IEC 60079-15:2017
(Main)Explosive atmospheres - Part 15: Equipment protection by type of protection "n"
Explosive atmospheres - Part 15: Equipment protection by type of protection "n"
IEC 60079-15:2017 specifies requirements for the construction, testing and marking for Group II electrical equipment with type of protection “n” which includes; sealed devices “nC”, hermetically sealed devices “nC”, non-incendive components “nC” and restricted breathing enclosures “nR” intended for use in explosive gas atmospheres. This part of IEC 60079 applies to electrical equipment where the rated input voltage does not exceed 15 kV r.m.s. AC or DC including where the internal working voltages of the Ex product exceeds 15 kV, for example starters for HID luminaires. This part of IEC 60079 supplements and modifies the general requirements of IEC 60079-0, except as indicated in Table 1 (Clause 1). Where a requirement of this part of IEC 60079 conflicts with a requirement of IEC 60079-0, the requirement of this part of IEC 60079 takes precedence. This fifth edition cancels and replaces the fourth edition, published in 2010, and constitutes a technical revision. Refer to the Forward of the document for a complete listing of the technical changes between edition 5.0 and the previous edition of the document.
Keywords: Group II electrical equipment with type of protection “n”
Atmosphères explosives - Partie 15: Protection du matériel par mode de protection " n "
IEC 60079-15:2017 spécifie les exigences de construction, d’essai et de marquage de l’appareil électrique du Groupe II avec mode de protection «n» qui inclut: les dispositifs clos «nC», les dispositifs hermétiquement scellés «nC», les composants non-propagateurs de flamme «nC» et les enveloppes à respiration limitée «nR», et qui est destiné à ętre utilisé en atmosphère explosive gazeuse. La présente partie de l’IEC 60079 s’applique à l’appareil électrique dont la tension assignée d’entrée ne dépasse pas la valeur efficace de 15 kV en courant alternatif ou en courant continu, y compris lorsque les tensions internes de service du produit Ex dépassent 15 kV, par exemple les starters pour luminaires DHI. La présente partie de l’IEC 60079 complète et modifie les exigences générales de l’IEC 60079-0, à l’exception de celles qui sont indiquées dans le Tableau 1 (Clause 1). Si une exigence de la présente partie de l’IEC 60079 est en conflit avec une exigence de l’IEC 60079-0, l’exigence de la présente partie de l’IEC 60079 prévaut. Cette cinquième édition annule et remplace la quatrième édition parue en 2010. Cette édition constitue une révision technique. Reportez-vous à l'avant-propos du document pour une liste complète des modifications techniques entre l'édition 5.0 et édition précédente du document.
Mots clés: électrique du Groupe II avec mode de protection «n»
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IEC 60079-15 ®
Edition 5.0 2017-12
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Explosive atmospheres –
Part 15: Equipment protection by type of protection "n"
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IEC 60079-15 ®
Edition 5.0 2017-12
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Explosive atmospheres –
Part 15: Equipment protection by type of protection "n"
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.260.20 ISBN 978-2-8322-5162-1
– 2 – IEC 60079-15:2017 RLV © IEC 2017
CONTENTS
FOREWORD . 5
1 Scope . 10
2 Normative references . 20
3 Terms and definitions . 22
4 General . 24
4.1 Equipment grouping and temperature classification . 24
4.2 Potential ignition sources . 24
4.3 Equipment requirements . 24
5 Maximum surface temperatures . 25
5.1 Maximum surface temperature .
5.2 Small components .
6 Requirements for electrical equipment . 25
6.1 General . 25
6.2 Opening times .
6.3 Minimum degree of protection .
6.4 Clearances, creepage distances and separations.
6.2 Electric strength insulation from earth or frame . 33
7 Connection facilities and terminal compartments .
8 Supplementary requirements for non-sparking electrical machines .
9 Supplementary requirements for non-sparking fuses and fuse assemblies .
10 Supplementary requirements for non-sparking plugs and sockets .
11 Supplementary requirements for non-sparking luminaires .
12 Supplementary requirements for equipment incorporating non-sparking cells and
batteries .
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 .
7 Requirements for non-incendive components. 58
7.1 Type testing . 58
7.2 Circuit limitations . 58
8 Supplementary Requirements for hermetically sealed devices
producing arcs, sparks or hot surfaces . 58
9 Supplementary Requirements for sealed devices
producing arcs, sparks or hot surfaces . 58
9.1 Non-metallic materials . 58
9.2 Opening . 59
9.3 Internal spaces . 59
9.4 Handling . 59
9.5 Gasket and seals . 59
9.6 Type tests . 59
10 Supplementary Requirements for restricted-breathing enclosures protecting
equipment producing arcs, sparks or hot surfaces . 59
10.1 General . 59
10.2 Constructional requirements . 60
10.2.1 Type of equipment . 60
10.2.2 Cells and batteries . 61
10.2.3 Cable glands and conduit entries . 61
10.2.4 Operating rods, spindles and shafts . 61
10.2.5 Windows . 61
10.2.6 Gasket and seal requirements . 62
10.2.7 Non-resilient seals . 62
10.2.8 Test port . 62
10.2.9 Internal fans . 63
10.3 Temperature limitation . 64
10.4 Additional requirements for restricted-breathing luminaires . 64
10.4.1 Mounting arrangement . 64
10.4.2 Reflectors . 64
10.4.3 Surface temperatures of restricted-breathing luminaires . 64
11 Type tests . 65
11.1 Tests for non incendive components . 65
11.1.1 Preparation of non-incendive component samples . 66
11.1.2 Test conditions for non-incendive components . 66
11.2 Tests for sealed devices . 67
11.2.1 Conditioning . 67
11.2.2 Voltage test . 67
11.3 Type test requirements for restricted-breathing enclosures . 69
11.3.1 General . 69
11.3.3 Alternative type test for equipment where the volume of the enclosure
changes due to pressure . 69
12 Routine verifications and tests . 74
12.1 Electric strength test . 74
12.2 Routine test requirements for restricted-breathing enclosures . 75
12.2.1 General . 75
12.2.2 Test procedure . 75
12.3 Routine temperature rise test . 76
12.4 Temperature calculation . 76
13 Marking . 77
13.1 General . 77
13.2 Examples of marking . 78
13.3 Warning markings . 79
14 Documentation . 79
15 Instructions . 79
21 General information on verification and tests .
Annex A (informative) Application, installation, and testing considerations for Ex “nA”
asynchronous machines .
