1 Scope

1DV Modification of Clause 1 to replace with the following:

This part of IEC 60079 standard gives the specific requirements for the construction, testing and marking of electrical equipment, parts of electrical equipment and Ex components with the type of protection encapsulation “m” intended for use in explosive gas atmospheres or explosive dust atmospheres.

This part standard applies only for encapsulated electrical equipment, encapsulated parts of electrical equipment and encapsulated Ex components (hereinafter always referred to as “m” equipment) where the rated voltage does not exceed 11 kV.

The application of electrical equipment in atmospheres, which may contain explosive gas as well as combustible dust simultaneously, may require additional protective measures.

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 take account of any risk due to an emission of flammable or toxic gas from the dust.

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.

Where references are made to other IEC 60079 standards, the referenced requirements found in these standards shall apply as modified by any applicable U.S. National Differences.

Summary of Topics

The revision to UL 60079-18 dated February 7, 2019, is being issued to incorporate the following changes:

Correction to the Cable Pull Test Procedure in 8.2.5.1

Please note that the national difference document incorporates all of the US National Differences for UL 60079-18 based on IEC 60079-18, Explosive Atmospheres - Part 18: Equipment Protection by Encapsulation “m”, (fourth edition issued December 2014).