SIST EN 60079-11:2007

SLOVENSKI STANDARD
SIST EN 60079-11:2007
01-december-2007
1DGRPHãþD
SIST EN 50020:2003
(NVSOR]LYQHDWPRVIHUHGHO=DãþLWDRSUHPH]ODVWQRYDUQRVWMRL,(&

Explosive atmospheres - Part 11: Equipment protection by intrinsic safety "i"
Explosionsfähige Atmosphäre - Teil 11: Geräteschutz durch Eigensicherheit "i"
Atmospheres explosives - Partie 11: Protection de l'équipement par sécurité intrinseque
"i"
Ta slovenski standard je istoveten z: EN 60079-11:2007
ICS:
29.260.20 (OHNWULþQLDSDUDWL]D Electrical apparatus for
HNVSOR]LYQDR]UDþMD explosive atmospheres
SIST EN 60079-11:2007 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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EUROPEAN STANDARD
EN 60079-11

NORME EUROPÉENNE
January 2007
EUROPÄISCHE NORM

ICS 29.260.20 Supersedes EN 50020:2002


English version


Explosive atmospheres -
Part 11: Equipment protection by intrinsic safety "i"
(IEC 60079-11:2006)


Atmosphères explosives -  Explosionsfähige Atmosphäre -
Partie 11: Protection de l'équipement Teil 11: Geräteschutz durch
par sécurité intrinsèque "i" Eigensicherheit "i"
(CEI 60079-11:2006 + corrigendum 2006) (IEC 60079-11:2006)




This European Standard was approved by CENELEC on 2006-10-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60079-11:2007 E

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EN 60079-11:2007 - 2 -
Foreword
The text of document 31G/159/FDIS, future edition 5 of IEC 60079-11, prepared by SC 31G, Intrincisally
safer apparatus, of IEC TC 31, Equipment for explosive atmospheres, was submitted to the IEC-
CENELEC parallel vote and was approved by CENELEC as EN 60079-11 on 2006-10-01.
This European Standard supersedes EN 50020:2002.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2007-08-01
– latest date by which the national standards conflicting
(dow) 2009-10-01
with the EN have to be withdrawn
This standard supplements and modifies the general requirements of EN 60079-0:2006, except as
indicated in Table 1 (see Scope).
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of
EC Directive 94/9/EC. See Annex ZZ.
Annexes ZA and ZZ have been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60079-11:2006 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60079-15 NOTE  Harmonized as EN 60079-15:2005 (not modified).
IEC 61086-1 NOTE  Harmonized as EN 61086-1:2004 (not modified).
__________

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- 3 - EN 60079-11:2007
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application 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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year
IEC 60079-0 (mod) 2004 Electrical apparatus for explosive gas EN 60079-0 2006
atmospheres -
Part 0: General requirements


1) 2)
IEC 60079-7 – Explosive atmospheres - EN 60079-7 2007
Part 7: Equipment protection by Increased
safety "e"


1) 2)
IEC 60079-25 – Electrical apparatus for explosive gas EN 60079-25 2004
atmospheres - + corr. April 2006
Part 25: Intrinsically safe systems


1) 2)
IEC 60079-27 – Electrical apparatus for explosive gas EN 60079-27 2006
atmospheres -
Part 27: Fieldbus intrinsically safe concept
(FISCO) and Fieldbus non-incendive concept
(FNICO)


1) 2)
IEC 60085 – Electrical insulation - Thermal classification EN 60085 2004


1) 2)
IEC 60112 – Method for the determination of the proof and EN 60112 2003
the comparative tracking indices of solid
insulating materials


IEC 60127 Series Miniature fuses EN 60127 Series


1)
IEC 60317-3 – Specifications for particular types of winding – –
wires -
Part 3: Polyester enamelled round copper
wire, class 155


1) 2)
IEC 60317-7 – Specifications for particular types of winding EN 60317-7 1994
wires -
Part 7: Polyimide enamelled round copper
wire, class 220


1) 2)
IEC 60317-8 – Specifications for particular types of winding EN 60317-8 1994
wires -
Part 8: Polyesterimide enamelled round
copper wire, class 180



1)
Undated reference.
2)
Valid edition at date of issue.

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EN 60079-11:2007 - 4 -
Publication Year Title EN/HD Year
1) 2)
IEC 60317-13 – Specifications for particular types of winding EN 60317-13 1994
wires -
Part 13: Polyester or polyesterimide
overcoated with polyamide-imide enamelled
round copper wire, class 200


1) 2)
IEC 60529 – Degrees of protection provided by enclosures EN 60529 1991
(IP Code) + corr. May 1993


IEC 60664-1 1992 Insulation coordination for equipment within
+ A1 2000 low-voltage systems -
+ A2 2002 Part 1: Principles, requirements and tests EN 60664-1 2003


IEC 60664-3 2003 Insulation coordination for equipment within EN 60664-3 2003
low-voltage systems -
Part 3: Use of coating, potting or moulding
for protection against pollution