Bibliography . 83
Figure 1 – Examples for determining clearances and creepage distances .
– 4 – IEC 60079-15:2017 RLV © IEC 2017
Table 1 – Relationship of this part IEC 60079-15 to IEC 60079-0 . 10
Table 2 – Minimum creepage distances, clearances and separations .
Table 3 – Tracking resistance of insulating materials .
Table 4 – Separation in compound-filled cable sealing boxes.
Table 5 – Assumed voltage of neutral points .
Table 6 – Potential air gap sparking risk assessment for cage rotor ignition risk factors .
Table 7 – Minimum distance between lamp and protective cover .
Table 8 – Creepage distances and clearances at peak values of pulse voltages greater
than 1,5 kV .
Table 9 – Types and use of cells and batteries .
Table 10 – Minimum creepage distances, clearances and separations for low power
equipment .
Table 11 – Insertion torque .
Table 12 – Minimum removal torque .
Table 13 – Explosion test mixtures .
Table 2 – Text of warning markings . 79
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 15: Equipment protection by type of protection "n"
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition. A vertical bar appears in the margin wherever a change
has been made. Additions are in green text, deletions are in strikethrough red text.
– 6 – IEC 60079-15:2017 RLV © IEC 2017
International Standard IEC 60079-15 has been prepared by IEC technical committee 31:
Equipment for explosive atmospheres.
This fifth edition cancels and replaces the fourth edition, published in 2010, and constitutes a
technical revision.
This edition includes the following significant changes with respect to the previous edition:
The text of this International Standard is based on the following documents:
FDIS Report on voting
31/1339/FDIS 31/1355/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be read in conjunction with IEC 60079-0.
A list of all parts of the IEC 60079 series, under the general title: Explosives atmospheres,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.
Type
Changes Clause Minor and Extension Major
editorial technical
changes changes
Requirements for enclosed break devices have - C1
been removed
Requirements for type of protection “nA” has - C2
been removed
Scope has been updated to allow equipment with 1 X
internal working voltages over 15 kV such as
starters for HID luminaires
Definition for cable sealing box removed 3 X
Definitions for creepage distance and clearance 3 X
removed as they are now in 60079-0
Definition of non-sparking device “nA” removed, 3 C2
as the concept has been transferred to 60079-7
Definition of duty cycle removed 3 X
Definition of enclosed break device moved as the 3 C1
concept has been transferred to 60079-1
Definition of hermetically sealed device revised 3 A1
Definition for normally sparking device added 3.2 X
Small component temperature clause removed, 5 C2
part of moving type of protection “nA” to 60079-7
Minimum degree of protection requirements; 6 C2
clearance, creepage and separation
requirements; determination of working voltage;
conformal coating; CTI requirement; Insulation
between conductive parts and measurement of
creepage and clearance requirements have been
removed.
Connection facilities and terminal compartment - C2
requirements have been removed
Supplementary requirements for non-sparking - C2
electrical rotating machines have been removed
Supplementary requirements for non-sparking - C2
fuses and fuse assemblies have been removed
Supplementary requirements for non-sparking - C2
plugs and sockets have been removed
Supplementary requirements for non-sparking - C2
luminaires have been removed
Supplementary requirements for equipment - C2
incorporating non-sparking cells and batteries
have been removed
Supplementary requirements for non-sparking low - C2
power equipment have been removed
Supplementary requirements for non-sparking - C2
current transformers have been removed
Requirements for other non-sparking electrical - C2
equipment have been removed
General supplementary requirements for - C2
equipment producing arcs, sparks or hot surfaces
have been removed
Requirements for enclosed break devices have - C1
been removed
Voltage and current limitations added for non- 7.2 C6
incendive components.
– 8 – IEC 60079-15:2017 RLV © IEC 2017
Type
Changes Clause Minor and Extension Major
editorial technical
changes changes
The requirements for sealed devices have been 9.1 X
extended to require more documentation,
The +20K requirement for luminaire materials has 9.5 C2
been removed
Notes 1-3 have been removed, as this information 10.1 X
is covered elsewhere
Entry device requirements added 10.1 X
Industrial standard compliance and battery 10.2.1.2 X
requirements added
The exemption for manually operated sparking 10.2.1.2 X
devices moved to here, creepage and clearance
requirements in industrial standards added for
switching devices, and cell and battery
requirements added
Requirements for cable glands and conduit 10.2.3 X
entries have been clarified
Requirements for gasketed windows expanded to 10.2.5.2 X
allow a removable window mounted in a frame.
Requirement to include documentation on the 10.2.6 C4
thermal stability of gaskets or seals added
Requirements reworded for clarity 10.2.7 X
Requirements for “nR” enclosures fitted with fans 10.2.9 C5
added.
Type test requirements for enclosed break “nC” - C1, C2
and “nA” equipment removed
The dielectric test after the leakage test for 11.2.2 X
sealed devices has been eliminated unless the
results of the leakage test are uncertain.
Tests for sealed devices, screw lampholders, - C2
starters, lamps, ignitors, and ignitor pulses for
luminaires have been removed
All testing for batteries has been removed. - C2
All testing for electrical machines removed - C2
Routine test requirements re-written for sealed 12 C1, C2
components, non-incendive components and
restricted breathing equipment to take out the
testing for enclosed break and nA equipment
Preparation of non-incendive component samples 11.1.1 C3
Marking requirements modified to remove - C1, C2
labelling requirements for enclosed break
components, nA equipment, and batteries.
Documentation requirements modified to remove 14 C1, C2
to remove labelling requirements for enclosed
break components, nA equipment, and batteries.
The instruction section has been expanded to 15 X
include new requirements
Annex A has been removed. - C2
NOTE The technical changes referred to include the significance of technical changes in the revised IEC
Standard, but they do not form an exhaustive list of all modifications from the previous version.
Explanation of the types of changes:
A) Definitions
1) Minor and editorial changes:
• Clarification
• Decrease of technical requirements
• Minor technical change
• Editorial corrections
These are changes which modify requirements in an editorial or a minor technical way.
They include changes of the wording to clarify technical requirements without any
technical change, or a reduction in level of existing requirement.
2) Extension: Addition of technical options
These are changes which add new or modify existing technical requirements, in a way
that new options are given, but without increasing requirements for equipment that was
fully compliant with the previous standard. Therefore, these will not have to be
considered for products in conformity with the preceding edition.
