IEC 60079-0:2011
(Main)Explosive atmospheres - Part 0: Equipment - General requirements
Explosive atmospheres - Part 0: Equipment - General requirements
IEC 60079-0:2011 specifies the general requirements for construction, testing and marking of electrical equipment and Ex Components intended for use in explosive atmospheres. Electrical equipment complying with this standard is intended for use in hazardous areas in which explosive gas atmospheres, caused by mixtures of air and gases, vapours or mists, exist under normal atmospheric conditions. The standard atmospheric conditions (relating to the explosion characteristics of the atmosphere) under which it may be assumed that electrical equipment can be operated are:
- temperature -20 °C to +60 °C;
- pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar); and
- air with normal oxygen content, typically 21 % v/v.
This standard and other standards supplementing this standard specify additional test requirements for equipment operating outside the standard temperature range, but further additional consideration and additional testing may be required for equipment operating outside the standard atmospheric pressure range and standard oxygen content, particularly with respect to types of protection that depend on quenching of a flame such as 'flameproof enclosure "d"' (IEC 60079-1) or limitation of energy, 'intrinsic safety "i"' (IEC 60079-11). This sixth edition cancels and replaces the fifth edition, published in 2007, and constitutes a full technical revision with numerous updates.
IEC 60079-0:2011 is also available as IEC Standards+ 60079-0:2011 which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
The contents of the corrigenda of November 2012 and December 2013, and the interpretation sheets of November 2013, October 2014, June 2018 and April 2019 have been included in this copy.
Atmosphères explosives - Partie 0: Matériel - Exigences générales
IEC 60079-0:2011 est disponible sous forme de IEC 60079-0:2011 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.
IEC 60079-0:2011 spécifie les exigences générales de construction, d'essais et de marquage du matériel électrique et des Composants Ex destinés à être utilisés dans des atmosphères explosives. Equipement électrique conforme à cette norme est destiné dans les zones dangereuses dans lequel les atmosphères explosives de gaz, causées par des mélanges d'air et de gaz, de vapeurs ou de brouillards, existent dans des conditions atmosphériques normales. Les conditions atmosphériques normales (relatives aux caractéristiques d'explosion de l'atmosphère) dans lesquelles il peut être supposé que l'appareil électrique peut être utilisé sont les suivantes:
- température de -20 °C à +60 °C;
- pression de 80 kPa (0,8 bar) à 110 kPa (1,1 bar) et;
- air avec teneur normale en oxygène, typiquement 21 % v/v.
La présente norme et les autres normes qui la complètent spécifient des exigences d'essai supplémentaires pour les équipements fonctionnant hors de la plage de température normale, une attention supplémentaire ultérieure et des essais complémentaires pouvant toutefois se révéler nécessaires pour les équipements fonctionnant hors de la plage de pression atmosphérique normale et de la teneur normale en oxygène, notamment pour les modes de protection qui dépendent de l'extinction d'une flamme tel qu'une "enveloppe antidéflagrante "d" (CEI 60079-1) ou de la limitation de l'énergie tel que la "sécurité intrinsèque "i"" (CEI 60079-11). Cette sixième édition annule et remplace la cinquième édition publiée en 2007 dont elle constitue une révision technique complète.
Le contenu des corrigenda de novembre 2012 et décembre 2013, et des feuilles d’interprétation de novembre 2013, octobre 2014, juin 2018 et avril 2019 a été pris en considération dans cet exemplaire.
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IEC 60079-0 ®
Edition 6.0 2011-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 0: Equipment – General requirements
Atmosphères explosives –
Partie 0: Matériel – Exigences générales
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IEC 60079-0 ®
Edition 6.0 2011-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 0: Equipment – General requirements
Atmosphères explosives –
Partie 0: Matériel – Exigences générales
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XD
ICS 29.260.20 ISBN 978-2-88912-519-7
TC 31/Publication 60079-0 (2011), sixth edition/I-SH 01
EXPLOSIVE ATMOSPHERES –
Part 0: Equipment – General requirements
INTERPRETATION SHEET 1
This interpretation sheet has been prepared by technical committee 31: Equipment for
explosive atmospheres, of IEC.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
31/1085/ISH 31/1095/RVD
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
Interpretation of Annex A
Questions:
Is the torque used for the tensile test of A.3.1.4 required to be the same torque as the initial
torque determined in A.3.1.1?
At what point in the testing sequence is the thermal endurance to heat test conducted?
