1 Scope
This part of IEC 60079 specifies the construction and testing of intrinsically safe apparatus intended for use in explosive atmospheres, and for associated apparatus which is intended for connection to intrinsically safe circuits which enter such atmospheres.
Modification of Clause 1 first paragraph as follows: Replace "part of IEC 60079" with "standard".
This Type of Protection is applicable to electrical equipment in which the electrical circuits themselves are incapable of causing ignition of a surrounding explosive atmosphere. This includes electrical equipment which contains circuits that are intrinsically safe only under certain conditions, for example under battery supply with mains supply removed.
This document is also applicable to electrical equipment or parts of electrical equipment located outside the explosive atmosphere or protected by another Type of Protection listed in IEC 60079-0, where the intrinsic safety of the electrical circuits in the explosive atmosphere may depend upon the design and construction of such electrical equipment or parts of such electrical equipment. The electrical circuits exposed to the explosive atmosphere are assessed for use in such atmospheres by applying this document.
Modification to Clause 1 third paragraph as follows: Replace "IEC 60079-0" with "UL 60079-0 and CSA C22.2 No. 60079-0".
This document applies to sensors connected to intrinsically safe circuits but does not apply to the protection of catalytic elements for Group IIC or Group IIB + H2.
This document does not apply to Ex Equipment cable glands.
The requirements for intrinsically safe systems are provided in IEC 60079-25.
Modification to Clause 1 sixth paragraph as follows: Replace "IEC 60079-25" with "UL 60079-25 and CSA C22.2 No. 60079-25".
This document supplements and modifies the general requirements of IEC 60079-0, except as indicated in . Where a requirement of this document conflicts with a requirement of IEC 60079-0, the requirement of this document takes precedence.
Modification to Clause 1 seventh paragraph as follows: Replace references "IEC 60079-0" with "UL 60079-0 and CSA C22.2 No. 60079-0".
Unless otherwise stated, the requirements in this document are applicable to both intrinsically safe apparatus and associated apparatus, and the generic term "apparatus" is used throughout the standard.
As this document applies only to electrical equipment, the term "equipment" used in the standard always means "electrical equipment".
This document applies to apparatus for use under the atmospheric conditions of IEC 60079-0 with additional requirements for use at extended atmospheric pressures in the range from 60 kPa (0,6 bar), up to 110 kPa (1,1 bar).
Modification to Clause 1 tenth paragraph as follows: Replace "IEC 60079-0" with "UL 60079-0 and CSA C22.2 No. 60079-0".
Modification to Clause 1 to add the following: Where references are made to other IEC, IEC/IEEE, ISO, or ISO/IEC standards, the referenced requirements found in these standards apply as modified by any applicable Canadian National Differences or US National Differences for the standard (see Clause 2).
Table 1 Applicability of specific clauses of IEC 60079-0
Clause or subclause of IEC 60079-0
IEC 60079-0 clause application to IEC 60079-11
Intrinsically safe apparatus
Associated apparatus
Ed.6
(2011)
Ed.7
(2017)
Clause / Subclause
title
Group I and Group II
Group III
(informative)
(informative)
(normative)
3
3
Terms and definitions
Applies
Applies
Applies
4
4
Equipment grouping
Applies
Applies
Applies
5
5
Temperatures
5.1
5.1
Environmental influences
Applies
Applies
Applies
5.2
5.2
Service temperature
Applies
Applies
Applies
5.3
5.3
Maximum surface temperature
Applies
Applies
Excluded
6
6
Requirements for all electrical apparatus
6.1
6.1
General
Applies
Applies
Applies
6.2
6.2
Mechanical strength
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
6.3
6.3
Opening times
Excluded
Excluded
Excluded
6.4
6.4
Circulating currents in enclosures (e.g. of large electric machines)
Excluded
Excluded
Excluded
6.5
6.5
Gasket retention
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
6.6
6.6
Electromagnetic and ultrasonic energy radiating equipment
–
6.6.1
General
Applies
Applies
Excluded
6.6.1
6.6.2
Radio frequency sources
Applies
Applies
Excluded
6.6.3
6.6.3
Ultrasonic sources
Applies
Applies
Excluded
6.6.2
6.6.4
Lasers, luminaires and other non-divergent continuous wave optical sources
Modified
Modified
Excluded
7
7
Non-metallic enclosures and non-metallic parts of enclosures
7.1
7.1
General
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
7.2
7.2
Thermal endurance
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
