1、 AMERICAN NATIONAL STANDARD ANSI/ISA-60079-7 (12.16.01)-2008 (R2013) Supercedes ANSI/ISA-60079-7 (12.16.01)-2002 Explosive Atmospheres - Part 7: Equipment protection by increased safety “e“ Approved 31 May 2013 Commitment for Amendments This standard is issued jointly by ISA and Underwriters Laborat
2、ories Incorporated (UL). Comments or proposals for revisions on any part of the standard may be submitted to ISA or UL at any time. Revisions to this standard will be made only after processing according to the standards development procedures of ISA and UL. ISA and UL will issue revisions to this s
3、tandard by means of a new edition or revised or additional pages bearing their date of issue. ISBN: 978-0-876640-23-4 Copyright 2013 By ISA These materials are subject to copyright claims of IEC, ANSI, and ISA. All rights reserved. Not for resale. Printed in the United States of America. No part of
4、this publication may be reproduced in any form, including an electronic retrieval system, without the prior written permission of ISA. All requests pertaining to this standard should be submitted to ISA. ISBN Copyright 2013 Underwriters Laboratories Incorporated Revisions of this standard will be ma
5、de by issuing revised or additional pages bearing their date of issue. A UL standard is current only if it incorporates the most recently adopted revisions, all of which are itemized on the transmittal notice that accompanies the latest set of revised requirements. The most recent designation of ANS
6、I/ISA-60079-7 and ANSI/UL 60079-7 as an American National Standard occurred on 31 May 2013. This ANSI/UL Standard for Safety, which consists of the fourth edition, is under continuous maintenance, whereby each revision is ANSI approved upon publication. Comments or proposals for revisions on any par
7、t of the standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. ISA Underwriters Laboratories Inc. ANSI/ISA-60079-7 ANSI/UL 60079-7 Fourth Edition Fourth Edition Explosive Atmospher
8、es - Part 7: Equipment protection by increased safety “e“ This page intentionally left blank.31 May 2013 ANSI/ISA-60079-7 ANSI/UL 60079-7 5 General Notes This is the common ISA and UL standard for Explosive Atmospheres - Part 7: Equipment protection by increased safety “e“. It is the fourth edition
9、of ANSI/ISA-60079-7 and the fourth edition of ANSI/UL 60079-7. The document is a modification of the IEC document and includes U.S. deviations encompassing both additions and deletions of information. ANSI/ISA-60079-7 and ANSI/UL 60079-7 contain identical requirements, and identical publication date
10、s. The presentation and format of the standards material may differ between the two published standards. This common standard was prepared by ISA and Underwriters Laboratories Inc. (UL). Although the intended primary application of this standard is stated in its scope, it is important to note that i
11、t remains the responsibility of the users of the standard to judge its suitability for their particular purpose. Level of harmonization This standard adopts the IEC text with deviations. The requirements are presented in different formats. The ISA version of the standard illustrates the national dif
12、ferences from the IEC text through the use of legislative text (strike-out and underline). The UL version of the standard illustrates national differences immediately following the IEC text. National differences between the UL version and the ISA version shall be word for word except for editorial c
13、hanges. Interpretations The interpretation by the SDO of an identical or equivalent standard shall be based on the literal text to determine compliance with the standard in accordance with the procedural rules of the SDO. If more than one interpretation of the literal text has been identified, a rev
14、ision shall be proposed as soon as possible to each of the SDOs to more accurately reflect the intent. UL Effective Date The requirements in this standard are effective 15 October 2011. This page intentionally left blank. 31 May 2013 ANSI/ISA-60079-7 ANSI/UL 60079-7 7 Preface This ISA standard is ba
15、sed on IEC Publication 60079-7. It is the intention of the ISA12 Committee to develop an ANSI Standard that is harmonized with IEC 60079-7 to the fullest extent possible. This preface, as well as all footnotes and annexes, is included for information purposes and is not part of ANSI/ISA-60079-7 (12.
