SIST EN IEC 61643-331:2018

SLOVENSKI STANDARD
SIST EN IEC 61643-331:2018
01-maj-2018
1DGRPHãþD
SIST EN 61643-331:2003
6HVWDYQLGHOL]DQL]NRQDSHWRVWQHQDSUDYH]D]DãþLWRSUHGSUHQDSHWRVWQLPLXGDUL
GHO=DKWHYH]DODVWQRVWLLQSUHVNXVQHPHWRGH]DNRYLQVNRRNVLGQHYDULVWRUMH
029
Components for low-voltage surge protection - Part 331: Performance requirements and
test methods for metal oxide varistors (MOV)
Ta slovenski standard je istoveten z: EN IEC 61643-331:2018
ICS:
29.120.50 9DURYDONHLQGUXJD Fuses and other overcurrent
PHGWRNRYQD]DãþLWD protection devices
31.040.20 Potenciometri, spremenljivi Potentiometers, variable
upori resistors
SIST EN IEC 61643-331:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 61643-331:2018

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SIST EN IEC 61643-331:2018


EUROPEAN STANDARD EN IEC 61643-331

NORME EUROPÉENNE

EUROPÄISCHE NORM
March 2018
ICS 31.040 Supersedes EN 61643-331:2003
English Version
Components for low-voltage surge protective devices - Part 331:
Performance requirements and test methods for metal oxide
varistors (MOV)
(IEC 61643-331:2017)
Composants pour protection par parafoudres basse tension Bauelemente für Überspannungsschutzgeräte für
- Partie 331: Exigences de performance et méthodes Niederspannung - Teil 331: Leistungsanforderungen und
d’essai pour les varistances à oxyde métallique (MOV) Prüfverfahren für Metalloxidvaristoren (MOV)
(IEC 61643-331:2017) (IEC 61643-331:2017)
This European Standard was approved by CENELEC on 2018-01-11. 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: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 61643-331:2018 E

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SIST EN IEC 61643-331:2018
EN IEC 61643-331:2018 (E)


European foreword
The text of document 37B/160/FDIS future edition 2 of IEC 61643-331, prepared by IEC/SC 37B:
“Specific components for surge arresters and surge protective devices”, of IEC/TC 37: “Surge
arresters”, was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN IEC
61643-331:2018.

The following dates are fixed:
(dop) 2018-10-11
• 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) 2021-01-11
standards conflicting with the
document have to be withdrawn

This document supersedes EN 61643-331:2003.

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.


Endorsement notice
The text of the International Standard IEC 61643-331:2017 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60068-2-6:2007 NOTE Harmonized as EN 60068-2-6:2008 (not modified).
IEC 60068-2-14:2009 NOTE Harmonized as EN 6008-2-14:2009 (not modified).
IEC 60068-2-29:1987 NOTE Harmonized as EN 6008-2-29:1993 (not modified).
IEC 60068-2-52:1996 NOTE Harmonized as EN 6008-2-52:1996 (not modified).
IEC 60060-1:2010 NOTE Harmonized as EN 60060-1:2010 (not modified).
IEC 61643-11:2011 NOTE Harmonized as EN 61643-11:2012 (not modified).
IEC 61051-1:2007 NOTE Harmonized as EN 61051-1:2008 (not modified).

2

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SIST EN IEC 61643-331:2018
EN IEC 61643-331:2018 (E)

Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 1  Where 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 60068-1 2013 Environmental testing -- Part 1: General EN 60068-1 2014
and guidance
IEC 60068-2-20 2008 Environmental testing -- Part 2-20: Tests - EN 60068-2-20 2008
Test T: Test methods for solderability and
resistance to soldering heat of devices with
leads
IEC 60068-2-21 2006 Environmental testing -- Part 2-21: Tests - EN 60068-2-21 2006
Test U: Robustness of terminations and
integral mounting devices
IEC 60068-2-78 2012 Environmental testing -- Part 2-78: Tests - EN 60068-2-78 2013
Test Cab: Damp heat, steady state
IEC 61000-4-2 2008 Electromagnetic compatibility (EMC) -- Part EN 61000-4-2 2009
4-2: Testing and measurement techniques
- Electrostatic discharge immunity test
IEC 61643-11 (mod) 2011 Low-voltage surge protective devices -- EN 61643-11 2012
Part 11: Surge protective devices
connected to low-voltage power systems -
Requirements and test methods
- -  + A11 2018


3

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SIST EN IEC 61643-331:2018




IEC 61643-331

®


Edition 2.0 2017-12




INTERNATIONAL



STANDARD








colour

inside










Components for low-voltage surge protective devices –

Part 331: Performance requirements and test methods for metal oxide varistors

(MOV)

























INTERNATIONAL

ELECTROTECHNICAL


COMMISSION





ICS 31.040.20 ISBN 978-2-8322-5095-2



  Warning! Make sure that you obtained this publication from an authorized distributor.


