IEC 60370:2017

IEC 60370 ®
Edition 2.0 2017-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Test procedure for thermal endurance of insulating resins and varnishes for
impregnation purposes – Electric breakdown methods

Méthode d’essai pour l’évaluation de l’endurance thermique des résines et
vernis isolants d’imprégnation – Méthodes de claquage électrique
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IEC 60370 ®
Edition 2.0 2017-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Test procedure for thermal endurance of insulating resins and varnishes for

impregnation purposes – Electric breakdown methods

Méthode d’essai pour l’évaluation de l’endurance thermique des résines et

vernis isolants d’imprégnation – Méthodes de claquage électrique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.035.01 ISBN 978-2-8322-5108-9

– 2 – IEC 60370:2017 © IEC 2017

CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Methods of test . 7
4.1 General . 7
4.2 Method 1 – Curved electrode system . 8
4.2.1 Specimen . 8
4.2.2 Impregnation process . 8
4.2.3 Curved electrode system . 9
4.2.4 Ageing ovens and ageing temperatures . 9
4.2.5 Test procedure . 10
4.3 Method 2 – Ball to plate method . 12
4.3.1 Specimen . 12
4.3.2 Impregnation process . 12
4.3.3 Electrode system . 13
4.3.4 Ageing ovens and ageing temperatures . 13
4.3.5 Test procedure . 14
5 Report . 16
Bibliography . 17

Figure 1 – Curved electrode fixture . 9
Figure 2 – Electric strength – Ageing time – Graph . 11
Figure 3 – Thermal endurance graph . 12
Figure 4 – Breakdown voltage – Ageing time – Graph . 15
Figure 5 – Thermal endurance graph . 15

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TEST PROCEDURE FOR THERMAL ENDURANCE OF INSULATING
RESINS AND VARNISHES FOR IMPREGNATION PURPOSES –
ELECTRIC BREAKDOWN METHODS
FOREWORD
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International Standard IEC 60370 has been prepared by IEC technical committee 15: Solid
electrical insulating materials.
This second edition cancels and replaces the first edition published in 1971. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) this document is now describing two methods, the existing one, following ASTM D1932
and new a method following the requirements of IEC 60455-2 and IEC 60464-2;
b) the theoretical background and way of calculation were removed, and replaced by
reference to IEC 60216;
c) the layout and numbering system was updated;
d) for better understanding and illustration purposes examples were added.

– 4 – IEC 60370:2017 © IEC 2017
The text of this International Standard is based on the following documents:
FDIS Report on voting
15/812/FDIS 15/819/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 web
...