IEC 61857-22:2008

IEC 61857-22
Edition 2.0 2008-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical insulation systems – Procedures for thermal evaluation –
Part 22: Specific requirements for encapsulated-coil model – Wire-wound
electrical insulation system (EIS)

Systèmes d’isolation électriques – Procédures d’évaluation thermique –
Partie 22: Exigences particulières pour modèle de bobine encapsulée – Système
d’isolation électrique (SIE) à enroulements à fil

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IEC 61857-22
Edition 2.0 2008-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical insulation systems – Procedures for thermal evaluation –
Part 22: Specific requirements for encapsulated-coil model – Wire-wound
electrical insulation system (EIS)

Systèmes d’isolation électriques – Procédures d’évaluation thermique –
Partie 22: Exigences particulières pour modèle de bobine encapsulée – Système
d’isolation électrique (SIE) à enroulements à fil

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
M
CODE PRIX
ICS 29.080.30 ISBN 2-8318-9945-1
– 2 – 61857-22 © IEC:2008
CONTENTS
FOREWORD.3
INTRODUCTION.5
1 Scope.6
2 Normative references .6
3 Terms and definitions .6
4 Construction .7
4.1 General information.7
4.2 ECM components .7
4.3 Assembly of the ECM .7
4.4 Similarity of reference and candidate ECM .8
5 Number of test objects.8
6 Test procedure .8
6.1 General .8
6.2 Initial screening test .8
6.2.1 General .8
6.2.2 Initial dielectric test .8
6.3 Thermal endurance test.9
6.3.1 Endurance test cycle .9
6.3.2 Thermal ageing .9
6.3.3 Mechanical stress.10
6.3.4 Thermal shock.10
6.3.5 Moisture exposure .10
6.3.6 Dielectric diagnostic test.10
7 End-of-life criterion.11
8 Analysing, reporting and classification.11
Annex A (informative) Similarity of reference and candidate specimens .12
Bibliography.13

Table 1 – Initial dielectric tests for ECM.9
Table 2 – Dielectric diagnostic tests for ECM .10

61857-22 © IEC:2008 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSULATION SYSTEMS –
PROCEDURES FOR THERMAL EVALUATION –

Part 22: Specific requirements for encapsulated-coil model –
Wire-wound electrical insulation system (EIS)

FOREWORD
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International Standard IEC 61857-22 has been prepared by IEC technical committee 112:
Evaluation and qualification of electrical insulating materials and systems.
This second edition cancels and replaces the first edition published in 2002, and constitutes
editorial revisions to make this standard compatible with Parts 1 and 21.
The text of this standard is based on the following documents:
CDV Report on voting
112/91/CDV 112/99/RVC
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.

– 4 – 61857-22 © IEC:2008
A list of all the parts in the IEC 61857 series, under the general title Electrical insulation
systems – Procedures for thermal evaluation, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.
61857-22 © IEC:2008 – 5 –
INTRODUCTION
A series of parts that will make up IEC 61857 is currently being developed, each of which will
address a specific test object and/or application with an associated test procedure.
Additional parts will be developed in cooperation with IEC technical committees responsible
for equipment.
– 6 – 61857-22 © IEC:2008
ELECTRICAL INSULATION SYSTEMS –
PROCEDURES FOR THERMAL EVALUATION –

Part 22: Specific requirements for encapsulated-coil model –
Wire-wound electrical insulation system (EIS)

1 Scope
This part of IEC 61857 provides a general-purpose procedure for the evaluation of wire-
wound systems using a general purpose encap
...