® Registered trademark of the International Electrotechnical Commission

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SIST EN IEC 61643-331:2018
– 2 – IEC 61643-331:2017 © IEC 2017
CONTENTS
CONTENTS . 2
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, symbols and abbreviated terms . 7
3.1 Ratings . 8
3.2 Characteristics . 9
3.3 Symbols . 10
3.4 Abbreviated terms . 11
4 Service conditions . 11
4.1 Operating and storage temperature ranges . 11
4.2 Altitude or atmospheric pressure range . 11
4.3 Relative Humidity . 11
5 Mechanical requirements and materials . 12
5.1 Robustness of terminations . 12
5.2 Solderability . 12
5.3 Marking . 12
6 General . 12
6.1 Failure rates . 12
6.2 Test standard atmospheric conditions . 12
7 Electrical requirements . 12
7.1 Nominal varistor voltage . 12
7.2 Maximum AC (DC) continuous operating voltage. 13
7.3 Standby current I . 13
DC
7.4 Capacitance . 13
7.5 Clamping voltage . 13
7.6 Electrostatic discharge (ESD) (for SMD type MOV only). 15
7.7 Rated impulse energy (W ) . 15
TM
7.8 Nominal discharge current I . 15
n
7.9 Endurance . 15
7.10 Limited current temporary overvoltage . 15
8 Standard design test criteria . 15
8.1 General . 15
8.2 Ratings . 15
8.2.1 Single-impulse maximum current (I ) . 15
TM
8.2.2 Next Impulse . 16
8.2.3 Continuous rated voltage (V ) . 16
M
8.3 Electrical characteristics . 16
8.3.1 Clamping voltage (V ) . 16
C
8.3.2 Standby current (I ) . 17
D
8.3.3 Nominal varistor voltage (V ) . 17
N
8.3.4 Capacitance (C ) . 17
V
8.4 Endurance . 18
8.5 ESD Test Method . 18
9 Nominal discharge current and limited current temporary overvoltage. 18

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SIST EN IEC 61643-331:2018
IEC 61643-331:2017 © IEC 2017 – 3 –
9.1 Thermally protected varistors – Sequence of tests . 18
9.2 Temperature and humidity cycle conditioning . 18
9.3 Nominal discharge current I(n) test description . 19
9.3.1 General . 19
9.3.2 Pass/fail criteria . 21
9.4 Limited current temporary overvoltage test description and procedure for
thermally protected varistors . 21
9.4.1 General . 21
9.4.2 Sample preparation . 21
9.4.3 Test conditions . 21
9.4.4 Pass/fail criteria . 22
9.5 Dielectric testing . 24
9.5.1 Test conditions . 24
9.5.2 Setup from foil to leads . 24
9.5.3 Pass criteria . 24
Annex A (informative) MOV testing according to IEC 61643-11:2011 – Surge
protective devices for the Class I, II and III . 25
A.1 General . 25
A.2 MOV selection . 25
A.3 Cross reference list of abbreviations, descriptions and definitions . 25
A.4 Operating duty test . 26
A.4.1 General . 26
A.4.2 Measured limiting voltage . 28
A.4.3 Class I and II operating duty tests (8.3.4.3) . 31
A.4.4 Additional duty test for test class I . 31
A.4.5 Class III operating duty tests . 32
A.4.6 Pass criteria for all operating duty tests and for the additional duty test
for test class I . 33
A.4.7 Preferred parameters of impulse discharge current I used for Class I

imp
additional duty tests . 33
A.4.8 Preferred values of impulse discharge current I used for Class I and
n
Class II residual voltage and operating duty tests . 33
A.4.9 Preferred values of combination waveshape used for Class III tests . 34
Annex B (informative) IEC 61051 Varistors for use in electronic equipment . 36
Annex C (informative) Accelerated endurance screening test . 37
C.1 Accelerated endurance screening test . 37
C.2 Preparation of sample . 37
C.3 Test conditions . 37
C.4 Pass criteria . 38
Annex D (informative) Proposed test method for determination of mean time to failure
(MTTF) . 39
D.1 Sampling plans . 39
D.2 Total test hours . 39
D.3 Samples. 39
D.4 Intermediate measurements . 40
D.5 Failure criteria . 40
D.6 Acceptance criteria . 40
Bibliography . 41

