15
9.4 Electrical test on oversheath of the cable . 15
10 Sample tests on cables . 16
10.1 General . 16
10.2 Frequency of tests . 16
10.3 Repetition of tests . 16
10.4 Conductor examination . 16
10.5 Measurement of electrical resistance of conductor and of metal screen/sheath. 16
10.6 Measurement of thickness of insulation and cable oversheath . 17
10.6.1 General . 17
10.6.2 Requirements for the insulation . 17
10.6.3 Requirements for the cable oversheath . 17
10.7 Measurement of thickness of metal sheath. 17
10.7.1 Lead or lead alloy sheath . 18
10.7.2 Plain or corrugated aluminium sheath . 18
10.8 Measurement of diameter . 18
10.9 Hot set test for XLPE and EPR insulations . 19
10.9.1 Procedure . 19
10.9.2 Requirements . 19
10.10 Measurement of capacitance . 19

62067 © IEC:2011 – 3 –
10.11 Measurement of density of HDPE insulation . 19
10.11.1 Procedure . 19
10.11.2 Requirements . 19
10.12 Lightning impulse voltage test . 19
10.13 Water penetration test . 19
10.14 Tests on components of cables with a longitudinally applied metal tape or
foil, bonded to the oversheath . 19
11 Sample tests on accessories . 20
11.1 Tests on components . 20
11.2 Tests on complete accessory . 20
12 Type tests on cable systems . 20
12.1 General . 20
12.2 Range of type approval . 20
12.3 Summary of type tests . 21
12.4 Electrical type tests on complete cable systems . 22
12.4.1 Test voltage values . 22
12.4.2 Tests and sequence of tests . 22
12.4.3 Bending test . 23
12.4.4 Partial discharge tests . 23
12.4.5 Tan δ measurement . 24
12.4.6 Heating cycle voltage test . 24
12.4.7 Impulse voltage tests . 24
12.4.8 Examination . 25
12.4.9 Resistivity of semi-conducting screens . 25
12.5 Non-electrical type tests on cable components and on complete cable . 26
12.5.1 Check of cable construction . 26
12.5.2 Tests for determining the mechanical properties of insulation before
and after ageing . 26
12.5.3 Tests for determining the mechanical properties of oversheaths
before and after ageing . 27
12.5.4 Ageing tests on pieces of complete cable to check compatibility of
materials . 27
12.5.5 Loss of mass test on PVC oversheaths of type ST . 28
12.5.6 Pressure test at high temperature on oversheaths . 28
12.5.7 Test on PVC oversheaths (ST and ST ) at low temperature . 28
1 2
12.5.8 Heat shock test for PVC oversheaths (ST and ST ) . 28
1 2
12.5.9 Ozone resistance test for EPR insulation . 29
12.5.10 Hot set test for EPR and XLPE insulations . 29
12.5.11 Measurement of density of HDPE insulation . 29
12.5.12 Measurement of carbon black content of black PE oversheaths (ST
and ST ) . 29
12.5.13 Test under fire conditions . 29
12.5.14 Water penetration test . 29
12.5.15 Tests on components of cables with a longitudinally applied metal
tape or foil, bonded to the oversheath . 30
13 Prequalification test of the cable system. 30
13.1 General and range of prequalification test approval . 30
13.2 Prequalification test on complete cable system . 30
13.2.1 Summary of prequalification tests . 30
13.2.2 Test voltage values . 31
13.2.3 Test arrangement . 31

– 4 – 62067 © IEC:2011
13.2.4 Heating cycle voltage test . 31
13.2.5 Lightning impulse voltage test . 32
13.2.6 Examination . 32
13.3 Tests for the extension of the prequalification of a cable system. 32
13.3.1 Summary of the extension of prequalification test . 32
13.3.2 Electrical part of the extension of prequalification tests on complete
cable system. 32
14 Type test on cables . 34
15 Type test on accessories . 34
16 Electrical test after installation . 34
16.1 General . 34
16.2 DC voltage test of the oversheath . 35
16.3 AC voltage test of the insulation . 35
Annex A (informative) Determination of the cable conductor temperature . 42
Annex B (normative) Rounding of numbers . 47
Annex C (informative) List of type and prequalification and extension of
prequalification tests of cable systems. 48
Annex D (normative) Method of measuring resistivity of semi-conducting screens . 50
Annex E (normative) Water penetration test . 52
Annex F (normative) Tests on components of cables with a longitudinally applied metal
tape or foil, bonded to the oversheath . 54
Annex G (normative) Tests of outer protection for joints . 57
Bibliography . 60

