【AS澳大利亚标准】AS 60079.11-2000 Electrical apparatus for explosive gas atmospheres Part 11 Intrinsic safety ‘i.doc

as/nzs 60079.11as/nzs 60079.11:2000iec 60079-11:1999(incorporating amendment no. 1)australian/new zealand standardelectrical apparatus for explosive gas atmospherespart 11:intrinsic safety ithe standard is downloaded from standard sharingas/nzs 60079.11:2000this joint australian/new zealand standard was prepared by joint technical committee el/14, electrical equipment in hazardous areas. it was approved on behalf of the council of standards australia on 16 june 2000. and on behalf of the council of standards new zealand on 28 april 2000.it was published on25 july 2000.the following interests are represented on committee el/14:association of consulting engineers australiaauckland regional chamber of commerceaustralian association of certification bodiesaustralian chamber of commerce and industryaustralian coal associationaustralian electrical and electronic manufacturers associationaustralian gas associationaustralian industry groupaustralian institute of petroleumaustralian institute of refrigeration air conditioning and heatingdepartment of mineral resources, n.s.w.department of mines and energy, qldelectricity supply association of australiainstitute of electrical inspectorsinstitute of instrumentation and control australiainstitution of engineers australiaministry of commerce new zealandnational electrical and communications associationnew zealand association of marine, aviation and power engineersnew zealand employers and manufacturers associationnew zealand hazardous areas electrical coordinating committeeregulatory authorities (electrical)workcover new south waleskeeping standards up-to-datestandards are living documents which reflect progress in science, technology and systems. to maintain their currency, all standards are periodically reviewed, and new editions are published. between editions, amendments may be issued. standards may also be withdrawn. it is important that readers assure themselves they are using a current standard, which should include any amendments which may have been published since the standard was purchased.detailed information about joint australian/new zealand standards can be found by visiting the standards australia web site at .au or standards new zealand web site at www.standards.co.nz and looking up the relevant standard in the on-line catalogue.alternatively, both organizations publish an annual printed catalogue with full details of all current standards. for more frequent listings or notification of revisions, amendments and withdrawals, standards australia and standards new zealand offer a number of update options. for information about these services, users should contact their respective national standards organization.we also welcome suggestions for improvement in our standards, and especially encourage readers to notify us immediately of any apparent inaccuracies or ambiguities. please address your comments to the chief executive of either standards australia international or standards new zealand at the address shown on the back cover.this standard was issued in draft form for comment as dr 99256.as/nzs 60079.11:2000(incorporating amendment no. 1)australian/new zealand standardelectrical apparatus for explosive gas atmospherespart 11:intrinsic safety ifirst published as as/nzs 60079.11:2000.reissued incorporating amendment no. 1 (february 2001).copyright standards australia/standards new zealandall rights are reserved. no part of this work may be reproduced or copied in any formor by any means, electronic or mechanical, including photocopying, without the written permission of the publisher.jointly published by standards australia international ltd, gpo box 5420, sydney, nsw 2001 and standards new zealand, private bag 2439, w ellington 6020isbn 0 7337 3507 xiiithe standard is downloaded from standard sharingprefacethis standard was prepared by the joint standards australia/standards new zealand committeeel/14, electrical equipment in hazardous areas.this standard incorporates amendment no. 1 (february 2001). the changes arising from the amendment are indicated in the text by a marginal bar and amendment number against the clause, note, table, figure, or part thereof affected.this standard is identical with and has been reproduced from iec 60079.11:1999, electrical apparatus for explosive gas atmospheres, part 11: intrinsic safety i.footnotes have been added to the original text of iec 60079-11:1999 to provide updated information and/or clarification on the specific items/aspects marked with *.the objective of this standard is to set out the requirements for the design, construction, testing and marking of intrinsically safe apparatus for use in explosive atmospheres, and to specify the requirements for associated apparatus intended for connection to intrinsically safe circuits entering such atmospheres.this standard will run concurrently with as 2380.7, electrical