IEC 60364-4-42:2010

Low-voltage electrical installations - Part 4-42: Protection for safety - Protection against thermal effects

IEC 60364-4-42:2010 applies to electrical installations with regard to measures for the protection of persons, livestock and property against:
- thermal effects, combustion or degradation of materials, and risk of burns caused by electrical equipment,
- flames in case of a fire hazard being propagated from electrical installations to other fire compartments segregated by barriers which are in the vicinity, and
- the impairment of the safe functioning of electrical equipment including safety services.
This third edition cancels and replaces the second edition, published in 2001, and constitutes a technical revision. The main changes with respect to the previous edition are listed below:
- The scope now includes protection against all thermal effects and flames in case of a fire hazard being propagated from electrical installations to other fire compartments segregated by barriers which are in the vicinity.
- Requirements associated with escape routes for evacuation in an emergency have been expanded/modified.
- Requirements associated with the nature of processed or stored materials have been expanded/modified.
- Requirements associated with combustible constructional materials have been expanded/modified.
- Requirements associated with fire propagating structures have been modified slightly.
- New requirements for the selection and erection of installations in locations which might endanger precious goods have been added.
- Protection against overheating now includes space heating appliances.

Installations électriques basse tension - Partie 4-42: Protection pour assurer la sécurité - Protection contre les effets thermiques

La CEI 60364-4-42:2010 s'applique aux installations électriques pour ce qui concerne les mesures de protection des personnes, du bétail et des biens contre
- les effets thermiques, la combustion ou la dégradation des matériaux, et le risque de brûlure provoqués par un matériel électrique,
- la propagation des flammes en cas de danger d'incendie, depuis les installations électriques vers d'autres compartiments feu séparés par des barrières se trouvant à proximité, et
- les atteintes à la sécurité de fonctionnement des matériels électriques, y compris les services de sécurité.
Cette troisième édition annule et remplace la seconde édition, publiée en 2001, et constitue une révision technique. Les principales modifications par rapport à l'édition précédente sont les suivantes:
- Le domaine d'application inclut désormais la protection contre tous les effets thermiques et la propagation des flammes en cas d'incendie, depuis les installations électriques vers d'autres compartiments feu séparés par des barrières se trouvant à proximité.
- Les exigences associées aux chemins d'évacuation en cas d'urgence ont été développées/modifiées.
- Les exigences associées à la nature des matériaux traités ou stockés ont été développées et modifiées.
- Les exigences associées aux matériaux de construction combustibles ont été développées/modifiées.
- Les exigences associées aux structures propagatrices du feu ont été légèrement modifiées.
- De nouvelles exigences pour le choix et la mise en oeuvre des installations dans des emplacements comportant un danger pour les biens irremplaçables ont été ajoutées.
- La protection contre les surchauffes inclut désormais les appareils de chauffage.

General Information

• Status: Published
• Publication Date: 12-Nov-2014
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.120.50 - Fuses and other overcurrent protection devices
• ICS: 91.140.50 - Electricity supply systems
• Technical Committee: TC 64 - Electrical installations and protection against electric shock
• Drafting Committee: MT 2 - TC 64/MT 2
• Current Stage: PPUB - Publication issued
• Start Date: 15-Jun-2010
• Completion Date: 19-May-2010

Relations

• Amended By: IEC 60364-4-42:2010/AMD1:2014 - Amendment 1 - Low-voltage electrical installation - Part 4-42: Protection for safety - Protection against thermal effects
• Effective Date: 05-Sep-2023
• Revises: IEC 60364-4-42:2001 - Electrical installations of buildings - Part 4-42: Protection for safety - Protection against thermal effects
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60364-4-42 ®
Edition 3.0 2010-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage electrical installations –
Part 4-42: Protection for safety – Protection against thermal effects

Installations électriques basse tension –
Partie 4-42: Protection pour assurer la sécurité – Protection contre les effets
thermiques
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 la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
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IEC 60364-4-42 ®
Edition 3.0 2010-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage electrical installations –
Part 4-42: Protection for safety – Protection against thermal effects

Installations électriques basse tension –
Partie 4-42: Protection pour assurer la sécurité – Protection contre les effets
thermiques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
S
CODE PRIX
ICS 29.120.50; 91.140.50 ISBN 978-2-88910-942-5
– 2 – 60364-4-42 © IEC:2010
CONTENTS
FOREWORD.3
420.1 Scope .5
420.2 Normative references .5
420.3 Terms and definitions.5
421 Protection against fire caused by electrical equipment .6
421.1 General requirements .6
422 Precautions where particular risks of fire exist.8
422.1 General .8
422.2 Conditions of evacuation in an emergency.8
422.3 Locations with risks of fire due to the nature of processed or stored
materials .9
422.4 Locations with combustible constructional materials .11
422.5 Fire propagating structures.12
422.6 Selection and erection of installations in locations with endangering
of irreplaceable goods .12
423 Protection against burns .13
424 Protection against overheating .13
424.1 Forced air heating systems.13
424.2 Appliances producing hot water or steam .13
424.3 Space heating appliances.14
Annex A (informative) List of notes concerning certain countries.15
Bibliography.19

