IEC 60079-7:2015

Explosive atmospheres - Part 7: Equipment protection by increased safety "e"

IEC 60079-7:2015 specifies the requirements for the design, construction, testing and marking of electrical equipment and Ex Components with type of protection increased safety "e" intended for use in explosive gas atmospheres. Electrical equipment and Ex Components of type of protection increased safety "e" are either:
- Level of Protection "eb" (EPL "Mb" or "Gb"); or
- Level of Protection "ec" (EPL "Gc"). Level of Protection "eb" applies to equipment or Ex Components, including their connections, conductors, windings, lamps, and batteries; but not including semiconductors or electrolytic capacitors. Level of Protection "ec" applies to equipment or Ex Components, including their connections, conductors, windings, lamps, and batteries; and also including semiconductors and electrolytic capacitors. The requirements of this standard apply to both Levels of Protection unless otherwise stated. For Level of Protection "eb", this standard applies to electrical equipment where the rated voltage does not exceed 11 kV r.m.s., a.c. or d.c. For Level of Protection "ec", this standard applies to electrical equipment where the rated voltage does not exceed 15 kV r.m.s., a.c. or d.c. 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 fifth edition cancels and replaces the fourth edition published in 2006, and constitutes a technical revision. Refer to the Foreword of the document for a complete listing of the technical changes between edition 5.0 and previous edition of the document. Keywords: electrical equipment and Ex Components with type of protection increased safety "e" intended for use in explosive gas atmospheres. The contents of the Interpretation sheet 1 of September 2016 have been included in this copy.

Atmosphères explosives - Partie 7: Protection du matériel par sécurité augmentée "e"

L'IEC 60079-7:2015 spécifie les exigences spécifiques de conception, de construction, d'essais et de marquage du matériel électrique et des composants Ex avec mode de protection de sécurité augmentée "e" destinés à être utilisés dans les atmosphères explosives gazeuses. Le matériel électrique et les composants Ex de mode de protection de sécurité augmentée "e" sont:
- d'un niveau de protection "eb" (EPL "Mb" ou "Gb"); ou
- d'un niveau de protection "ec" (EPL "Gc"). Le niveau de protection "eb" s'applique au matériel ou aux composants Ex, y compris leurs connexions, conducteurs, enroulements, lampes et batteries; mais n'inclut pas les semi-conducteurs ou les condensateurs électrolytiques. Le niveau de protection "ec" s'applique au matériel ou aux composants Ex, y compris leurs connexions, conducteurs, enroulements, lampes et batteries; cela inclut également les semi-conducteurs ou les condensateurs électrolytiques. Sauf indication contraire, les exigences de la présente norme s'appliquent aux deux niveaux de protection. Pour le niveau de protection "eb", la présente norme s'applique au matériel électrique si la tension assignée n'est pas supérieure à une valeur efficace de 11 kV, c.a. ou c.c. Pour le niveau de protection "ec", la présente norme s'applique au matériel électrique si la tension assignée n'est pas supérieure à une valeur efficace de 15 kV, c.a. ou c.c. La présente norme complète et modifie les exigences générales de l'IEC 60079-0. Lorsqu'une exigence de la présente norme entre en conflit avec une exigence de l'IEC 60079-0, l'exigence de la présente norme prévaut. Cette cinquième édition annule et remplace la quatrième édition parue en 2006. Cette édition constitue une révision technique. Reportez-vous à l'avant-propos du document pour une liste complète des modifications techniques entre l'édition 5.0 et édition précédente du document. Mots clés: matériel électrique et des composants Ex avec mode de protection de sécurité augmentée "e" destinés à être utilisés dans les atmosphères explosives gazeuses Le contenu de la feuille d'interprétation 1 de septembre 2016 a été pris en considération dans cet exemplaire.

General Information

• Status: Published
• Publication Date: 25-Jun-2015
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.260.20 - Electrical apparatus for explosive atmospheres
• Technical Committee: TC 31 - Equipment for explosive atmospheres
• Drafting Committee: MT 60079-7 - TC 31/MT 60079-7
• Current Stage: PPUB - Publication issued
• Start Date: 30-Jun-2015
• Completion Date: 26-Jun-2015

Relations

• Amended By: IEC 60079-7:2015/AMD1:2017 - Amendment 1 - Explosive atmospheres - Part 7: Equipment protection by increased safety "e"
• Effective Date: 05-Sep-2023
• Revised: IEC 60079-7:2015/ISH1:2016 - Intrepretation sheet 1 - Explosive atmospheres - Part 7: Equipment protection by increased safety "e"
• Effective Date: 05-Sep-2023
• Revises: IEC 60079-7:2006 - Explosive atmospheres - Part 7: Equipment protection by increased safety "e"
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60079-7 ®
Edition 5.0 2015-06
INTERNATIONAL
STANDARD
Explosive atmospheres –
Part 7: Equipment protection by increased safety ''e''
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.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
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 15
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 60 000 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: [e-mail].
IEC 60079-7 ®
Edition 5.0 2015-06
INTERNATIONAL
STANDARD
Explosive atmospheres –
Part 7: Equipment protection by increased safety ''e''