equipment for explosive atmospheresexplosion-protection techniques, part 7: intrinsic safety i, until the as/nzs 60079 series is complete, at which time the as 2380 series will be withdrawn.in january 1997, the iec commenced numbering its standards from 60000 by adding 60000 to the number of each existing standard. this coordinates iec numbering with iso numbering. during the transition period an iec standard might be identified by its new number or its old number (for example, iec 60050 or iec 50).a reference to an international standard identified in the normative references clause by strikethrough (example) is replaced by a reference to the australian or australian/new zealand standard(s) listed immediately thereafter and identified by shading (example).as this standard is reproduced from an international standard a full point should be substituted for a comma when referring to a decimal marker.the terms normative and informative have been used in this standard to define the application of the annex to which they apply. a normative annex is an integral part of a standard, whereas aninformative annex is only for information and guidance.contentspageclause1scope . 12normative references . 23definitions .3 4grouping and classification of intrinsically safe apparatus andassociated apparatus. 75categories of electrical apparatus . 76apparatus construction . 97components on which intrinsic safety depends . 258infallible components, infallible assemblies of components andinfallible connections . 319diode safety barriers . 3710type verifications and type tests. 3811routine verifications and tests . 4612marking . 4713documentation . 49annex a (normative)assessment of intrinsically safe circuits . 50annex b (normative)spark test apparatus for intrinsically safe circuits . 71annex c (informative)measurement of creepage distances, clearancesand separation distances through casting compoundand through solid insulation . 80annex d (normative)encapsulation . 83vthe standard is downloaded from standard sharingnotesstandards australia/standards new zealandaustralian/new zealand standardelectrical apparatus for explosive gas atmospherespart 11: intrinsic safety i1scope1.1this part of as/nzs 60079 specifies the construction and testing of intrinsically safe apparatus, intended for use in potentially explosive atmospheres and for associated apparatus, which is intended for connection to intrinsically safe circuits which enter such atmospheres. it also contains details of the test apparatus previously published as iec 60079-3.1.2this standard supplements iec 60079-0:1998, the requirements of which apply to intrinsically safe apparatus and to associated apparatus except as indicated in the following list.if associated apparatus is protected by a type of protection listed in iec 60079-0 then the requirements of that method of protection together with the relevant parts of iec 60079-0 also apply to the associated apparatus. the list of exclusions which follows is directly applicable to associated apparatus intended for use in situations where there is no potentially explosive atmosphere and in other circumstances should be used in combination with the requirements of the other methods of protection.clause of iec 60079-0:1998clause or subclause excludedintrinsically safeapparatusassociated apparatus3.1electrical apparatusyesyes4.2.2marking of maximum surface temperaturenoyes5.1maximum surface temperaturenoyes5.3surface temperature and ignition temperaturenoyes6.2enclosure opening delayyesyes7.1.1definition of plastics materialnoyes7.1.2requirement of plastics materialyesyes7.1.3verification of plastics material compliancenoyes7.2thermal enduranceyesyes7.3electrostatic charges on plastics enclosuresnoyes7.3.1electrical apparatus of group i (notes 1 and 2 only)yesyes7.3.2electrical apparatus of group ii (notes 1 and 2 only)yesyes7.4threaded holes in plasticsyesyes8.1light metal enclosure materialsnoyes8.2threaded holes in light metalsyesyes3the standard is downloaded from standard sharingclause of iec 60079-0:1998clause or subclause excludedintrinsically safeapparatusassociated apparatus9fastenersyesyes10interlocking devicesyesyes11bushingsyesyes12materials used for cementingyesyes14connection facilities and terminal compartmentsyesyes15connection facilities for earthing or bonding conductorsyesyes16cable and conduit entriesyesyes17 to 22supplementary requirements for certain electrical apparatusyesyestest for resistance to impactyesyesdrop test (no prior impact test necessary)noyesrequired resultsnoyes23.4.5torque test for bushingsyesyestemperature measurementnoyesthermal shock testyesyes totests on non-metallic enclosuresyesyesinsulation resistance test of parts of enclosures of plastics materialsnoyes27.7examples of markingyesyesannex bex cable entriesyesyes1.3this standard is applicable to electrical apparatus in which the electrical circuits themselves are incapable of causing an explosion in the surrounding explosive atmospheres.1.4this