IEC 60156:2018

Insulating liquids - Determination of the breakdown voltage at power frequency - Test method

IEC 60156:2018 specifies the method for determining the dielectric breakdown voltage of insulating liquids at power frequency. The test procedure is performed in a specified apparatus, where the oil sample is subjected to an increasing AC electrical field until breakdown occurs. The method applies to all types of insulating liquids of nominal viscosity up to 350 mm2/s at 40 °C. It is appropriate both for acceptance testing on unused liquids at the time of their delivery and for establishing the condition of samples taken in monitoring and maintenance of equipment. This third edition cancels and replaces the second edition published in 1995. This edition constitutes a technical revision and, mainly, confirms the content of the previous edition even if some advances are included. The test method has not been changed for practical reason due to the very large number of instrumentation disseminated around the world, even if the use of stirring is now recommended.

Isolants liquides - Détermination de la tension de claquage à fréquence industrielle - Méthode d’essai

L'IEC 60156:2018 spécifie la méthode de détermination de la tension de claquage diélectrique des isolants liquides à fréquence industrielle. La procédure d’essai est réalisée dans un appareil spécifié dans lequel l’échantillon d’huile est soumis à un champ électrique alternatif croissant jusqu’à l’obtention du claquage. La méthode est applicable à tous les types d’isolants liquides de viscosité nominale allant jusqu’à 350 mm2/s à 40 °C. Elle convient aussi bien pour les essais de réception de liquides neufs à la livraison que pour définir l’état des échantillons prélevés lors de la surveillance et de la maintenance des matériels. Cette troisième édition annule et remplace la deuxième édition parue en 1995. Cette édition constitue une révision technique et valide essentiellement le contenu de l’édition précédente même si elle comporte certaines améliorations. La méthode d’essai n’a pas été modifiée pour des raisons pratiques et du fait du très grand nombre de dispositifs de mesure utilisés au niveau international, même si l’emploi de l’agitateur est maintenant recommandé.

General Information

• Status: Published
• Publication Date: 16-Aug-2018
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.040 - Insulating fluids
• Technical Committee: TC 10 - Fluids for electrotechnical applications
• Drafting Committee: MT 30 - TC 10/MT 30
• Current Stage: PPUB - Publication issued
• Start Date: 07-Sep-2018
• Completion Date: 17-Aug-2018

Standards Content (Sample)

IEC 60156 ®
Edition 3.0 2018-08
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Insulating liquids – Determination of the breakdown voltage at power
frequency – Test method
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
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International Standards for all electrical, electronic and related technologies.

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IEC 60156 ®
Edition 3.0 2018-08
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Insulating liquids – Determination of the breakdown voltage at power

frequency – Test method
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.040 ISBN 978-2-8322-5987-0

– 2 – IEC 60156:2018 RLV © IEC 2018
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references. 7
3 Terms and definitions . 7
4 Electrical apparatus . 7
4.1 General . 7
4.2 Voltage regulator . 8
4.3 Step-up transformer . 8
4.4 Switching system . 8
4.5 Current-limiting resistors . 9
4.6 Measuring device system . 9
5 Test assembly . 9
5.1 General . 9
5.2 Test cell . 9
5.3 Electrodes. 12
5.4 Stirring device (optional) . 12
6 Preparation of electrodes . 13
7 Test assembly preparation . 13
8 Sampling . 14
Condition of the sample .
9 Test procedure . 14
9.1 Sample preparation . 14
9.2 Filling of the cell . 15
10 Application of the voltage . 15
11 Report . 15
12 Test data dispersion and reproducibility . 16
12.1 Test data dispersion . 16
12.2 Reproducibility . 17
Annex A (informative) Improved test method . 18
A.1 Test procedure for improved test method . 18
A.2 Report . 19
Annex B (informative) Special test methods for low volume samples . 20
B.1 Low volume sample test . 20
Annex C (informative) Representative material for a performance test . 22
Bibliography . 23