7.3
7.3
Resistance to ultraviolet light
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
7.4
7.4
Electrostatic charges on external non-metallic materials
Applies
Applies
Excluded
7.5
7.5
Attached external conductive parts
Applies
Applies
Excluded
8
8
Metallic enclosures and metallic parts of enclosures
Applies
Applies
Excluded
9
9
Fasteners
Excluded
Excluded
Excluded
10
10
Interlocking devices
Applies
Applies
Excluded
11
11
Bushings
Excluded
Excluded
Excluded
12
–
Materials used for cementing
Excluded except when 1 is applied
Excluded except when 1 are applied
Excluded except when 1 is applied
–
12
(Reserved for future use)
–
–
–
13
13
Ex Components
Applies
Applies
Applies
14
14
Connection facilities
14.1
14.1
General
Applies
Applies
Applies
14.2
–
Termination compartment
Applies
Applies
Applies
14.3
14.2
Type of Protection
Applies
Applies
Modified
14.4
14.3
Creepage and clearance
Applies
Applies
Applies
15
15
Connection facilities for earthing or bonding conductors
Excluded
Excluded
Excluded
16
16
Entries into enclosures
16.1
16.1
General
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
16.2
16.2
Identification of entries
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
16.3
16.3
Cable Glands
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
16.4
16.4
Blanking elements
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
16.5
16.5
Thread adapters
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
16.6
16.6
Temperature at branching point and entry point
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
16.7
16.7
Electrostatic charges of cable sheaths
Applies
Applies
Applies
17
17
Supplementary requirements for electric machines
Excluded
Excluded
Excluded
18
18
Supplementary requirements for switchgear
Excluded
Excluded
Excluded
19
–
Supplementary requirements for fuses
Excluded
Excluded
Excluded
–
19
Reserved for future use
–
–
–
20
20
Supplementary requirements for external plugs, socket outlets and connectors for field wiring connection
Excluded
Excluded
Excluded
21
21
Supplementary requirements for luminaires
Excluded
Excluded
Excluded
22
22
Supplementary requirements for caplights and handlights
22.1
22.1
Group I caplights
Applies
Excluded
Excluded
22.2
22.2
Group II and Group III caplights and handlights
Excluded
Excluded
Excluded
23
23
Equipment incorporating cells and batteries
23.1
23.1
General
Applies
Applies
Applies
23.2
23.2
Interconnection of cells to form batteries
Excluded
Excluded
Excluded
23.3
23.3
Cell types
Modified
Modified
Modified
23.4
23.4
Cells in a battery
Applies
Applies
Applies
23.5
23.5
Ratings of batteries
Applies
Applies
Applies
23.6
23.6
Interchangeability
Applies
Applies
Applies
23.7
23.7
Charging of primary batteries
Applies
Applies
Applies
23.8
23.8
Leakage
Applies
Applies
Applies
23.9
23.9
Connections
Applies
Applies
Applies
23.10
23.10
Orientation
Applies
Applies
Applies
23.11
23.11
Replacement of cells or batteries
Applies
Applies
Applies
23.12
23.12
Replaceable battery pack
Applies
Applies
Applies
24
24
Documentation
Applies
Applies
Applies
25
25
Compliance of prototype or sample with documents
Applies
Applies
Applies
26
26
Type tests
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
26.4.1
26.4.1
Order of tests
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
26.4.2
26.4.2
Resistance to impact
Excluded except see a
Excluded except see a
Excluded except see a
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 (IP) by enclosures
Applies
Applies
Applies
26.5
26.5
Thermal tests
26.5.1
26.5.1
Temperature measurement
26.5.1.1
26.5.1.1
General
Applies
Applies
Excluded
26.5.1.2
26.5.1.2
Service temperature
Applies
Applies
Applies
26.5.1.3
26.5.1.3
Maximum surface temperature
Modified
Modified
Excluded
26.5.2
26.5.2
Thermal shock test
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
26.5.3
26.5.3
Small component ignition test (Group I and Group II)
Applies
Excluded
Excluded
26.6
26.6
Torque test for bushings
Excluded
Excluded
Excluded
26.7
26.7
Non-metallic enclosures or non-metallic parts of enclosures
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
26.8
26.8
Thermal endurance to heat
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
26.9
26.9
Thermal endurance to cold
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
26.10
26.10
Resistance to UV light
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
26.11
26.11
Resistance to chemical agents for Group I equipment
Excluded except when 1 is applied
Excluded
Excluded
26.12
26.12
Earth continuity
Excluded
Excluded
Excluded
26.13
26.13
Surface resistance test of parts of enclosures of non-metallic materials
Applies
Applies
Excluded
26.14
26.14
Measurement of capacitance