Table 42.1 – Temperature limits in normal service for accessible parts of equipment
within arm’s reach.13

60364-4-42 © IEC:2010 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE ELECTRICAL INSTALLATIONS –

Part 4-42: Protection for safety –
Protection against thermal effects

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 60364-4-42 has been prepared by IEC technical committee 64:
Electrical installations and protection against electric shock.
This third edition cancels and replaces the second edition, published in 2001, and constitutes
a technical revision.
The main changes with respect to the previous edition are listed below:
– The scope now includes protection against all thermal effects and flames in case of a fire
hazard being propagated from electrical installations to other fire compartments
segregated by barriers which are in the vicinity.
– Requirements associated with escape routes for evacuation in an emergency have been
expanded/modified.
– Requirements associated with the nature of processed or stored materials have been
expanded/modified.
– 4 – 60364-4-42 © IEC:2010
– Requirements associated with combustible constructional materials have been
expanded/modified.
– Requirements associated with fire propagating structures have been modified slightly.
– New requirements for the selection and erection of installations in locations which might
endanger precious goods have been added.
– Protection against overheating now includes space heating appliances.
The text of this standard is based on the following documents:
FDIS Report on voting
64/1725/FDIS 64/1729/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 reader's attention is drawn to the fact that Annex A lists all of the "in-some-country"
clauses on differing practices of a less permanent nature relating to the subject of this
standard.
A list of all parts in the IEC 60364 series, under the general title Low-voltage electrical
installations, can be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged until
the stability 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.
60364-4-42 © IEC:2010 – 5 –
LOW-VOLTAGE ELECTRICAL INSTALLATIONS –

Part 4-42: Protection for safety –
Protection against thermal effects

420.1 Scope
This part of IEC 60364 applies to electrical installations with regard to measures for the
protection of persons, livestock and property against
– thermal effects, combustion or degradation of materials, and risk of burns caused by
electrical equipment,
– flames in case of a fire hazard being propagated from electrical installations to other fire
compartments segregated by barriers which are in the vicinity, and
– the impairment of the safe functioning of electrical equipment inc
...

IEC 60364-4-42 ®
Edition 3.1 2014-11
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage electrical installations –
Part 4-42: Protection for safety – Protection against thermal effects

Installations électriques basse tension –
Partie 4-42: Protection pour assurer la sécurité – Protection contre les effets
thermiques
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.

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IEC 60364-4-42 ®
Edition 3.1 2014-11
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Low-voltage electrical installations –

Part 4-42: Protection for safety – Protection against thermal effects

Installations électriques basse tension –

Partie 4-42: Protection pour assurer la sécurité – Protection contre les effets

thermiques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.50; 91.140.50 ISBN 978-2-8322-1929-4

IEC 60364-4-42 ®
Edition 3.1 2014-11
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Low-voltage electrical installations –
Part 4-42: Protection for safety – Protection against thermal effects

Installations électriques basse tension –
Partie 4-42: Protection pour assurer la sécurité – Protection contre les effets
thermiques
– 2 – IEC 60364-4-42:2010
+AMD1:2014 CSV  IEC 2014
CONTENTS
FOREWORD . 3
420.1 Scope . 5
420.2 Normative references . 5
420.3 Terms and definitions . 5
421 Protection against fire caused by electrical equipment . 6
421.1 General requirements . 6
422 Precautions where particular risks of fire exist . 8
422.1 General . 8
422.2 Conditions of evacuation in an emergency . 8
422.3 Locations with risks of fire due to the nature of processed or stored
materials . 9
422.4 Locations with combustible constructional materials . 12
422.5 Fire propagating structures . 13
422.6 Selection and erection of installations in locations with endangering of
irreplaceable goods . 13
423 Protection against burns . 13
424 Protection against overheating . 14
424.1 Forced air heating systems . 14
424.2 Appliances producing hot water or steam . 14
424.3 Space heating appliances . 14
Annex A (informative) List of notes concerning certain countries . 15
Annex B (informative) Arc fault detection devices (AFDD) . 20
Bibliography . 21

Table 42.1 – Temperature limits in normal service for accessible parts of equipment
within arm’s reach . 14

+AMD1:2014 CSV  IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE ELECTRICAL INSTALLATIONS –
Part 4-42: Protection for safety –
Protection against thermal effects
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.
This consolidated version of the official IEC Standard and its amendment has been prepared
for user convenience.
IEC 60364-4-42 edition 3.1 contains the third edition (2010-05) [documents 64/1725/FDIS and
64/1729/RVD] and its amendment 1 (2014-11) [documents 64/1974/FDIS and 64/1982/RVD].
In this Redline version, a vertical line in the margin shows where the technical content is
modified by amendment 1. Additions and deletions are displayed in red, with deletions being
struck through. A separate Final version with all changes accepted is available in this
publication.
– 4 – IEC 60364-4-42:2010
+AMD1:2014 CSV  IEC 2014
International Standard IEC 60364-4-42 has been prepared by IEC technical committee 64:
Electrical installations and protection against electric shock.
The main changes with respect to the previous edition of this standard are listed below:
– The scope now includes protection against all thermal effects and flames in case of a fire
hazard being propagated from electrical i
...