1)
ANSI/UL 248-1 – Low-voltage Fuses - – –
Part 1: General requirements

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- 5 - EN 60079-11:2007
Annex ZZ
(informative)

Coverage of Essential Requirements of EC Directives
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and within its scope the standard covers only the
following essential requirements out of those given in Annex II of the EC Directive 94/9/EC:
– ER 1.0.1, ER 1.0.2, ER 1.0.4, ER 1.0.5 (partly), ER 1.0.6 (partly)
– ER 1.1 (partly)
– ER 1.2.1 (partly), ER 1.2.2 (partly), ER 1.2.5, ER 1.2.6
– ER 1.3.1
– ER 1.6.4
– ER 2.0.1.1, ER 2.0.1.2, ER 2.0.1.3 (partly), ER 2.0.1.4
– ER 2.0.2.1, ER 2.0.2.2, ER 2.0.2.3 (partly)
– ER 2.1.1.1 to ER 2.1.1.3
– ER 2.2.1.1 to ER 2.2.1.3
Compliance with this standard provides one means of conformity with the specified essential
requirements of the Directive concerned.
WARNING: Other requirements and other EC Directives may be applicable to the products falling within
the scope of this standard.

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IEC 60079-11
Edition 5.0 2006-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 11: Equipment protection by intrinsic safety "i"

Atmosphères explosives –
Partie 11: Protection de l’équipement par sécurité intrinsèque «i»

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XE
CODE PRIX
ICS 29.260.20 ISBN 2-8318-8749-6

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60079-11  IEC:2006 – 3 – – 2 – 60079-11 © IEC:2006
CONTENTS
FOREWORD.6

Scope.8
1
2 Normative references.10
3 Terms and definitions .11
4 Grouping and classification of intrinsically safe apparatus and associated apparatus .16
5 Levels of protection and ignition compliance requirements of electrical apparatus.16
5.1 General .16
5.2 Level of protection "ia" .16
5.3 Level of protection "ib" .17
5.4 Level of protection "ic" .17
5.5 Spark ignition compliance .18
5.6 Thermal ignition compliance .18
5.7 Simple apparatus.22
6 Apparatus construction .22
6.1 Enclosures .23
6.2 Facilities for connection of external circuits .23
6.3 Separation distances .27
6.4 Protection against polarity reversal .38
6.5 Earth conductors, connections and terminals .38
6.6 Encapsulation.40
7 Components on which intrinsic safety depends.40
7.1 Rating of components .40
7.2 Connectors for internal connections, plug-in cards and components .41
7.3 Fuses .41
7.4 Primary and secondary cells and batteries .42
7.5 Semiconductors.46
7.6 Failure of components, connections and separations.47
7.7 Piezo-electric devices .48
7.8 Electrochemical cells for the detection of gases .48
8 Infallible components, infallible assemblies of components and infallible
connections on which intrinsic safety depends.48
8.1 Mains transformers.48
8.2 Transformers other than mains transformers.50
8.3 Infallible windings .5 1
8.4 Current-limiting resistors.52
8.5 Blocking capacitors.52
8.6 Shunt safety assemblies .53
8.7 Wiring, printed circuit board tracks, and connections. .54
8.8 Galvanically separating components .56

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60079-11 © IEC:200660079-11  IEC:2006 – 5 – – 3 –
9 Diode safety barriers.57
9.1 General . 57
9.2 Construction .57
10 Type verifications and type tests .57
10.1 Spark ignition test.57
10.2 Temperature tests .62
10.3 Dielectric strength tests .62
10.4 Determination of parameters of loosely specified components.63
10.5 Tests for cells and batteries.63
10.6 Mechanical tests.65
10.7 Tests for apparatus containing piezoelectric devices .65
10.8 Type tests for diode safety barriers and safety shunts .66
10.9 Cable pull test .67
10.10 Transformer tests .67
11 Routine verifications and tests .67
11.1 Routine tests for diode safety barriers.67
11.2 Routine tests for infallible transformers .68
12 Marking .68
12.1 General .68
12.2 Marking of connection facilities .69
12.3 Warning markings .69
12.4 Examples of marking .70
13 Documentation .7 1

Annex A (normative) Assessment of intrinsically safe circuits.72
Annex B (normative) Spark test apparatus for intrinsically safe circuits .94
Annex C (informative) Measurement of creepage distances, clearances and separation
distances through casting compound and through solid insulation.103
Annex D (informative) Encapsulation .106
Annex E (informative) Transient energy test .110
Annex F (normative) Alternative separation distances for assembled printed circuit
boards and separation of components .113

Bibliography .117

Figure 1 – Separation of intrinsically safe and non-intrinsically safe terminals .25
Figure 2 – Example of separation of conducting parts.30
Figure 3 – Determination of creepage distances .34
Figure 4 – Creepage distances and clearances on printed circuit boards.35
Figure 5– Examples of independent and non-independent connecting elements.39
Figure 6 – Infallible solder connection of surface mount component in accordance
with 8.7 c) 3). .55
Figure A.1 – Resistive circuits .75
Figure A.2 – Group I capacitive circuits .76
Figure A.3 – Group II capacitive circuits .77
Figure A.4 – Inductive circuits of Group II .78