Applies
Applies
Excluded
26.15
26.15
Verification of ratings of ventilating fans
Excluded
Excluded
Excluded
26.16
26.16
Alternative qualification of elastomeric sealing O-rings
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
NR
26.17
Transferred charge test
Applies
Excluded
Excluded
27
27
Routine tests
Applies
Applies
Applies
28
28
Manufacturer's responsibility
Applies b
Applies b
Applies
29
29
Marking
29.1
29.1
Applicability
Applies
Applies
Applies
29.2
29.2
Location
Applies
Applies
Applies
29.3
29.3
General
Applies
Applies
Applies
29.4
29.4
Ex marking for explosive gas atmospheres
Applies
Excluded
Applies
29.5
29.5
Ex marking for explosive dust atmospheres
Excluded
Applies
Applies
29.6
29.6
Combined types (or levels) of protection
Applies
Applies
Applies
29.7
29.7
Multiple types of protection
Applies
Applies
Applies
29.8
29.8
Ga equipment using two independent Gb types (or levels) of protection
Applies
Excluded
Excluded
NR
29.9
Boundary wall
Applies
Applies
Excluded
29.9
29.10
Ex Components
Applies
Applies
Applies
29.10
29.11
Small Ex Equipment and small Ex Components
Applies
Applies
Applies
29.11
29.12
Extremely small equipment and extremely small Ex Components
Applies
Applies
Applies
29.12
29.13
Warning markings
Applies
Applies
Applies
29.13
–
Alternate marking of Equipment Protection Levels (EPLs)
Applies
Applies
Applies
29.13.1
–
Alternate marking of Type of Protection for explosive gas atmospheres
Applies
Excluded
Applies
29.13.2
–
Alternate marking of Type of Protection for explosive dust atmospheres
Excluded
Applies
Applies
29.14
29.14
Cells and batteries
Applies
Applies
Applies
29.15
29.15
Electrical machines operated with a converter
Excluded
Excluded
Excluded
29.16
29.16
Examples of marking
Examples only
Examples only
Examples only
30
30
Instructions
30.1
30.1
General
Applies
Applies
Applies
30.2
30.2
Cells and batteries
Applies
Applies
Applies
30.3
30.3
Electric machines
Excluded
Excluded
Excluded
30.4
30.4
Ventilating fans
Excluded
Excluded
Excluded
–
30.5
Cable Glands
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
Annex A
Annex A
Supplementary requirements for cable glands
Excluded except when 1 is applied
Excluded except when 1 is applied
Excluded except when 1 is applied
Annex B
Annex B
Requirements for Ex Components
Applies
Applies
Applies
Annex C
Annex C
Example of rig for resistance to impact test
Informative Annex
Informative Annex
Informative Annex
Annex D
Annex D
Electric machines connected to converters
Informative Annex
Informative Annex
Informative Annex
Annex E
Annex E
Temperature evaluation of electric machines
Informative Annex
Informative Annex
Informative Annex
Annex F
Annex F
Guideline flowchart for tests of non-metallic enclosures
Informative Annex
Informative Annex
Informative Annex
or non-metallic parts of enclosures (26.4)
–
Annex G
Guidance flowchart for tests of cable glands
Informative Annex
Informative Annex
Informative Annex
–
Annex H
Shaft voltages resulting in motor bearing or shaft brush sparking. Discharge energy calculation
Informative Annex
Informative Annex
Informative Annex
Applies – This Clause / Subclause of IEC 60079-0 is applied without change.
Excluded – This Clause / Subclause of IEC 60079-0 does not apply.
Modified – This Clause / Subclause of IEC 60079-0 is modified as detailed in this document.
NOTE 1 The applicable Clauses / Subclauses of IEC 60079-0 are identified by the Clause / Subclause title which is normative. This document was written against the specific requirements of IEC 60079-0:2017 (Ed.7). The Clause / Subclause numbers for the 7th and previous edition are shown for information only. This is to enable the general requirements of IEC 60079-0:2011 (Ed.6) to be used where necessary with this part of IEC 60079. Where there were no requirements in the 6th edition but there are for the 7th edition (indicated by NR against the 6th edition only), or where there is a conflict between requirements, the later edition requirements take precedence.
NOTE 2 A shaded row in the above table indicates that this is a Clause heading. In cases where the applicability is the same for all the subclauses the 'Applies' or 'Excluded' is listed in the heading row and the subclauses are not expanded. Where the application of the individual sub-clauses may be different, these are expanded in the above table and the applicability for each is listed.
a Excluded except when 1 is applied, or as required by 1 or 11.
b Excluded for simple apparatus. See 5 and 5.
Modification of Table 1 to replace the following references as follows:
-
“IEC 60079-0” to “UL 60079-0 and CSA C22.2 No. 60079-0”
-
“IEC 60079-11 to “UL 60079-11 and CSA C22.2 No. 60079-11”
-