EN 61251:2016
(Main)Electrical insulating materials and systems - A.C. voltage endurance evaluation
Electrical insulating materials and systems - A.C. voltage endurance evaluation
IEC 61251:2015 describes many of the factors involved in voltage endurance tests on electrical insulating materials and systems. It describes the voltage endurance graph, lists test methods illustrating their limitations and gives guidance for evaluating the sinusoidal a.c. voltage endurance of insulating materials and systems from the results of the tests. This International Standard is applicable over the voltage frequency range 20 Hz to 1 000 Hz. The general principles can also be applicable to other voltage shapes, including impulse voltages. The terminology to be used in voltage endurance is defined and explained. This first edition of IEC 61251 cancels and replaces the second edition of IEC TS 61251, published in 2008. This edition constitutes a technical revision and includes the following significant technical changes with respect to the second edition of IEC TS 61251: a) upgrade from Technical Specification to an International Standard; b) clarification of issues raised since publication of IEC TS 61251.
Elektrische Isolierstoffe und -systeme - Ermittlung der Wechselspannungsbeständigkeit
Systèmes et matériaux isolants électriques - Évaluation de l'endurance a la tension alternative
L'IEC 61251:2015 décrit plusieurs des facteurs intervenant dans les essais d'endurance à la tension de systèmes et de matériaux isolants électriques. Elle décrit le graphe d'endurance à la tension, donne une liste des méthodes d'essai en indiquant leurs limites et donne des lignes directrices pour évaluer l'endurance à la tension alternative de systèmes et de matériaux isolants à partir des résultats des essais. La présente Norme internationale est applicable sur la plage de fréquences de la tension allant de 20 Hz à 1 000 Hz. Les principes généraux peuvent également être applicables à d'autres formes de tension, y compris les tensions de chocs. La terminologie à utiliser dans le cadre de l'endurance à la tension est définie et expliquée. Cette première édition de l'IEC 61251 annule et remplace la deuxième édition de l'IEC TS 61251 parue en 2008. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à la deuxième édition de l'IEC TS 61251: a) transformation d'une Spécification technique en Norme internationale; b) clarification des questions soulevées depuis la publication de l'IEC TS 61251.
Elektroizolacijski materiali - Ocenjevanje vzdržljivosti pri izmenični napetosti (IEC 61251:2015)
V tem mednarodnem standardu so opisani številni dejavniki, ki so vključeni v preskuse napetostne vzdržljivosti na elektroizolacijskih materialih in sistemih. Opisuje graf napetostne vzdržljivosti, navaja preskusne metode in prikazuje njihove omejitve ter na podlagi rezultatov preskusov podaja navodila za ocenjevanje sinusne vzdržljivosti pri izmenični napetosti za izolacijske materiale in sisteme. Ta mednarodni standard se uporablja za frekvenčno območje napetosti 20–1000 Hz. Splošna načela se lahko uporabljajo tudi za druge oblike napetosti, vključno z impulznimi napetostmi. Opredeljeni in razloženi so izrazi, ki se uporabljajo za napetostno vzdržljivost.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2016
(OHNWURL]RODFLMVNLPDWHULDOL2FHQMHYDQMHY]GUåOMLYRVWLSULL]PHQLþQLQDSHWRVWL ,(&
Electrical insulating materials - A.C. voltage endurance evaluation (IEC 61251:2015)
Matériaux isolants électriques - Evaluation de l'endurance à la tension alternative
Ta slovenski standard je istoveten z: EN 61251:2016
ICS:
17.220.99 Drugi standardi v zvezi z Other standards related to
elektriko in magnetizmom electricity and magnetism
29.035.01 Izolacijski materiali na Insulating materials in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN 61251
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2016
ICS 17.220.99; 29.035.01
English Version
Electrical insulating materials and systems - A.C. voltage
endurance evaluation
(IEC 61251:2015)
Systèmes et matériaux isolants électriques - Évaluation de Elektrische Isolierstoffe und -systeme - Ermittlung der
l'endurance a la tension alternative Wechselspannungsbeständigkei
(IEC 61251:2015) (IEC 61251:2015)
This European Standard was approved by CENELEC on 2015-12-23. 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, 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
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61251:2016 E
European foreword
The text of document 112/338/FDIS, future edition 1 of IEC 61251, 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 61251:2016.
The following dates are fixed:
(dop) 2016-09-23
• 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) 2018-12-23
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 61251:2015 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 60243-1 NOTE Harmonized as EN 60243-1.
IEC 60243-2 NOTE Harmonized as EN 60243-2.
IEC 60243-3 NOTE Harmonized as EN 60243-3.
IEC 60343 NOTE Harmonized as EN 60343.
IEC 61649 NOTE Harmonized as EN 61649.
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 62539 - Guide for the statistical analysis of - -
electrical insulation breakdown data
IEC 61251 ®
Edition 1.0 2015-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical insulating materials and systems – AC voltage endurance evaluation
Systèmes et matériaux isolants électriques – Évaluation de l'endurance à la
tension alternative
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.99; 29.035.01 ISBN 978-2-8322-2990-3
– 2 – IEC 61251:2015 © IEC 2015
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and symbols. 6
3.1 Terms and definitions . 6
3.2 Symbols . 7
4 Voltage endurance . 7
4.1 Voltage endurance testing . 7
4.2 Electrical stress . 7
4.3 Voltage endurance (VE) graph . 8
4.4 Short-time electric strength . 8
4.5 Voltage endurance coefficient (VEC) . 9
4.6 Differential VEC (n ) . 9
d
4.7 Electrical threshold stress (E ) . 9
t
4.8 Voltage endurance relationship . 10
5 Test methods . 11
5.1 Introductory remarks . 11
5.2 Tests at constant stress . 11
5.2.1 Conventional VE test . 11
5.2.2 Diagnostic measurements . 12
5.2.3 Detection of an electrical threshold . 12
5.3 Tests at higher frequency. 12
5.4 Progressive stress tests . 13
5.5 Preliminary tests to determine the initial part of the VE line . 15
5.6 Recommended test procedure . 15
6 Evaluation of voltage endurance . 15
6.1 Significance of the VEC . 15
6.2 Significance of the electrical threshold stress . 16
6.3 Dispersion of data and precision requirements . 16
6.4 Presentation of the results . 16
Annex A (informative) The Weibull distribution . 18
A.1 Weibull distribution times to dielectric breakdown . 18
A.2 Weibull distribution dielectric breakdown stresses . 18
A.3 Generalized Weibull distribution of the dielectric breakdown stresses . 18
A.4 Inverse power model for the time to dielectric breakdown . 19
Bibliography . 20
Figure 1 – General voltage endurance line . 8
Figure 2 – Determination of the differential VEC n at a generic point P of the VE line . 9
d
Figure 3 – Plotting the VE line in a progressive stress test using different rates of
stress rise . 14
IEC 61251:2015 © IEC 2015 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSULATING MATERIALS AND SYSTEMS –
AC VOLTAGE ENDURANCE EVALUATION
FOREWORD
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61251 has been prepared by IEC technical committee 112:
Evaluation and qualification of electrical insulating materials and systems.
This first edition of IEC 61251 cancels and replaces the second edition of IEC TS 61251,
published in 2008. This edition
...
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