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60079-11  IEC:2006 – 7 – – 4 – 60079-11 © IEC:2006
Figure A.5 – Group I inductive circuits .79
Figure A.6 – Group IIC inductive circuits.80
Figure A.7 – Simple inductive circuit.8 1
Figure A.8 – Simple capacitive circuit .8 1
Figure A.9 – Equivalent capacitance.93
Figure B.1 – Spark test apparatus for intrinsically safe circuits.97
Figure B.2 – Cadmium contact disc .98
Figure B.3 – Wire holder .98
Figure B.4 – Example of a practical design of spark test apparatus.99
Figure B.5 – Example of an explosion pressure switch.100
Figure B.6 – Example of automatic stopping by means of an explosion pressure switch .1 01
Figure B.7 – Arrangement for fusing tungsten wires.102
Figure B.8 – Circuit diagram for fusing tungsten wires .102
Figure C.1 – Measurement of clearance .103
Figure C.2 – Measurement of composite distances .103
Figure C.3 – Measurement of creepage.104
Figure C.4 – Measurement of composite creepage .105
Figure D.1 – Examples of encapsulated assemblies conforming to 6.3.4 and 6.6 .107
Figure D.2 – Applications of encapsulation without enclosure.108
Figure E1 – Example of test circuit .112
Figure E2 – Example of output waveform.112

Table 1 – Exclusion of specific clauses of IEC 60079-0 .8
Table 2 – Assessment of temperature classification according to component size and
ambient temperature .19
Table 3 – Temperature classification of copper wiring (in a maximum ambient
temperature of 40 °C).20
Table 4 – Temperature classification of tracks on printed circuit boards (in a maximum
ambient temperature of 40 °C) .21
Table 5 – Clearances, creepage distances and separations .29
Table 6 – Minimum foil thickness or minimum wire diameter of the screen in relation to
the rated current of the fuse .49
Table 7 – Compositions of explosive test mixtures adequate for 1,0 safety factor.59
Table 8 – Compositions of explosive test mixtures adequate for 1,5 safety factor.59
Table 9 – Routine test voltages for infallible transformers .68
Table 10 – Text of warning markings .69
Table A.1 – Permitted short-circuit current corresponding to the voltage and the
apparatus group.82
Table A.2 – Permitted capacitance corresponding to the voltage and the apparatus
group .87
Table A.3 – Permitted reduction of effective capacitance when protected by a series
resistance .93

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60079-11 © IEC:200660079-11  IEC:2006 – 9 – – 5 –
Table F.1 – Clearances, creepage distances and separations for level of protection ”ia”
and “ib” when ingress protected, and special conditions of material and installation are
fulfilled. 115
Table F.2 – Clearances, creepage distances and separations for level of protection”ic”
when ingress is protected by an enclosure or by special conditions of installation . 116

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60079-11  IEC:2006 – 11 – – 6 – 60079-11 © IEC:2006
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

EXPLOSIVE ATMOSPHERES –

Part 11: Equipment protection by intrinsic safety "i"


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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 60079-11 has been prepared by subcommittee 31G: Intrinsically
safe apparatus, of IEC technical committee 31: Equipment for explosive atmospheres.
This fifth edition cancels and replaces the fourth edition published in 1999 and constitutes a full
technical revision.
The significant changes with respect to the previous edition are listed below:
– introduction of level of protection “ic” (this level of protection has been introduced to allow
removal of the 'energy limitation' concept from 60079-15);
– introduction of Annex F that allows reduction in segregation distance requirements when
the pollution degree has been reduced by installation or enclosure;
– introduction of alternative spark test apparatus construction when used with high current
circuits;
– introduction of Annex E that provides a method for transient energy test;

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60079-11 © IEC:200660079-11  IEC:2006 – 13 – – 7 –
– changes in the table of 'Temperature classification of tracks on PCB's' to allow correlation
with IPC-2152;
– allowing alternative methods of rating resistors when used to limit the discharge from
capacitance;
– introduction of methods to deal with the spark ignition energy consideration when high
current low voltage cells and batteries are used;
– introduction of tests to measure the maximum pressure in sealed battery containers;
– introduction of methods to deal with fault application on voltage enhancement IC's;
– introduction of infallible connection methods for SMD's (surface mount devices);
– introduction of alternative methods to deal with the spark ignition energy in circuits with
both inductance and capacitance;
– introduction of alternative high voltage test for transformers;
– introduction of methods to assess the reduction of effective capacitance when protected by
series resistances;
– introduction of Group I data for permitted short circuit current and permitted capacitance in
the tables of Annex A.
The text of this standard is based on the following documents:
FDIS Report on voting
31G/159/FDIS 31G/161/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This standard supplements and modifies the general requirements of IEC 60079-0, except as
indicated in Table 1 (see Scope).
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list o
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