3) Major technical changes:
• addition of technical requirements
• increase of technical requirements
These are changes to technical requirements (addition, increase of the level or
removal) made in a way that a product in conformity with the preceding edition will not
always be able to fulfil the requirements given in the later edition. These changes have
to be considered for products in conformity with the preceding edition. For these
changes additional information is provided in Clause B below.
NOTE These changes represent current technological knowledge. However, these changes should not
normally have an influence on equipment already placed on the market.
B) Information about the background of changes
A1 – It was determined that this was already covered by the sealed device definition
C1 – Enclosed break devices “nC” are now designated as “dc” and the requirements are
located in IEC 60079-1:2014.
C2 – Type of protection “nA” is now designated as type of protection “ec” and the
requirements for “ec” equipment are located in IEC 60079-7:2015.
C3 – Test time for the preparation of non-incendive component samples has been
specified.
C4 – Additional documentation requirements for seals and gaskets.
C5 – As the pressure inside an enclosure fitted with fans can be affected by the
operation of the fan, it is now specified that the restricted breathing test is
conducted with fans operating and stationary.
C6 – The limitations from IEC 60079-15 Ed 3 were added.
– 10 – IEC 60079-15:2017 RLV © IEC 2017
EXPLOSIVE ATMOSPHERES –
Part 15: Equipment protection by type of protection "n"
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” which includes; sealed devices “nC”,
hermetically sealed devices “nC”, non-incendive components “nC” and restricted breathing
enclosures “nR” intended for use in explosive gas atmospheres. This part of IEC 60079
applies to electrical equipment where the rated input voltage does not exceed 15 kV r.m.s. AC or
DC including where the internal working voltages of the Ex product exceeds 15 kV, for example
starters for HID luminaires.
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 part of IEC 60079 supplements and modifies the general requirements of IEC 60079-0,
except as indicated in Table 1. Where a requirement of this part of IEC 60079 conflicts with a
requirement of IEC 60079-0, the requirement of this part of IEC 60079 takes precedence.
Table 1 – Relationship of this part IEC 60079-15 to IEC 60079-0
IEC 60079-0 clause application to IEC 60079-
Clause of IEC 60079-0
Ed. 5.0 1 Clause / Subclause
Ed. 6.0
Protected Non Restricted
(2007) title
(future
sparking sparking breathing
edition)
(normative)
(informative)
nC nA nR
(informative)
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 Applies Applies Applies
particular explosive
atmosphere
5.1 5.1 Environmental Applies Applies Applies
influences
5.1.1 5.1.1 Ambient temperature Applies Applies Applies
5.1.2 5.1.2 External source of Applies Applies Applies
heating or cooling
5.2 5.2 Service temperature Applies Applies Applies
5.3.1 5.3.1 Determination of Applies Applies Applies
maximum surface
temperature
___________
Under consideration.
IEC 60079-0 clause application to IEC 60079-
Clause of IEC 60079-0
Ed. 5.0 1 Clause / Subclause
Ed. 6.0
Protected Non Restricted
(2007) title
(future
sparking sparking breathing
edition)
(normative)
(informative)
nC nA nR
(informative)
5.3.2.1 5.3.2.1 Group I electrical Excluded Excluded Excluded
equipment
5.3.2.2 5.3.2.2 Group II electrical Applies Applies Applies
equipment
5.3.2.3 5.3.2.3 Group III electrical Excluded Excluded Excluded
equipment
5.3.3 5.3.3 Small component Applies Applies Excluded
temperature for Group I
and Group II electrical
equipment
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 Applies Applies Applies
ultrasonic radiating
equipment
7.1.1 7.1.1 Applicability Applies Applies Applies
7.1.2 7.1.2 Specification of Applies Applies Applies
materials
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 Applies Applies Applies
external non-metallic
materials
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 Excluded Excluded Excluded
fasteners
10 10 Interlocking devices Excluded Excluded Excluded
11 11 Bushings Applies Applies Applies
12 12 Materials used for Modified Modified Modified
cementing
13 13 Ex components Applies Applies Applies
14 14 Connection facilities and Modified Modified Modified
termination
compartments
– 12 – IEC 60079-15:2017 RLV © IEC 2017
IEC 60079-0 clause application to IEC 60079-
Clause of IEC 60079-0
Ed. 5.0 1 Clause / Subclause
Ed. 6.0
Protected Non Restricted
(2007) title
(future
sparking sparking breathing
edition)
(normative)
(informative)
nC nA nR
(informative)
15 15 Connection facilities for Applies Applies Applies
earthing and bonding
conductors
16 16 Entries into enclosures Applies Applies Applies
17 17 Supplementary Excluded Modified Excluded
requirements for rotating
electrical machines
18 18 Supplementary Applies Applies Applies
requirements for
switchgear
19 19 Supplementary Modified Modified Modified
requirements for fuses
20 20 Supplementary Modified Modified Modified
requirements for plugs
and sockets
21 21 Supplementary Modified Modified Modified
requirements for
luminaires
22 22 Supplementary Applies Applies Applies
requirements for
caplights and handlights
23 23 Equipment incorporating Modified Modified Modified
cells and batteries
24 24 Documentation Applies Applies Applies
25 25 Compliance of prototype Applies Applies Applies
or sample with
documents
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 Applies Applies Applies
mixtures
26.4 26.4 Tests of enclosures Applies Applies Applies
26.4.1.1 26.4.1.1 Metallic enclosures, Applies Applies Applies
metallic parts of
enclosures and glass
parts of enclosures
26.4.1.2.1 26.4.1.2.1 Group I electrical Excluded Excluded Excluded
equipment
26.4.1.2.2 26.4.1.2.2 Group II and Group III Applies Applies Applies
electrical equipment
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 Applies Applies Applies
enclosure
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 Modified Modified Modified
or non-metallic parts of
enclosures
IEC 60079-0 clause application to IEC 60079-
Clause of IEC 60079-0
Ed. 5.0 1 Clause / Subclause
Ed. 6.0
Protected Non Restricted
(2007) title
(future
sparking sparking breathing
edition)
(normative)
(informative)
nC nA nR
(informative)
26.8 26.8 Thermal endurance to Modified Modified Modified
heat
26.9 26.9 Thermal endurance to Applies Applies Applies
cold
26.10 26.10 Resistance to light Applies Applies Applies
26.11 26.11 Resistance to chemical Excluded Excluded Excluded
agents for Group I
electrical equipment
26.12 26.12 Earth continuity Applies Applies Applies
26.13 26.13 Surface resistance test Applies Applies Applies
of parts of enclosures of
non-metallic materials
26.14 - Charging tests Applies Applies Applies
26.15 26.14 Measurement of Applies Applies Applies
capacitance
27 27 Routine tests Applies Applies Applies
28 28 Manufacturers Applies Applies Applies
responsibility
29 29 Marking Applies Applies Applies
30 30 Instructions Applies Applies Applies
Annex A Annex A Supplementary Applies Applies Applies
requirements for Ex
cable glands
Annex B Annex B Requirements for Ex Applies Applies Applies
components
Annex C Annex C Example of rig for Applies Applies Applies
resistance to impact test
Annex D Annex D Introduction to an Applies Applies Applies
alternative risk
assessment method
encompassing
“equipment protection
levels” fro Ex equipment
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.
