SIST EN IEC 60156:2025
(Main)Insulating liquids - Determination of the breakdown voltage at power frequency - Test method
Insulating liquids - Determination of the breakdown voltage at power frequency - Test method
IEC 60156:2025 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.
Isolierflüssigkeiten - Bestimmung der Durchschlagspannung bei Netzfrequenz - Prüfverfahren
Isolants liquides - Détermination de la tension de claquage à fréquence industrielle - Méthode d’essai
L'IEC 60156:2025 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.
Izolacijske tekočine - Ugotavljanje prebojne napetosti pri mrežni frekvenci - Testna metoda
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2025
Nadomešča:
SIST EN 60156:1997
Izolacijske tekočine - Ugotavljanje prebojne napetosti pri mrežni frekvenci - Testna
metoda
Insulating liquids - Determination of the breakdown voltage at power frequency - Test
method
Isolierflüssigkeiten - Bestimmung der Durchschlagspannung bei Netzfrequenz -
Prüfverfahren
Isolants liquides - Détermination de la tension de claquage à
fréquence industrielle - Méthode d’essai
Ta slovenski standard je istoveten z: EN IEC 60156:2025
ICS:
29.040.01 Izolacijski fluidi na splošno Insulating fluids in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 60156
NORME EUROPÉENNE
EUROPÄISCHE NORM March 2025
ICS 29.040 Supersedes EN 60156:1995
English Version
Insulating liquids - Determination of the breakdown voltage at
power frequency - Test method
(IEC 60156:2025)
Isolants liquides - Détermination de la tension de claquage Isolierflüssigkeiten - Bestimmung der Durchschlagspannung
à fréquence industrielle - Méthode d'essai bei Netzfrequenz - Prüfverfahren
(IEC 60156:2025) (IEC 60156:2025)
This European Standard was approved by CENELEC on 2025-03-07. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
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same status as the official versions.
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European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60156:2025 E
European foreword
The text of document 10/1241/FDIS, future edition 4 of IEC 60156, prepared by TC 10 "Fluids for
electrotechnical applications" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 60156:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-03-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-03-31
document have to be withdrawn
This document supersedes EN 60156:1995 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60156:2025 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 60060-3 NOTE Approved as EN 60060-3
IEC 60052:2002 NOTE Approved as EN 60052:2002 (not modified)
IEC 60060-2:2010 NOTE Approved as EN 60060-2:2011 (not modified)
ISO 21920-2:2021 NOTE Approved as EN ISO 21920-2:2022 (not modified)
IEC 60296 NOTE Approved as EN IEC 60296
IEC 60422 NOTE Approved as EN IEC 60422
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60475 - Method of sampling insulating liquids EN IEC 60475 -
IEC 60156 ®
Edition 4.0 2025-01
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 978-2-8327-0140-9
– 2 – IEC 60156:2025 © IEC 2025
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Electrical apparatus . 6
4.1 General . 6
4.2 Voltage regulator . 6
4.3 Step-up transformer . 7
4.4 Switching system . 7
4.5 Current-limiting resistors . 7
4.6 Measuring system . 7
5 Test assembly . 7
5.1 General . 7
5.2 Test cell . 8
5.3 Electrodes . 9
5.4 Stirring device . 9
6 Preparation of electrodes. 9
7 Test assembly preparation . 9
8 Sampling . 10
9 Test procedure . 10
9.1 Sample preparation . 10
9.2 Filling of the cell . 10
9.3 Application of the voltage . 10
10 Report . 11
11 Test data dispersion and reproducibility . 11
11.1 Test data dispersion . 11
11.2 Reproducibility . 12
Annex A (informative) Improved test method . 13
A.1 Test procedure for improved test method . 13
A.2 Report. 14
Annex B (informative) Special test method for low volume samples . 15
Annex C (informative) Representative material for a performance test . 16
Bibliography . 17
Figure 1 – Example of test cell with spherical electrodes 12,5 mm to 13,0 mm diameter . 8
Figure 2 – Example of test cell with partially hemispherical electrodes with 25 mm
radius and 36 mm diameter . 8
Figure 3 – Graphical representation of coefficient of variation versus mean breakdown
voltage . 12
Figure A.1 – Example of a sequence of breakdown shots for determination of the
breakdown voltage . 14
IEC 60156:2025 © IEC 2025 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATING LIQUIDS – DETERMINATION OF THE BREAKDOWN
VOLTAGE AT POWER FREQUENCY – TEST METHOD
FOREWORD
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