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.260.20 ISBN 978-2-8322-2710-7

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60079-7
Edition 5.0  2015-06
EXPLOSIVE ATMOSPHERES –
Part 7: Equipment protection by increased safety 'e'

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
31/1258/ISH 31/1272/RVD
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
increased safety “e”
Question:
Do the requirements given in 5.2.3 prohibit the use of a terminal box opened to the interior of
a motor rated 1 kV or greater, provided the interior of the machine has an ingress protection
of IP54 or greater?
5.2.3 Degrees of protection provided by electrical machines, Level of Protection “ec”
The requirements of 4.10 apply, except that terminal boxes attached to electrical machines
operating at voltages up to 1 kV, may be opened to the interior of the machine, only when the
degree of protection of the electrical machine is at least IP44. Covers and entries of the
terminal box shall provide at least degree of protection IP54.
ICS 29.260.20
– 2 – IEC 60079-7:2015/ISH1:2016  IEC 2016
Answer:
No. As long as the interior of the machine has an ingress protection of IP54 or greater,
determined in accordance with IEC 60079-0, there is no limitation to less than 1 kV. If the
interior of the machine has an ingress rating of IP44 or lower, the use of a terminal box open
to the interior of a motor rated 1 kV or greater is not permitted.
NOTE Many manufacturers opt to declare IP44 for the machine for certification purposes, whilst claiming a rating
of IP54 or higher, by assessment, for contractual purposes in order to avoid the difficult testing required for
certification of the IP of larger machines. As such, this additional IP rating need only comply with IEC 60529 or
IEC 60034-5 as applicable, and not with any of the testing detailed in IEC 60079-0.

– 2 – IEC 60079-7:2015 © IEC 2015
CONTENTS
FOREWORD . 8
1 Scope . 14
2 Normative references . 15
3 Terms and definitions . 17
4 Constructional requirements . 21
4.1 Level of Protection . 21
4.2 Electrical connections . 21
4.2.1 General . 21
4.2.2 Field wiring connections . 22
4.2.3 Factory connections. 23
4.2.4 External plug and socket connections for field wiring connection . 25
4.3 Clearances . 26
4.4 Creepage distances . 26
4.5 Printed wiring boards with conformal coating, Level of Protection “ec” . 32
4.6 Solid electrical insulating materials . 33
4.6.1 Specification . 33
4.6.2 Long-term thermal stability . 33
4.7 Windings . 34
4.7.1 General . 34
4.7.2 Insulated conductors . 34
4.7.3 Winding impregnation . 34
4.7.4 Conductor dimensions . 34
4.7.5 Sensing elements . 35
4.8 Temperature limitations . 35
4.8.1 General . 35
4.8.2 Conductors . 35
4.8.3 Insulated windings . 36
4.9 Wiring internal to equipment . 36
4.10 Degrees of protection provided by enclosures . 37
4.11 Fasteners . 38
5 Supplementary requirements for specific electrical equipment . 38
5.1 General . 38
5.2 Electrical machines . 38
5.2.1 General . 38
5.2.2 Degrees of protection provided by electrical machines, Level of
Protection “eb” . 39
5.2.3 Degrees of protection provided by electrical machines, Level of
Protection “ec” . 39
5.2.4 Connection facilities for external conductors . 39
5.2.5 Internal fans . 39
5.2.6 Minimum air gap . 39
5.2.7 Rotating electrical machines with cage rotors . 40
5.2.8 Limiting temperature . 42
5.2.9 Machines with permanent magnet rotors . 45
5.2.10 Stator winding insulation system . 45
5.2.11 Supplemental winding requirements Level of Protection “eb” . 46

5.2.12 Bearing seals and shaft seals . 46
5.2.13 Neutral point connections . 47
5.3 Luminaires, hand lights, or caplights . 47
5.3.1 General . 47
5.3.2 Light source . 48
5.3.3 Minimum distance between lamp and protective cover . 49
5.3.4 Electrical spacings . 49
5.3.5 Lampholders and lamp caps . 50
5.3.6 Auxiliaries for Luminaires in Level of Protection “ec” . 53
5.3.7 Surface temperatures . 54
5.3.8 Limiting temperatures . 55
5.3.9 Luminaires for tubular fluorescent bi-pin lamps . 55
5.3.10 Tests for resistance to impact . 56
5.4 Analog measuring instruments and instrument transformers . 56
5.4.1 General . 56
5.4.2 Limiting temperature . 56
5.4.3 Short-circuit currents . 56
5.4.4 Short time thermal current . 57
5.4.5 Measuring instruments supplied by current transformers . 57
5.4.6 Moving coils . 57
5.4.7 External secondary circuits . 57
5.5 Transformers other than instrument transformers . 57
5.6 Supplementary requirements for equipment incorporating cells and batteries . 58
5.6.1 Type of cells and batteries . 58
5.6.2 Requirements for cells and batteries ≤25 Ah . 59
5.6.3 Requirements for valve-regulated or vented cells or batteries >25 Ah . 62
5.6.4 Charging of cells and batteries . 65
5.7 General purpose connection and junction boxes . 66
5.8 Resistance heating equipment (other than trace heating systems) . 66
5.8.1 General . 66
5.8.2 Heating resistors .
...

