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.

1DV.1 Modification of Clause 1, first paragraph as follows:

1DV.1.1 Replace “part of IEC 60079” with “standard”.

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.

1DV.2 Modification of Clause 1, second paragraph as follows:

1DV.2.1 Replace “part of IEC 60079” with “standard”.

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

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

Table 1DV – 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 (2009)	Ed. 6.01 (future edition) 1Under consideration	Clause / Subclause title	Protected sparking	Non sparking	Restricted breathing
(informative)	(informative)	(normative)	nC	nA	nR
4	4	Equipment grouping	Applies	Applies	Applies
–	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	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
–	7.5	Accessible metal parts	Excluded	Excluded	Excluded
–	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	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	Resistance to chemical agents for Group I electrical equipment	Excluded	Excluded	Excluded
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
–	26.15	Verification of ratings of ventilating fans	Excluded	Excluded	Excluded
–	26.16	Alternative qualification of elastomeric sealing O-rings	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
–	Annex E	Temperature rise testing of electric machines	Applies	Applies	Applies
–	Annex F	Guideline flowchart for tests of non-metallic enclosures or non-metallic parts of enclosures	Applies	Applies	Applies
–	Annex G	Common standards – safety requirements for electrical equipment	Applies	Applies	Applies
–	Annex H	United States Major National Differences	Applies	Applies	Applies
–	Annex I	Equipment grounding	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.

1DV.3 Addition of 1DV.3.1

1DV.3.1 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.

• Cover
• Transmittal
• UL Harmonized Standard Title Page
• Table of Contents
• Foreword
• Deviations
• IEC Foreword
• Explosive atmospheres – Part 15: Equipment protection by type of protection "n"
• 1 Scope
• 2 Normative references
• 3 Terms and definitions
• 4 General
• 4.1 Equipment grouping and temperature classification
• 4.2 Potential ignition sources
• 5 Temperatures
• 5.1 Maximum surface temperature
• 5.2 Small components
• 6 Requirements for electrical equipment
• 6.1 General
• 6.2 Opening times
• 6.3 Minimum degree of protection
• 6.4 Clearances, creepage distances and separations
• 6.5 Electric strength
• 7 Connection facilities and terminal compartments
• 7.1 General
• 7.2 Field wiring connections
• 7.3 Factory connections
• 8 Supplementary requirements for non-sparking electrical rotating machines
• 8.1 General
• 8.2 Machine enclosure
• 8.3 Terminal boxes
• 8.4 Conduit stopping boxes, cable sealing and dividing boxes
• 8.5 Connection facilities for external conductors
• 8.6 Neutral point connections
• 8.7 Radial air gap
• 8.8 Rotor cages
• 8.9 Stator winding insulation system
• 8.10 Surface temperature limitation
• 9 Supplementary requirements for non-sparking fuses and fuse assemblies
• 9.1 Fuses
• 9.2 Temperature class of equipment
• 9.3 Fuse mounting
• 9.4 Fuse enclosures
• 9.5 Replacement fuse identification
• 10 Supplementary requirements for non-sparking plugs and sockets
• 10.1 Plugs and sockets for external connections
• 10.2 Maintaining degree of protection (IP code)
• 10.3 Sockets that do not have plugs inserted in normal operation
• 11 Supplementary requirements for non-sparking luminaires
• 11.1 General
• 11.2 Construction
• 11.3 Luminaires for tubular fluorescent bi-pin lamps
• 11.4 Other equipment containing light sources
• 12 Supplementary requirements for equipment incorporating non-sparking cells and batteries
• 12.1 General
• 12.2 Categorization of cells and batteries
• 12.3 General requirements for cells and batteries of types 1 and 2
• 12.4 Charging of type 1 and type 2 cells and batteries
• 12.5 Requirements for type 3 secondary batteries
• 12.6 Verification and tests
• 13 Supplementary requirements for non-sparking low power equipment
• 14 Supplementary requirements for non-sparking current transformers
• 15 Other non-sparking electrical equipment
• 16 General supplementary requirements for equipment producing arcs, sparks or hot surfaces
• 17 Supplementary requirements for enclosed-break devices and non-incendive components producing arcs, sparks or hot surfaces
• 17.1 Type testing
• 17.2 Ratings
• 17.3 Construction of enclosed-break devices
• 18 Supplementary requirements for hermetically sealed devices producing arcs, sparks or hot surfaces
• 19 Supplementary requirements for sealed devices producing arcs, sparks or hot surfaces
• 19.1 Non-metallic materials
• 19.2 Opening
• 19.3 Internal spaces
• 19.4 Handling
• 19.5 Gasket and seals
• 19.6 Type tests
• 20 Supplementary requirements for restricted-breathing enclosures protecting equipment producing arcs, sparks or hot surfaces
• 20.1 General
• 20.2 Constructional requirements
• 20.3 Temperature limitation
• 20.4 Additional requirements for restricted breathing luminaires
• 21 General information on verification and tests
• 22 Type tests
• 22.1 Representative samples
• 22.2 Test configuration
• 22.3 Tests for enclosures on which the type of protection depends
• 22.4 Tests for enclosed break devices and non incendive components
• 22.5 Tests for sealed devices
• 22.6 Type test requirements for restricted-breathing enclosures
• 22.7 Test for screw lampholders
• 22.8 Test for starter holders for luminaires
• 22.9 Tests for electronic starters for tubular fluorescent lamps and for ignitors for high pressure sodium or metal halide lamps
• 22.10 Test for wiring of luminaires subject to high-voltage impulses from ignitors
• 22.11 Mechanical shock test for batteries
• 22.12 Insulation resistance test for batteries
• 22.13 Additional ignition tests for large or high-voltage machines
• 23 Routine verifications and tests
• 23.1 General
• 23.2 Specific routine tests
• 24 Marking
• 24.1 General
• 24.2 Additional marking for batteries
• 24.3 Examples of marking
• 25 Documentation
• 26 Instructions
• Annex A (informative)Application, installation, and testing considerations for Ex “nA” asynchronous machines
• Bibliography