16、16.01)-2008 (R2013). The standards referenced within this document may contain provisions which, through reference in this text, constitute requirements of this document. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements b
17、ased on this document are encouraged to investigate the possibility of applying the most recent editions of the standards indicated within this document. Members of IEC and ISO maintain registers of currently valid International Standards. ANSI maintains registers of currently valid U.S. National St
18、andards. This document has been prepared as part of the service of ISA toward a goal of uniformity in the field of instrumentation. To be of real value, this document should not be static but should be subject to periodic review. Toward this end, the Society welcomes all comments and criticisms and
19、asks that they be addressed to the Secretary, Standards and Practices Board; ISA; 67 Alexander Drive; P. O. Box 12277; Research Triangle Park, NC 27709; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: standardsisa.org. The ISA Standards and Practices Department is aware of the growing need for
20、 attention to the metric system of units in general, and the International System of Units (SI) in particular, in the preparation of instrumentation standards. The Department is further aware of the benefits to USA users of ISA standards of incorporating suitable references to the SI (and the metric
21、 system) in their business and professional dealings with other countries. Toward this end, this Department will endeavor to introduce SI-acceptable metric units in all new and revised standards, recommended practices, and technical reports to the greatest extent possible. Standard for Use of the In
22、ternational System of Units (SI): The Modern Metric System, published by the American Society for Testing b) provide a means to avoid loosening of the connection in service; c) be such that contact is assured without damage to the conductors such that would impair the ability of the conductors to fu
23、lfil their function, even if multi-stranded conductors are used in connections intended for direct clamping of a single conductor; d) provide a positive compression force to assure contact pressure in service; e) be constructed in such a way that the contact they assure is not appreciably impaired b
24、y temperature changes occurring in normal service; f) except as permitted by the earth continuity test of IEC 60079-0, provide contact pressure that is not applied through insulating materials; g) not be specified to accommodate more than one individual conductor in a clamping point unless specifica
25、lly designed and assessed for doing so; h) if intended for stranded conductors, employ a means to protect the conductors and distribute the contact pressure evenly. The method of applying contact pressure shall be capable, on installation, of reliably forming the stranded conductor into an effective
26、ly solid shape that does not subsequently change in service. Alternatively, the method of applying the contact pressure should be such that it is designed to accommodate any settlement of the strands in service; i) for screw connections, have a specified torque value; j) for screwless connections, i
27、ntended for class 5 and/or class 6 fine-stranded conductors according to IEC 60228, the fine-stranded wire shall be equipped with a ferrule or the termination shall have a method to open the clamping mechanism so that neither the conductors nor the clamping mechanism is are not damaged during the in
28、stallation of the conductor. NOTE 1 The use of aluminium wire may cause difficulties by compromising critical creepage and clearance distances when anti-oxidant materials are applied. The connection of aluminium wire to terminals may be accomplished by the use of suitable bi-metallic connection devi
29、ces providing a copper connection to the terminal. NOTE 2 Special precautions against vibration and mechanical shock may be required. NOTE 3 Special precautions against electrolytic corrosion should be considered. NOTE 4 Special precautions against corrosion should be considered where ferrous materi
30、als are used. NOTE 5 The limiting temperature of the insulation of terminal blocks and accessories will usually be based on the limiting temperature of the insulation in accordance with item a) of 4.7.2 but the limiting temperature allocated to the terminal when used in equipment will also depend on
31、 the maximum cable insulation temperature rating of the cable which is to be connected. 31 May 2013 ANSI/ISA-60079-7 ANSI/UL 60079-7 26 4.2.2 Field wiring connections 4.2.2.1 General Terminals for field wiring shall be generously dimensioned to permit the effective connection of copper conductors of
32、 cross-section equal to at least that corresponding to the rated current of the electrical apparatus. Connections shall be located in a position such that where required to be inspected in service they are reasonably accessible. The number and size of copper conductors that can be safely connected s
33、hall be specified in the descriptive documentation according to IEC 60079-0 ANSI/ISA-60079-0. NOTE: ANSI/UL 1059 and ANSI/UL 486E require terminals to be identified with the permitted wire sizes in AWG or kcmil. 4.2.2.2 Connections made using terminals complying with ANSI/UL 60947-7-1IEC 60947-7-1,
