IEC 60079-18:2014
(Main)Explosive atmospheres - Part 18: Equipment protection by encapsulation "m"
Explosive atmospheres - Part 18: Equipment protection by encapsulation "m"
IEC 60079-18:2014 is available as IEC 60079-18:2014 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60079-18:2014 gives the specific requirements for the construction, testing and marking of electrical equipment, parts of electrical equipment and Ex components with the type of protection encapsulation "m" intended for use in explosive gas atmospheres or explosive dust atmospheres. This part applies only for encapsulated electrical equipment, encapsulated parts of electrical equipment and encapsulat ed Ex components (hereinafter always referred to as "m" equipment) where the rated voltage does not exceed 11 kV. The application of electrical equipment in atmospheres, which may contain explosive gas as well as combustible dust simultaneously, may require additional protective measures. This standard does not apply to dusts of explosives, which do not require atmospheric oxygen for combustion, or to pyrophoric substances. This standard does not take account of any risk due to an emission of flammable or toxic gas from the dust. This standard supplements and modifies the general requirements of IEC 60079-0. Where a requirement of this standard conflicts with a requirement of IEC 60079-0, the requirement of this standard takes precedence. This fourth edition cancels and replaces the third edition of IEC 60079-18:2009, and constitutes a technical revision. Please refer to the foreword of the document for a listing of the technical changes with respect to the previous edition. Keywords: encapsulation "m", explosive gas atmospheres, explosive dust atmospheres
This publication is to be read in conjunction with IEC 60079-0:2011.
The contents of the corrigendum of July 2018 have been included in this copy.
Atmosphères explosives - Partie 18: Protection du matériel par encapsulage "m"
IEC 60079-18:2014 est disponible sous forme de IEC 60079-18:2014 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.
IEC 60079-18:2014 définit les exigences spécifiques à la construction, aux essais et au marquage des matériels électriques, des parties de matériels électriques et des composants Ex protégés par encapsulage de type "m" et destinés à une utilisation dans les atmosphères explosives gazeuses ou les atmosphères explosives poussiéreuses. La présente partie ne s'applique qu'aux matériels électriques protégés par encapsulage, aux parties de matériel électrique protégées par encapsulage et aux composants Ex protégés par encapsulage (ci-après toujours dénommés matériel "m") pour lesquels la tension assignée n'excède pas 11 kV. L'utilisation du matériel électrique en atmosphère pouvant contenir simultanément du gaz explosif et des poussières combustibles peut nécessiter des mesures de protection supplémentaires. La présente Norme ne s'applique pas aux poussières d'explosifs qui n'exigent pas d'oxygène de l'air pour leur combustion ni aux substances pyrophoriques. La présente Norme ne tient pas compte des risques, quels qu'ils soient, résultant d'une émission de gaz inflammable ou toxique provenant de la poussière. La présente Norme complète et modifie les exigences générales de l'IEC 60079-0. Si une exigence de la présente Norme est en conflit avec une exigence de l'IEC 60079-0, l'exigence de la présente Norme a préséance. Cette quatrième édition annule et remplace la troisième édition de l'IEC 60079-18:2009. Cette édition constitue une révision technique. Se référer à l'avant-propos du document pour obtenir une liste des modifications techniques par rapport à l'édition précédente. Mots clés: encapsulage de type "m", atmosphères explosives gazeuses, atmosphères explosives poussiéreuses
Cette publication doit être lue conjointement avec la CEI 60079-0:2011.
Le contenu du corrigendum de juillet 2018 a été pris en considération dans cet exemplaire.
General Information
Relations
Buy Standard
Standards Content (Sample)
IEC 60079-18 ®
Edition 4.0 2014-12
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Explosive atmospheres –
Part 18: Equipment protection by encapsulation “m”
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.
IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and
CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC 60079-18 ®
Edition 4.0 2014-12
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Explosive atmospheres –
Part 18: Equipment protection by encapsulation “m”
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.260.20 ISBN 978-2-8322-2078-8
– 2 – IEC 60079-18:2014 RLV IEC 2014
CONTENTS
FOREWORD . 5
1 Scope . 8
2 Normative references. 8
3 Terms and definitions . 9
4 General . 11
4.1 Level of protection (equipment protection level (EPL)) . 11
4.2 Additional requirements for levels of protection “ma” and “mb” . 11
4.3 Additional requirements for level of protection “ma” . 11
4.4 Rated voltage and prospective short circuit current . 11
5 Requirements for compounds . 11
5.1 General . 11
5.2 Specification . 12
5.3 Properties of the compound . 12
5.3.1 Water absorption . 12
5.3.2 Dielectric strength . 12
6 Temperatures . 12
6.1 General . 12
6.2 Determination of the limiting temperatures . 13
6.2.1 Maximum surface temperature . 13
6.2.2 Temperature of the compound . 13
6.3 Temperature limitation . 13
7 Constructional requirements . 13
7.1 General . 13
7.2 Determination of faults . 14
7.2.1 Fault examination . 14
7.2.2 Components considered as not subject to fail . 14
7.2.3 Isolating components . 15
7.2.4 Infallible separation distances . 15
7.3 Free space in the encapsulation . 17
7.3.1 Group III “m” equipment . 17
7.3.2 Group I and Group II “m” equipment . 17
7.4 Thickness of the compound . 18
7.4.1 “m” equipment . 18
7.4.2 Windings for electrical machines . 20
7.4.3 Rigid, multi-layer printed wiring boards with through connections . 20
7.5 Switching contacts . 22
7.5.1 General . 22
7.5.2 Level of protection “ma” . 22
7.5.3 Level of protection “mb” . 23
7.5.4 Level of protection “mc” . 23
7.6 External connections . 23
7.6.1 General . 23
7.6.2 Additional requirements for “ma” equipment . 23
7.7 Protection of bare live pa rt s . 23
7.8 Cells and batteries . 24
7.8.1 General . 24
7.8.2 Prevention of gassing . 24
7.8.3 Protection against inadmissible temperatures and damage to the cells
or batteries . 24
7.8.4. Reverse current . 25
7.8.5 Current limitation . 25
7.8.6 Protection against the polarity inversion and deep discharge of the cells . 25
7.8.7 Charging of cells or batteries . 26
7.8.8 Requirements for control safety devices for cells or batteries . 26
7.9 Protective devices . 26
7.9.1 General . 26
7.9.2 Electrical protective devices . 27
7.9.3 Thermal protec tiv e devices . 28
7.9.4 Built-in protective devices . 28
8 Type tests . 29
8.1 Tests on the compound . 29
8.1.1 Water absorption test . 29
8.1.2 Dielectric strength test . 29
8.2 Tests on the apparatus . 29
8.2.1 Test sequence . 29
8.2.2 Maximum t e mperat ure . 29
8.2.3 Thermal endurance test. 30
8.2.4 Dielectric strength test . 30
8.2.5 Cable pull test . 31
8.2.6 Pressure test for Group I and Group II electrical equipment . 32
8.2.7 Test for resettable thermal protective device . 32
8.2.8 Sealing test for built-in protective devices . 33
9 Routine verifications and tests . 33
9.1 Visual inspections . 33
9.2 Dielectric strength test . 33
10 Marking . 34
Annex A (informative) Basic requirements for compounds for “m” equipment . 35
Annex B (normative informative) Allocation of test samples . 36
Bibliography . . 37
Figure 1 – Dimensional key for thickness through the compound . 19
Figure 2 – Minimum distances for multi-layer printed wiring boards . 22
Figure 3 – Fitting of blocking diodes . 25
Figure A.1 Basic requirements for compounds for “m” equipment . 35
Table 1 – Distances through the compound . 16
Table 2 – Minimum thickness of compound adjacent to free space for Group III “m”
equipment . . 17
Table 3 – Minimum thickness of compound adjacent to free space for Group I and
Group II “m” equipment . 18
Table 4 – Thickness of the compound . 20
– 4 – IEC 60079-18:2014 RLV IEC 2014
Table 5 – Minimum distances for multi-layer printed wiring boards . 21
Table 6 – Test pressure . 32
Table B.1 Allocation of test samples . 36
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 18: Equipment protection by encapsulation “m”
FOREWORD
1) The International Electrotechnical Commission (IEC) is a w
...
IEC 60079-18 ®
Edition 4.0 2014-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 18: Equipment protection by encapsulation “m”
Atmosphères explosives –
Partie 18: Protection du matériel par encapsulage "m"
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 14
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.
IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 55 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,
77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.
A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.
Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient plus de 30 000 termes et définitions en
Spécifications techniques, Rapports techniques et autres
anglais et en français, ainsi que les termes équivalents dans
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
14 langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.
Recherche de publications IEC - www.iec.ch/searchpub
Glossaire IEC - std.iec.ch/glossary
Plus de 55 000 entrées terminologiques électrotechniques, en
La recherche avancée permet de trouver des publications IEC
en utilisant différents critères (numéro de référence, texte, anglais et en français, extraites des articles Termes et
comité d’études,…). Elle donne aussi des informations sur les Définitions des publications IEC parues depuis 2002. Plus
projets et les publications remplacées ou retirées. certaines entrées antérieures extraites des publications des
CE 37, 77, 86 et CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished
Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just
Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur cette
Disponible en ligne et aussi une fois par mois par email. publication ou si vous avez des questions contactez-nous:
csc@iec.ch.
IEC 60079-18 ®
Edition 4.0 2014-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 18: Equipment protection by encapsulation “m”
Atmosphères explosives –
Partie 18: Protection du matériel par encapsulage "m"
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX W
ICS 29.260.20 ISBN 978-2-8322-1994-2
– 2 – IEC 60079-18:2014 IEC 2014
CONTENTS
FOREWORD . 5
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General . 10
4.1 Level of protection (equipment protection level (EPL)) . 10
4.2 Additional requirements for levels of protection “ma” and “mb” . 10
4.3 Additional requirements for level of protection “ma” . 10
4.4 Rated voltage and prospective short circuit current . 11
5 Requirements for compounds . 11
5.1 General . 11
5.2 Specification . 11
5.3 Properties of the compound . 11
5.3.1 Water absorption . 11
5.3.2 Dielectric strength . 11
6 Temperatures . 12
6.1 General . 12
6.2 Determination of the limiting temperatures . 12
6.2.1 Maximum surface temperature . 12
6.2.2 Temperature of the compound . 12
6.3 Temperature limitation . 12
7 Constructional requirements . 12
7.1 General . 12
7.2 Determination of faults . 13
7.2.1 Fault examination . 13
7.2.2 Components considered as not subject to fail . 13
7.2.3 Isolating components . 14
7.2.4 Infallible separation distances . 14
7.3 Free space in the encapsulation . 15
7.3.1 Group III “m” equipment . 15
7.3.2 Group I and Group II “m” equipment . 16
7.4 Thickness of the compound. 17
7.4.1 “m” equipment . 17
7.4.2 Windings for electrical machines . 19
7.4.3 Rigid, multi-layer printed wiring boards with through connections . 19
7.5 Switching contacts . 20
7.5.1 General . 20
7.5.2 Level of protection “ma” . 21
7.5.3 Level of protection “mb” . 21
7.5.4 Level of protection “mc” . 21
7.6 External connections . 21
7.6.1 General . 21
7.6.2 Additional requirements for “ma” equipment . 21
7.7 Protection of bare live parts . 21
7.8 Cells and batteries . 21
7.8.1 General . 21
7.8.2 Prevention of gassing . 22
7.8.3 Protection against inadmissible temperatures and damage to the cells
or batteries . 22
7.8.4 Reverse current . 22
7.8.5 Current limitation . 23
7.8.6 Protection against the polarity inversion and deep discharge of the cells . 23
7.8.7 Charging of cells or batteries . 23
7.8.8 Requirements for control safety devices for cells or batteries. 24
7.9 Protective devices . 24
7.9.1 General . 24
7.9.2 Electrical protective devices . 25
7.9.3 Thermal protective devices . 25
7.9.4 Built-in protective devices . 26
8 Type tests . 26
8.1 Tests on the compound . 26
8.1.1 Water absorption test . 26
8.1.2 Dielectric strength test . 26
8.2 Tests on the apparatus . 26
8.2.1 Test sequence . 26
8.2.2 Maximum temperature . 27
8.2.3 Thermal endurance test . 27
8.2.4 Dielectric strength test . 28
8.2.5 Cable pull test .
...
