EN 61857-31:2017

SLOVENSKI STANDARD
01-junij-2017
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Electrical insulation systems-procedures for thermal evaluation - Part 31: Applications
with a designed life less than 5000 hours (IEC 61857-31:2017)
Ta slovenski standard je istoveten z: EN 61857-31:2017
ICS:
29.080.30 Izolacijski sistemi Insulation systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 61857-31

NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2017
ICS 29.080.30
English Version
Electrical insulation systems - Procedures for thermal evaluation
- Part 31: Applications with a designed life of 5 000 h or less
(IEC 61857-31:2017)
Systèmes d'isolement électrique - Modes opératoires pour Elektrische Isoliersysteme - Verfahren zur thermischen
l'évaluation thermique - Partie 31 : Applications à durée de Bewertung - Teil 31: Anwendungen mit einer vorgesehenen
vie nominale inférieure à 5 000 heures Betriebsdauer von weniger als 5 000 h
(IEC 61857-31:2017) (IEC 61857-31:2017)
This European Standard was approved by CENELEC on 2017-02-28. 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
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61857-31:2017 E
European foreword
The text of document 112/356/CDV, future edition 1 of IEC 61857-31, prepared by
IEC/TC 112 "Evaluation and qualification of electrical insulating materials and systems" was submitted
to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61857-31:2017.

The following dates are fixed:
(dop) 2017-11-28
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2020-02-28
standards conflicting with the
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 61857-31:2017 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 61857 (series) NOTE Harmonized as EN 61857 (series).

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When 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.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60505 -  Evaluation and qualification of electrical EN 60505 -
insulation systems
IEC 61857-1 -  Electrical insulation systems - Procedures EN 61857-1 -
for thermal evaluation -- Part 1: General
requirements - Low-voltage
IEC 61857-21 -  Electrical insulation systems - Procedures EN 61857-21 -
for thermal evaluation -- Part 21: Specific
requirements for general-purpose models -
Wire-wound applications
IEC 61857-22 -  Electrical insulation systems - Procedures EN 61857-22 -
for thermal evaluation -- Part 22: Specific
requirements for encapsulated-coil model -
Wire-wound electrical insulation system
(EIS)
IEC/TR 61857-2 -  Electrical insulation systems - Procedures - -
for thermal evaluation - Part 2: Selection of
the appropriate test method for evaluation
and classification of electrical insulation
systems
IEC 61857-31 ®
Edition 1.0 2017-01
INTERNATIONAL
STANDARD
Electrical insulation systems – Procedures for thermal evaluation –

Part 31: Applications with a designed life of 5 000 h or less

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.080.30 ISBN 978-2-8322-3843-1

– 2 – IEC 61857-31:2017  IEC 2017
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 EIS evaluation . 7
5 Test objects . 7
6 Test procedures . 7
6.1 Procedure A: Establishing a TE for applications with a designed life of
1 500 h or less: one-temperature ageing . 7
6.2 Procedure B: Establishing a TE rating for applications with a designed life of
5 000 h or less: one-temperature ageing . 8
6.3 Procedure C: Establishing a TE rating for applications with a designed life of
5 000 h or less: two-temperature ageing . 8
7 Data analysis . 8
7.1 Analysis – Test Procedures A and B (See 6.1 and 6.2) . 8
7.2 Analysis – Test Procedure C (See 6.3) . 9
8 Test report . 9
Bibliography . 10

IEC 61857-31:2017  IEC 2017 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSULATION SYSTEMS – PROCEDURES
FOR THERMAL EVALUATION –
Part 31: Applications with a designed life of 5 000 h or less

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
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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 61857-31 has been prepared by IEC technical committee 112:
Evaluation and qualification of electrical insulating materials and systems.
The text of this International Standard is based on the following documents:
CDV Report on voting
112/356/CDV 112/375/RVC
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.

– 4 – IEC 61857-31:2017  IEC 2017
A list of all parts in the IEC 61857 series, published 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 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.
A bilingual version of this publication may be issued at a later date.

IEC 61857-31:2017  IEC 2017 – 5 –
INTRODUCTION
IEC 61857-1 provides the general structure to be followed for an electrical insulation system
(EIS) evaluation and classification.
IEC TR 61857-2 provides guidelines to identify the application and to select the preferred test
method based on the application.
This part of IEC 61857 provides a test method for EIS applications, such as the automotive
industry, when the designed life is 5 000 h or less.
The selection of this test method can be decided by the end product application.

– 6 – IEC 61857-31:2017  IEC 2017
ELECTRICAL INSULATION SYSTEMS – PROCEDURES
FOR THERMAL EVALUATION –
Part 31: Applications with a designed life of 5 000 h or less

1 Scope
This part of IEC 61857 establishes an EIS evaluation for applications with a designed life of
5 000 h or less. This test method follows the procedures of IEC 60505 and is modified based
on the range of designed life.
2 Normative references
The following documents are referred to in t
...