CSA Preface 

This is the second edition of CSA C22.2 No. 60079-25, Explosive atmospheres - Part 25: Intrinsically safe electrical systems, which is an adoption, with Canadian deviations, of the identically titled IEC (International Electrotechnical Commission) Standard 60079-25 (third edition, 2020-06). It supersedes the previous edition, published in 2014 as CAN/CSA-C22.2 No. 60079-25 (adopted IEC 60079-25:2010). It is one in a series of Standards issued by CSA Group under Part II of the Canadian Electrical Code. For brevity, this Standard will be referred to as "CSA C22.2 No. 60079-25" throughout. This Standard is intended to be used in conjunction with CSA C22.2 No. 60079-0, Explosive atmospheres - Part 0: Equipment - General requirements. This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard. This Standard was reviewed for Canadian adoption by the CSA Integrated Committee on Hazardous Location Products, under the jurisdiction of the CSA Technical Committee on Industrial Products and the CSA Strategic Steering Committee on Requirements for Electrical Safety, and has been formally approved by the Technical Committee. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. 

Scope 

This part of IEC 60079 contains the specific requirements for design, construction and assessment of intrinsically safe systems, Type of Protection "i", intended for use, as a whole or in part, in locations in which the use of Group I, II or III Ex Equipment is required. 

NOTE 1 This standard is intended for use by the designer of the system e.g. a person who could be a manufacturer, a specialist consultant or a member of the end-user’s staff. This document supplements and modifies the general requirements of IEC 60079-0 and the intrinsic safety standard IEC 60079-11. Where a requirement of this standard conflicts with a requirement of IEC 60079-0 or IEC 60079-11, the requirement of this standard takes precedence. The installation requirements of Group II or Group III systems designed in accordance with this standard are specified in IEC 60079-14. 

NOTE 2 Group I installation requirements are presently not provided in IEC 60079-14. Installation requirements for Group I are being considered.