CSA C22.2 No. 60079-31:15

(IEC 60079-31:2013, MOD)

National Standard of Canada Norme nationale du Canada (reaffirmed/confirmée en 2020)

CSA C22.2 No. 60079-31:15

Explosive atmospheres — Part 31: Equipment dust ignition protection by enclosure "t"

(IEC 60079-31:2013, MOD)

CSA C22.2 No. 60079-31:15

Atmosphères explosives — Partie 31 : Protection contre l’inflammation de poussières par enveloppe “t” relative au matériel (IEC 60079-31:2013, MOD)

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  Title: Explosive atmospheres — Part 31: Equipment dust ignition protection by enclosure "t"

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National Standard of Canada

CSA C22.2 No. 60079-31:15

Explosive atmospheres — Part 31: Equipment dust ignition protection by enclosure "t"

(IEC 60079-31:2013, MOD)

Prepared by

International Electrotechnical Commission

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ICS 29.260.20

ISBN 978-1-4883-0045-5

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CSA C22.2 No. 60079-31:15

Explosive atmospheres — Part 31: Equipment dust ignition

protection by enclosure "t"

CSA C22.2 No. 60079-31:15

Explosive atmospheres — Part 31: Equipment dust ignition protection by enclosure "t"

(IEC 60079-31:2013, MOD)

CSA Preface

This is the second edition of CAN/CSA-C22.2 No. 60079-31, Explosive atmospheres — Part 31: Equipment dust ignition protection by enclosure “t”, which is an adoption, with Canadian deviations, of the identically titled IEC (International Electrotechnical Commission) Standard 60079-31

(second edition, 2013-11). It supersedes the previous edition published in 2012 as

CAN/CSA-C22.2 No. 60079-31 (adopted IEC 60079-31:2008). 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 “CAN/CSA-C22.2 No. 60079-31” throughout.

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.

Interpretations: The Strategic Steering Committee on Requirements for Electrical Safety has provided the following direction for the interpretation of standards under its jurisdiction: “The literal text shall be used in judging compliance of products with the safety requirements of this Standard. When the literal text cannot be applied to the product, such as for new materials or construction, and when a relevant committee interpretation has not already been published, CSA Group’s procedures for interpretation shall be followed to determine the intended safety principle.”

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October 2015 © 2015 Canadian Standards Association CSA/8

CSA C22.2 No. 60079-31:15

Explosive atmospheres — Part 31: Equipment dust ignition

protection by enclosure "t"

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October 2015 © 2015 Canadian Standards Association CSA/9

IEC 60079-31

®

Edition 2.0 2013-11

INTERNATIONAL STANDARD

NORME INTERNATIONALE

Explosive atmospheres –

Part 31: Equipment dust ignition protection by enclosure "t"

Atmosphères explosives –

IEC 60079-31:2013

Partie 31: Protection contre l’inflammation de poussières par enveloppe “t” relative au matériel

– 2 – 60079-31 © IEC:2013

CONTENTS

FOREWORD 3

1. Scope 6

2. Normative references 6

3. Terms and definitions 6

4. General 7

   1. Levels of protection 7

   2. Equipment groups and ingress protection 7

   3. Requirements for electrical equipment with level of protection “ta” 8

      1. Fault current 8

      2. Maximum surface temperature 8

      3. Overpressure 8

      4. Dust exclusion 8

      5. Protective devices 8

      6. Protection for arcing and sparking parts 9

   4. Requirements for electrical equipment with Level of Protection “tb” and

      “tc” 9

      1. Maximum surface temperature 9

      2. Over pressure 9

      3. Dust exclusion 9

5. Construction 9

   1. Joints 9

      1. General 9

      2. Threaded joints 10

      3. Gaskets and seals 10

      4. Cemented joints 10

      5. Operating rods, spindles and shafts 10

      6. Windows 10

   2. Cable glands 11

   3. Entries 11

      1. Plain entries 11

      2. Threaded entries 11

6. Verification and tests 11

   1. Type tests 11

      1. Type tests for dust exclusion by enclosures 11

      2. Thermal tests 12

   2. Routine tests 12

7. Marking 12

Bibliography 14

Table 1 – Level of Protection, equipment group and ingress protection (IP) relationship 7

CAN/CSA-C22.2 No. 60079-31:15

– 6 – 60079-31 © IEC:2013

EXPLOSIVE ATMOSPHERES –

Part 31: Equipment dust ignition protection by enclosure "t"

1. Scope

   
   

   This part of IEC 60079 is applicable to electrical equipment protected by enclosure and surface temperature limitation for use in explosive dust atmospheres. It specifies requirements for design, construction and testing of electrical equipment and Ex Components.

   
   

   This standard supplements and modifies the general requirements of IEC 60079-0. Where a requirement of this standard conflicts with a requirement of IEC 60079-0, the requirement of this standard takes precedence.

   
   

   This standard does not apply to dusts of explosives, which do not require atmospheric oxygen for combustion, or to pyrophoric substances.

   
   

   This standard does not apply to electrical 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 standard does not take account of any risk due to an emission of flammable or toxic gas from the dust.

   
   

   Consideration of additional protective measures is required where the application of electrical equipment is in atmospheres, which can contain combustible dust as well as explosive gas, whether simultaneously or separately.

   
   

   Where the electrical equipment has to meet other environmental conditions, for example, protection against ingress of water and resistance to corrosion, additional measures can be necessary. The measures used should not adversely affect the integrity of the enclosure.

   
   

2. Normative references

   
   

   The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

   
   

   IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements

   
   

   IEC 60127 (all parts), Miniature fuses

   
   

   IEC 60691, Thermal-links – Requirements and application guide

   
   

   ISO 965-1, ISO general-purpose metric screw threads – Tolerances – Part 1: Principles and basic data

   
   

3. Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 60079-0, as well as the following definitions, apply.

NOTE Additional definitions applicable to explosive atmospheres can be found in IEC 60050-426.

CAN/CSA-C22.2 No. 60079-31:15