1 Scope
Modification of Clause 1 to replace with the following: This
part of IEC 60079
standard
specifies general and testing requirements for electrical resistance trace heaters for application in explosive atmospheres with the exclusion of those for EPL Ga and Da. This standard covers trace heaters that comprise either factory or field (work-site) assembled units, and which may be series trace heaters, parallel trace heaters, trace heater pads, or trace heater panels that have been assembled and/or terminated in accordance with the manufacturer’s instructions. This standard also includes requirements for termination assemblies and control methods used with trace heating systems. The explosive atmospheres referred to in this standard are those defined in IEC 60079-10-1 and IEC 60079-10-2.
Annexes D and E outline the application of this standard for those users applying the Division method of area classification.
This standard supplements and modifies the general requirements of
IEC 60079-0
UL 60079-0
, except as indicated in . Where a requirement of this standard conflicts with a requirement of IEC 60079-0
UL 60079-0
, the requirement of this standard takes precedence.
Where references are made to other IEC 60079 standards, the reference requirements found in these standards apply as modified by any applicable U.S. National Differences.
Table 1 Application or exclusion of specific clauses of <p>IEC 60079-0</p><p>UL 60079-0</p>
IEC
UL
60079-0
Electrical resistance trace heaters and integral components
Terminations as separate components
Ed. 6.0 (2011)
(informative)
Clause / Subclause title (normative)
Group I and Group II
Group III
1
Scope
Applies
Applies
Applies
2
Normative references
Applies
Applies
Applies
3
Terms and definitions
Applies, except ambient temperature, see 1
Applies, except ambient temperature, see 1
Applies, except ambient temperature, see 1
4
Equipment grouping
Applies
Applies
Applies
4.1
Group I
Applies
Excluded
Applies
4.2
Group II
Applies, always IIC
Excluded
Applies
4.3
Group III
Excluded
Applies, outside of thermal insulation only, always IIIC
Applies, outside of thermal insulation only
4.4
Equipment for a particular explosive atmosphere
Excluded
Excluded
Applies
5.1
Environmental influences
Applies
Applies
Applies
5.1.1
Ambient temperature
Replaced by 1e)
Replaced by 1e)
Applies, see 1
5.1.2
External source of heating or cooling
Applies
Applies
Applies
5.2
Service temperature
Modified
Modified
Applies
5.3.1
Determination of maximum surface temperature
Replaced by 5 in conjunction with 13
Replaced by 5 in conjunction with 13 only when tested in accordance with 3.
Applies
5.3.2.1
Group I electrical equipment
Applies
Excluded
Applies
5.3.2.2
Group II electrical equipment
Applies
Excluded
Applies
5.3.2.3.1
Group III electrical equipment, Maximum surface temperature determined without a dust layer
Excluded
Applies, where the maximum sheath temperatures determined by IEC/IEEE 60079-30-1 are used in place of the method for temperature determination from
IEC 60079-0
UL 60079-0
.
Applies
5.3.2.3.2
Group III electrical equipment Maximum surface temperature with respect to dust layers
Excluded
Applies, where the maximum sheath temperature is determined only for those surfaces that are specified to be exposed to layers of combustible dust.
Applies
Does not apply for trace heaters specified to be covered by thermal insulation.
5.3.3
Small component temperature for Group I and Group II electrical equipment
Excluded
Excluded
Applies
6.1
Requirements for all electrical equipment – General
Applies
Applies
Applies
6.2
Mechanical strength
Replaced by 2
Replaced by 2
When in direct contact with the trace heater, may be substituted by 2
6.3
Opening times
Excluded
Excluded
Applies
6.4
Circulating currents in enclosures (e.g. of large electrical machines)
Excluded
Excluded
Excluded
6.5
Gasket retention
Excluded
Excluded
Applies
6.6
Electromagnetic and ultrasonic radiating equipment
Excluded
Excluded
Applies
7.1.1
Non-metallic enclosures and non-metallic parts of enclosures – Applicability
Replaced by the last paragraph of 1
Replaced by the last paragraph of 1
Applies
7.1.2.1
Specification of materials, General
Replaced by the last paragraph of 1
Replaced by the last paragraph of 1
Applies
7.1.2.2
Specification of materials, plastic materials
Replaced by the last paragraph of 1
Replaced by the last paragraph of 1
Applies
7.1.2.3
Elastomers
Replaced by the last paragraph of 1
Replaced by the last paragraph of 1
Applies
7.2
Thermal endurance
Replaced by requirements and tests of this standard
Replaced by requirements and tests of this standard
Applies
7.3
Resistance to light
Replaced by 16 for trace heaters and integral components specified for outdoor exposure
Replaced by 16 for trace heaters and integral components specified for outdoor exposure
Applies
7.4.1
Electrostatic charges on external non-metallic materials, Applicability
