1、BSI Standards PublicationExplosive atmospheresPart 31: Equipment dust ignition protection by enclosure “t”BS EN 60079-31:2014National forewordThis British Standard is the UK implementation of EN 60079-31:2014. It isidentical to IEC 60079-31:2013. It supersedes BS EN 60079-31:2009 which iswithdrawn.T
2、he UK participation in its preparation was entrusted to TechnicalCommittee EXL/31, Equipment for explosive atmospheres.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contra
3、ct. Users are responsible for its correct application. The British Standards Institution 2014.Published by BSI Standards Limited 2014ISBN 978 0 580 78740 9ICS 29.260.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the author
4、ity of theStandards Policy and Strategy Committee on 31 July 2014.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60079-31:2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60079-31 July 2014 ICS 29.260.20 Supersedes EN 60079-31:2009 English Version Explo
5、sive atmospheres - Part 31: Equipment dust ignition protection by enclosure “t“ (IEC 60079-31:2013) Atmosphres explosives - Partie 31: Protection contre linflammation de poussires par enveloppe “t“ relative au matriel (CEI 60079-31:2013) Explosionsgefhrdete Bereiche - Teil 31: Gerte-Staubexplosionss
6、chutz durch Gehuse “t“ (IEC 60079-31:2013) This European Standard was approved by CENELEC on 2014-01-01. 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 altera
7、tion. 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 m
8、ade 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
9、 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 King
10、dom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CENELEC All rights of exploitation in any form and by any means reserved
11、 worldwide for CENELEC Members. Ref. No. EN 60079-31:2014 E BS EN 60079-31:2014EN 60079-31:2014 - 2 - Foreword The text of document 31/1079/FDIS, future edition 2 of IEC 60079-31, prepared by IEC/TC 31 “Equipment for explosive atmospheres“ was submitted to the IEC-CENELEC parallel vote and approved
12、by CENELEC as EN 60079-31:2014. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2015-01-01 latest date by which the national standards conflicting with the document have
13、to be withdrawn (dow) 2017-01-01 This document supersedes EN 60079-31:2009. The State of the Art is included in Annex ZY “Significant changes between this European Standard and EN 60079-31:2009”. For the significant changes with respect to EN 60079-31:2009, see Annex ZY. This standard is to be read
14、in conjunction with EN 60079-0. 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. This document has been prepared under a mandate given
15、to CENELEC by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive. For the relationship with EU Directive see informative Annex ZZ, which is an integral part of this document. Endorsement notice The text of the International Standard I
16、EC 60079-31:2013 was approved by CENELEC as a European Standard without any modification. BS EN 60079-31:2014- 3 - EN 60079-31:2014 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are
17、 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 modifi
18、ed 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 60079-0 - Explosive atmospheres - Part 0: Equipment
19、- General requirements EN 60079-0 - IEC 60127 Series Miniature fuses EN 60127 Series IEC 60691 - Thermal-links - Requirements and application guide EN 60691 - ISO 965-1 - ISO general-purpose metric screw threads - Tolerances - Part 1: Principles and basic data - - BS EN 60079-31:2014EN 60079-31:2014
20、 - 4 - Annex ZZ (informative) Coverage of Essential Requirements of EU Directives This European Standard has been prepared under a mandate given to CENELEC by the European Commission and the European Free Trade Association and within its scope the standard covers only the following essential require
21、ments out of those given in Annex II of the EU Directive 94/9/EC: ER 1.0.1, ER 1.0.2 (partly), ER 1.0.4, ER 1.0.5 (partly) ER 1.1 ER 1.2.1 (partly), ER 1.2.2 (partly) ER 1.2.4 ER 1.2.7 ER 1.2.8 (partly) ER 1.3.1 ER 1.6.4 ER 2.1 ER 2.2 ER 2.3 Compliance with this standard provides one means of confor
22、mity with the specified essential requirements of the Directive concerned. WARNING: Other requirements and other EU Directives may be applicable to the products falling within the scope of this standard. BS EN 60079-31:2014- 5 - EN 60079-31:2014 Annex ZY (informative) Significant changes between thi
23、s European Standard and EN 60079-31:2009 This European Standard supersedes EN 60079-31:2009. The significant changes with respect to EN 60079-31:2009 are as listed below. Type Changes Clause Minor and editorial changes Extension Major technical changes Document has been restructured from the first e
24、dition Numerous X The marked maximum surface temperature shall be measured on the external surfaces of the enclosure and the surfaces of the internal components for equipment with types of protection “ta” 4.3.2 C1 Additional protection for arcing and sparking parts for “ta” 4.3.6 C2 Limiting the int
25、ernal pressure test to enclosures where the seal is not physically constrained from moving. 4.4.2 X Requirements for tapered threaded joints without an additional seal or gasket added. 5.1.2 X Requirements for cable gland aligned for all levels and Groups the only difference is now the required IP p
26、rotection 5.2 X Requirements for plain entries added 5.3.1 X 5 threads for parallel threads only required when no seal is used 5.3.2 X Test for internal enclosure for level “ta” added. 6.1.1.2 C 3 Eliminating of the “fault” table and reduction of the dust layer depth for the thermal test for type of
27、 protection “ta”. 6.1.2 X NOTE The technical changes referred to include the significance of technical changes in the revised EN standard, but they do not form an exhaustive list of all modifications from the previous version. More guidance may be found by referring to the Redline Version of the sta
28、ndard. BS EN 60079-31:2014EN 60079-31:2014 - 6 - Explanations: A) Definitions Minor and editorial changes clarification decrease of technical requirements minor technical change editorial corrections These are changes which modify requirements in an editorial or a minor technical way. They include c
