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.
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 inIEC 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.
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 inIEC 60079‑25.
This document supplements and modifies the general requirements of IEC 60079‑0, except as indicated inTable 1. Where a requirement of this document conflicts with a requirement of IEC 60079‑0, the requirement of this document takes precedence.
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).
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)
(informative)
|
Ed.7 (2017)
(informative)
|
Clause / Subclause title
(normative)
|
Group I and Group II | Group III | |
| 3 | 3 | Terms and definitions | Applies | Applies | Applies |
| 4 | 4 | Equipment grouping | Applies | Applies | Applies |
| 5 | 5 | Tempe ratu res | |||
| 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 7.2 | 7.2 | Thermal endurance | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 7.3 | 7.3 | Resistance to ultraviolet light | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 are applied | Excluded except when 6.2.5.1 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 16.2 | 16.2 | Identification of entries | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 16.3 | 16.3 | Cable Glands | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 16.4 | 16.4 | Blanking elements | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 16.5 | 16.5 | Thread adapters | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 16.6 | 16.6 | Temperature at branching point and entry point | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 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 | Interc h ang ea bility | 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 | Docume ntatio n | 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 26.8 | 26.8 | Thermal endurance to heat | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 26.9 | 26.9 | Thermal endurance to cold | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 26.10 | 26.10 | Resistance to UV light | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| 26.11 | 26.11 | Resistance to chemical agents for Group I equipment | Excluded except when 6.2.5.1 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 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 | Applicab ility | 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 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied |
| Annex A | Annex A | Supplementary requirements for cable glands | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 is applied | Excluded except when 6.2.5.1 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 or non-metallic parts of enclosures (26.4) | Informative Annex | Informative Annex | Informative Annex |
| — | 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.