Interpretation:
In A.3.1.1, a torque is applied to either the screws of a flanged compression element or the
nut of a screwed compression element to compress the sealing ring to secure the mandrel. A
tensile force is then applied to the mandrel to confirm the securement. The tensile force is
applied for not less than 6 h. The test is carried out at an ambient temperature of (20 ± 5) °C.
The torque value needed for clamping to be assured by the sealing ring is acceptable if the
slippage of the mandrel or cable sample as a result of the tensile force is not more than
6 mm.
Subsequently, either the complete cable gland and mandrel assembly used for the
determination described above, or a new sample prepared using the same torque values, is
then to be subjected to the thermal endurance tests. The maximum service temperature is
considered to be 75 °C unless otherwise specified by the manufacturer.
NOTE 1 The 75 °C service temperature is the median of the branching point and entry point temperatures.
NOTE 2 Cable glands employing only metallic sealing rings and metallic parts do not require thermal endurance
tests.
The subsequent test conditions and acceptance criteria are given in A.3.1.4. Prior to the
application of the tensile force, the gland may be re-tightened in accordance with the
manufacturer’s instructions.
NOTE The torque applied to the screws or nut during retightening is not required to be the same as the initial
torque applied in A.3.1.1.
In A.3.1.5, the “value needed to prevent slipping” is the torque required for A.3.1.4.
It is intended that this interpretation will be introduced in IEC 60079-0 Edition 7 and therefore
an Interpretation Sheet will not be required for this or future editions.
November 2013 ICS 29.260.20
TC 31/IEC 60079-0 (2011), sixth edition/I-SH 02
EXPLOSIVE ATMOSPHERES –
Part 0: Equipment – General requirements
INTERPRETATION SHEET 2
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
31/1132/ISH 31/1153/RVISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
Following decision No 16 of the TC 31 meeting in Melbourne in 2011, the issuing of an
th
Interpretation Sheet for IEC 60079-0:2011 (6 edition ) was requested, in order to clarify the
th
significance of the changes with respect to the 5 edition.
Question
th
What are the minor editorial, extensions, and major technical changes of the 6 edition with
th
respect to the 5 edition?
Answer
The following table shows the significance of the changes.
The significance of the changes between IEC Standard, IEC 60079-0, Edition 5, 2007-10
(Including Corrigendum No.1 and Interpretation Sheet I-SH 01) and IEC 60079-0, Edition 6,
2011-06 are as listed below:
October 2014 ICS 29.260.20
Type
Explanation of the significance of the changes Clause Minor and Extension Major
editorial technical
changes changes
Expansion of material specification data for 7.1.2 x
plastics and elastomers, including UV resistance
Addition of alternative qualification for O-rings 7.2.3 x
Addition of alternative criteria for surface 7.4.2 a) x
resistance
Addition of alternative breakdown voltage limit for 7.4.2 c) x
non-metallic layers applied to metallic enclosures
Expansion of “X” marking options for non-metallic 7.4.2 d) x
enclosure materials not meeting basic electrostatic 7.4.2 e)
requirements
Clarification that non-metallic enclosure 7.4.3 x
requirements also apply to painted or coated metal
enclosures
Clarification of test to determine capacitance of 7.5 C1
accessible metal parts with reduction in acceptable Table 9
capacitance
Addition of limits on zirconium content for Group III 8.3 x
and Group II (Gb only) enclosures 8.4
Introduction of “X” marking for Group III enclosures 8.4 x
not complying with basic material requirements,
similar to that existing for Group II
Addition of button-head cap screws to permitted 9.2 x
“Special Fasteners”
Reference for protective earthing (PE) 15.3 x
requirements for electrical machines to IEC 60034
Addition of requirements for ventilating fans 17.1.5 C2
Addition of requirement for temperature rating of 17.2 x
bearing lubricants
Addition of alternative construction for 18.2 x
disconnectors
Removal of voltage limits on plugs and sockets 20.2 x
Addition of test requirements for arc-quenching 20.2 C3
test on plugs and sockets
Additional information on cell voltages 23.3 C4
Table 12
Revision to impact test of glass parts 26.4.2 x
Revision to impact test procedure to address 26.4.2 x
“bounce” of impact head
Clarification of the test requirements for “service” 26.5.1.2 x
and “surface” temperature 26.5.1.3
Clarification of temperature rise tests for 26.5.1.3 x
converter-fed motors
Addition of alternative test method for thermal 26.8 x
endurance Table 15
Removal of “charging test” and addition of note Formerly C5
providing guidance 26.14
Clarification of test for the measurement of 26.14 C6
capacitance, revision of maximum capacitance
Addition of tests for ventilating fans 26.15 C2
Addition of alternative o-ring testing 26.16 x
Addition of a “Schedule of Limitations” to 28.2 x
October 2014 ICS 29.260.20
Type
Explanation of the significance of the changes Clause Minor and Extension Major
editorial technical
changes changes
certificates for Ex Components
Clarification of the marking for multiple 29.4 d) x
temperature classes
29.5 d)
Addition of marking for converter-fed motors 29.15 x
Removal of IP marking for Group III 29.5 x
Addition of specific instructions for electrical 30.3 x
machines and for ventilating fans 30.4
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. More guidance
may be found by referring to the Redline Version of the standard.