29、hanges of the wording to clarify technical requirements without any technical change, or a reduction in level of existing requirement. Extension addition of technical options These are changes which add new or modify existing technical requirements, in a way that new options are given, but without i
30、ncreasing requirements for equipment that was fully compliant with the previous standard. Therefore, these will not have to be considered for products in conformity with the preceding edition. Major technical changes addition of technical requirements increase of technical requirements These are cha
31、nges to technical requirements (addition, increase of the level or removal) made in a way that a product in conformity with the preceding edition will not always be able to fulfil the requirements given in the later edition. These changes have to be considered for products in conformity with the pre
32、ceding edition. For these changes additional information is provided in Clause B) below. NOTE These changes represent current technological knowledge. However, these changes should not normally have an influence on equipment already placed on the market. B) Information about the background of Major
33、Technical Changes C1 A requirement was added for “ta” to require the temperature marking to be based on the highest of either the temperature produced by the internal components or the external surface temperature. C2 Requirements were added for “ta” equipment that contains a normally arcing part to
34、 require a supplementary internal enclosure around the arcing part. C3 Requires an impact test on the supplementary enclosure for “ta” equipment. BS EN 60079-31:2014 2 60079-31 IEC:2013 CONTENTS 1 Scope 6 2 Normative references 6 3 Terms and definitions 6 4 General . 7 4.1 Levels of protection 7 4.2
35、 Equipment groups and ingress protection. 7 4.3 Requirements for electrical equipment with level of protection “ta” . 8 Fault current . 8 4.3.1Maximum surface temperature 8 4.3.2Overpressure 8 4.3.3Dust exclusion 8 4.3.4Protective devices 8 4.3.5Protection for arcing and sparking parts 9 4.3.64.4 Re
36、quirements for electrical equipment with Level of Protection “tb” and “tc” . 9 Maximum surface temperature 9 4.4.1Over pressure . 9 4.4.2Dust exclusion 9 4.4.35 Construction 9 5.1 Joints . 9 General 9 5.1.1Threaded joints . 10 5.1.2Gaskets and seals 10 5.1.3Cemented joints 10 5.1.4Operating rods, sp
37、indles and shafts 10 5.1.5Windows . 10 5.1.65.2 Cable glands 11 5.3 Entries . 11 Plain entries . 11 5.3.1Threaded entries 11 5.3.26 Verification and tests . 11 6.1 Type tests 11 Type tests for dust exclusion by enclosures 11 6.1.1Thermal tests 12 6.1.26.2 Routine tests 12 7 Marking . 12 Bibliography
38、 14 Table 1 Level of Protection, equipment group and ingress protection (IP) relationship . 7 BS EN 60079-31:2014 6 60079-31 IEC:2013 EXPLOSIVE ATMOSPHERES Part 31: Equipment dust ignition protection by enclosure “t“ 1 Scope This part of IEC 60079 is applicable to electrical equipment protected by e
39、nclosure and surface temperature limitation for use in explosive dust atmospheres. It specifies requirements for design, construction and testing of electrical equipment and Ex Components. This standard supplements and modifies the general requirements of IEC 60079-0. Where a requirement of this sta
40、ndard conflicts with a requirement of IEC 60079-0, the requirement of this standard takes precedence. 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 apply to electrical equipment or Ex C
41、omponents intended for use in underground parts of mines as well as those parts of surface installations of such mines endangered by firedamp and/or combustible dust. This standard does not take account of any risk due to an emission of flammable or toxic gas from the dust. Consideration of addition
42、al protective measures is required where the application of electrical equipment is in atmospheres, which can contain combustible dust as well as explosive gas, whether simultaneously or separately. Where the electrical equipment has to meet other environmental conditions, for example, protection ag
43、ainst ingress of water and resistance to corrosion, additional measures can be necessary. The measures used should not adversely affect the integrity of the enclosure. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensab
44、le 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. IEC 60079-0, Explosive atmospheres Part 0: Equipment General requirements IEC 60127 (all parts), Miniature fuses IEC
45、 60691, Thermal-links Requirements and application guide ISO 965-1, ISO general-purpose metric screw threads Tolerances Part 1: Principles and basic data 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60079-0, as well as the following definitions, a
46、pply. NOTE Additional definitions applicable to explosive atmospheres can be found in IEC 60050-426. BS EN 60079-31:201460079-31 IEC:2013 7 3.1 dust ignition protection by enclosure “t” type of protection for explosive dust atmospheres where electrical equipment is provided with an enclosure providi
47、ng dust ingress protection and a means to limit surface temperatures 3.2 joint place where the corresponding surfaces of two parts of an enclosure, or the conjunction of enclosures, come together 3.3 gasket compressible element provided in a joint to provide a degree of protection against the ingres
48、s of solid foreign objects and /or against ingress water/dust 4 General 4.1 Levels of protection Type of protection “t” is divided into three Levels of Protection based on the risk of the electrical equipment becoming an ignition source in an explosive dust atmosphere. Electrical equipment with dust
49、 ignition protection by enclosure “t” shall be either: Level of Protection “ta” (EPL “Da”), or Level of Protection “tb” (EPL “Db”), or Level of Protection “tc” (EPL “Dc”). The construction and marking requirements apply to all electrical equipment, and in addition, the requirements for “ta“ as given in 4.3 and the requirements for “tb“ and “tc“ as given in 4.4. Failure modes as defined in the industrial standard for particular components shall be taken into account when considering applicabl
