SIST EN IEC 60947-3:2021

SLOVENSKI STANDARD
01-maj-2021
Nadomešča:
SIST EN 60947-3:2009
SIST EN 60947-3:2009/A1:2012
SIST EN 60947-3:2009/A2:2016
Nizkonapetostne stikalne in krmilne naprave - 3. del: Stikala, ločilniki, ločilna
stikala in stikalni aparati z varovalkami (IEC 60947-3:2020)
Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-
disconnectors and fuse-combination units (IEC 60947-3:2020)
Niederspannungsschaltgeräte - Teil 3: Lastschalter, Trennschalter, Lasttrennschalter und
Schalter-Sicherungs-Einheiten (IEC 60947-3:2020)
Appareillage à basse tension - Partie 3: Interrupteurs, sectionneurs, interrupteurs-
sectionneurs et combinés-fusibles (IEC 60947-3:2020)
Ta slovenski standard je istoveten z: EN IEC 60947-3:2021
ICS:
29.130.20 Nizkonapetostne stikalne in Low voltage switchgear and
krmilne naprave controlgear
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60947-3

NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2021
ICS 29.120.40; 29.130.20 Supersedes EN 60947-3:2009 and all of its amendments
and corrigenda (if any)
English Version
Low-voltage switchgear and controlgear - Part 3: Switches,
disconnectors, switch-disconnectors and fuse-combination units
(IEC 60947-3:2020)
Appareillage à basse tension - Partie 3: Interrupteurs, Niederspannungsschaltgeräte - Teil 3: Lastschalter,
sectionneurs, interrupteurs-sectionneurs et combinés- Trennschalter, Lasttrennschalter und Schalter-Sicherungs-
fusibles Einheiten
(IEC 60947-3:2020) (IEC 60947-3:2020)
This European Standard was approved by CENELEC on 2020-05-27. 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 CEN-CENELEC
Management Centre 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 CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60947-3:2021 E