Excluded
Excluded
Applies
7.4.2
Avoidance of a build-up of electrostatic charge on Group I or Group II electrical equipment
Excluded
Excluded
Applies
7.4.3
Avoidance of a build-up of electrostatic charge on equipment for Group III
Excluded
Excluded
Applies
7.5
Accessible metal parts
Excluded
Excluded
Applies
8.1
Material composition
Excluded
Excluded
Applies
8.2
Group I
Excluded
Excluded
Applies
8.3
Group II
Excluded
Excluded
Applies
8.4
Group III
Excluded
Excluded
Applies
9
Fasteners
Excluded
Excluded
Applies
10
Interlocking devices
Excluded
Excluded
Applies
11
Bushings
Excluded
Excluded
Applies
12
Materials used for cementing
Replaced by the last paragraph of 1
Replaced by the last paragraph of 1
Applies
13
Ex Components
Applies
Applies
Applies
14
Connection facilities and termination compartments
Covered by the requirements of this standard
Covered by the requirements of this standard
Applies
15
Connection facilities for earthing and bonding conductors
Replaced by 15
Replaced by 15
Applies
16
Entries into enclosures
Excluded
Excluded
Applies
17
Supplementary requirements for rotating electrical machines
Excluded
Excluded
Excluded
18
Supplementary requirements for switchgear
Excluded
Excluded
Excluded
19
Supplementary requirements for fuses
Excluded
Excluded
Applies
20
Supplementary requirements for plugs and sockets
Excluded
Excluded
Applies
21
Supplementary requirements for luminaires
Excluded
Excluded
Excluded
22
Supplementary requirements for caplights and handlights
Excluded
Excluded
Excluded
23
Equipment incorporating cells and batteries
Excluded
Excluded
Applies
24
Documentation
Applies
Applies
Applies
25
Compliance of prototype or sample with documents
Applies
Applies
Applies
26.1
General
Applies
Applies
Applies
26.2
Test configuration
Applies
Applies.
Applies
26.3
Tests in explosive test mixtures
Excluded
Excluded
Applies
26.4
Tests of enclosures
Excluded
Excluded
Applies
26.4.1
Order of tests
Excluded
Excluded
Applies
26.4.1.1
Metallic enclosures, metallic parts of enclosures and glass parts of enclosures
Excluded
Excluded
Applies
26.4.1.2
Non-metallic enclosures or non-metallic parts of enclosures
Excluded
Excluded
Applies
26.4.2
Resistance to impact
Replaced by 5
Replaced by 5
Applies
26.4.3
Drop test
Excluded
Excluded
Excluded
26.4.4
Acceptance criteria
Replaced by 5
Replaced by 5
Applies
26.4.5
Degree of protection by enclosure
Replaced by 8 and/or 9
Replaced by 8 and/or 9
Applies
26.5
Thermal tests
Modified.
Modified
Applies
26.5.1
Temperature measurement
Replaced by 13
Replaced by 13
Applies
26.5.2
Thermal shock test
Excluded
Excluded
Applies
26.5.3
Small component ignition test
Excluded
Excluded
Applies
26.6
Torque test for bushings
Excluded
Excluded
Applies
26.7
Non-metallic enclosures or non-metallic parts of enclosures
Excluded
Excluded
Applies
26.8
Thermal endurance to heat
Replaced by 11
Replaced by 11
Applies
26.9
Thermal endurance to cold
Replaced by 7
Replaced by 7
Applies
26.10
Resistance to light
Replaced by 16 for trace heaters and integral components specified for outdoor exposure
Replaced by 16 for trace heaters and integral components specified for outdoor exposure
Applies
26.11
Resistance to chemical agents for Group I electrical equipment
Applies for Group I
Excluded
Applies
26.12
Earth continuity
Excluded
Excluded
Applies
26.13
Surface resistance test of parts of enclosures of non-metallic materials
Excluded
Excluded
Applies
26.14
Measurement of capacitance
Excluded
Excluded
Applies
26.15
Verification of ratings of ventilating fans
Excluded
Excluded
Excluded
26.16
Alternative qualification of elastomeric sealing O-rings
Excluded
Excluded
Applies
27
Routine tests
Applies
Applies
Applies
28
Manufacturers responsibility
Applies
Applies
Applies
29
Marking
Modified
Modified
Applies
30
Instructions
Modified
Modified
Applies
Annex A
Supplementary requirements for Ex cable glands
Excluded
Excluded
Applies
Annex B
Requirements for Ex components
Excluded
Excluded
Applies
Annex C
Example of rig for resistance to impact test
Replaced by 5
Replaced by 5
Applies
Annex D
Motors supplied by converters
Excluded
Excluded
Excluded
Annex E
Temperature rise testing of electric machines
Excluded
Excluded
Excluded
Annex F
Guideline flowchart for tests of non-metallic enclosures or non-metallic parts of enclosures (26.4)
Excluded
Excluded
Applies
NOTE 1 Clause numbers in the three right-hand columns of this table refer to IEC/IEEE 60079-30-1
NOTE 2 The clause number in the above table is shown for information only. The applicable requirements of
IEC 60079-0
UL 60079-0
are identified by the clause title which is normative.
Applies: this requirement of
IEC 60079-0
UL 60079-0
is applied without change.
Excluded: this requirement of
IEC 60079-0
UL 60079-0
does not apply.
Modified: this requirement of
IEC 60079-0
UL 60079-0
is modified as detailed in this standard.