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 ‘Major technical changes’
C1 – The values in the table have been significantly reduced based on information that is intended to be published
in IEC TS 60079-32-1 (currently in preparation).
C2 – The requirements for fans was added at the request of the IECEx International Product Certification Scheme.
C3 – The test has been introduced for all disconnectors as an alternative to the voltage and current restrictions in
the previous standard which were considered to be arbitrary.
C4 – There has been a slight increase in some cell voltages. This is a minor change for most protection concepts
but
...
IEC 60079-0 ®
Edition 6.0 2011-06
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Explosive atmospheres –
Part 0: Equipment – General requirements
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
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IEC 60079-0 ®
Edition 6.0 2011-06
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Explosive atmospheres –
Part 0: Equipment – General requirements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.260.20 ISBN 978-2-8891-2519-7
IEC 60079-0 ®
Edition 6.0 2011-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 0: Equipment – General requirements
Atmosphères explosives –
Partie 0: Matériel – Exigences générales
TC 31/Publication 60079-0 (2011), sixth edition/I-SH 01
EXPLOSIVE ATMOSPHERES –
Part 0: Equipment – General requirements
INTERPRETATION SHEET 1
This interpretation sheet has been prepared by technical committee 31: Equipment for
explosive atmospheres, of IEC.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
31/1085/ISH 31/1095/RVD
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
Interpretation of Annex A
Questions:
Is the torque used for the tensile test of A.3.1.4 required to be the same torque as the initial
torque determined in A.3.1.1?
At what point in the testing sequence is the thermal endurance to heat test conducted?
Interpretation:
In A.3.1.1, a torque is applied to either the screws of a flanged compression element or the
nut of a screwed compression element to compress the sealing ring to secure the mandrel. A
tensile force is then applied to the mandrel to confirm the securement. The tensile force is
applied for not less than 6 h. The test is carried out at an ambient temperature of (20 ± 5) °C.
The torque value needed for clamping to be assured by the sealing ring is acceptable if the
slippage of the mandrel or cable sample as a result of the tensile force is not more than
6 mm.
Subsequently, either the complete cable gland and mandrel assembly used for the
determination described above, or a new sample prepared using the same torque values, is
then to be subjected to the thermal endurance tests. The maximum service temperature is
considered to be 75 °C unless otherwise specified by the manufacturer.
NOTE 1 The 75 °C service temperature is the median of the branching point and entry point temperatures.
NOTE 2 Cable glands employing only metallic sealing rings and metallic parts do not require thermal endurance
tests.
The subsequent test conditions and acceptance criteria are given in A.3.1.4. Prior to the
application of the tensile force, the gland may be re-tightened in accordance with the
manufacturer’s instructions.
NOTE The torque applied to the screws or nut during retightening is not required to be the same as the initial
torque applied in A.3.1.1.
In A.3.1.5, the “value needed to prevent slipping” is the torque required for A.3.1.4.
It is intended that this interpretation will be introduced in IEC 60079-0 Edition 7 and therefore
an Interpretation Sheet will not be required for this or future editions.
November 2013 ICS 29.260.20
TC 31/IEC 60079-0 (2011), sixth edition/I-SH 02
EXPLOSIVE ATMOSPHERES –
Part 0: Equipment – General requirements
INTERPRETATION SHEET 2
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
31/1132/ISH 31/1153/RVISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
Following decision No 16 of the TC 31 meeting in Melbourne in 2011, the issuing of an
th
Interpretation Sheet for IEC 60079-0:2011 (6 edition ) was requested, in order to clarify the
th
significance of the changes with respect to the 5 edition.
Question
th
What are the minor editorial, extensions, and major technical changes of the 6 edition with
th
respect to the 5 edition?