European foreword
The text of document 121A/340/FDIS, future edition 4 of IEC 60947-3, prepared by SC 121A “Low-
voltage switchgear and controlgear” of IEC/TC 121 “Switchgear and controlgear and their assemblies
for low voltage” was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2021–08-19
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024–02-19
document have to be withdrawn
This document supersedes EN 60947-3:2009 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directive(s) see informative Annexes ZZA and ZZB, which is an integral
part of this document.
Endorsement notice
The text of the International Standard IEC 60947-3:2020 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 60364-5-52 NOTE Harmonized as HD 60364-5-52
IEC 60447:2004 NOTE Harmonized as EN 60447:2004 (not modified)
IEC 60664-1:2007 NOTE Harmonized as EN 60664-1:2007 (not modified)
IEC 60898-1:2015 NOTE Harmonized as EN 60898-1:2019
IEC 60947-2:2016 NOTE Harmonized as EN 60947-2:2017 (not modified)
IEC 60947-4-1:2018 NOTE Harmonized as EN IEC 60947-4-1:2019 (not modified)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the
relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-441 - Electrotechnical Vocabulary – Switchgear, - -
controlgear and fuses
IEC 60034-12 2016 Rotating electrical machines - Part 12: EN 60034-12 2017
Starting performance of single-speed
three-phase cage induction motors
IEC 60034-30-1 2014 Rotating electrical machines - Part 30–1: EN 60034-30-1 2014
Efficiency classes of line operated AC
motors (IE code)
IEC 60068-2-14 2009 Environmental testing – Part 2–14: Tests – EN 60068-2-14 2009
Test N: Change of temperature
IEC 60228 2004 Conductors of insulated cables EN 60228 2005
+AC 2005
IEC 60269 (all parts) Low-voltage fuses EN 60269 (series)
IEC 60417 - Graphical symbols for use on equipment - -
IEC 60695-2-11 2014 Fire hazard testing - Part 2–11: EN 60695-2-11 2014
Glowing/hot-wire based test methods -
Glow-wire flammability test method for end
products (GWEPT)
IEC 60947-1 2020 Low-voltage switchgear and controlgear - EN IEC 60947-1 2021
Part 1: General rules
IEC 60947-5-1 2016 Low-voltage switchgear and controlgear - EN 60947-5-1 2017
Part 5–1: Control circuit devices and
+ CORR 1 2016 switching elements - Electromechanical
control circuit devices
IEC 61000-4-2 2008 Electromagnetic compatibility (EMC) – Part EN 61000-4-2 2009
4–2: Testing and measurement techniques
– Electrostatic discharge immunity test
IEC 61000-4-3 2006 , Electromagnetic compatibility (EMC) – EN 61000-4-3 2006
Part 4–3: Testing and measurement
+A1 2007 techniques – Radiated, radio-frequency, +A1 2008
+A2 2010 electromagnetic field immunity test +A2 2010
Publication Year Title EN/HD Year
IEC 61000-4-4 2012 Electromagnetic compatibility (EMC) – Part EN 61000-4-4 2012
4–4: Testing and measurement techniques
– Electrical fast transient/burst immunity
test
IEC 61000-4-5 2014 Electromagnetic compatibility (EMC) – Part EN 61000-4-5 2014
4–5: Testing and measurement techniques
+A1 2017 – Surge immunity test +A1 2017
IEC 61000-4-6 2013 Electromagnetic compatibility (EMC) – Part EN 61000-4-6 2014
4–6: Testing and measurement techniques +AC1 2015
– Immunity to conducted disturbances,
induced by radio-frequency fields
IEC 61238-1-1 - Compression and mechanical connectors EN IEC 61238-1- 2019
for power cables - Part 1–1: Test methods 1
and requirements for compression and
mechanical connectors for power cables
for rated voltages up to 1 kV (Um = 1,2 kV)
tested on non-insulated conductors
IEC 61545 1996 Connecting devices - Devices for the - -
connection of aluminium conductors in
clamping units of any material and copper
conductors in aluminium bodied clamping
units
IEC 62208 2011 Empty enclosures for low-voltage EN 62208 2011
switchgear and controlgear assemblies -
General requirements
IEC 62475 2010 High-current test techniques - Definitions EN 62475 2010
and requirements for test currents and
measuring systems
ISO 2859-1 1999 Sampling procedures for inspection by - -
attributes - Part 1: Sampling schemes
+A1 2011 indexed by acceptance quality limit (AQL)
for lot-by-lot inspection
CISPR 11 2015 Industrial, scientific and medical equipment EN 55011 2016
– Radio-frequency disturbance (modified)
