EN 50020:2002
(Main)Electrical apparatus for potentially explosive atmospheres - Intrinsic safety 'i'
Electrical apparatus for potentially explosive atmospheres - Intrinsic safety 'i'
To be read with EN 50014:1997 * Superseded by EN 60079-11:2007
Elektrische Betriebsmittel für explosionsgefährdete Bereiche - Eigensicherheit 'i'
Matériel électrique pour atmosphères explosibles - Sécurité intrinsèque 'i'
Električne naprave za potencialno eksplozivne atmosfere - Lastna varnost ''i''
General Information
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Standards Content (Sample)
SLOVENSKI SIST EN 50020:2003
STANDARD
marec 2003
Električne naprave za potencialno eksplozivne atmosfere - Lastna varnost ''i''
Electrical apparatus for potentially explosive atmospheres - Intrinsic safety "i"
ICS 29.260.20 Referenčna številka
© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno
EUROPEAN STANDARD EN 50020
NORME EUROPÉENNE
EUROPÄISCHE NORM June 2002
ICS 29.260.20 Supersedes EN 50020:1994
English version
Electrical apparatus for potentially explosive atmospheres -
Intrinsic safety 'i'
Matériel électrique Elektrische Betriebsmittel
pour atmosphères explosibles - für explosionsgefährdete Bereiche -
Sécurité intrinsèque 'i' Eigensicherheit 'i'
This European Standard was approved by CENELEC on 2002-02-01. 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, Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,
Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and 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
© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50020:2002 E
Foreword
This European Standard was prepared by SC 31-3, Intrinsically safe apparatus and systems "i", of
Technical Committee CENELEC TC 31, Electrical apparatus for explosive atmospheres.
The text of the draft was submitted to the CENELEC Unique Acceptance Procedure and was approved by
CENELEC as EN 50020 on 2002-02-01.
This European Standard supersedes EN 50020:1994 and its corrigendum February 1998.
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) 2003-02-01
- latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2003-06-30
This European Standard is to be read in conjunction with EN 50014:1997, Electrical apparatus for
potentially explosive atmospheres – General requirements, and with the third editions of the European
Standards for the specific types of protection.
- 3 - EN 50020:200X
Contents
1 Scope.4
2 Normative references.6
3 Definitions.7
4 Grouping and classification of intrinsically safe apparatus
and associated apparatus .10
5 Intrinsically safe levels of protection of electrical apparatus.11
6 Apparatus construction.13
7 Components on which intrinsic safety depends .30
8 Infallible components, infallible assemblies of components
and infallible connections .36
9 Diode safety barriers.42
10 Type verification and type tests.43
11 Routine verifications and tests.52
12 Marking.52
13 Documentation .53
Annex A (normative) Assessment of intrinsically safe circuits.54
Annex B (normative) Spark test apparatus for intrinsically safe circuits.77
Annex C (informative) Measurement of creepage distances, clearances
and separation distances through casting compound and through solid insulation.86
Annex D (normative) Encapsulation .89
Annex E (normative) Certification requirements for torches.93
1 Scope
1.1 This European Standard specifies the construction and testing of intrinsically safe apparatus,
intended for use in potentially explosive atmospheres and for associated apparatus, which is intended for
connection to intrinsically safe circuits which enter such atmospheres.
1.2 This European Standard supplements EN 50014 the requirements of which apply to intrinsically safe
apparatus and to associated apparatus except as indicated in the following list.
If associated apparatus is protected by a type of protection listed in EN 50014, then the requirements of
that method of protection together with the relevant parts of EN 50014 also apply to the associated
apparatus. The list of exclusions which follows is directly applicable to associated apparatus intended for
use in situations where there is no potentially hazardous atmosphere and in other circumstances should
be used in combination with the requirements of the other method of protection.
- 5 - EN 50020:200X
Clause of EN 50014:1997 Clause excluded
Intrinsically Associated
safe apparatus
apparatus
3.1 Electrical apparatus Yes Yes
4.2.2 Marking of maximum surface temperature No Yes
5.1 Maximum surface temperature No Yes
5.3 Surface temperature and ignition temperature No Yes
6.2 Enclosure opening delay Yes Yes
7.1.1 Definition of plastics material No Yes
7.1.2 Requirements of plastics material compliance Yes Yes
7.1.3 Verification of plastics material compliance No Yes
7.2 Thermal endurance Yes Yes
7.3 Electrostatic charges on plastics enclosures No Yes
7.4 Threaded holes in plastics Yes Yes
8.1 Light metal enclosure materials No Yes
8.2 Threaded holes in light metals Yes Yes
9 Fasteners Yes Yes
10 Interlocking devices Yes Yes
11 Bushings Yes Yes
12 Materials used for cementing Yes Yes
14 Connection facilities and terminal compartments Yes Yes
15 Connection facilities for earthing or bonding conductors Yes Yes
16 Cable and conduit entries Yes Yes
17 to 22 Supplementary requirements for certain electrical Yes Yes
apparatus
23.4.3.1 Test for resistance to impact Yes Yes
23.4.3.2 Drop test (no prior impact test necessary) No Yes
23.4.3.3 Required results No Yes
23.4.5 Torque test for bushings Yes Yes
23.4.6.1 Temperature measurement No Yes
23.4.6.2 Thermal shock test Yes Yes
23.4.7.1 Tests on non-metallic enclosures Yes Yes
to 23.4.7.7
23.4.7.8 Insulation resistance test of parts of enclosures of plastics No Yes
materials
Annex B Ex cable entries Yes Yes
1.3 This standard is applicable to electrical apparatus in which the electrical circuits themselves are
incapable of causing an explosion in the surrounding explosive atmosphere.
