BS EN 60079-15:2010 - Page 2

Explosive atmospheres. Equipment protection by type of protection "n" | Status: Current, Partially replaced, Superseded

1 Scope This part of IEC 60079 specifies requirements for the construction, testing and marking for Group II electrical equipment with type of protection, "n" intended for use in explosive gas atmospheres. This standard applies to electrical equipment where the rated voltage does not exceed 15 kV r.m.s. a.c. or d.c. This part of IEC 60079 is applicable to non-sparking electrical equipment and also to electrical equipment with parts or circuits producing arcs or sparks or having hot surfaces which, if not protected in one of the ways specified in this standard, could be capable of igniting a surrounding explosive gas atmosphere. This standard describes several different methods by which this can be achieved which may be combined with other methods described in IEC 60079‑0. 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 requirement of this standard takes precedence. Table 1 — Relationship of this part to IEC 60079‑0 Clause of IEC 60079‑0 IEC 60079‑0 clause application to IEC 60079‑15 Ed. 5.0 (2007) (informative) Ed. 6.01 (future edition) (informative) Clause / Subclause title (normative) Protected spar king Non sparking Restricted breathing nC nA nR 4 4 Equipment grouping Applies Applies Applies 4.1 4.1 Group I Excluded Excluded Excluded 4.2 4.2 Group II Applies Applies Applies 4.3 4.3 Group III Excluded Excluded Excluded 4.4 4.4 Equipment for a particular explosive atmosphere Applies Applies Applies 5.1 5.1 Environmental influences Applies Applies Applies 5.1.1 5.1.1 Ambient temperature Applies Applies Applies 5.1.2 5.1.2 External source of heating or cooling Applies Applies Applies 5.2 5.2 Service temperature Applies Applies Applies 5.3.1 5.3.1 Determination of maximum surface temperature Applies Applies Applies 5.3.2.1 5.3.2.1 Group I electrical equipment Excluded Excluded Excluded 5.3.2.2 5.3.2.2 Group II electrical equipment Applies Applies Applies 5.3.2.3 5.3.2.3 Group III electrical equipment Excluded Excluded Excluded 5.3.3 5.3.3 Small component temperature for Group I and Group II electrical equipment Applies Applies Excluded 6.1 6.1 General Applies Applies Applies 6.2 6.2 Mechanical strength Applies Applies Applies 6.3 6.3 Opening times Excluded Excluded Applies 6.4 6.4 Circulating currents Applies Applies Applies 6.5 6.5 Gasket retention Applies Applies Applies 6.6 6.6 Electromagnetic and ultrasonic radiating equipment Applies Applies Applies 7.1.1 7.1.1 Applicability Applies Applies Applies 7.1.2 7.1.2 Specification of materials Applies Applies Applies 7.1.3 7.1.2.2 Plastic materials Applies Applies Applies 7.1.4 7.1.2.3 Elastomeric materials Applies Applies Applies 7.2 7.2 Thermal endurance Applies Applies Applies 7.3 7.3 Resistance to light Applies Applies Applies 7.4 7.4 Electrostatic charges on external non-metallic materials Applies Applies Applies 7.5 9.1 Threaded holes Applies Applies Applies 8.1.1 8.2 Group I Excluded Excluded Excluded 8.1.2 8.3 Group II Applies Applies Applies 8.1.3 8.4 Group III Excluded Excluded Excluded 8.2 9.1 Threaded holes Applies Applies Applies 9.1 9.1 General Applies Applies Applies 9.2 9.2 Special fasteners Excluded Excluded Excluded 9.3 9.3 Holes for special fasteners Excluded Excluded Excluded 10 10 Interlocking devices Excluded Excluded Excluded 11 11 Bushings Applies Applies Applies 12 12 Materials used for cementing Modified Modified Modified 13 13 Ex components Applies Applies Applies 14 14 Connection facilities and termination compartments Modified Modified Modified 15 15 Connection facilities for earthing and bonding conductors Applies Applies Applies 16 16 Entries into enclosures Applies Applies Applies 17 17 Supplementary requirements for rotating electrical machines Excluded Modified Excluded 18 18 Supplementary requirements for switchgear Applies Applies Applies 19 19 Supplementary requirements for fuses Modified Modified Modified 20 20 Supplementary requirements for plugs and sockets Modified Modified Modified 