CSA C22.2 NO. 60079-31:25

Preface This is the harmonized CSA Group and ULSE standard for Explosive Atmospheres – Part 31: Equipment Dust Ignition Protection by Enclosure "t" . It is the third edition of CSA C22.2 No. 60079-31:25, and the third edition of UL 60079-31. This edition of CSA No. C22.2 60079-31 supersedes the previous edition published in October 2015. This edition of UL 60079-31 supersedes the previous edition published on June 2015. This harmonized standard is based on IEC Publication IEC 60079-31: Third edition Explosive Atmospheres – Part 31: Equipment Dust Ignition Protection by Enclosure "t" issued January 2022. IEC 60079-31 is copyrighted by the IEC. This harmonized standard was prepared by CSA Group and ULSE. The efforts and support of the Technical Harmonization Subcommittee, THC 79-31 on the Harmonization of Electrotechnical Standards of the Nations of the Americas (CANENA), are gratefully acknowledged. This standard is considered suitable for use for conformity assessment within the stated scope of the standard. This standard was reviewed 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 CSA Technical Committee. This standard has been developed in compliance with the 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 is applicable to equipment protected by enclosure and surface temperature limitation for use in explosive dust atmospheres. It specifies requirements for design, construction and testing of Ex Equipment and Ex Components. 1DV.1 DR Modification of Clause 1 first paragraph as follows: Replace "part of IEC 60079" with "document". This document supplements and modifies the general requirements of IEC 60079-0. Where a requirement of this document conflicts with a requirement of IEC 60079-0, the requirement of this document takes precedence. 1DV.2 DR Modification of Clause 1 second paragraph as follows: Replace "IEC 60079-0" with "UL 60079-0 and CSA C22.2 No. 60079-0". This document does not apply to dusts of explosives, which do not require atmospheric oxygen for combustion, or to pyrophoric substances. This document does not apply to Ex Equipment or Ex Components 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 document does not take account of any hazard due to an emission of flammable or toxic gas from the dust. This document does not contain requirements for Ex Equipment used in areas where both combustible dust and explosive gas atmospheres can occur, whether simultaneously or separately. Requirements for explosive gas atmospheres can be found in other parts of the IEC 60079 series. Guidance on Ex Equipment to be used where combustible dust and explosive gas atmospheres occur simultaneously ("hybrid mixtures") can be found in IEC 60079-14. 1DV.3 DR Modification of Clause 1 sixth paragraph as follows: Replace "IEC 60079" with "UL 60079 and CSA C22.2 No. 60079". Where the Ex Equipment has to meet other environmental conditions, for example, protection against ingress of water and resistance to corrosion, additional measures which do not adversely affect the integrity of the enclosure can be necessary. 1DV.4 DR Modification of Clause 1 to add the following: Where references are made to other IEC 60079 standards, the referenced requirements found in these standards apply as modified by any applicable US National Differences and Canadian National Differences for the standard (see Clause 2).