IEC 60079-7 ®
Edition 5.0 2015-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 7: Equipment protection by increased safety «e»

Atmosphères explosives –
Partie 7: Protection du matériel par sécurité augmentée «e»

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.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
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 15
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 60 000 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: [e-mail].
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
15 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 60 000 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:
[e-mail].
IEC 60079-7 ®
Edition 5.0 2015-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 7: Equipment protection by increased safety «e»

Atmosphères explosives –
Partie 7: Protection du matériel par sécurité augmentée «e»

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-2885-2

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60079-7
Edition 5.0  2015-06
EXPLOSIVE ATMOSPHERES –
Part 7: Equipment protection by increased safety 'e'

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
31/1258/ISH 31/1272/RVD
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
increased safety “e”
Question:
Do the requirements given in 5.2.3 prohibit the use of a terminal box opened to the interior of
a motor rated 1 kV or greater, provided the interior of the machine has an ingress protection
of IP54 or greater?
5.2.3 Degrees of protection provided by electrical machines, Level of Protection “ec”
The requirements of 4.10 apply, except that terminal boxes attached to electrical machines
operating at voltages up to 1 kV, may be opened to the interior of the machine, only when the
degree of protection of the electrical machine is at least IP44. Covers and entries of the
terminal box shall provide at least degree of protection IP54.
ICS 29.260.20
– 2 – IEC 60079-7:2015/ISH1:2016  IEC 2016
Answer:
No. As long as the interior of the machine has an ingress protection of IP54 or greater,
determined in accordance with IEC 60079-0, there is no limitation to less than 1 kV. If the
interior of the machine has an ingress rating of IP44 or lower, the use of a terminal box open
to the interior of a motor rated 1 kV or greater is not permitted.
NOTE Many manufacturers opt to declare IP44 for the machine for certification purposes, whilst claiming a rating
of IP54 or higher, by assessment, for contractual purposes in order to avoid the difficult testing required for
certification of the IP of larger machines. As such, this additional IP rating need only comply with IEC 60529 or
IEC 60034-5 as applicable, and not with any of the testing detailed in IEC 60079-0.

– 2 – IEC 60079-7:2015 © IEC 2015
CONTENTS
FOREWORD . 8
1 Scope . 14
2 Normative references . 15
3 Terms and definitions . 17
4 Constructional requirements . 21
4.1 Level of Protection . 21
4.2 Electrical connections . 21
4.2.1 General . 21
4.2.2 Field wiring connections . 22
4.2.3 Factory connections. 23
4.2.4 External plug and socket connections for field wiring connection . 25
4.3 Clearances . 26
4.4 Creepage distances . 26
4.5 Printed wiring boards with conformal coating, Level of Protection “ec” . 32
4.6 Solid electrical insulating materials . 33
4.6.1 Specification . 33
4.6.2 Long-term thermal stability . 33
4.7 Windings . 34
4.7.1 General . 34
4.7.2 Insulated conductors . 34
4.7.3 Winding impregnation . 34
4.7.4 Conductor dimensions . 34
4.7.5 Sensing elements . 35
4.8 Temperature limitations . 35
4.8.1 General . 35
4.8.2 Conductors . 35
4.8.3 Insulated windings . 36
4.9 Wiring internal to equipment . 36
4.10 Degrees of protection provided by enclosures . 37
4.11 Fasteners . 38
5 Supplementary requirements for specific electrical equipment . 38
5.1 General . 38
5.2 Electrical machines . 38
5.2.1 General . 38
5.2.2 Degrees of protection provided by electrical machines, Level of
Protection “eb” . 39
5.2.3 Degrees of protection provided by electrical machines, Level of
Protection “ec” . 39
5.2.4 Connection facilities for external conductors . 39
5.2.5 Internal fans . 39
5.2.6 Minimum air gap . 39
5.2.7 Rotating electrical machines with cage rotors . 40
5.2.8 Limiting temperature . 42
5.2.9 Machines with permanent magnet rotors . 45
5.2.10 Stator winding insulation system . 45
5.2.11 Supplemental winding requirements Level of Protection “eb” . 46

5.2.12 Bearing seals and shaft seals . 46
5.2.13 Neutral point connections . 47
5.3 Luminaires, hand lights, or caplights .
...

