WG 22 - TC 31/WG 22

IEC 60050-426:2020 gives terms specifically relevant to explosive atmospheres. This new edition reviews and complements the previous one. This terminology is consistent with the terminology developed in the other specialized parts of the IEV.
It has the status of a horizontal standard in accordance with IEC Guide 108.

IEC 60079-0:2017 is also available as IEC 60079-0:2017 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60079-0:2017 specifies the general requirements for construction, testing and marking of Ex Equipment and Ex Components intended for use in explosive atmospheres. The standard atmospheric conditions (relating to the explosion characteristics of the atmosphere) under which it may be assumed that Ex Equipment can be operated are:
-temperature –20 °C to +60 °C;
-pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar); and
-air with normal oxygen content, typically 21 % v/v.
This part of IEC 60079 and other standards supplementing this standard specify additional test requirements for Ex Equipment operating outside the standard temperature range, but further additional consideration and additional testing may be required for Ex Equipment operating outside the standard atmospheric pressure range and standard oxygen content. Such additional testing may be particularly relevant with respect to Types of Protection that depend on quenching of a flame such as ‘flameproof enclosures “d”’ (IEC 60079-1) or limitation of energy, ‘intrinsic safety “i”’ (IEC 60079-11). This seventh edition cancels and replaces the sixth edition, published in 2011. This edition constitutes a technical revision. Refer to the Foreword of the document for a complete listing of the technical changes between edition 7.0 and the previous edition of the document.
Keywords: Ex Equipment and Ex Components intended for use in explosive atmospheres
The contents of the interpretation sheet 1 of April 2019, of the interpretation sheet 2 of June 2019 and the corrigendum 1 of January 2020 have been included in this copy.

IEC 60079-6:2015 specifies the requirements for the design, construction, testing and marking of Ex Equipment and Ex Components with type of protection liquid immersion "o" intended for use in explosive gas atmospheres. Ex Equipment and Ex Components of type of protection liquid immersion "o" are either:
- Level of Protection "ob" (EPL "Mb" or "Gb") or
- Level of Protection "oc" (EPL "Gc"). For Level of Protection "ob", this standard applies where the rated voltage does not exceed 11 kV r.m.s. a.c. or d.c. For Level of Protection "oc", this standard applies where the rated voltage does not exceed 15 kV r.m.s. a.c. or d.c. 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 fourth edition cancels and replaces the third edition, published in 2007. This edition constitutes a technical revision. The significant changes with respect to the previous edition are:
- Edition 4 represents a major technical revision of the requirements for oil immersion "o" and should be considered as introducing all new requirements. The normal "Table of Significant Changes" has not been included for this reason. In particular:
- The requirements for oil immersion "o" have been redefined into liquid immersion, levels of protection "ob" and "oc" as recommended by the responses to 31/715/DC;
- The ability to protect sparking contacts has been added to both "ob" and "oc". Additional requirements have been introduced for the protective liquid. Keywords: Ex Equipment and Ex Components with type of protection liquid immersion "o"

IEC 60079-5:2015 is available as IEC 60079-5:2015 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60079-5:2015 contains specific requirements for the construction, testing and marking of electrical equipment, parts of electrical equipment and Ex components in the type of protection powder filling "q", intended for use in explosive gas atmospheres. 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 applies to electrical equipment, parts of electrical equipment and Ex components with:
- a rated supply current less than or equal to 16 A;
- a rated supply voltage less than or equal to 1 000 V;
- a rated power consumption less than or equal to 1 000 W. This fourth edition cancels and replaces the third edition, published in 2007, and constitutes a technical revision. Refer to the Foreword of the document for a complete listing of the technical changes between edition 4.0 and previous edition of the document. Keywords: electrical equipment and Ex components in the type of protection powder filling "q"

IEC 60079-0:2011 specifies the general requirements for construction, testing and marking of electrical equipment and Ex Components intended for use in explosive atmospheres. Electrical equipment complying with this standard is intended for use in hazardous areas in which explosive gas atmospheres, caused by mixtures of air and gases, vapours or mists, exist under normal atmospheric conditions. The standard atmospheric conditions (relating to the explosion characteristics of the atmosphere) under which it may be assumed that electrical equipment can be operated are:
- temperature -20 °C to +60 °C;
- pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar); and
- air with normal oxygen content, typically 21 % v/v.
This standard and other standards supplementing this standard specify additional test requirements for equipment operating outside the standard temperature range, but further additional consideration and additional testing may be required for equipment operating outside the standard atmospheric pressure range and standard oxygen content, particularly with respect to types of protection that depend on quenching of a flame such as 'flameproof enclosure "d"' (IEC 60079-1) or limitation of energy, 'intrinsic safety "i"' (IEC 60079-11). This sixth edition cancels and replaces the fifth edition, published in 2007, and constitutes a full technical revision with numerous updates.
  IEC 60079-0:2011 is also available as IEC Standards+ 60079-0:2011 which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
The contents of the corrigenda of November 2012 and December 2013, and the interpretation sheets of November 2013, October 2014, June 2018 and April 2019 have been included in this copy.