1.4 This standard is also applicable to electrical apparatus or parts of electrical apparatus located
outside the potentially explosive atmosphere or protected by another type of protection listed in
EN 50014, where the intrinsic safety of the electrical circuits in the potentially explosive atmosphere, may
depend upon the design and construction of such electrical apparatus or parts of such electrical
apparatus. The electrical circuits exposed to the potentially explosive atmosphere are evaluated for use in
such an atmosphere by applying this standard.
NOTE Methods of interconnection of intrinsically safe apparatus and associated apparatus are specified in EN 50039.
1.5 Where intrinsically safe apparatus is required to be Category 1 G equipment in accordance with
EN 50284 it must comply with the requirements in this standard and also comply with the relevant
requirements of EN 50284. In particular 4.3, 4.4 and 4.5 impose additional requirements.
1.6 Where intrinsically safe apparatus is required to be Category M1 equipment in accordance with
EN 50303 it must comply with the requirements of this standard and also comply with the relevant
requirements of EN 50303.
NOTE Associated apparatus intended for interconnection to Category 1 G and Category M1 equipment only requires to comply
with the requirements of “ia” associated apparatus in accordance with this standard but should be marked in accordance with the
relevant Category 1 standard.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this European Standard only when incorporated in it by amendment or revision. For undated
references the latest edition of the publication referred to applies (including amendments).
Publication Year Title
EN 50014 1997 Electrical apparatus for potentially explosive atmospheres - General
+ corr. April 1998 requirements
+ A1 1999
+ A2 1999
EN 50019 Electrical apparatus for potentially explosive atmospheres - Increased
safety ‘e’
EN 50039 Electrical apparatus for potentially explosive atmospheres - Intrinsically
safe electrical systems ‘i’
EN 50284 1999 Special requirements for construction, test and marking of electrical
apparatus for equipment group II, Category 1 G
EN 50303 2000 Group I, Category M1 equipment intended to remain functional in
atmospheres endangered by firedamp and/or coal dust
EN 60127-1 Miniature fuses - Part 1: Definitions for miniature fuses and general
requirements for miniature fuse-links (IEC 60127-1)
EN 60127-2 Miniature fuses - Part 2: Cartridge fuse-links (IEC 60127-2)
EN 60127-3 Miniature fuses - Part 3: Sub-miniature fuse-links (IEC 60127-3)
EN 60317-3 1994 Specifications for particular types of winding wires - Part 3: Polyester
+ A1 1998 enamelled round copper wire, class 155
(IEC 60317-3:1990 + A1:1997)
EN 60317-7 1994 Specifications for particular types of winding wires - Part 7: Polyimide
+ A1 1997 enamelled round copper wire, class 220
+ A2 1998 (IEC 60317-7:1990 + A1:1997 + A2:1997)
- 7 - EN 50020:200X
Publication Year Title
EN 60317-8 1994 Specifications for particular types of winding wires -
+ A1 1997 Part 8: Polyesterimide enamelled round copper wire, class 180
+ A2 1998 (IEC 60317-8:1990 + A1:1997 + A2:1997)
EN 60529 Degrees of protection provided by enclosures (IP code)
HD 214 S2 1980 Method for determining the comparative and the proof tracking indices of
solid insulating materials under moist conditions
(IEC 60112:1979)
HD 566 S1 1990 Thermal evaluation and classification of electrical insulation
(IEC 60085:1984)
3 Definitions
For the purpose of this European Standard, the definitions in EN 50014 and the following definitions
apply:
3.1
intrinsically safe circuit
circuit in which any spark or any thermal effect produced in the conditions specified in this standard,
which include normal operation and specified fault conditions, is not capable of causing ignition of a given
explosive gas atmosphere
3.2
electrical apparatus
assembly of electrical components, electrical circuits or parts of electrical circuits normally contained in a
single enclosure
NOTE 1 The term “normally” has been introduced to indicate that an apparatus may occasionally be in more than one enclosure,
for example, a telephone or a radio transceiver with a hand microphone.
NOTE 2 This definition is more precise than that contained in EN 50014.
3.3
intrinsically safe apparatus
electrical apparatus in which all the circuits are intrinsically safe circuits
3.4
associated apparatus
electrical apparatus, which contains both intrinsically safe circuits and non-intrinsically safe circuits and is
constructed so that the non-intrinsically safe circuit, cannot adversely affect the intrinsically safe circuits
NOTE Associated apparatus may be either
- electrical apparatus which has another type of protection listed in EN 50014 for use in the appropriate explosive gas
atmosphere, or
- electrical apparatus not so protected and which, therefore, will not be used within an explosive gas atmosphere, for example a
recorder which is not itself in an explosive gas atmosphere, but is connected to a thermocouple situated within an explosive
atmosphere where only the recorder input circuit is intrinsically safe.
3.5
normal operation
operation of intrinsically safe apparatus or associated apparatus such that it conforms electrically and
mechanically with the design specification produced by its manufacturer
3.6
fault
any defect of any component, separation, insulation or connection between components, not defined as
infallible by this standard, upon which the intrinsic safety of a circuit depends
3.7
countable fault
fault which occurs in parts of electrical apparatus conforming to the constructional requirements of this
standard
3.8
non-countable fault
fault which occurs in parts of electrical apparatus not conformi
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