Answer
The following table shows the significance of the changes.
The significance of the changes between IEC Standard, IEC 60079-0, Edition 5, 2007-10
(Including Corrigendum No.1 and Interpretation Sheet I-SH 01) and IEC 60079-0, Edition 6,
2011-06 are as listed below:
October 2014 ICS 29.260.20
Type
Explanation of the significance of the changes Clause Minor and Extension Major
editorial technical
changes changes
Expansion of material specification data for 7.1.2 x
plastics and elastomers, including UV resistance
Addition of alternative qualification for O-rings 7.2.3 x
Addition of alternative criteria for surface 7.4.2 a) x
resistance
Addition of alternative breakdown voltage limit for 7.4.2 c) x
non-metallic layers applied to metallic enclosures
Expansion of “X” marking options for non-metallic 7.4.2 d) x
enclosure materials not meeting basic electrostatic 7.4.2 e)
requirements
Clarification that non-metallic enclosure 7.4.3 x
requirements also apply to painted or coated metal
enclosures
Clarification of test to determine capacitance of 7.5 C1
accessible metal parts with reduction in acceptable Table 9
capacitance
Addition of limits on zirconium content for Group III 8.3 x
and Group II (Gb only) enclosures 8.4
Introduction of “X” marking for Group III enclosures 8.4 x
not complying with basic material requirements,
similar to that existing for Group II
Addition of button-head cap screws to permitted 9.2 x
“Special Fasteners”
Reference for protective earthing (PE) 15.3 x
requirements for electrical machines to IEC 60034
Addition of requirements for ventilating fans 17.1.5 C2
Addition of requirement for temperature rating of 17.2 x
bearing lubricants
Addition of alternative construction for 18.2 x
disconnectors
Removal of voltage limits on plugs and sockets 20.2 x
Addition of test requirements for arc-quenching 20.2 C3
test on plugs and sockets
Additional information on cell voltages 23.3 C4
Table 12
Revision to impact test of glass parts 26.4.2 x
Revision to impact test procedure to address 26.4.2 x
“bounce” of impact head
Clarification of the test requirements for “service” 26.5.1.2 x
and “surface” temperature 26.5.1.3
Clarification of temperature rise tests for 26.5.1.3 x
converter-fed motors
Addition of alternative test method for thermal 26.8 x
endurance Table 15
Removal of “charging test” and addition of note Formerly C5
providing guidance 26.14
Clarification of test for the measurement of 26.14 C6
capacitance, revision of maximum capacitance
Addition of tests for ventilating fans 26.15 C2
Addition of alternative o-ring testing 26.16 x
Addition of a “Schedule of Limitations” to 28.2 x
October 2014 ICS 29.260.20
Type
Explanation of the significance of the changes Clause Minor and Extension Major
editorial technical
changes changes
certificates for Ex Components
Clarification of the marking for multiple 29.4 d) x
temperature classes
29.5 d)
Addition of marking for converter-fed motors 29.15 x
Removal of IP marking for Group III 29.5 x
Addition of specific instructions for electrical 30.3 x
machines and for ventilating fans 30.4
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. More guidance
may be found by referring to the Redline Version of the standard.
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 ‘Major technical changes’
C1 – The values in the table have been significantly reduced based on information that is intended to be published
in IEC TS 60079-32-1 (currently in preparation).
C2 – The requirements for fans was added at the request of the IECEx International Product Certification Scheme.
C3 – The test has been introduced for all disconnectors as an alternative to the voltage and current restrictions in
the previous standard which were considered to be arbitrary.
C4 – There has been a slight increase in some cell voltages. This is a minor change for most protection concepts
but should be regarded as a major change for equipment having a type of protection relying on energy limitation,
e.g. IEC 60079-11
C5 – The charging test was removed as it had been found to be not repeatable. Guidance will be given in IEC TS
60079-32-1 (currently in preparation).
C6 – The limits for capacitance have been decreased based on technical information in CLC/TR 50404.
October 2014 ICS 29.260.20
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60079-0
Edition 6.0 2011-06
EXPLOSIVE ATMOSPHERES –
Part 0: Equipment – General requirements
INTERPRETATION SHEET 3
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
FDIS Report on voting
31/1376/FDIS 31/1386/RVD
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
Question:
How shall marking be shown for equipment covered by both the electrical and non-electrical
standards (IEC 60079 and ISO 80079 series)?
Answer:
Equipment which includes both an electrical part and a non-electrical part shall have
combined marking. For example:
Ex db
...
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