+A1 2016 characteristics – Limits and methods of +A1 2017
measurement
CISPR 32 2015 Electromagnetic compatibility of multimedia EN 55032 2015
equipment - Emission requirements +AC 2016
Annex ZZA
(informative)
Relationship between this European standard and the essential
requirements of Directive 2014/30/EU [2014 OJ L96] aimed to be
covered
This European standard has been prepared under the European Commission standardization request
C(2016) 7641 final of 30.11.2016 , ('M/552'), as regards harmonized standards in support of Directive
2014/30/EU relating to electromagnetic compatibility, to provide one voluntary means of conforming to
essential requirements of Directive 2014/30/EU of the European Parliament and of the Council of 26
February 2014 on the harmonization of the laws of the Member States relating to electromagnetic
compatibility [2014 OJ L96].
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZZA.1 confers, within the limits
of the scope of this standard, a presumption of conformity with the corresponding essential
requirements of that Directive, and associated EFTA regulations.
Table ZZA.1 — Correspondence between this European standard and the Essential
Requirements set out in Directive 2014/30/EU [2014 OJ L96]
Clause(s) / sub-clause(s)
Essential requirements of Directive
Remarks / Notes
2014/30/EU
of this EN
Annex I. 1(a) (electromagnetic disturbances) 8.3.3, 9.4.3, D.9.4
Annex I. 1(b) (electromagnetic immunity) 8.3.2, 9.4.2, D.9.4
WARNING 1: Presumption of conformity stays valid only as long as a reference to this European
standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2: Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.
COMMISSION IMPLEMENTING DECISION C(2016) 7641 final of 30.11.2016 on a standardisation request to the European
Committee for Standardisation, to the European Committee for Electrotechnical Standardisation and to the European
Telecommunications Standards Institute as regards harmonised standards in support of Directive 2014/30/EU of the European
Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to
electromagnetic compatibility.
Annex ZZB
(informative)
Relationship between this European standard and the safety
objectives of Directive 2014/35/EU [2014 OJ L96] aimed to be
covered
This European standard has been prepared under a Commission’s standardization request relating to
harmonized standards in the field of the Low Voltage Directive, M/511, to provide one voluntary means
of conforming to safety objectives of Directive 2014/35/EU of the European Parliament and of the
Council of 26 February 2014 on the harmonization of the laws of the Member States relating to the
making available on the market of electrical equipment designed for use within certain voltage limits
[2014 OJ L96].
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZZB.1 confers, within the limits
of the scope of this standard, a presumption of conformity with the corresponding safety objectives of
that Directive, and associated EFTA regulations.
Table ZZB.1 — Correspondence between this European standard and Annex I of Directive
2014/35/EU [2014 OJ L96]
Safety objectives of Clause(s) / sub-clause(s) of this EN Remarks/note
Directive 2014/35/EU
1 a) 1, 2, 3, 6.2, 6.3, Annex D, Annex E
1 b) 1, 2, 3, 6.2, 6.3, Annex C, Annex D,
Annex E
1 c) 1, 2, 3, 5, 6, 7, A.1, A.2, C.1, D.1, D.2, Also refer to 2 a) to 2 d) and 3 a)
E.1, E.6.3 to 3 c) in this table
2 a) 1, 2, 3, 8.1, 8.2, 9.1, 9.3, 9.5, Annex A,
Annex C, Annex D
2 b) 1, 2, 3, 5, 8.1, 8.2.2, 9.3, Annex A,
Annex C, Annex D, Annex E
2 c) 1, 2, 3, 6, 8.1, 8.2, 8.3, 9.1, 9.2, 9.3,
Annex A, Annex C, Annex D, Annex E
2 d) 1, 2, 3, 4.3, 5, 6.2, 6.3, 8.1, 8.2, 9.1,
9.2, 9.3, 9.5, Annex A, Annex C,
Annex D, Annex E
3 a) 1, 2, 3, 5, 6, 8.2, 8.3, 9.1, 9.2, 9.3, 9.5,
Annex A, Annex C, Annex D, Annex E
3 b) 1, 2, 3, 6.2, 6.3, 7, Annex D
3 c) 1, 2, 3, 6.3, 8.3, 9.3, Annex D, Annex E
WARNING 1: Presumption of conformity stays valid only as long as a reference to this European
standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2: Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.
IEC 60947-3 ®
Edition 4.0 2020-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage switchgear and controlgear –

Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination

units
Appareillage à basse tension –

Partie 3: Interrupteurs, sectionneurs, interrupteurs-sectionneurs et combinés-

fusibles
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.120.40; 29.130.20 ISBN 978-2-8322-8153-6

– 2 – IEC 60947-3:2020 © IEC 2020
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 11
3 Terms, definitions and index of terms . 12
3.1 General . 12
3.2 Alphabetical index of terms . 12
3.3 General terms . 13
4 Classification . 15
4.1 According to the utilization category . 15
4.2 According to the method of operation . 15
4.2.1 Manually operated equipment . 15
4.2.2 Remotely operated equipment . 15
4.3 According to suitability for isolation . 16
4.4 According to the degree of protection provided . 16
4.5 Summary of symbols for equipment types . 16
5 Characteristics . 16
5.1 Summary of characteristics . 16
5.2 Type of equipment . 17
5.3 Rated and limiting values for the main circuit . 17
5.3.1 General . 17
5.3.2 Rated voltages . 17
5.3.3 Currents . 17
5.3.4 Rated frequency . 17
5.3.5 Rated duty . 18
5.3.6 Normal load and overload characteristics . 18
5.3.7 Short-circuit characteristics . 18
5.4 Utilization category . 19
5.5 Control circuits . 20
5.6 Auxiliary circuits . 20
5.7 Relays and releases . 20
5.8 Co-ordination with short-circuit protective devices (SCPD) . 20
6 Product information . 20
6.1 Nature of information . 20
6.2 Marking . 20
6.3 Instructions for installation, operation and maintenance, decommissioning
and dismantling. 22
7 Normal service, mounting and transport conditions . 22
8 Constructional and performance requirements . 22
8.1 Constructional requirements . 22
8.1.1 General . 22
8.2 Performance requirements . 23
8.2.1 Operating conditions . 23
8.2.2 Temperature-rise . 24
8.2.3 Dielectric properties . 24

IEC 60947-3:2020 © IEC 2020 – 3 –
8.2.4 Ability to make and break under no-load, normal load and
overload conditions . 24
8.2.5 Ability to make, break or withstand short-circuit currents . 27
8.2.6 Void . 27
8.2.7 Additional performance requirements for equipment suitable for
isolation . 27
8.2.8 Critical load current performance: DC equipment . 27
8.2.9 Overload requirements for equipment incorporating fuses. 27
8.3 Electromagnetic compatibility (EMC) . 27
8.3.1 General . 27
8.3.2 Immunity . 27
8.3.3 Emission . 28
9 Tests . 29
9.1 Kinds of test . 29
9.1.1 General . 29
9.1.2 Type tests . 29
9.1.3 Routine tests . 29
9.1.4 Sampling tests . 30
9.1.5 Special tests . 30
9.2 Compliance with constructional requirements . 30
9.2.1 General . 30
9.3 Performance . 31
9.3.1 General . 31
9.3.2 Test sequences . 31
9.3.3 General test conditions . 32
9.3.4 Test sequence I: general performance characteristics . 35
9.3.5 Test sequence II: operational performance capability . 39
9.3.6 Test sequence III: short-circuit performance capability. 41
9.3.7 Test sequence IV: conditional short-circuit current . 45
9.3.8 Test sequence V: overload performance capability . 48
9.3.9 Test sequence VI: critical load current performance of equipment with a
DC rating . 49
9.4 Electromagnetic compatibility tests . 51
9.4.1 General . 51
9.4.2 Immunity . 52
9.4.3 Emission . 52
9.5 Special tests . 52
9.5.1 Mechanical and electrical durability . 52
9.5.2 Mechanical durability . 52
9.5.3 Electrical durability . 52
9.5.4 Damp heat, salt mist, vibration and shock . 53
Annex A (normative) Equipment for direct switching of a single motor . 54
A.1 General . 54
A.2 Rated . 54
A.2.1 Intermittent periodic duty or intermittent duty . 54
A.2.2 Temporary duty . 54
A.3 Making and breaking capacities . 54
A.4 Utilization category . 54
A.5 Operational performance . 57