21 21 Supplementary requirements for luminaires Modified Modified Modified 22 22 Supplementary requirements for caplights and handlights Applies Applies Applies 23 23 Equipment incorporating cells and batteries Modified Modified Modified 24 24 Documentation Applies Applies Applies 25 25 Compliance of prototype or sample with documents Applies Applies Applies 26.1 26.1 General Applies Applies Applies 26.2 26.2 Test configuration Applies Applies Applies 26.3 26.3 Tests in explosive test mixtures Applies Applies Applies 26.4 26.4 Tests of enclosures Applies Applies Applies 26.4.1.1 26.4.1.1 Metallic enclosures, metallic parts of enclosures and glass parts of enclosures Applies Applies Applies 26.4.1.2.1 26.4.1.2.1 Group I electrical equipment Excluded Excluded Excluded 26.4.1.2.2 26.4.1.2.2 Group II and Group III electrical equipment Applies Applies Applies 26.4.2 26.4.2 Resistance to impact Applies Applies Applies 26.4.3 26.4.3 Drop test Applies Applies Applies 26.4.4 26.4.4 Acceptance criteria Applies Applies Applies 26.4.5 26.4.5 Degree of protection by enclosure Applies Applies Applies 26.5 26.5 Thermal tests Applies Applies Applies 26.6 26.6 Torque test for bushings Applies Applies Applies 26.7 26.7 Non-metallic enclosures or non-metallic parts of enclosures Modified Modified Modified 26.8 26.8 Thermal endurance to heat Modified Modified Modified 26.9 26.9 Thermal endurance to cold Applies Applies Applies 26.10 26.10 Resistance to light Applies Applies Applies 26.11 26.11 Resistance to chemical agents for Group I electrical equipment Excluded Excluded Excluded 26.12 26.12 Earth continuity Applies Applies Applies 26.13 26.13 Surface resistance test of parts of enclosures of non-metallic materials Applies Applies Applies 26.14 - Charging tests Applies Applies Applies 26.15 26.14 Measurement of capacitance Applies Applies Applies 27 27 Routine tests Applies Applies Applies 28 28 Manufacturers responsibility Applies Applies Applies 29 29 Marking Applies Applies Applies 30 30 Instructions Applies Applies Applies Annex A Annex A Supplementary requirements for Ex cable glands Applies Applies Applies Annex B Annex B Requirements for Ex components Applies Applies Applies Annex C Annex C Example of rig for resistance to impact test Applies Applies Applies Annex D Annex D Introduction to an alternative risk assessment method encompassing “equipment protection levels” fro Ex equipment Applies Applies Applies Applies : this requirement of IEC 60079‑0 is applied without change. Excluded : this requirement of IEC 60079‑0 does not apply. Modified : this requirement of IEC 60079‑0 is modified as detailed in this standard.

NOTE 1 The clause number in the above table is shown for information only. The applicable requirements of IEC 60079‑0 are identified by the clause title which is normative. This document was written against the specific requirements of IEC 60079‑0 (ed. 5.0). The clause numbers for the previous edition are shown for information only. This is to enable the General Requirements IEC 60079‑0 (ed. 5.0) to be used where necessary with this part of IEC 60079. Where there were no requirements, indicated by “NR” or there is a conflict between requirements, the later edition requirements take precedence.

NOTE 2 A non-incendive component is limited in use to the particular circuit for which it has been shown to be non-ignition capable and, therefore, cannot be separately assessed as complying with this standard.

NOTE 3 Compliance with this standard does not imply any removal of, or lowering of the requirements of any other standard with which the electrical equipment complies.

NOTE 4 This part of IEC 60079 supplements, and may enhance, the requirements for equipment for normal industrial applications. Where compliance with other IEC standards is indicated, such as IEC 60034 for motors and IEC 60598‑2 for luminaires, proving compliance to those standards is normally the responsibility of the manufacturer.

NOTE 5 Type of protection “n” provides Equipment Protection Level (EPL) Gc. For further information, see IEC 60079‑0.