Figure 1 – Extension of prequalification test arrangement for the prequalification of a
system with another joint, designed for rigid as well as for flexible installation . 33
Figure A.1 – Typical test set-up for the reference loop and the main test loop . 43
Figure A.2 – Example of an arrangement of the temperature sensors on the conductor
of the reference loop . 44
Figure D.1 – Preparation of samples for measurement of resistivity of conductor and
insulation screens . 51
Figure E.1 – Schematic diagram of apparatus for water penetration test . 53
Figure F.1 – Adhesion of metal foil . 54
Figure F.2 – Example of overlapped metal foil . 55
Figure F.3 – Peel strength of overlapped metal foil . 55

Table 1 – Insulating compounds for cables . 35
Table 2 – Oversheathing compounds for cables . 35
Table 3 – Tan δ requirements for insulating compounds for cables . 35
Table 4 – Test voltages . 36
Table 5 – Non-electrical type tests for insulating and oversheathing compounds for
cables . 37
Table 6 – Test requirements for mechanical characteristics of insulating compounds for
cables (before and after ageing) . 38
Table 7 – Test requirements for mechanical characteristics of oversheathing
compounds for cables (before and after ageing) . 39
Table 8 – Test requirements for particular characteristics of insulating compounds for
cables . 40

62067 © IEC:2011 – 5 –
Table 9 – Test requirements for particular characteristics of PVC oversheathing for
cables . 41
Table C.1 – Type tests on cable systems . 48
Table C.2 – Prequalification tests on cable systems . 49
Table C.3 – Extension of prequalification tests on cable systems . 49
Table G.1 – Impulse voltage tests . 58

– 6 – 62067 © IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
POWER CABLES WITH EXTRUDED INSULATION AND
THEIR ACCESSORIES FOR RATED VOLTAGES
ABOVE 150 kV (U = 170 kV) UP TO 500 kV (U = 550 kV) –
m m
TEST METHODS AND REQUIREMENTS
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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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 62067 has been prepared by IEC technical committee 20: Electric
cables.
This second edition of IEC 62067 cancels and replaces the first edition, published in 2001, and
its Amendment 1 (2006), and constitutes a technical revision.
The significant technical changes with respect to the previous edition are as follows:
– addition of the extension of prequalification test, requiring significant less time to be
completed compared with the full prequalification test;
– during the routine tests on the main insulation of prefabricated accessories the required
sensitivity level for the partial discharge test is reduced from 10 pC to 5 pC.

