UL 60079-25-2015 UL Standard for Safety Explosive Atmospheres - Part 25 Intrinsically Safe Electrical Systems (Second Edition).pdf

1、 UL 60079-25 STANDARD FOR SAFETY Explosive Atmospheres - Part 25: Intrinsically Safe Electrical Systems UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT P

2、ERMISSION FROM UL UL Standard for Safety for Explosive Atmospheres - Part 25: Intrinsically Safe Electrical Systems, UL 60079-25 Second Edition, Dated December 2, 2011 Summary of Topics Adoption of ANSI/ISA 60079-25, Standard for Explosive Atmospheres - Part 25: Intrinsically Safe Electrical Systems

3、 as ANSI/UL 60079-25. This Standard is being issued to update the title page to reflect the reaffirmation of its ANSI approval. No changes in requirements have been made. Although this is the first-time publication of this Standard by UL, it is being published as the Second edition in order to align

4、 ULs edition number with that of the ISA and IEC Standards. Please note that as this is a simple reaffirmation of an existing ISA standard, National Differences are shown in ISAs format. All future revisions for this standard will be published using ULs National Differences. These requirements are s

5、ubstantially in accordance with Proposal(s) on this subject dated September 25, 2015. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical photocopying, recording, or otherwise without prior

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10、79-25-2011 (R2015) Second Edition Underwriters Laboratories Inc. ANSI/UL 60079-25 Second Edition Explosive Atmospheres - Part 25: Intrinsically Safe Electrical Systems December 2, 2011 (Title Page Reprinted: November 20, 2015) ANSI/ISA/UL 60079-25-2011 (R2015) UL COPYRIGHTED MATERIAL NOT AUTHORIZED

11、FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL Commitment for Amendments This standard is issued jointly by ISA and Underwriters Laboratories Incorporated (UL). Comments or proposals for revisions on any part of the standard may be submitted to UL at any time. ISBN 978-1-941546-

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15、including revisions through November 20, 2015. The most recent designation of ANSI/UL 60079-25 as a Reaffirmed American National Standard (ANS) occurred on November 20, 2015. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page, or effective date information. T

16、he National Difference Page and IEC Foreword are also excluded from the ANSI approval of IEC-based standards. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standard

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19、SION FROM UL 1 ANSI/ISA-60079-25-2011 (R2015) ANSI/UL 60079-25 November 20, 2015 General Notes This UL Standard is based on IEC Publication IEC 60079-25: Second edition, Explosive Atmospheres - Part 25: Intrinsically Safe Electrical Systems, and is copyrighted by the IEC. Efforts have been made to s

20、ynchronize the UL edition number with that of the corresponding IEC standard with which this standard is harmonized. As a result, one or more UL edition numbers have been skipped to match that of the IEC edition number. This is the common ISA and UL standard for Explosive Atmospheres - Part 25: Intr

21、insically Safe Electrical Systems. It is the Second edition of ANSI/ISA-60079-25 (superseding ANSI/ISA-12.02.05)-2011 and the Second edition of ANSI/UL 60079-25. The document is a modification of the IEC document and includes U.S. national differences encompassing both additions and deletions of inf

22、ormation. As the publication of this standard by UL is being done as a result of a simple reaffirmation of ISAs currently published standard, National Differences are shown using ISAs format. All future publications of this standard will show National Differences using ULs format. This common standa

23、rd was prepared by the (ISA) - The International Society of Automation on November 23, 2011 but is now being maintained by Underwriters Laboratories Inc. (UL). Note: Although the intended primary application of this standard is stated in its scope, it is important to note that it remains the respons

24、ibility of the users of the standard to judge its suitability for their particular purpose. Level of harmonization This standard adopts the IEC text with national differences. The requirements in this Standard are not presented in different formats by UL and ISA as this is a simple reaffirmation of

25、an existing ISA standard. Therefore, the UL version of the standard is being published as the ISA version of the standard which illustrates the national differences from the IEC text through the use of legislative text (strike-out and underline). Interpretations The interpretation by the SDO of an i

26、dentical 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 revision shall be proposed as soon as possible to each of the SD

27、Os to more accurately reflect the intent. UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL November 20, 2015 ANSI/ISA-60079-25-2011 (R2015) ANSI/UL 60079-25 2 Preface (ISA) The preface, as well as all footnotes and annexes, is included for in

28、formation purposes and is not part of ANSI/ISA-60079-25-2011(R2015). 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. The ISA St

29、andards and Practices Department is aware of the growing need for 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 standar

30、ds of incorporating suitable references to the SI (and the metric system) in their business and professional dealings with other countries. Toward this end, this Department will endeavour to introduce SI-acceptable metric units in all new and revised standards, recommended practices, and technical r

31、eports to the greatest extent possible. Standard for Use of the International System of Units (SI): The Modern Metric System, published by the American Society for Testing any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governm

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39、 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. UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PE

40、RMISSION FROM UL November 20, 2015 ANSI/ISA-60079-25-2011 (R2015) ANSI/UL 60079-25 8 International Standard IEC 60079-25 has been prepared by subcommittee 31G: Intrinsically safe apparatus, of IEC technical committee 31: Equipment for explosive atmospheres. This second edition cancels and replaces t

41、he first edition published in 2003 and constitutes a technical revision. The significant changes with respect to the previous edition are listed below: extension of the scope from Group II to Groups I, II and III; introduction of level of protection “ic”; addition of requirements for cables and mult

42、i-core cables; reference to IEC 60079-11 regarding the termination of intrinsically safe circuit; requirements for the assessment of an expanded and clarified intrinsically safe system regarding level of protection “ic”, simple apparatus and faults in multi-core cables; introduction of predefined sy

43、stems and merging of the system requirements for FISCO from IEC 60079-27; addition of requirements for simple intrinsically safe systems containing both lumped inductance and lumped capacitance; addition of a method for testing the electrical parameters of cables; additional information for the use

44、of simple apparatus in systems. The text of this standard is based on the following documents: FDIS Report on voting 31G/202/FDIS 31G/203/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

45、drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts of IEC 60079 series, under the general title Explosive atmospheres can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged until the maintenance result date i

46、ndicated 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; UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 9 ANSI/ISA-60079-25-201

47、1 (R2015) ANSI/UL 60079-25 November 20, 2015 replaced by a revised edition; or amended. UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL November 20, 2015 ANSI/ISA-60079-25-2011 (R2015) ANSI/UL 60079-25 10 This page intentionally left blank.

48、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 11 ANSI/ISA-60079-25-2011 (R2015) ANSI/UL 60079-25 November 20, 2015 CONTENTS 1 Scope 16 2 Normative References 16 3 Terms, definitions and abbreviations 17 3.1 Terms and definitions 17 3.2 Abb

49、reviations 18 4 Descriptive system document . 18 5 Grouping and classification 19 6 Levels of protection 19 6.1 General . 19 6.2 Level of protection “ia” 19 6.3 Level of protection “ib” 19 6.4 Level of protection “ic” 20 7 Ambient temperature rating 20 8 Interconnecting wiring / cables used in an intrinsically safe electrical system . 20 9 Requirements of cables and multi-core multi-conductor cables . 20 9.1 General . 20 9.2 Multi-core Multi-conductor cables 21 9.