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Figure 1 – V-I characteristic of a MOV . 10
Figure 2 – Symbol for MOV . 10
Figure 3 – Symbol for thermally protected MOV . 11
Figure 4 – Test circuit for impulse peak current clamping voltage (V ) at peak impulse
C
current (I ) . 16
P
Figure 5 – Test circuit for measuring leakage current . 17
Figure 6 – Test circuit for measuring nominal varistor voltage (V ) . 17
V
Figure 7 – Nominal Discharge Current Flowchart . 20
Figure 8 – Sequence of the I Test . 21

n
Figure 9 – Temporary Overvoltage Limited Current test procedure Flowchart. 23
Figure A.1 – Flow chart of the operating duty test . 27
Figure A.2 – Test set-up for operating duty test . 28
Figure A.3 – Flow chart of testing to determine the measured limiting voltage . 30
Figure A.4 – Operating duty test timing diagram for test classes I and II . 31
Figure A.5 – Additional duty test timing diagram for test class I . 32
Figure A.6 – Operating duty test timing diagram for test class III . 32
Figure C.1 – Circuit of accelerated ageing test . 37
Figure D.1 – Test Circuit of MTTF . 40

Table 1 – Voltage ratings for disc types . 13
Table 2 – Typical Voltage Ratings for SMD types . 14
Table A.1 – Comparison of IEC 61643-11 and IEC 61643-311 . 26
Table A.2 – Preferred parameters for class I test . 33
Table A.3 – Preferred values for class I and class II tests . 34
Table A.4 – Preferred values for class III tests . 35
Table D.1 – Sampling plans . 39

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SIST EN IEC 61643-331:2018
IEC 61643-331:2017 © IEC 2017 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

COMPONENTS FOR LOW-VOLTAGE SURGE PROTECTIVE DEVICES –

Part 331: Performance requirements and test methods
for metal oxide varistors (MOV)

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 61643-331 has been prepared by subcommittee 37B: Specific
components for surge arresters and surge protective devices, of IEC technical committee 37:
Surge arresters.
This second edition cancels and replaces the first edition published in 2003. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Update of the nominal varistor voltage test method;
b) Addition of thermally protected varistors – component symbol and test methods;
c) Addition of nominal discharge current – test methods;
d) Addition of voltage ratings for disc types (Table 1);

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SIST EN IEC 61643-331:2018
– 6 – IEC 61643-331:2017 © IEC 2017
e) Addition of test currents for clamping voltage of disc types (Table 2);
f) Addition of typical voltage ratings of SMD types (Table 3); and
g) Addition of Limited current and temporary overvoltage tests for thermally protected
varistors.
The text of this International Standard is based on the following documents:
FDIS Report on voting
37B/160/FDIS 37B/164/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.
A list of all parts of IEC 61643 series, under the general title Components for low-voltage
surge protective devices, 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.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.

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SIST EN IEC 61643-331:2018
IEC 61643-331:2017 © IEC 2017 – 7 –
COMPONENTS FOR LOW-VOLTAGE SURGE PROTECTIVE DEVICES –

Part 331: Performance requirements and test methods
for metal oxide varistors (MOV)



1 Scope
This part of IEC 61643 is a test specification for metal oxide varistors (MOV), which are used
for applications up to 1 000 V AC or 1 500 V DC in power line, or telecommunication, or
signalling circuits. They are designed to protect apparatus or personnel, or both, from high
transient voltages.
This specification applies to MOVs having two electrodes and hybrid overvoltage protection
components. This specification also does not apply to mountings and their effect on the
MOV’s characteristics. Characteristics given apply solely to the MOV mounted only in the
ways described for the tests.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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 60068-1:2013, Environmental testing – Part 1: General and guidance
IEC 60068-2-20:2008, Environmental testing – Part 2-20: Tests – Test T: Test methods for
solderability and resistance to soldering heat of devices with leads
IEC 60068-2-21:2006, Environmental testing – Part 2-21: Tests – Test U: Robustness of
terminations and integral mounting devices
IEC 60068-2-78:2012, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat,
steady state
IEC 61643-11:2011, Low-voltage surge protective devices – Part 11: Surge protective devices
connected to low-voltage power systems – Requirements and test methods
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
3 Terms, definitions, symbols and abbreviated terms
For the purposes of this document, the following terms, definitions, symbols and abbreviated
terms apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.ele
...