62067 © IEC:2011 – 7 –
NOTE For a more detailed history of events leading up to this second edition, see the Introduction.
The text of this standard is based on the following documents:
FDIS Report on voting
20/1268/FDIS 20/1278A/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.
The committee has decided that the contents of this publication will remain unchanged until the
stability 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.
– 8 – 62067 © IEC:2011
INTRODUCTION
As a result of major developments in cable systems with extruded insulation for voltages above
150 kV, CIGRE Study Committee (SC) 21 set up Working Group (WG) 21.03 in 1990. The
terms of reference of WG 21.03 were "to prepare recommendations for electrical type tests,
sample and routine tests, based on extending IEC 60840:1988 up to 400 kV and to make
proposals for prequalification/development tests which, as a minimum, should be performed ".
WG 21.03 reported that the extension of IEC 60840 to voltages above 150 kV needed extra
consideration because of the following factors:
– such cables form part of the backbone of the transmission system and, therefore, reliability
considerations are of the highest priority;
– these cables and their accessories operate with higher electrical stresses than cables up to
150 kV and, as a result, have a smaller safety margin with respect to the intrinsic
performance boundaries of the cable system;
– such cables and accessories have a thicker insulation wall than those up to 150 kV and, as
a result, are subjected to greater thermomechanical effects;
– the design and coordination of the cables and accessories becomes more difficult with
increasing system voltage levels.
The recommendations of the WG 21.03 were published in Electra No. 151 in December 1993
and taken into account by IEC in 1995 in the preparation of this standard for cable systems
with extruded insulation for voltages above 150 kV. IEC considered that the new standard
should also cover the 500 kV level. Thus, at its meeting in September 1996, CIGRE SC 21 set
up task force 21.18 to study the extension of the initial recommendations to the 500 kV level.
The updated recommendations were cited in Electra No. 193 in December 2000 and thus were
also taken into account by IEC Technical Committee (TC) 20 in the preparation of the first
edition of this standard.
On the advice of CIGRE, a long term accelerated ageing test was introduced in the first edition,
in order to gain some indication of the long term reliability of a cable system. This test, known
as the "prequalification test", was to be performed on the complete system comprising the
cable, joints and terminations in order to demonstrate the performance of the system.
In addition, CIGRE WG 21.09, published recommendations for “tests after installation on high-
voltage extruded insulation cable systems” in Electra No 173 in August 1997. These
recommendations (which state, amongst other things, that d.c. tests should be avoided on the
main insulation, as they are both ineffective and potentially damaging) were also taken into
account in the first edition of this standard.
At its meeting in November 2004, TC 20 concluded that the next revision of IEC 62067 should
include the recommendation for testing of HV and EHV extruded cables that was under
preparation by the CIGRE SC B1 (previously SC 21) WG B1.06. This was made available as a
CIGRE Technical Brochure 303 before the meeting of TC 20 in October 2006, which confirmed
this view. Therefore Technical Brochure 303 has been considered by TC 20 and major parts
implemented in this standard. This has resulted in some modifications to the prequalification
test requirements, a major change being the addition of the extension of prequalification test.
The latter test requires approximately one quarter of the time to complete when compared with
the full prequalification test.
A list of relevant CIGRE references is given in the bibliography.

