EN 61857-22:2002

SLOVENSKI SIST EN 61857-22:2003

STANDARD
april 2003
Electrical insulation systems - Procedures for thermal evaluation - Part 22: Specific
requirements for encapsulated-coil model - Wire-wound electrical insulation system
(EIS)
ICS 29.080.30 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD EN 61857-22
NORME EUROPÉENNE
EUROPÄISCHE NORM October 2002

ICS 29.080.30
English version
Electrical insulation systems -
Procedures for thermal evaluation
Part 22: Specific requirements for encapsulated-coil model -
Wire-wound electrical insulation system (EIS)
(IEC 61857-22:2002)
Systèmes d'isolation électrique - Elektrische Isoliersysteme -
Procédures d'évaluation thermique Verfahren zur thermischen Bewertung
Partie 22: Exigences particulières Teil 22: Spezielle Bedingungen
pour modèle de bobine encapsulée - für ein umhülltes Spulenmodell -
Système d'isolation électrique Elektrisches Isoliersystem
(SIE) à enroulements à fil aus Drahtwicklungen (EIS)
(CEI 61857-22:2002) (IEC 61857-22:2002)

This European Standard was approved by CENELEC on 2002-10-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,
Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 61857-22:2002 E
Foreword
The text of document 98/164/FDIS, future edition 1 of IEC 61857-22, prepared by IEC TC 98, Electrical
insulation systems (EIS), was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 61857-22 on 2002-10-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2003-07-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2005-10-01
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annex ZA is normative and annexe A is informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61857-22:2002 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 61857-22:2002
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
1) 2)
IEC 61857-1 - Electrical insulation systems - EN 61857-1 1999
Procedures for thermal evaluation
Part 1: General requirements -
Low-voltage
1)
Undated reference.
2)
Valid edition at date of issue.

NORME CEI
INTERNATIONALE IEC
61857-22
INTERNATIONAL
Première édition
STANDARD
First edition
2002-08
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
Electrical insulation systems –
Procedures for thermal evaluation –
Part 22:
Specific requirements for encapsulated-coil
model – Wire-wound electrical insulation
system (EIS)
© IEC 2002 Droits de reproduction réservés ⎯ Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch  Web: www.iec.ch
CODE PRIX
K
Commission Electrotechnique Internationale PRICE CODE
International Electrotechnical Commission
ɆɟɠɞɭɧɚɪɨɞɧɚɹɗɥɟɤɬɪɨɬɟɯɧɢɱɟɫɤɚɹɄɨɦɢɫɫɢɹ
Pour prix, voir catalogue en vigueur
For price, see current catalogue

61857-22 © IEC:2002 – 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
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61857-22 has been prepared by IEC technical committee 98:
Electrical insulation systems (EIS).
The text of this standard is based on the following documents:
FDIS Report on voting
98/164/FDIS 98/170/RVD
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 3.
Annex A is for information only.
The committee has decided that the contents of this publication will remain unchanged until
2006. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
61857-22 © IEC:2002 – 5 –
INTRODUCTION
A series of parts of IEC 61857 is being developed, each of which will address a specific test
object and/or application with an associated test procedure.
This part of IEC 61857 provides a general purpose procedure for the evaluation of wire-wound
systems using a general purpose encapsulated model (ECM) where the application is
unknown.
As a function of the horizontal committee concept, additional parts will be developed in
cooperation with IEC technical committees responsible for equipment.

61857-22 © IEC:2002 – 7 –
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 specifies an encapsulated-coil model (ECM) that can be used for the
evaluation of encapsulated wire-wound EIS.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 61857-1, Electrical insulation systems – Procedures for thermal evaluation – Part 1:
General requirements – Low-voltage
3 Terms and definitions
For the purposes of this part of IEC 61857, the terms and definitions given in IEC 61857-1 as
well as the following definitions apply:
3.1
encapsulant
electrical insulating material (EIM) that completely encases the coil except for connections to
the exterior, and is part of the electrical insulation system (EIS)
NOTE The encapsulated-coil model (ECM) does not employ a supplemental shell.
3.2
encapsulation
process of applying an encapsulant
NOTE For the purpose of evaluating an electrical insulation system (EIS), the process may consist of injection
moulding, compression moulding, casting or other techniques.
3.3
bobbin
form around which a coil is wound
3.4
coil
continuous winding of insulated wire
3.5
interwinding insulation
electrical insulating material (EIM) between individual coils

61857-22 © IEC:2002 – 9 –
3.6
earth insulation
electrical insulating material (EIM) between a coil and earthed metal
4 Construction
4.1 General information
The ECM is useful in evaluating the compatibility of EIMs used in a candidate EIS. It is equally
capable of simulating the influences of actual manufacturing processes such as winding
techniques, termination techniques and encapsulation.
The essential parts of the ECM are a bobbin, winding wire, wire connectors and encapsulant.
The winding wires may be connected to binding posts or to lead wires, either of which extends
through the encapsulant wall.
4.2 ECM components
a) Coil: the coils may be wound with two wires in parallel (bifilar winding) or may be wound
with a single wire.
b) Wire: winding wire, heavy film coated; 0,4 mm to 0,6 mm diameter wire size is preferred.
c) Earth insulation: the EIM used as the bobbin and the EIM used as the encapsulant function
as coil-to-earth insulation. An EIM evaluated only as a coil bobbin shall not also be used as
an encapsulant material. An EIM used as an encapsulant shall be evaluated as such.
d) Tape: electrical tape may be used but unless electrically stressed and evaluated is not part
of the EIS.
e) Connectors: the winding wires are connected inside the encapsulant to binding posts or
lead wires. These connections are essential parts of the ECM.
f) Electrical impregnating resin/varnish: this may be part of the EIS if applied prior to the
encapsulation process.
NOTE A metal frame or a lamination stack that may be incorporated into the test object is not an essential part of
the test object if it does not function as a fault path.
4.3 Assembly of the ECM
a) Wind the winding wire over the bobbin using accepted winding techniques.
b) As appropriate, use electrical grade tape or other components to secure the winding wire in
place.
c) Connect the winding wire to the binding posts or lead wires.
d) If part of the candidate EIS, apply impregnating resin/varnish.
e) Apply the encapsulant material.

61857-22 © IEC:2002 – 11 –
4.4 Similarity of reference and candidate ECM
The physical shape and assembly of the reference and candidate ECM must be similar. It is
essential that the size of the winding wire used in the reference and candidate ECM be within
±0,2 mm of each other. Refer to annex A for more information. Details of the construction of
the reference and candidate ECM shall be reported according to 7.4 of IEC 61857-1.
5 Number of test objects
The minimum number of test objects for each EIS for each ageing temperature shall be ten.
6 Test procedures
6.1 General
All test objects shall be subjected to initial screening tests followed by repeated thermal
endurance test cycles in the following order:
a) a thermal ageing subcycle;
b) a subcycle of pre-diagnostic mechanical stress, other pre-diagnostic requirements, and
moisture exposure, in that order;
c) a dielectric diagnostic test.
6.2 Initial screening test
6.2.1 General
Prior to exposure to an elevated temperature on the first thermal ageing subcycle, all test
objects shall be subjected to initial screening tests in order to eliminate defective test objects.
The initial scr
...