SIST EN 60371-2:2005

SLOVENSKI SIST EN 60371-2:2005

STANDARD
december 2005
Specifikacija izolacijskih snovi iz sljude – 2. del: Preskusne metode (IEC
60371-2:2004)
Specification for insulating materials based on mica - Part 2: Methods of test (IEC
60371-2:2004)
ICS 29.035.50 Referenčna številka
SIST EN 60371-2:2005(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

---------------------- Page: 1 ----------------------

EUROPEAN STANDARD EN 60371-2
NORME EUROPÉENNE
EUROPÄISCHE NORM November 2004

ICS 17.220.99; 29.035.50 Supersedes EN 60371-2:1997


English version


Specification for insulating materials based on mica
Part 2: Methods of test
(IEC 60371-2:2004)


Spécification pour les matériaux isolants  Bestimmung für Isoliermaterialien
à base de mica aus Glimmer
Partie 2: Méthodes d'essais Teil 2: Prüfverfahren
(CEI 60371-2:2004) (IEC 60371-2:2004)






This European Standard was approved by CENELEC on 2004-09-01. 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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, 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


© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60371-2:2004 E

---------------------- Page: 2 ----------------------

EN 60371-2:2004 - 2 -
Foreword
The text of document 15C/1610/FDIS, future edition 3 of IEC 60371-2, prepared by SC 15C,
Specifications, of IEC TC 15, Insulating materials, was submitted to the IEC-CENELEC parallel vote
and was approved by CENELEC as EN 60371-2 on 2004-09-01.
This European Standard supersedes EN 60371-2:1997.
The main changes with respect to EN 60371-2:1997 are as follows:
a) All clauses re-numbered.
b) Relevant template of ISO 67 has been added to this standard as Annex A.
c) Clause 8: Tensile strength and elongation at break
Procedure modified to give "rate of movement" instead of "time limit". Different rate of movement
for raw mica as opposed to reinforced and/or impregnated mica.
d) Clause 11: Stiffness
Size of test specimen revised. wording modified so that standard covers materials using carriers
other than woven glass cloth and materials that are 3-ply. Revision of terms "machine direction"
and "transverse direction".
e) Clause 13: Elastic compression and plastic compression
Tolerance on measurement of height of stack changed to within 0,01 mm.
Times for change in pressure in procedure changed to 1 min.
f) Clause 16: Electric strength
Modified in line with Amendment 1:1994 to IEC 60371-2:1987 (included in EN 60371-2:1997).
Changes relate to latest edition of EN 60243-1.
g) Clause 19: Detection of defects and conductive particles
Revised subclause.
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) 2005-06-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2007-09-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60371-2:2004 was approved by CENELEC as a European
Standard without any modification.
__________

---------------------- Page: 3 ----------------------

- 3 - EN 60371-2:2004
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
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.
NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60216 Series Electrical insulating materials - Thermal EN 60216 Series
endurance properties

IEC 60243-1 1998 Electrical strength of insulating materials - EN 60243-1 1998
Test methods
Part 1: Tests at power frequencies

IEC 60250 1969 Recommended methods for the - -
determination of the permittivity and
dielectric dissipation factor of electrical
insulating materials at power, audio and
radio frequencies including metre
wavelengths

IEC 60371-3 Series Specifications for insulating materials EN 60371-3 Series
based on mica
Part 3: Specifications for individual
materials

1) 2)
ISO 178 - Plastics - Determination of flexural EN ISO 178 2003
properties





1)
Undated reference.
2)
Valid edition at date of issue.

---------------------- Page: 4 ----------------------

NORME CEI
INTERNATIONALE IEC
60371-2
INTERNATIONAL
Troisième édition
STANDARD
Third edition
2004-06
Spécification pour les matériaux isolants
à base de mica –
Partie 2:
Méthodes d'essais
Specification for insulating materials
based on mica –
Part 2:
Methods of test
© IEC 2004 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
PRICE CODE U
Commission Electrotechnique Internationale
International Electrotechnical Commission
ɆɟɠɞɭɧɚɪɨɞɧɚɹɗɥɟɤɬɪɨɬɟɯɧɢɱɟɫɤɚɹɄɨɦɢɫɫɢɹ
Pour prix, voir catalogue en vigueur
For price, see current catalogue