– 14 – IEC 60079-15:2017 RLV © IEC 2017
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 2 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
3 3 Definitions Applies Applies
4 4 Equipment grouping
4.1 4.1 Group I Excluded Excluded
4.2 4.2 Group II Applies Applies
4.3 4.3 Group III Excluded Excluded
4.4 4.4 Equipment for a Applies Applies
particular explosive
atmosphere
5 5 Temperatures
5.1 5.1 Environmental Applies Applies
influences
5.2 5.2 Service temperature Applies Applies
5.3 5.3 Maximum surface
temperature
5.3.1 5.3.1 Determination of Applies Applies
maximum surface
temperature
5.3.2 5.3.2 Limitation of maximum
surface temperature
5.3.2.1 5.3.2.1 Group I equipment Excluded Excluded
5.3.2.2 5.3.2.2 Group II equipment Applies Applies
5.3.2.3 5.3.2.3 Group III equipment Excluded Excluded
5.3.3 5.3.3 Small component Applies Excluded
temperature for Group I
and Group II equipment
- 5.3.4 Component temperature Applies Excluded
of smooth surfaces for
Group I or Group II
equipment
(Applies for smaller than
10 000 mm only)
6 6 Requirements for all
electrical apparatus
6.1 6.1 General Applies Applies
6.2 6.2 Mechanical strength Applies Applies
6.3 6.3 Opening times Excluded Applies
6.4 6.4 Circulating currents Applies Applies
6.5 6.5 Gasket retention Applies Applies
6.6 6.6 Electromagnetic and Applies Applies
ultrasonic radiating
equipment
7 7 Non-metallic enclosures
and non-metallic parts of
enclosures
7.1 7.1 General
___________
Under preparation. Stage at the time of publication: IEC/FDIS 60079-0:2017.
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 2 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
7.1.1 7.1.1 Applicability Applies Applies
7.1.2 7.1.2 Specification of Applies Applies
materials
7.2 7.2 Thermal endurance
7.2.1 7.2.1 Tests for thermal Applies Applies
resistance
7.2.2 - Material selection Modified Modified
- 7.2.2 Material selection Applies Applies
7.2.3 7.2.3 Alternative qualification Applies Applies
for elastomeric sealing
O-rings
7.3 7.3 Resistance to ultraviolet Applies Applies
light
7.4 7.4 Electrostatic charges on
external non-metallic
materials
7.4.1 7.4.1 Applicability Applies Applies
7.4.2 7.4.2 Avoidance of build-up of Applies Applies
electrostatic charge on
Group I or Group II
electrical equipment
7.4.3 7.4.3 Avoidance of build-up of Excluded Excluded
electrostatic charge on
equipment for Group III
7.5 7.5 External conductive Applies Applies
parts
8 8 Metallic enclosures and
metallic parts of
enclosures
8.1 8.1 Material composition Applies Applies
8.2 8.2 Group I Excluded Excluded
8.3 8.3 Group II Applies Applies
8.4 8.4 Group III Excluded Excluded
NR 8.5 Copper alloys Applies Applies
9 9 Fasteners
9.1 9.1 General Applies Applies
9.2 9.2 Special fasteners Excluded Excluded
9.3 9.3 Holes for special Excluded Excluded
fasteners
9.3.3 - Hexagon socket set Excluded Excluded
screws
- 9.4 Hexagon socket set Excluded Excluded
screws
10 10 Interlocking devices Excluded Excluded
11 11 Bushings Applies Applies
– 16 – IEC 60079-15:2017 RLV © IEC 2017
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 2 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
12 - Materials used for Modified Modified
cementing
- 12 Reserved for future use. Excluded Excluded
13 13 Ex components Applies Applies
14 14 Connection facilities Applies Applies
15 15 Connection facilities for Applies Applies
earthing and bonding
conductors
16 16 Entries into enclosures Applies Applies
17 17 Supplementary Excluded Excluded
requirements for electric
machines
18 18 Supplementary Excluded
requirements for
switchgear
18.1 18.1 Flammable dielectric Excluded Applies
18.2 18.2 Disconnectors Excluded Applies
18.3 18.3 Group I – Provisions for Excluded Excluded
locking
18.4 18.4 Doors and covers Excluded Applies
19 - Supplementary Excluded Excluded
requirements for fuses
- 19 Reserved for future use. Excluded Excluded
20 20 Supplementary
requirements for plugs
and sockets
20.1 20.1 General Applies Applies
20.2 20.2 Explosive gas Excluded Excluded
atmospheres
20.3 20.3 Explosive dust Excluded Excluded
atmospheres
20.4 20.4 Energized plugs Applies Applies
21 21 Supplementary
requirements for
luminaires
21.1 21.1 General Applies Applies
21.2 21.2 Covers for luminaires of Excluded Excluded
EPL Mb, EPL Gb or EPL
Db
21.3 21.3 Covers for luminaires of Applies Applies
EPL Gc or EPL Dc
21.4 21.4 Sodium lamps Applies Applies
22 22 Supplementary
requirements for
caplights and handlights
22.1 22.1 Group I caplights Excluded Excluded
22.2 22.2 Group II and Group III Excluded Applies
caplights and handlights
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 2 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
23 23 Equipment incorporating Applies Applies
cells and batteries
23.12 23.12 Replacement battery Applies Applies
pack
24 24 Documentation Modified Modified
25 25 Compliance of prototype Applies Applies
or sample with
documents
26 26 Type tests Applies Applies
26.4 26.4 Tests of enclosures
26.4.1 26.4.1 Order of tests
26.4.1.1 26.4.1.1 Metallic enclosures, Applies Applies
metallic parts of
enclosures and glass or
ceramic parts of
enclosures
26.4.1.2 26.4.1.2 Non-metallic enclosures
or non-metallic parts of
enclosures
26.4.1.2.1 26.4.1.2.1 General Applies Applies
26.4.1.2.2 26.4.1.2.2 Group I electrical Excluded Excluded
equipment
26.4.1.2.3 - Group II and Group III Modified Modified
electrical equipment
- 26.4.1.2.3 Group II and Group III Applies Applies
electrical equipment
26.4.2 26.4.2 Resistance to impact Applies Applies
26.4.3 26.4.3 Drop test Applies Applies
26.4.4 26.4.4 Acceptance criteria Applies Applies
26.4.5 26.4.5 Degree of protection by Applies Applies
enclosure
26.5 26.5 Thermal tests
Applies Applies
26.5.1 26.5.1 Temperature
measurement
Applies Applies
26.5.1.1 26.5.1.1 General
Applies Applies
26.5.1.2 26.5.1.2 Service Temperature
Applies Applies
26.5.2 26.5.2 Thermal shock test
26.5.3 26.5.3 Small component Applies Excluded
ignition test (Group I and
Group II)
26.6 26.6 Torque test for bushings Applies Applies
26.7 26.7 Non-metallic enclosures
or non-metallic parts of
enclosures
26.7.1 26.7.1 General Applies Applies
26.7.2 - Test temperatures Modified Modified
- 26.7.2 Test temperatures Applies Applies
– 18 – IEC 60079-15:2017 RLV © IEC 2017
Clause of IEC 6007
...