IEC 60079-7 ®
Edition 5.1 2017-08
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 7: Equipment protection by increased safety "e"
Atmosphères explosives –
Partie 7: Protection du matériel par sécurité augmentée «e»
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.: [phone]
3, rue de Varembé [e-mail]
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: [e-mail].
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:
[e-mail].
IEC 60079-7 ®
Edition 5.1 2017-08
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 7: Equipment protection by increased safety "e"

Atmosphères explosives –
Partie 7: Protection du matériel par sécurité augmentée «e»

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-4708-2

IEC 60079-7 ®
Edition 5.1 2017-08
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Explosive atmospheres –
Part 7: Equipment protection by increased safety "e"

Atmosphères explosives –
Partie 7: Protection du matériel par sécurité augmentée «e»

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60079-7
Edition 5.0  2015-06
EXPLOSIVE ATMOSPHERES –
Part 7: Equipment protection by increased safety 'e'

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
31/1258/ISH 31/1272/RVD
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
increased safety “e”
Question:
Do the requirements given in 5.2.3 prohibit the use of a terminal box opened to the interior of
a motor rated 1 kV or greater, provided the interior of the machine has an ingress protection
of IP54 or greater?
5.2.3 Degrees of protection provided by electrical machines, Level of Protection “ec”
The requirements of 4.10 apply, except that terminal boxes attached to electrical machines
operating at voltages up to 1 kV, may be opened to the interior of the machine, only when the
degree of protection of the electrical machine is at least IP44. Covers and entries of the
terminal box shall provide at least degree of protection IP54.
ICS 29.260.20
– 2 – IEC 60079-7:2015/ISH1:2016  IEC 2016
Answer:
No. As long as the interior of the machine has an ingress protection of IP54 or greater,
determined in accordance with IEC 60079-0, there is no limitation to less than 1 kV. If the
interior of the machine has an ingress rating of IP44 or lower, the use of a terminal box open
to the interior of a motor rated 1 kV or greater is not permitted.
NOTE Many manufacturers opt to declare IP44 for the machine for certification purposes, whilst claiming a rating
of IP54 or higher, by assessment, for contractual purposes in order to avoid the difficult testing required for
certification of the IP of larger machines. As such, this additional IP rating need only comply with IEC 60529 or
IEC 60034-5 as applicable, and not with any of the testing detailed in IEC 60079-0.

– 2 – IEC 60079-7:2015+AMD1:2017 CSV
© IEC 2017
CONTENTS
FOREWORD . 8
1 Scope . 14
2 Normative references . 15
3 Terms and definitions . 17
4 Constructional requirements . 21
4.1 Level of Protection . 21
4.2 Electrical connections . 21
4.2.1 General . 21
4.2.2 Field wiring connections . 22
4.2.3 Factory connections. 23
4.2.4 External plug and socket connections for field wiring connection . 25
4.3 Clearances . 26
4.4 Creepage distances . 26
4.5 Printed wiring boards with conformal coating, Level of Protection “ec” . 32
4.6 Solid electrical insulating materials . 33
4.6.1 Specification . 33
4.6.2 Long-term thermal stability . 33
4.7 Windings . 34
4.7.1 General . 34
4.7.2 Insulated conductors . 34
4.7.3 Winding impregnation . 34
4.7.4 Conductor dimensions . 34
4.7.5 Sensing elements . 35
4.8 Temperature limitations . 35
4.8.1 General . 35
4.8.2 Conductors . 35
4.8.3 Insulated windings . 36
4.9 Wiring internal to equipment . 37
4.10 Degrees of protection provided by enclosures . 37
4.11 Fasteners . 38
5 Supplementary requirements for specific electrical equipment . 38
5.1 General . 38
5.2 Electrical machines . 38
5.2.1 General . 38
5.2.2 Degrees of protection provided by electrical machines, Level of
Protection “eb” . 39
5.2.3 Degrees of protection provided by electrical machines, Level of
Protection “ec” . 39
5.2.4 Connection facilities for external conductors . 39
5.2.5 Internal fans . 40
5.2.6 Minimum air gap . 40
5.2.7 Rotating electrical machines with cage rotors . 41
5.2.8 Limiting temperature . 43
5.2.9 Machines with permanent magnet rotors . 46
5.2.10 Stator winding insulation system . 46
5.2.11 Supplemental winding requirements Level of Protection “eb” . 47

© IEC 2017
5.2.12 Bearing seals and shaft seals . 47
5.2.13 Neutral point connections . 48
5.3 Luminaires, hand lights, or caplights . 48
5.3.1 General .
...