---------------------- Page: 5 ----------------------

60371-2 © IEC:2004 – 3 –
CONTENTS
FOREWORD.7
INTRODUCTION.11
1 Scope.13
2 Normative references.13
3 Preparation methods of test specimens for curable materials .13
3.1 General.13
3.2 Method 1.13
3.3 Method 2.15
4 Thickness.17
4.1 Test apparatus.17
4.2 Test specimen.17
4.3 Procedure.19
4.4 Statement of results.21
5 Density.21
6 Calculated density.21
7 Composition.21
7.1 Test specimen.21
7.2 Mass per unit area in the "as received" condition .21
7.3 Content of volatiles and mass per unit area of dried material.21
7.4 Binder content.23
’
7.5 Mass per unit area of reinforcement material (m′ ) .25
r
7.6 Mica content.27
7.7 Size of splittings.27
8 Tensile strength and elongation at break .29
8.1 Test apparatus.29
8.2 Test specimen.29
8.3 Procedure.29
8.4 Statement of results.29
9 Flexural strength and elastic modulus in bend .31
9.1 Test specimen.31
9.2 Procedure.31
10 Folding.31
11 Stiffness.31
11.1 Conditioning and test atmosphere .31
11.2 Test specimens.31
11.3 Procedure.31
11.4 Statement of results.33
12 Resistance to exudation and displacement .33
12.1 Test apparatus.33
12.2 Test specimen.33
12.3 Procedure.33
12.4 Statement of results.35

---------------------- Page: 6 ----------------------

60371-2 © IEC:2004 – 5 –
13 Elastic compression and plastic compression .35
13.1 Test apparatus.35
13.2 Test specimen.35
13.3 Procedure.35
13.4 Statement of results.37
14 Resin flow and consolidation .37
14.1 Test specimen.37
14.2 Procedure.37
14.3 Statement of results.39
15 Gel time.39
16 Electric strength.39
16.1 Electrodes.39
16.2 Test specimen.41
16.3 Procedure.41
16.4 Statement of results.41
17 Dissipation factor/temperature characteristics at frequencies of between 48 Hz
and 62 Hz.41
17.1 Test specimen.41
17.2 Test conditions.41
17.3 Electrodes.41
17.4 Procedure.41
17.5 Statement of results.43
18 Dissipation factor/voltage characteristics at frequencies of between 48 Hz and
62 Hz .43
18.1 Test specimen.43
18.2 Test conditions.43
18.3 Electrodes.43
18.4 Procedure.43
18.5 Statement of results.43
19 Detection of defects and conductive particles .43
20 Penetration.43
20.1 Test apparatus.43
20.2 Test specimens.45
20.3 Method of test .45
20.4 Statement of results.45
21 Thermal endurance.45
Annex A (normative) .55
Figure 1 – Assembly of stacks for preparing test laminates.47
Figure 2 – Conditions for press procedure .47
Figure 3 – Apparatus for measurement of stiffness .49
Figure 4 – Apparatus for measurement of stiffness .49
Figure 5 – Elastic compression, plastiac compression.51
Figure 6 – Standard Williams type penetrometer.53

---------------------- Page: 7 ----------------------

60371-2 © IEC:2004 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SPECIFICATION FOR INSULATING MATERIALS
BASED ON MICA –
Part 2: Methods of test
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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 60371-2 has been prepared by subcommittee 15C: Specifications,
of IEC technical committee 15: Insulating materials. prescription
This third edition of IEC 60371-2 cancels and replaces the second edition, published in 1987,
and its amendment 1 (1994), and constitutes a technical revision.
The main changes from the previous edition are as follows:
a) All clauses re-numbered.
b) Relevant template of ISO 67 has been added to this standard as Annex A.
c) Clause 8: Tensile strength and elongation at break
Procedure modified to give “rate of movement” instead of "time limit". Different rate of
movement for raw mica as opposed to reinforced and/or impregnated mica.

---------------------- Page: 8 ----------------------

60371-2 © IEC:2004 – 9 –
d) Clause 11: Stiffness
Size of test specimen revised. Wording modified so that standard covers materials using
carriers other than woven glass cloth and materials that are 3-ply. Revision of terms
"“machine direction” and “transverse direction”. (These were incorrect in second edition
(1987).)
e) Clause 13: Elastic compression and plastic compression
Tolerance on measurement of height of stack changed to within 0,01 mm.
Times for change in pressure in procedure changed to 1 min.
f) Clause 16: Electric strength
Modified in line with Amendment 1 (1994) to the second edition (1987). Changes relate to
latest edition of IEC 60243-1.
g) Clause 19: Detection of defects and conductive particles
Revised subclause.
The text of this standard is based on the following documents:
FDIS Report on voting
15C/1610/FDIS 15C/1643/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 2.
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.

---------------------- Page: 9 ----------------------

60371-2 © IEC:2004 – 11 –
INTRODUCTION
This part of IEC 60371 is one of a series which deals with insulating materials for use in
electrical equipment built up from mica splittings or mica paper, with or without reinforcement,
and with mica paper in its pure state.
IEC 60371 consists of three parts under the main title Specification for insulating materials
based on mica:
Part 1 Definitions and general requirements
Part 2 Methods of test
Part 3 Specifications for individual materials