IEC 60079-15 ®
Edition 5.0 2017-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 15: Equipment protection by type of protection "n"
Atmosphères explosives –
Partie 15: Protection du matériel par mode de protection «n»
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IEC 60079-15 ®
Edition 5.0 2017-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 15: Equipment protection by type of protection "n"
Atmosphères explosives –
Partie 15: Protection du matériel par mode de protection «n»
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-5047-1
– 2 – IEC 60079-15:2017 © IEC 2017
CONTENTS
FOREWORD . 4
1 Scope . 9
2 Normative references . 15
3 Terms and definitions . 16
4 General . 17
4.1 Equipment grouping and temperature classification . 17
4.2 Potential ignition sources . 17
4.3 Equipment requirements . 17
5 Maximum surface temperatures . 17
6 Requirements for electrical equipment . 18
6.1 General . 18
6.2 Electric strength insulation from earth or frame . 18
7 Requirements for non-incendive components. 18
7.1 Type testing . 18
7.2 Circuit limitations . 18
8 Requirements for hermetically sealed devices . 18
9 Requirements for sealed devices . 19
9.1 Non-metallic materials . 19
9.2 Opening . 19
9.3 Internal spaces . 19
9.4 Handling . 19
9.5 Gasket and seals . 19
9.6 Type tests . 19
10 Requirements for restricted-breathing enclosures . 19
10.1 General . 19
10.2 Constructional requirements . 20
10.2.1 Type of equipment . 20
10.2.2 Cells and batteries . 20
10.2.3 Cable glands and conduit entries . 20
10.2.4 Operating rods, spindles and shafts . 21
10.2.5 Windows . 21
10.2.6 Gasket and seal requirements . 21
10.2.7 Non-resilient seals . 21
10.2.8 Test port . 22
10.2.9 Internal fans . 23
10.3 Temperature limitation . 23
10.4 Additional requirements for restricted-breathing luminaires . 23
10.4.1 Mounting arrangement . 23
10.4.2 Reflectors . 23
10.4.3 Surface temperatures of restricted-breathing luminaires . 23
11 Type Tests . 24
11.1 Tests for non incendive components . 24
11.1.1 Preparation of non-incendive component samples . 24
11.1.2 Test conditions for non-incendive components . 24
11.2 Tests for sealed devices . 25
11.2.1 Conditioning . 25
11.2.2 Voltage test . 25
11.2.3 Leakage tests on sealed devices . 25
11.3 Type test requirements for restricted-breathing enclosures . 26
11.3.1 General . 26
11.3.2 Equipment where the volume of the enclosure will be unchanged due to
pressure . 26
11.3.3 Alternative type test for equipment where the volume of the enclosure
changes due to pressure . 26
12 Routine verifications and tests . 27
12.1 Electric strength test . 27
12.2 Routine test requirements for restricted-breathing enclosures . 27
12.2.1 General . 27
12.2.2 Test procedure . 27
12.3 Routine temperature rise test . 28
12.4 Temperature calculation . 28
13 Marking . 29
13.1 General . 29
13.2 Examples of marking . 29
13.3 Warning markings . 29
14 Documentation . 29
15 Instructions . 30
Bibliography . 31
Table 1 – Relationship of IEC 60079-15 to IEC 60079-0 . 9
Table 2 – Text of warning markings . 29
– 4 – IEC 60079-15:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 15: Equipment protection by type of protection "n"
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60079-15 has been prepared by IEC technical committee 31:
Equipment for explosive atmospheres.
This fifth edition cancels and replaces the fourth edition, published in 2010, and constitutes a
technical revision.
This edition includes the following significant changes with respect to the previous edition:
The text of this International Standard is based on the following documents:
FDIS Report on voting
31/1339/FDIS 31/1355/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be read in conjunction with IEC 60079-0.
A list of all parts of the IEC 60079 series, under the general title: Explosives atmospheres,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 60079-15:2017 © IEC 2017
Type
Changes Clause Minor and Extension Major
editorial technical
changes changes
Requirements for enclosed break devices have - C1
been removed
Requirements for type of protection “nA” has - C2
been removed
Scope has been updated to allow equipment with 1 X
internal working voltages over 15 kV such as
starters for HID luminaires
Definition for cable sealing box removed 3 X
Definitions for creepage distance and clearance 3 X
removed as they are now in 60079-0
Definition of non-sparking device “nA” removed, 3 C2
as the concept has been transferred to 60079-7
Definition of duty cycle removed 3 X
Definition of enclosed break device moved as the 3 C1
concept has been transferred to 60079-1
Definition of hermetically sealed device revised 3 A1
Definition for normally sparking device added 3.2 X
Small component temperature clause removed, 5 C2
part of moving type of protection “nA” to 60079-7
Minimum degree of protection requirements; 6 C2
clearance, creepage and separation
requirements; determination of working voltage;
conformal coating; CTI requirement; Insulation
between conductive parts and measurement of
creepage and clearance requirements have been
removed.
