IEC_60079-0-2004-En.pdf

Electrical apparatus for explosive gas atmospheres Part 0:General requirements Reference number IEC 60079-0:2004(E)INTERNATIONAL STANDARD IEC60079-0 Fourth edition2004-01 This English-language version is derived from the original bilingual publication by leaving out all French-language pages.Missing page numbers correspond to the French-language pages.Document provided by IHS Licensee=Agip KOC/5950653001,02/11/2004 06:44:03 MSTQuestions or comments about this message:please call the Document Policy Groupat 1-800-451-1584.-,-,-Publication numbering As from 1 January 1997 all IEC publications are issued with a designation in the 60000 series.For example,IEC 34-1 is now referred to as IEC 60034-1.Consolidated editions The IEC is now publishing consolidated versions of its publications.For example,edition numbers 1.0,1.1 and 1.2 refer,respectively,to the base publication,the base publication incorporating amendment 1 and the base publication incorporating amendments 1 and 2.Further information on IEC publications The technical content of IEC publications is kept under constant review by the IEC,thus ensuring that the content reflects current technology.Information relating to this publication,including its validity,is available in the IEC Catalogue of publications(see below)in addition to new editions,amendments and corrigenda.Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication,as well as the list of publications issued,is also available from the following:IEC Web Site(www.iec.ch)Catalogue of IEC publications The on-line catalogue on the IEC web site(www.iec.ch/searchpub)enables you to search by a variety of criteria including text searches,technical committees and date of publication.On-line information is also available on recently issued publications,withdrawn and replaced publications,as well as corrigenda.IEC Just Published This summary of recently issued publications(www.iec.ch/online_news/justpub)is also available by email.Please contact the Customer Service Centre(see below)for further information.Customer Service Centre If you have any questions regarding this publication or need further assistance,please contact the Customer Service Centre:Email:custserviec.ch Tel:+41 22 919 02 11 Fax:+41 22 919 03 00 Document provided by IHS Licensee=Agip KOC/5950653001,02/11/2004 06:44:03 MSTQuestions or comments about this message:please call the Document Policy Groupat 1-800-451-1584.-,-,-Electrical apparatus for explosive gas atmospheres Part 0:General requirements For price,see current catalogue IEC 2004 Copyright-all rights reserved 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 the publisher.International Electrotechnical Commission,3,rue de Varemb,PO Box 131,CH-1211 Geneva 20,SwitzerlandTelephone:+41 22 919 02 11 Telefax:+41 22 919 03 00 E-mail:inmailiec.ch Web:www.iec.ch INTERNATIONAL STANDARD IEC60079-0 Fourth edition2004-01 XB Commission Electrotechnique InternationaleInternational Electrotechnical Commission PRICE CODE Document provided by IHS Licensee=Agip KOC/5950653001,02/11/2004 06:44:03 MSTQuestions or comments about this message:please call the Document Policy Groupat 1-800-451-1584.-,-,-60079-0 IEC:2004 3 CONTENTS FOREWORD.11 INTRODUCTION.17 1 Scope.19 2 Normative references.21 3 Terms and definitions.27 4 Apparatus grouping and temperature classification.39 4.1 Apparatus grouping.39 4.2 Group II.39 5 Temperatures.39 5.1 Environmental influences.39 5.2 Service temperature.41 5.3 Maximum surface temperature.41 5.4 Surface temperature and ignition temperature.43 5.5 Small components.43 6 Requirements for all electrical apparatus.45 6.1 General.45 6.2 Mechanical strength of apparatus.45 6.3 Opening times.45 6.4 Circulating currents.47 6.5 Gasket retention.47 7 Non-metallic enclosures and non-metallic parts of enclosures.47 7.1 General.47 7.2 Thermal endurance.49 7.3 Electrostatic charges on external non-metallic materials of enclosures.49 7.4 Threaded holes.51 8 Enclosures containing light metals.53 8.1 Material composition.53 8.2 Threaded holes.53 Fasteners.53 9.1 General.53 9.2 Special fasteners.55 9.3 Holes for special fasteners.55 10 Interlocking devices.59 11 Bushings.59 12 Materials used for cementing.59 13 Ex components.59 13.1 General.59 13.2 Mounting internal to apparatus.59 13.3 Mounting external to apparatus.61 14 Connection facilities and terminal compartments.61 14.1 General.61 14.2 Connection space.61 14.3 Type of protection.61 14.4 Creepage and clearance.61 Document provided by IHS Licensee=Agip KOC/5950653001,02/11/2004 06:44:03 MSTQuestions or comments about this message:please call the Document Policy Groupat 1-800-451-1584.-,-,-60079-0 IEC:2004 5 15 Connection facilities for earthing or bonding conductors.61 15.1 Internal.61 15.2 External.61 15.3 Apparatus no