IEC 60079-18 ®
Edition 4.1 2017-08
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 18: Equipment protection by encapsulation “m”
Atmosphères explosives –
Partie 18: Protection du matériel par encapsulage "m"
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and definitions clause of
IEC publications issued between 2002 and 2015. Some
IEC Customer Service Centre - webstore.iec.ch/csc entries have been collected from earlier publications of IEC
If you wish to give us your feedback on this publication or TC 37, 77, 86 and CISPR.
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.
A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.
Recherche de publications IEC - Electropedia - www.electropedia.org
webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au
La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en
en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans
comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire
projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.
IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary
Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais
Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et définitions des
Disponible en ligne et une fois par mois par email. publications IEC parues entre 2002 et 2015. Plus certaines
entrées antérieures extraites des publications des CE 37, 77,
Service Clients - webstore.iec.ch/csc 86 et CISPR de l'IEC.
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC 60079-18 ®
Edition 4.1 2017-08
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 18: Equipment protection by encapsulation “m”
Atmosphères explosives –
Partie 18: Protection du matériel par encapsulage "m"
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-4770-9
IEC 60079-18 ®
Edition 4.1 2017-08
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Explosive atmospheres –
Part 18: Equipment protection by encapsulation “m”
Atmosphères explosives –
Partie 18: Protection du matériel par encapsulage "m"
– 2 – IEC 60079-18:2014+AMD1:2017 CSV
IEC 2017
CONTENTS
FOREWORD . 5
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General . 10
4.1 Level of protection (equipment protection level (EPL)) . 10
4.2 Additional requirements for levels of protection “ma” and “mb” . 10
4.3 Additional requirements for level of protection “ma” . 10
4.4 Rated voltage and prospective short circuit current . 11
5 Requirements for compounds . 11
5.1 General . 11
5.2 Specification . 11
5.3 Properties of the compound . 11
5.3.1 Water absorption . 11
5.3.2 Dielectric strength . 11
6 Temperatures . 12
6.1 General . 12
6.2 Determination of the limiting temperatures . 12
6.2.1 Maximum surface temperature . 12
6.2.2 Temperature of the compound . 12
6.3 Temperature limitation . 12
7 Constructional requirements . 12
7.1 General . 12
7.2 Determination of faults . 13
7.2.1 Fault examination . 13
7.2.2 Components considered as not subject to fail . 13
7.2.3 Isolating components . 14
7.2.4 Infallible separation distances . 14
7.3 Free space in the encapsulation . 15
7.3.1 Group III “m” equipment . 15
7.3.2 Group I and Group II “m” equipment . 16
7.4 Thickness of the compound. 17
7.4.1 “m” equipment . 17
7.4.2 Windings for electrical machines . 19
7.4.3 Rigid, multi-layer printed wiring boards with through connections . 19
7.5 Switching contacts . 20
7.5.1 General . 20
7.5.2 Level of protection “ma” . 21
7.5.3 Level of protection “mb” . 21
7.5.4 Level of protection “mc” . 21
7.6 External connections . 21
7.6.1 General . 21
7.6.2 Additional requirements for “ma” equipment . 21
7.7 Protection of bare live parts . 21
7.8 Cells and batteries . 21
7.8.1 General . 21
IEC 2017
7.8.2 Prevention of gassing . 22
7.8.3 Protection against inadmissible temperatures and damage to the cells
or batteries . 22
7.8.4 Reverse current . 22
7.8.5 Current limitation . 23
7.8.6 Protection against the polarity inversion and deep discharge of the cells . 23
7.8.7 Charging of cells or batteries . 23
7.8.8 Requirements for control safety devices for cells or batteries. 24
7.9 Protective devices . 24
7.9.1 General . 24
7.9.2 Electrical protective devices . 25
7.9.3 Thermal protective devices . 25
7.9.4 Built-in protective devices . 26
8 Type tests . 26
8.1 Tests on the compound . 26
8.1.1 Water absorption test . 26
8.1.2 Dielectric strength test . 26
8.2 Tests on the apparatus . 26
8.2.1 Test sequence . 26
8.2.2 Maximum temperature . 27
8.2.3 Thermal endurance test . 27
8.2.4 Dielectric strength test . 28
8.2.5 Cable pull test . 28
8.2.6 Pressure test for Group I and Group II electrical equipment . 29
8.2.7 Test for resettable therma
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.