34、ANSI/UL 60947-7-2 IEC 60947-7-2, ANSI/UL 1059, or ANSI/UL 486E, IEC 60999-1, or IEC 60999-2 Such terminals are intended for the connection of copper conductors with the insulation locally removed and without the addition of intermediate parts other than those replicating the form of a bare conductor
35、, such as a ferrule. Terminals shall be subject to the terminal insulation material tests of 6.9. Terminals with a rated voltage greater than 1500 V shall be subjected to the applicable examination and tests of ANSI/UL 1059 and ANSI/UL 486E except for the dielectric tests which shall be conducted in
36、 accordance with 6.10. Terminals shall be capable of being fixed in their mountings. The temperature rise of the conductor bar shall not exceed 45 K at a test current of 110 % of rated current according to the method of the temperature-rise test of IEC 60947-7-1ANSI/UL 60947-7-1. NOTE 1 The temperat
37、ure rise limit in ANSI/UL 1059 is more restrictive and is limited to a rise of 30K at 100% of rated current. NOTE 2 This test relates to the absolute maximum current rating of the terminal when tested without any enclosure. For practical purposes, when terminals are used in multiple within enclosure
38、s, it will be necessary to establish reduced current ratings according to the particular circumstances. See 5.8, 6.7 and Annex E. Terminals for connecting conductors of rated cross-section not exceeding 4 mm2 (12 AWG) shall also be suitable for the effective connection of conductors at least two ISO
39、 wire sizes smaller if not otherwise specified in the certificate. See Annex F. NOTE 2 Subclause 4.2.2.2 is primarily intended to give requirements for terminals as components. When mounted in equipment any consequent limitations given in this standard apply. 4.2.2.3 Field wiring connection faciliti
40、es integral to “e” apparatus or components Terminals shall meet the requirements of 4.2.2.2, where applicable. 31 May 2013 ANSI/ISA-60079-7 ANSI/UL 60079-7 27 Temperatures for the verification of the thermal stability of materials shall be determined using a test sample configured to represent the c
41、omplete apparatus, from a heating perspective, in accordance with ANSI/ISA-60079-0 IEC 60079-0. 4.2.2.4 Connections designed to be used with cable lugs and similar devices Such connections shall be fixed in their mountings. A means of securing the cable to prevent rotation or movement shall be provi
42、ded to avoid either loosening or compromising creepage and clearance. Alternatively, it shall be demonstrated that such rotation or movement is not reasonably foreseeable. 4.2.2.5 Connections using permanent arrangements These connections are typically tails with crimping or soldering facilities tha
43、t are intended to be connected during installation using appropriate connection methods. Either a means of fixing the completed connections to a suitable location is to be provided or the completed connections are to be provided with means of reliably insulating them to the requirements of this stan
44、dard. If the method of connection is by soldering, a method of providing mechanical support of the completed connection shall be provided. The security of the joint shall not be permitted to rely solely on the solder. 4.2.3 Factory connections 4.2.3.1 General Factory connections shall be either fixe
45、d in a specific location or be provided with means of meeting the creepage and clearance requirements of this standard. 4.2.3.2 Field wiring connection methods used for factory connections Any of the connection methods suitable for use as field wiring connections may be used for a factory connection
46、, except in this case, the terminal insulation material tests of 6.9 need not be conducted. 4.2.3.3 Permanent connections Permanent connections shall only be made by a) crimping, b) brazing, c) welding, d) soldering, provided that the conductors are not supported by the soldered connection alone. Te
47、rminals with a rated voltage greater than 1500 V shall be subjected to the applicable examination and tests of ANSI/UL 1059 and ANSI/UL 486E except for the dielectric tests which shall be conducted in accordance with 6.10. 31 May 2013 ANSI/ISA-60079-7 ANSI/UL 60079-7 28 4.2.3.4 Pluggable connections
48、 These connections are designed to be readily connected or disconnected during assembly, maintenance, or repair. NOTE Typical examples are plug-in components, and card edge connectors. Pluggable connections shall provide the following: a) each connection shall employ at least two contact arrangement
49、s where the effectiveness of each is substantially independent of the other; b) each connection or group of connections shall be provided with a mechanical retaining device, which, excluding internal friction, provides a force resisting separation of at least 30 N. Where a group of individual connections is mechanically linked and the separable component weighs more than 0,25 kg or carries more than 10 cables, special consideration shall be given to the security of the connection; c) for a lightweight connecting component relying on friction to remain in p