62067 © IEC:2011 – 9 –
POWER CABLES WITH EXTRUDED INSULATION AND
THEIR ACCESSORIES FOR RATED VOLTAGES
ABOVE 150 kV (U = 170 kV) UP TO 500 kV (U = 550 kV) –
m m
TEST METHODS AND REQUIREMENTS
1 Scope
This International Standard specifies test methods and requirements for power cable systems,
cables with extruded insulation and their accessories for fixed installations, for rated voltages
above 150 kV (U = 170 kV) up to and including 500 kV (U = 550 kV).
m m
The requirements apply to single-core cables and to their accessories for usual conditions of
installation and operation, but not to special cables and their accessories, such as submarine
cables, for which modifications to the standard tests may be necessary or special test
conditions may need to be devised.
This standard does not cover transition joints between cables with extruded insulation and
paper insulated cables.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE The IEC 60811 series is currently undergoing a revision, which will lead to a restructuring of its parts. A
description of this, as well as a cross-reference table between the current and planned parts will be given in
IEC 60811-100.
IEC 60060-1 High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60183, Guide to the selection of high-voltage cables
IEC 60228, Conductors of insulated cables
IEC 60229:2007, Electric cables – Tests on extruded oversheaths with a special protective
function
IEC 60230, Impulse tests on cables and their accessories
IEC 60287-1-1:2006, Electric cables – Calculation of the current rating – Part 1-1: Current
rating equations (100 % load factor) and calculation of losses – General
IEC 60332-1-2, Tests on electric and optical fibre cables under fire conditions – Part 1-2: Test
for vertical flame propagation for a single insulated wire or cable – Procedure for 1 kW pre-mixed
flame
IEC 60811-1-1:1993, Common test methods for insulating and sheathing materials of electric
cables and optical cables – Section 1-1: Methods for general application – Measurement of
thickness and overall dimensions – Tests for determining the mechanical properties
Amendment 1 (2001)
– 10 – 62067 © IEC:2011
IEC 60811-1-2:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 1: Methods for general application – Section Two: Thermal ageing methods
Amendment 1 (1989)
Amendment 2 (2000)
IEC 60811-1-3:1993, Common test methods for insulating and sheathing materials of electric
cables – Part 1-3: General application – Methods for determining the density – Water
absorption tests – Shrinkage test
Amendment 1 (2001)
IEC 60811-1-4:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 1: Methods for general application – Section Four: Tests at low temperature
Amendment 1 (1993)
Amendment 2 (2001)
IEC 60811-2-1:1998, Common test methods for insulating and sheathing materials of electric
and optical cables – Part 2-1: Methods specific to elastomeric compounds – Ozone resistance,
hot set and mineral oil immersion tests
Amendment 1 (2001)
IEC 60811-3-1:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 3: Methods specific to PVC compounds – Section 1: Pressure test at high
temperature – Tests for resistance to cracking
Amendment 1 (1994)
Amendment 2 (2001)
IEC 60811-3-2:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 3: Methods specific to PVC compounds – Section two: Loss of mass test –
Thermal stability test
Amendment 1 (1993)
Amendment 2 (2003)
IEC 60811-4-1:2004, Insulating and sheathing materials of electric and optical cables –
Common test methods – Part 4-1: Methods specific to polyethylene and polypropylene
compounds – Resistance to environmental stress cracking –Measurement of the melt flow
index – Carbon black and/or mineral filler content measurement in polyethylene by direct
combustion – Measurement of carbon black content by thermogravimetric analysis (TGA) –
Assessment of carbon black dispersion in polyethylene using a microscope
IEC 60885-3, Electrical test methods for electric cables – Part 3: Test methods for partial
discharge measurements on lengths of extruded power cables
3 Terms and definitions
For the purposes of this document the following terms and definitions apply.
3.1 Definitions of dimensional values (thicknesses, cross-sections, etc.)
3.1.1
nominal value
value by which a quantity is designated and which is often used in tables
NOTE Usually, in this standard, nominal values give rise to values to be checked by measurements taking into
account specified tolerances.
62067 © IEC:2011 – 11 –
3.1.2
median value
when several test results have been obtained and ordered in an increasing (or decreasing)
succession, middle value if the number of available values is odd, and mean of the two middle
values if the number is even
3.2 Definitions concerning tests
3.2.1
routine test
tests made by the manufacturer on each manufactured component (length of cable or
accessory) to check that the component meets the specified requirements
3.2.2
sample test
tests made by the manufacturer on samples of complete cable, or components taken from a
complete cable or accessory, at a specified frequency, so as to verify that the finished product
meets the specified requirements
3.2.3
type test
tests made before supplying, on a general commercial basis, a type of cable system covered
by this standard, in order to demonstrate satisfactory performance characteristics to meet the
intended application
NOTE Once successfully completed, these tests need not be repeated, unless changes are made in the cable or
accessory with respect to materials, manufacturing process, design or design electrical stress levels, which might
adversely change the performance characteristics.
3.2.4
prequalification test
test made before supplying, on a general commercial basis, a type of cable system covered by
this standard, in order to demonstrate satisfactory long term performance of the complete
cable system
3.2.5
extension of prequalification test
tests made before supplying, on a general commercial basis, a type of cable system covered
by this standard, in order to demonstrate satisfactory long term performance of the complete
cable system, taking into account an already prequalified cable system
3.2.6
electrical test after installation
tests made to demonstrate the integrity of the cable system as installed
3.3 Other definitions
3.3.1
cable system
cable with installed accessories including components used for thermomechanical restraint of
systems limited to those used for terminations and joints only
3.3.2
nominal electrical stress
electrical stress calculated at U using nominal dimensions
– 12 – 62067 © IEC:2011
4 Voltage designations and materials
4.1 Rated voltages
In this standard, the symbols U , U and U are used to designate the rated voltages of cables
0 m
and accessories where these symbols have the meanings given in IEC 60183.
4.2 Cable insulating materials
This standard applies to cables insulated with the materials listed in Table 1. It also specifies,
for cables with each type of insulating compound, the maximum operating conductor
temperatures on which the specified test conditions are based.
4.3 Cable metal screens/sheaths
This standard applies to the various designs in use. It covers designs providing a radial water
tightness and other designs.
Designs that provide radial watertightness mainly consist of
• metal sheaths,
• longitudinally applied metal tapes or foils bonded to the oversheath,
• composite screens, involving a bunch of wires and, in addition, either a metal sheath or a
metal tape or foil bonded to the oversheath, acting as a radial water impermeable barrier
(see Clause 5),
and other designs such as
• bunch of metal wires only.
NOTE In all cases the metal screen/sheath should be able to carry the total fault current.
4.4 Cable oversheathing materials
Tests are specified for four types of oversheath, as follows:
– ST and ST based on polyvinyl chloride (PVC);
1 2
– ST and ST based on polyethylene (PE).
3 7
The choice of the type of oversheath will depend on the design of the cable and the mechanical
and thermal and fire constraints during operation.
The maximum conductor temperatures in normal operation for different types of oversheathing
materials covered by this standard are given in Table 2.
NOTE For some applications, the oversheath may be covered by a functional layer (e.g. semi-conductive).
5 Precautions against water penetration in cables
When cable systems are installed in the ground, in easily flooded galleries or in water, a radial
water impermeable barrier around the cable is recommended.
NOTE A test for radial water penetration is not currently available.
Longitudinal water barriers may also be applied in order to avoid the need to replace long
sections of cable in case of damage in the presence of water.
A test for longitudinal water penetration is given in 12.5.14.

