FprEN IEC 60156:2024

SLOVENSKI STANDARD
oSIST prEN IEC 60156:2023
01-oktober-2023
Izolacijske tekočine - Ugotavljanje prebojne napetosti pri mrežni frekvenci - Testna
metoda
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
Ta slovenski standard je istoveten z: prEN IEC 60156:2023
ICS:
29.040.01 Izolacijski fluidi na splošno Insulating fluids in general
oSIST prEN IEC 60156:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN IEC 60156:2023
oSIST prEN IEC 60156:2023
10/1201/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60156 ED4
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-08-04 2023-10-27
SUPERSEDES DOCUMENTS:
10/1190/CD, 10/1200/CC
IEC TC 10: FLUIDS FOR ELECTROTECHNICAL APPLICATIONS
SECRETARIAT: SECRETARY:
Italy Mr Massimo Pompili
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

TC 14, SC 17A, TC 20, SC 36A, TC 38
Other TC/SCs are requested to indicate their interest, if any, in this
CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of CENELEC,
is drawn to the fact that this Committee Draft for Vote (CDV) is
submitted for parallel voting.
The CENELEC members are invited to vote through the CENELEC
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This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which they are aware
and to provide supporting documentation.
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included should this proposal proceed. Recipients are reminded that the CDV stage is the final stage for submitting ISC clauses. (SEE
AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Insulating liquids – Determination of the breakdown voltage at power frequency – Test method

PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
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oSIST prEN IEC 60156:2023
– 2 – IEC CDV 60156 © IEC 2023
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 . 8
5.4 Stirring . 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 methods for low volume samples . 15
B.1 Low volume sample test . 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 spherical electrodes with 25 mm radius
and diameter of 36 mm . 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

oSIST prEN IEC 60156:2023
IEC CDV 60156 © IEC 2023 – 3 –

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
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any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
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6) All users should ensure that they have the latest edition of this publication.
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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 60156 has been prepared by IEC technical committee TC 10: Fluids
for electrotechnical applications.
This fourth edition cancels and replaces the third edition published in 2018. 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 instrumentations disseminated around the world.
The text of this International Standard is based on the following documents:
FDIS Report on voting
10/XXXX/FDIS 10/XXXX/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.

oSIST prEN IEC 60156:2023
– 4 – IEC CDV 60156 © IEC 2023
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.
The National Committees are requested to note that for this document the stability date
is 20xx.
THIS TEXT IS INCLUDED FOR THE INFORMATION OF THE NATIONAL COMMITTEES AND WILL BE DELETED
AT THE PUBLICATION STAGE.
oSIST prEN IEC 60156:2023
IEC CDV 60156 © IEC 2023 – 5 –
1 INTRODUCTION
2 As normally applied, breakdown voltage of insulating liquids is not a basic material property but
3 an empirical test procedure intended to indicate the presence of contaminants such as water
4 and solid suspended matter and the advisability of carrying out drying and filtration treatment.
5 The AC breakdown voltage value of insulating liquids strongly depends on the particular set of
6 conditions used in its measurement. Therefore, standardized testing procedures and equipment
7 are essential for the unambiguous interpretation of test results.
8 The method described in this document applies to either acceptance tests on new deliveries of
9 insulating liquids, or testing of treated liquids prior to or during filling into electrical equipment,
10 or to the monitoring and maintenance of insulating liquid -filled apparatus in service. It specifies
11 rigorous sample-handling procedures and temperature control that should be adhered to when
12 certified results are required. For routine tests, especially in the field, less stringent procedures
13 may be practicable and it is the responsibility of the user to determine their effect on the results.
14 Annex A (informative) describes, for comparison, an alternative test method which could be
15 introduced in the future. Annex B (informative) describes special test methods, using cells which
16 may include low volume samples. Annex C (informative) describes a reference material for a
17 performance test and check according to IEC 60060-3 [1] .
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