Explosive Atmospheres - Part 11: Equipment Protection by Intrinsic Safety "i"

UL 60079-11

1 Scope

This part of IEC 60079 specifies the construction and testing of intrinsically safe apparatus intended for use in an explosive gas atmosphere and for associated apparatus, which is intended for connection to intrinsically safe circuits which enter such atmospheres.

1DV.1 Modification of the Clause 1 first paragraph, replace with the following:

1DV.1.1 This standard specifies the construction and testing of intrinsically safe apparatus intended for use in Class I, Zone 0, 1, or 2 hazardous (classified) locations as defined by the National Electrical Code, NFPA 70 and for associated apparatus, which is intended for connection to intrinsically safe circuits which enter such atmospheres.

This type of protection is applicable to electrical apparatus in which the electrical circuits themselves are incapable of causing an explosion in the surrounding explosive atmospheres.

This standard is also applicable to electrical apparatus or parts of electrical apparatus located outside the explosive gas atmosphere or protected by another type of protection listed in IEC 60079-0, where the intrinsic safety of the electrical circuits in the explosive gas atmosphere may depend upon the design and construction of such electrical apparatus or parts of such electrical apparatus. The electrical circuits exposed to the explosive gas atmosphere are evaluated for use in such an atmosphere by applying this standard.

The requirements for intrinsically safe systems are provided in IEC 60079-25. The requirements for intrinsically safe concepts for fieldbus are provided in IEC 60079-27. 1DV.2 Modification of Clause 1 fourth paragraph as follows:



1DV.2.1 Delete first sentence.

This standard supplements and modifies the general requirements of IEC 60079-0, except as indicated in Table 1. Where a requirement of this standard conflicts with a requirement of IEC 60079-0, the requirements of this standard shall take precedence.

If associated apparatus is placed in the explosive gas atmosphere, it must be protected by an appropriate type of protection listed in IEC 60079-0, and then the requirements of that method of protection together with the relevant parts of IEC 60079-0 also apply to the associated apparatus.

1.3DV Addition of 1.3DV:

1.3DV.1 The U.S. version of IEC 60079-11 does not include requirements for Group I electrical apparatus. Requirements for Group I electrical apparatus included in this document are to be considered omitted in all instances where they appear.

1.4DV Addition of 1.4DV:

1.4DV.1 Where references are made to IEC 60079 standards, the referenced requirements found in these standards shall apply as modified by any applicable U.S. National Differences.Table 1 - Exclusion of specific clauses of IEC 60079-0