62067 © IEC:2011 – 13 –
6 Cable characteristics
For the purpose of carrying out the cable system tests described in this standard and recording
the results, the cable shall be identified. The following characteristics shall be known or
declared:
a) Name of manufacturer, type, designation and manufacturing date or date code.

b) Rated voltage: values shall be given for U , U, U (see 4.1 and 8.4).
0 m
c) Type of conductor, its material and nominal cross-sectional area, in square millimetres;
conductor construction; presence, if any, and nature of measures taken to reduce skin
effect; presence, if any, and nature of measures taken to achieve longitudinal
watertightness. If the nominal cross-sectional area is not in accordance with IEC 60228, the
d.c. conductor resistance corrected to 1 km length and to 20 °C shall be declared ;
d) Material and nominal thickness of insulation (t ) (see 4.2);
n
e) Type of manufacturing process for insulation system;
f) Presence, if any, and nature of watertightness measures in the screening area;
g) Material and construction of metal screen, e.g. number and diameter of wires. (The d.c.
resistance of the metal screen shall be declared.) Material, construction and nominal
thickness of metal sheath, or longitudinally applied metal tape or foil bonded to the
oversheath, if any;
h) Material and nominal thickness of oversheath;
i) Nominal diameter of the conductor (d);
j) Nominal overall diameter of the cable (D);
k) Nominal inner diameter (d ) and calculated nominal outer diameter (D ) of the insulation;
ii io
l) Nominal capacitance, corrected to 1 km length, between conductor and metal
screen/sheath;
m) Calculated nominal electrical stress at conductor screen (E ) and at insulation screen (E ):
i o
2U
E =
i
d ×ln(D / d )
ii io ii
2U
E =
o
D ×ln(D / d )
io io ii
where
D = d + 2t ;
io ii n
d is the declared nominal inner diameter of the insulation;
ii
D is the calculated nominal outer diameter of the insulation;
io
t is the declared nominal insulation thickness.
n
The value of U is given in Table 4;
7 Accessory characteristics
For the purpose of carrying out the cable system or accessory tests described in this standard
and recording the results, the accessory shall be identified.
The following characteristics shall be known or declared:
a) cables used for testing accessories shall be correctly identified as in Clause 6;
b) conductor connections used within the accessories shall be correctly identified, where
applicable, with respect to
– 14 – 62067 © IEC:2011
– assembly technique,
– tooling, dies and necessary setting,
– preparation of contact surfaces,
– type, reference number and any other identification of the connector,
– details of the type test approval of the connector if applicable;
c) accessories to be tested shall be correctly identified with respect to
– name of manufacturer,
– type, designation and manufacturing date or date code,
– rated voltage (see 6 b) above),
– installation instructions (reference and date).
8 Test conditions
8.1 Ambient temperature
Unless otherwise specified in the details for the particular test, tests shall be carried out at an
ambient temperature of (20 ± 15) °C.
8.2 Frequency
...