Figure − Example of suitable cell and spherical electrodes .
Figure − Example of suitable cell and partially spherical electrodes .
Figure 1 – Examples of test cells with spherical electrodes 12,5 mm to 13,0 mm
diameter . 12
Figure 2 – Examples of test cells with partially spherical electrodes with 25 mm radius
and diameter of 36 mm . 12

Figure 3 – Graphical representation of coefficient of variation (standard deviation/mean
ratio) versus mean breakdown voltage . 17
Figure A.1 – Example of a sequence of breakdown shots for determination of the
breakdown voltage . 19
Figure B.1 – Example of low volume test cell, fixed electrode distance of 2 mm with
2 ml active volume under dielectric stress . 20
Figure B.2 – Example of low volume test cell, fixed electrode distance of 2,5 mm
(150 ml to 200 ml) . 21

– 4 – IEC 60156:2018 RLV © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATING LIQUIDS – DETERMINATION OF THE BREAKDOWN
VOLTAGE AT POWER FREQUENCY – TEST METHOD

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
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International Standard IEC 60156 has been prepared by IEC technical committee TC 10:
Fluids for electrotechnical applications.
This third edition cancels and replaces the second edition published in 1995. This edition
constitutes a technical revision and, mainly, confirms the content of the previous edition even
if some advances are included. The test method has not been changed for practical reason
due to the very large number of instrumentation disseminated around the world, although the
use of stirring is now recommended.
The text of this International Standard is based on the following documents:
FDIS Report on voting
10/1061/FDIS 10/1065/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
t
...

IEC 60156 ®
Edition 3.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Insulating liquids – Determination of the breakdown voltage at power
frequency – Test method
Isolants liquides – Détermination de la tension de claquage à fréquence
industrielle – Méthode 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.

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IEC Central Office Tel.: [phone]
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CH-1211 Geneva 20 www.iec.ch
Switzerland
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.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

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IEC 60156 ®
Edition 3.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Insulating liquids – Determination of the breakdown voltage at power

frequency – Test method
Isolants liquides – Détermination de la tension de claquage à fréquence

industrielle – Méthode d’essai

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.040 ISBN 978-2-8322-5959-7

– 2 – IEC 60156:2018 © IEC 2018
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references. 7
3 Terms and definitions . 7
4 Electrical apparatus . 7
4.1 General . 7
4.2 Voltage regulator . 7
4.3 Step-up transformer . 8
4.4 Switching system . 8
4.5 Current-limiting resistors . 8
4.6 Measuring system . 8
5 Test assembly . 8
5.1 General . 8
5.2 Test cell . 9
5.3 Electrodes. 9
5.4 Stirring device . 10
6 Preparation of electrodes . 10
7 Test assembly preparation . 10
8 Sampling . 11
9 Test procedure . 11
9.1 Sample preparation . 11
9.2 Filling of the cell . 11
10 Application of the voltage . 11
11 Report . 12
12 Test data dispersion and reproducibility . 12
12.1 Test data dispersion . 12
12.2 Reproducibility . 13
Annex A (informative) Improved test method . 14
A.1 Test procedure for improved test method . 14
A.2 Report . 15
Annex B (informative) Special test methods for low volume samples . 16
B.1 Low volume sample test . 16
Annex C (informative) Representative material for a performance test . 18
Bibliography . 19

Figure 1 – Examples of test cells with spherical electrodes 12,5 mm to 13,0 mm
diameter . 9
Figure 2 – Examples of test cells with partially spherical electrodes with 25 mm radius
and diameter of 36 mm . 9
Figure 3 – Graphical representation of coefficient of variation versus mean breakdown
voltage . 13
Figure A.1 – Example of a sequence of breakdown shots for determination of the
breakdown voltage . 15

Figure B.1 – Example of low volume test cell, fixed electrode distance of 2 mm with
2 ml active volume under dielectric stress . 16
Figure B.2 – Example of low volume test cell, fixed electrode distance of 2,5 mm
(150 ml to 200 ml) . 17

– 4 – IEC 60156:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATING LIQUIDS – DETERMINATION OF THE BREAKDOWN
VOLTAGE AT POWER FREQUENCY – TEST METHOD

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 co
...