---------------------- Page: 10 ----------------------

60371-2 © IEC:2004 – 13 –
SPECIFICATION FOR INSULATING MATERIALS
BASED ON MICA –
Part 2: Methods of test
1 Scope
This part of IEC 60371 defines the methods of test which are applicable to built-up mica
materials, products based on them and mica paper.
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 60216 (all parts), Electrical insulating materials − Thermal endurance properties
IEC 60243-1:1998, Electrical strength of insulating materials – Part 1: Tests at power
frequencies
IEC 60250:1969, Recommended methods for the determination of the permittivity and
dielectric dissipation factor of electric insulating materials at power, audio and radio
frequencies including metre wavelengths
IEC.60371-3 (all parts), Specification for insulating materials based on mica – Part 3:
Specifications for individual materials
ISO 178:2001, Plastics – Determination of flexural properties
3 Preparation methods of test specimens for curable materials
3.1 General
Test specimens are prepared in accordance with the following methods which are applicable
only to curable materials.
3.2 Method 1
Clean off all loose particles and projecting fibres from sufficient material to provide the test
pieces required for the particular test.
Cut and stack the pieces required to form the test laminate. For tape material, build up the
laminate to the required thickness using half-lapped layers with successive layers at right
angles, where necessary cutting the sides to obtain the required dimensions.
Adjust the press temperature to 160 °C ± 5 K, unless otherwise specified.

---------------------- Page: 11 ----------------------

60371-2 © IEC:2004 – 15 –
Place the test laminate in the centre of two caul plates not exceeding 1,5 mm in thickness and
at a temperature of 15 °C to 35 °C.
Insert stops of a size to provide the required test laminate thickness.
Insert the assembly of plates and the test piece in the centre of the preheated press.
Close the press immediately and apply sufficient pressure to reach stops. Cure the test piece
for a minimum of 30 min.
Remove the test piece and post-cure for the length of time and at the temperature given in
IEC 60371-3 or according to the recommendation of the supplier.
Unless otherwise specified, condition the test piece for 24 h in a controlled atmosphere of
(50 ± 5) % r.h. and at 23 °C ± 2 K before the test.
3.3 Method 2
Clean off all loose particles and projecting fibres from sufficient material to provide the test
sheets required for the particular test.
For full-width and sheet material, cut and stack the sheets required to form the test laminate.
There are two suggested ways of producing a laminate from tape material:
a) Cut the tape in pieces to the length of the laminate. Stack the pieces parallel and half-
overlapped. The second and following layers shall be moved sideways, so that the
overlapping edges do not lie one upon another. In order to fix the pieces, the use of a hot
iron is recommended.
b) Take a metal sheet of the size of the required laminate and of a thickness of 2 mm to
3 mm. Wind the tape half-overlapped and always in the same direction around this sheet
until the required thickness is reached. It is recommended to start each layer separately
and to move the second and the following layers sideways, so that the overlapping edges
do not lie one upon another. It is necessary to put an interleaving release material
between the metal sheet and the tape. Two laminates with the same thickness are formed.
The prepared stacks, having a composition as shown in Figure 1, shall be put in the press.
The following press procedure, illustrated in Figure 2, provides an example:
– Close the cold press and bring it to a pressure of 0,15 MPa.
– Heat the press to 70 °C under pressure of 0,15 MPa.
– Reduce the pressure down to zero, open the press for a short time (ventilate).
– Heat the press to 90 °C under pressure of 0,15 MPa.
– Reduce the pressure down to zero, open the press for a short time (ventilate).
– Heat the press to 110 °C under pressure of 0,15 MPa.
– Reduce the pressure down to zero, open the press for a short time (ventilate).
– Heat the press to 160 °C ± 5 K under pressure of 0,15 MPa until the resin starts to gel.
This point of time is visually controlled by a test rod. As soon as the resin starts to gel,
bring the pressure up to 3 MPa.

---------------------- Page: 12 ----------------------

60371-2 © IEC:2004 – 17 –
– Cure under 3 MPa and 160 °C for 60 min or at a temperature otherwise specified.
– Specimen to be cooled under pressure.
After this press procedure, post-cure the laminate for the time and temperature specified in
the specification sheets of IEC 60371-3 or according to the recommendation of the supplier.
Other press procedures shall be subject to contract.
4 Thickness
4.1 Test apparatus
Depending on the materials to be tested, the apparatus for measuring thickness is as follows:
4.1.1 A constant pressure measurement device having flat measuring faces of 6 mm to
8 mm diameter, the graduations being in divisions of 0,01 mm and permitting reading to within
0,005 mm. The pressure exerted on the specimen shall be 0,1 MPa ± 10 %. The accuracy of
measurement, when checked by a setting gauge, shall be within 0,005 mm. Measurement
shall be made at ambient temperature and at least 5 s after the application of pressure.
4.1.2 A device as described in 4.1.1, but with a pressure of 0,7 MPa ± 10 % exerted on the
specimen.
4.1.3 A device as described in 4.1.1, but with a pressure of 7,0 MPa ± 10 % exerted on the
specimen.
4.1.4 Test apparatus capable of producing a constant pressure of 30 MPa ± 10 % uniformly
distributed over the faces of the
...