Connection facilities and terminal compartment - C2
requirements have been removed
Supplementary requirements for non-sparking - C2
electrical rotating machines have been removed
Supplementary requirements for non-sparking - C2
fuses and fuse assemblies have been removed
Supplementary requirements for non-sparking - C2
plugs and sockets have been removed
Supplementary requirements for non-sparking - C2
luminaires have been removed
Supplementary requirements for equipment - C2
incorporating non-sparking cells and batteries
have been removed
Supplementary requirements for non-sparking low - C2
power equipment have been removed
Supplementary requirements for non-sparking - C2
current transformers have been removed
Requirements for other non-sparking electrical - C2
equipment have been removed
General supplementary requirements for - C2
equipment producing arcs, sparks or hot surfaces
have been removed
Requirements for enclosed break devices have - C1
been removed
Voltage and current limitations added for non- 7.2 C6
incendive components.
Type
Changes Clause Minor and Extension Major
editorial technical
changes changes
The requirements for sealed devices have been 9.1 X
extended to require more documentation,
The +20K requirement for luminaire materials has 9.5 C2
been removed
Notes 1-3 have been removed, as this information 10.1 X
is covered elsewhere
Entry device requirements added 10.1 X
Industrial standard compliance and battery 10.2.1.2 X
requirements added
The exemption for manually operated sparking 10.2.1.2 X
devices moved to here, creepage and clearance
requirements in industrial standards added for
switching devices, and cell and battery
requirements added
Requirements for cable glands and conduit 10.2.3 X
entries have been clarified
Requirements for gasketed windows expanded to 10.2.5.2 X
allow a removable window mounted in a frame.
Requirement to include documentation on the 10.2.6 C4
thermal stability of gaskets or seals added
Requirements reworded for clarity 10.2.7 X
Requirements for “nR” enclosures fitted with fans 10.2.9 C5
added.
Type test requirements for enclosed break “nC” - C1, C2
and “nA” equipment removed
The dielectric test after the leakage test for 11.2.2 X
sealed devices has been eliminated unless the
results of the leakage test are uncertain.
Tests for sealed devices, screw lampholders, - C2
starters, lamps, ignitors, and ignitor pulses for
luminaires have been removed
All testing for batteries has been removed. - C2
All testing for electrical machines removed - C2
Routine test requirements re-written for sealed 12 C1, C2
components, non-incendive components and
restricted breathing equipment to take out the
testing for enclosed break and nA equipment
Preparation of non-incendive component samples 11.1.1 C3
Marking requirements modified to remove - C1, C2
labelling requirements for enclosed break
components, nA equipment, and batteries.
Documentation requirements modified to remove 14 C1, C2
to remove labelling requirements for enclosed
break components, nA equipment, and batteries.
The instruction section has been expanded to 15 X
include new requirements
Annex A has been removed. - C2
NOTE The technical changes referred to include the significance of technical changes in the revised IEC
Standard, but they do not form an exhaustive list of all modifications from the previous version.
– 8 – IEC 60079-15:2017 © IEC 2017
Explanation of the types of changes:
A) Definitions
1) Minor and editorial changes:
• Clarification
• Decrease of technical requirements
• Minor technical change
• Editorial corrections
These are changes which modify requirements in an editorial or a minor technical way.
They include changes of the wording to clarify technical requirements without any
technical change, or a reduction in level of existing requirement.
2) Extension: Addition of technical options
These are changes which add new or modify existing technical requirements, in a way
that new options are given, but without increasing requirements for equipment that was
fully compliant with the previous standard. Therefore, these will not have to be
considered for products in conformity with the preceding edition.
3) Major technical changes:
• addition of technical requirements
• increase of technical requirements
These are changes to technical requirements (addition, increase of the level or
removal) made in a way that a product in conformity with the preceding edition will not
always be able to fulfil the requirements given in the later edition. These changes have
to be considered for products in conformity with the preceding edition. For these
changes additional information is provided in Clause B below.
NOTE These changes represent current technological knowledge. However, these changes should not
normally have an influence on equipment already placed on the market.
B) Information about the background of changes
A1 – It was determined that this was already covered by the sealed device definition
C1 – Enclosed break devices “nC” are now designated as “dc” and the requirements are
located in IEC 60079-1:2014.
C2 – Type of protection “nA” is now designated as type of protection “ec” and the
requirements for “ec” equipment are located in IEC 60079-7:2015.
C3 – Test time for the preparation of non-incendive component samples has been
specified.
C4 – Additional documentation requirements for seals and gaskets.
C5 – As the pressure inside an enclosure fitted with fans can be affected by the
operation of the fan, it is now specified that the restricted breathing test is
conducted with fans operating and stationary.
C6 – The limitations from IEC 60079-15 Ed 3 were added.
EXPLOSIVE ATMOSPHERES –
Part 15: Equipment protection by type of protection "n"
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” which includes; sealed devices “nC”,
hermetically sealed devices “nC”, non-incendive components “nC” and restricted breathing
enclosures “nR” intended for use in explosive gas atmospheres. This part of IEC 60079
applies to electrical equipment where the rated input voltage does not exceed 15 kV r.m.s. AC or
DC including where the internal working voltages of the Ex product exceeds 15 kV, for example
starters for HID luminaires.
This part of IEC 60079 supplements and modifies the general requirements of IEC 60079-0,
except as indicated in Table 1. Where a requirement of this part of IEC 60079 conflicts with a
requirement of IEC 60079-0, the requirement of this part of IEC 60079 takes precedence.
Table 1 – Relationship of IEC 60079-15 to IEC 60079-0
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 1 Clause / Subclause
Ed. 7.0
(2011) title
(future Protected sparking Restricted breathing
edition)
(informative) (normative)
“nC” “nR”
(informative)
3 3 Definitions Applies Applies
4 4 Equipment grouping
4.1 4.1 Group I Excluded Excluded
4.2 4.2 Group II Applies Applies
4.3 4.3 Group III Excluded Excluded
4.4 4.4 Equipment for a Applies Applies
particular explosive
atmosphere
5 5 Temperatures
5.1 5.1 Environmental Applies Applies
influences
5.2 5.2 Service temperature Applies Applies
5.3 5.3 Maximum surface
temperature
5.3.1 5.3.1 Determination of Applies Applies
maximum surface
temperature
5.3.2 5.3.2 Limitation of maximum
surface temperature
5.3.2.1 5.3.2.1 Group I equipment Excluded Excluded
5.3.2.2 5.3.2.2 Group II equipment Applies Applies
5.3.2.3 5.3.2.3 Group III equipment Excluded Excluded
___________
Under preparation. Stage at the time of publication: IEC/FDIS 60079-0:2017.