standard is also applicable to electrical apparatus or parts of electrical apparatus located outside the potentially explosive atmosphere or protected by another type of protection listed in iec 60079-0, where the intrinsic safety of the electrical circuits in the potentially explosive atmosphere may depend upon the design and construction of such electrical apparatus or parts of such electrical apparatus. the electrical circuits exposed to the potentially explosive atmosphere are evaluated for use in such an atmosphere by applying this standard.2normative referencesthe following normative documents contain provisions which, through reference in this text, constitute provisions of this part of as/nzs 60079. at the time of publication, the editions indicated were valid. all normative documents are subject to revision, and parties to agreements based on this part of as/nzs 6079 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. members of iec and iso maintain registers of currently valid international standards.references to international standards that are struck through in this clause are replaced by references to identical australian or australian/new zealand standards that are listed immediately thereafter and identified by shading.iec 60079-0:1998, electrical apparatus for explosive gas atmospheres part 0: general requirementsas/nzs 60079.0:2000, electrical apparatus for explosive gas atmospheres, part 0: general requirements (identical to iec 60079-0:1998)iec 60079-7:1990, electrical apparatus for explosive gas atmospheres part 7: increased safety eiec 60085:1984, thermal evaluation and classification of electrical insulationiec 60112:1979, method for determining the comparative and the proof tracking indices of solid insulating materials under moist conditionsas/nzs 4695.112:1996, fire hazard testing of electrotechnical products, part 112: method for determining the comparative and the proof tracking indices of solid insulating materials under moist conditions (identical to iec 60112:1979)iec 60127-1:1988, miniature fuses part 1: definitions for miniature fuses and general requirements for miniature fuse-linksiec 60127-2:1989, miniature fuses part 2: cartridge fuse-linksiec 60127-3:1988, miniature fuses part 3: sub-miniature fuse-linksiec 60529:1989, degrees of protection provided by enclosures (ip code)as 19391990, degrees of protection provided by enclosures for electrical equipment (ip code) (identical to iec 60529:1989)3definitionsfor the purpose of this part of as/nzs 60079, the definitions in iec 60079-0 and the following definitions apply:3.1intrinsically safe circuitcircuit in which any spark or any thermal effect produced in the conditions specified in this standard, which include normal operation and specified fault conditions, is not capable of causing ignition of a given explosive gas atmosphere3.2electrical apparatusassembly of electrical components, electrical circuits or parts of electrical circuits normally contained in a single enclosurenote 1 the term normally has been introduced to indicate that an apparatus may occasionally be in more than one enclosure, for example, a telephone or a radio transceiver with a hand microphone.note 2 this definition is more precise than that contained in iec 60079-0.3.3intrinsically safe apparatuselectrical apparatus in which all the circuits are intrinsically safe circuits3.4associated apparatuselectrical apparatus which contains both intrinsically safe circuits and non-intrinsically safe circuits and is constructed so that the non-intrinsically safe circuits cannot adversely affect the intrinsically safe circuitsnote associated apparatus may be eithera) electrical apparatus which has another type of protection listed in iec 60079-0 for use in the appropriate explosive gas atmosphere, or5the standard is downloaded from standard sharingb) electrical apparatus not so protected and which, therefore, shall not be used within an explosive gas atmosphere, for example a recorder which is not itself in an explosive gas atmosphere, but is connected to a thermocouple situated within an explosive atmosphere where only the recorder input circuit is intrinsically safe.3.5normal operationoperation of intrinsically safe apparatus or associated apparatus such that it conforms electrically and mechanically with the design specification produced by its manufacturer3.6faultany defect of any component, separation, insulation or connection between components, not defined as infallible by this standard, upon which the intrinsic safety of a circuit depends3.7countable faultfault which occurs in parts of electrical apparatus conforming to the constructional require- ments of this standard3.8non-countable faultfault which occurs in parts of electrical apparatus not conforming to the constructional requirements of this standard3.9infallible component or infallible assembly of componentscomponent or assembly of components that is considered as not subject to certain fault modes as specifi