– 10 – IEC 60079-15:2017 © IEC 2017
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 1 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
5.3.3 5.3.3 Small component Applies Excluded
temperature for Group I
and Group II equipment
- 5.3.4 Component temperature Applies Excluded
of smooth surfaces for
Group I or Group II
equipment
(Applies for smaller than
10 000 mm only)
6 6 Requirements for all
electrical apparatus
6.1 6.1 General Applies Applies
6.2 6.2 Mechanical strength Applies Applies
6.3 6.3 Opening times Excluded Applies
6.4 6.4 Circulating currents Applies Applies
6.5 6.5 Gasket retention Applies Applies
6.6 6.6 Electromagnetic and Applies Applies
ultrasonic radiating
equipment
7 7 Non-metallic enclosures
and non-metallic parts of
enclosures
7.1 7.1 General
7.1.1 7.1.1 Applicability Applies Applies
7.1.2 7.1.2 Specification of Applies Applies
materials
7.2 7.2 Thermal endurance
7.2.1 7.2.1 Tests for thermal Applies Applies
resistance
7.2.2 - Material selection Modified Modified
- 7.2.2 Material selection Applies Applies
7.2.3 7.2.3 Alternative qualification Applies Applies
for elastomeric sealing
O-rings
7.3 7.3 Resistance to ultraviolet Applies Applies
light
7.4 7.4 Electrostatic charges on
external non-metallic
materials
7.4.1 7.4.1 Applicability Applies Applies
7.4.2 7.4.2 Avoidance of build-up of Applies Applies
electrostatic charge on
Group I or Group II
electrical equipment
7.4.3 7.4.3 Avoidance of build-up of Excluded Excluded
electrostatic charge on
equipment for Group III
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 1 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
7.5 7.5 External conductive Applies Applies
parts
8 8 Metallic enclosures and
metallic parts of
enclosures
8.1 8.1 Material composition Applies Applies
8.2 8.2 Group I Excluded Excluded
8.3 8.3 Group II Applies Applies
8.4 8.4 Group III Excluded Excluded
NR 8.5 Copper alloys Applies Applies
9 9 Fasteners
9.1 9.1 General Applies Applies
9.2 9.2 Special fasteners Excluded Excluded
9.3 9.3 Holes for special Excluded Excluded
fasteners
9.3.3 - Hexagon socket set Excluded Excluded
screws
- 9.4 Hexagon socket set Excluded Excluded
screws
10 10 Interlocking devices Excluded Excluded
11 11 Bushings Applies Applies
12 - Materials used for Modified Modified
cementing
- 12 Reserved for future use. Excluded Excluded
13 13 Ex components Applies Applies
14 14 Connection facilities Applies Applies
15 15 Connection facilities for Applies Applies
earthing and bonding
conductors
16 16 Entries into enclosures Applies Applies
17 17 Supplementary Excluded Excluded
requirements for electric
machines
18 18 Supplementary Excluded
requirements for
switchgear
18.1 18.1 Flammable dielectric Excluded Applies
18.2 18.2 Disconnectors Excluded Applies
18.3 18.3 Group I – Provisions for Excluded Excluded
locking
18.4 18.4 Doors and covers Excluded Applies
19 - Supplementary Excluded Excluded
requirements for fuses
- 19 Reserved for future use. Excluded Excluded
20 20 Supplementary
requirements for plugs
and sockets
– 12 – IEC 60079-15:2017 © IEC 2017
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 1 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
20.1 20.1 General Applies Applies
20.2 20.2 Explosive gas Excluded Excluded
atmospheres
20.3 20.3 Explosive dust Excluded Excluded
atmospheres
20.4 20.4 Energized plugs Applies Applies
21 21 Supplementary
requirements for
luminaires
21.1 21.1 General Applies Applies
21.2 21.2 Covers for luminaires of Excluded Excluded
EPL Mb, EPL Gb or EPL
Db
21.3 21.3 Covers for luminaires of Applies Applies
EPL Gc or EPL Dc
21.4 21.4 Sodium lamps Applies Applies
22 22 Supplementary
requirements for
caplights and handlights
22.1 22.1 Group I caplights Excluded Excluded
22.2 22.2 Group II and Group III Excluded Applies
caplights and handlights
23 23 Equipment incorporating Applies Applies
cells and batteries
23.12 23.12 Replacement battery Applies Applies
pack
24 24 Documentation Modified Modified
25 25 Compliance of prototype Applies Applies
or sample with
documents
26 26 Type tests Applies Applies
26.4 26.4 Tests of enclosures
26.4.1 26.4.1 Order of tests
26.4.1.1 26.4.1.1 Metallic enclosures, Applies Applies
metallic parts of
enclosures and glass or
ceramic parts of
enclosures
26.4.1.2 26.4.1.2 Non-metallic enclosures
or non-metallic parts of
enclosures
26.4.1.2.1 26.4.1.2.1 General Applies Applies
26.4.1.2.2 26.4.1.2.2 Group I electrical Excluded Excluded
equipment
26.4.1.2.3 - Group II and Group III Modified Modified
electrical equipment
- 26.4.1.2.3 Group II and Group III Applies Applies
electrical equipment
26.4.2 26.4.2 Resistance to impact Applies Applies
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 1 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
26.4.3 26.4.3 Drop test Applies Applies
26.4.4 26.4.4 Acceptance criteria Applies Applies
26.4.5 26.4.5 Degree of protection by Applies Applies
enclosure
26.5 26.5 Thermal tests
Applies Applies
26.5.1 26.5.1 Temperature
measurement
Applies Applies
26.5.1.1 26.5.1.1 General
Applies Applies
26.5.1.2 26.5.1.2 Service Temperature
Applies Applies
26.5.2 26.5.2 Thermal shock test
26.5.3 26.5.3 Small component Applies Excluded
ignition test (Group I and
Group II)
26.6 26.6 Torque test for bushings Applies Applies
26.7 26.7 Non-metallic enclosures
or non-metallic parts of
enclosures
26.7.1 26.7.1 General Applies Applies
26.7.2 - Test temperatures Modified Modified
- 26.7.2 Test temperatures Applies Applies
26.8 - Thermal endurance to Modified Modified
heat
- 26.8 Thermal endurance to Applies Applies
heat
26.9 26.9 Thermal endurance to Applies Applies
cold
26.10 26.10 Resistance to light
26.10.1 26.10.1 General Applies Applies
26.10.2 26.10.2 Light exposure Applies Applies
26.10.3 26.10.3 Acceptance criteria Applies Applies
26.11 26.11 Resistance to chemical Excluded Excluded
agents for Group I
electrical equipment
26.12 26.12 Earth continuity Applies Applies
26.13 26.13 Surface resistance test Applies Applies
of parts of enclosures of
non-metallic materials
26.14 26.14 Measurement of
capacitance
26.14.1 26.14.1 General Applies Applies
26.14.2 26.14.2 Test procedure Applies Applies
26.15 26.15 Verification of ratings of Excluded Excluded
ventilating fans
26.16 26.16 Alternative qualification Applies Applies
of elastomeric sealing O-
rings
– 14 – IEC 60079-15:2017 © IEC 2017
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 1 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
- 26.17 Transferred charge test Applies Applies
27 27 Routine tests Applies Applies
28 28 Manufacturers Applies Applies
responsibility
29 29 Marking
29.1 29.1 Applicability Applies Applies
29.2 29.2 Location Applies Applies
29.3 29.3 General Applies Applies
29.4 29.4 Ex marking for explosive Applies Applies
gas atmospheres
29.5 29.5 Ex marking for explosive Excluded Excluded
dust atmospheres
29.6 29.6 Combined types (or Applies Applies
levels) of protection
29.7 29.7 Multiple types of Applies Applies
protection
29.8 29.8 Ga equipment using two Excluded Excluded
independent Gb types
(or levels) of protection
- 29.9 Boundary wall Excluded Excluded
29.9 29.10 Ex Components Applies Applies
29.10 29.11 Small Ex Equipment and Applies Applies
small Ex Components
29.11 29.12 Extremely small Applies Applies
equipment and
extremely small Ex
Components
29.12 29.13 Warning markings Applies Applies
29.13 - Alternate marking of Applies Applies
equipment protection
levels (EPLs)
29.13.1 - Alternate marking of Applies Applies
type of protection for
explosive gas
atmospheres
29.13.2 - Alternate marking of Excluded Excluded
type of protection for
explosive dust
atmospheres
29.14 29.14 Cells and batteries Applies Applies
29.15 29.15 Electrical machines Applies Applies
operated with a
converter
29.16 29.16 Examples of marking Examples only Examples only
30 30 Instructions
30.1 30.1 General Applies Applies
30.2 30.2 Cells and batteries Applies Applies
30.3 30.3 Electric machines Excluded Excluded
Clause of IEC 60079-0 IEC 60079-0 clause application to IEC 60079-15
Ed. 6.0 1 Clause / Subclause
Ed. 7.0
(2011) title
Protected sparking Restricted breathing
(future
edition)
(informative) (normative)
“nC” “nR”
(informative)
30.4 30.4 Ventilating fans Excluded Excluded
- 30.5 Cable glands Applies Applies
Annex A Annex A Supplementary Applies Applies
requirements for Ex
cable glands
Annex B Annex B Requirements for Ex Applies Applies
components
Annex C Annex C Example of rig for Informative Annex Informative Annex
resistance to impact test
Annex D Annex D Motors supplied by Informative Annex Informative Annex
converters
Annex E Annex E Temperature evaluation Informative Annex Informative Annex
of electric machines
Annex F Annex F Guideline flowchart for Informative Annex Informative Annex
tests of non-metallic
enclosures
or non-metallic parts of
enclosures (26.4)
- Annex G Guidance flowchart for Informative Annex Informative Annex
tests of cable glands
- Annex H Shaft voltages resulting Informative Annex Informative Annex
in motor bearing or shaft
brush sparking.
Discharge energy
calculation
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. 7.0). The clause numbers for the previous edition are shown for information
only. This is to enable the general requirements of IEC 60079-0 (ed. 6.0) to be used where necessary with this
part of IEC 60079. 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 of the sub-clauses the ‘Applies’ or ‘Excluded’ is listed in the heading row and the
sub-clauses 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.
NOTE 3 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.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
– 16 – IEC 60079-15:2017 © IEC 2017
IEC 60079-7, Explosive atmospheres – Part 7: Equipment protection by increased safety "e"
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60079-0 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
devices and components “nC”
3.1.1
hermetically-sealed device “nC”
device which is so constructed that it cannot be opened and is sealed effectively by fusion to
prevent entry of an external atmosphere
3.1.2
non-incendive component “nC”
component having contacts for making or breaking a specified ignition capable circuit but in
which the contacting mechanism is designed and constructed so that the component is not
capable of causing ignition of the specified explosive gas atmosphere
Note 1 to entry: The enclosure of the non-incendive component is not intended to either exclude the explosive
gas atmosphere or contain an explosion. This is usually applied to specially constructed switch contacts that are
mechanically designed to quench any arc or spark so that they are not a source of ignition.
3.1.3
sealed device “nC”
device which is so constructed that it cannot be opened during normal service and is sealed
effectively to prevent entry of an external atmosphere
3.2
normally sparking device
device with spacings in line with the industrial requirements and which produces arcs and
sparks during normal operating conditions
Note 1 to entry: Normally sparking devices include switches, relays, and contactors not otherwise Ex protected.
3.3
restricted-breathing enclosure “nR”
enclosure that is designed to restrict the entry of gases, vapours and mists
3.4
sealing device
device employing a method other than encapsulation to prevent the flow of a gas or a liquid
between equipment and a conduit or between separate parts of the equipment by providing
sealing facilities
Note 1 to entry: This device is not a device covered by IEC TS 60079-40.
3.5
separation
shortest distance through solid insulating material between two conductive parts
3.6
test port
facility to test the integrity of restricted breathing equipment in the field after installation,
during initial inspection and during maintenance
3.7
type of protection "n"
type of protection applied to electrical equipment such that, in normal operation and in certain
specified regular expected occurrences, it is not capable of igniting a surrounding explosive
gas atmosphere
Note 1 to entry: Additionally, the requirements of this standard are intended to ensure that a malfunction capable
of causing ignition is not likely to occur.
4 General
4.1 Equipment grouping and temperature classification
Equipment grouping and temperature classification shall be in accordance with the equipment
grouping and temperature classifi
...
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