– 4 – IEC 60947-3:2020 © IEC 2020
A.6 Mechanical durability . 58
A.7 Electrical durability . 58
A.8 Verification of making and breaking capacities . 58
A.9 Operational performance test . 58
A.10 Special tests . 58
A.10.1 General . 58
A.10.2 Mechanical durability test . 59
A.10.3 Electrical durability test. 59
A.11 Critical load current performance for DC equipment . 60
Annex B (informative) Items subject to agreement between manufacturer and user . 61
Annex C (normative) Single pole operated three-pole switches . 62
C.1 General . 62
C.2 Tests . 63
C.3 Test set-up and sequence . 63
C.3.1 Making and breaking capacities (9.3.4.4) and operational performance
(9.3.5.2) . 63
C.3.2 Fuse protected short-circuit test (9.3.7.3) . 63
C.4 Condition of equipment after tests . 63
C.5 Instructions for use . 63
Annex D (normative) Switches, disconnectors, switch-disconnectors and fuse-
combination units for use in photovoltaic (PV) DC applications . 64
D.1 General . 64
D.1.1 Background . 64
D.1.2 Object . 64
D.2 Normative references . 64
D.3 Terms and definitions . 64
D.4 Classification . 65
D.4.1 According to the utilization category . 65
D.5 Characteristics . 65
D.6 Product information . 66
D.7 Normal service, mounting and transport conditions . 66
D.8 Constructional and performance requirements . 66
D.9 Tests . 70
Annex E (normative) Additional requirements for LV switchgear intended for
connection of aluminium conductors . 76
E.1 Object . 76
E.2 Normative references . 76
E.3 Terms, definitions and index of terms . 76
E.4 Classification . 77
E.5 Characteristics . 77
E.6 Product information . 77
E.6.1 Nature of information . 77
E.6.2 Marking . 77
E.6.3 Instructions for installation, operation and maintenance,
decommissioning and dismantling . 77
E.7 Normal service, mounting and transport conditions . 78
E.8 Constructional and performance requirements . 78
E.9 Tests . 78
E.9.1 General . 78

IEC 60947-3:2020 © IEC 2020 – 5 –
E.9.2 Current cycling test. 79
E.9.3 Mechanical properties of terminals . 84
E.9.4 Test for insertability of unprepared round aluminium conductors having
the maximum cross-section . 85
Annex F (informative) Power loss. 88
F.1 General . 88
F.2 Test methods . 88
F.2.1 General . 88
F.2.2 General case for AC switches and/or disconnectors . 88
F.2.3 General case for AC fused combination units and fuse disconnectors . 88
F.2.4 Switches and/or disconnectors of rated current not exceeding 400 A . 89
F.2.5 Fused combination units and fuse disconnectors of rated current not
exceeding 400 A . 89
F.3 Test procedure . 90
Bibliography . 93

Figure C.1 – Typical arrangements . 62
Figure E.1 – General test arrangement . 80
Figure E.2 – Mounting of terminals for the current cycling test . 80
Figure F.1 – Example of power loss measurement according to F.2.2 . 90
Figure F.2 – Example of power loss measurement according to F.2.3 . 91
Figure F.3 – Example of power loss measurement according to F.2.4 . 91
Figure F.4 – Example of power loss measurement according to F.2.5 . 92

Table 1 – Summary of equipment definitions . 16
Table 2 – Utilization categories . 19
Table 3 – Product information . 21
Table 4 – Verification of rated making and breaking capacities (see 9.3.4.4) –
Conditions for making and breaking corresponding to the various utilization categories . 25
Table 5 – Verification of operational performance – Number of operating cycles
corresponding to the rated operational current . 26
Table 6 – Test circuit parameters for Table 5 . 26
Table 7 – Immunity tests . 28
Table 8 – Emission limits . 28
Table 9 – List of type tests applicable to a given equipment . 31
Table 10 – Overall scheme of test sequences . 32
Table 11 – Test sequence I: general performance characteristics . 36
Table 12 – Temperature-rise limits for terminals and accessible parts . 39
Table 13 – Test sequence II: operational performance capability . 40
Table 14 – Test sequence III: short-circuit performance capability . 42
Table 15 – Test sequence IV: conditional short-circuit current – circuit-breaker
protected . 46
Table 16 – Test sequence IV: conditional short-circuit current – fuse protected . 47
Table 17 – Test sequence V: overload performance capability . 49
Table 18 – Number of operating cycles corresponding to the critical load current . 51
Table 19 – Test circuit parameters for Table 18 . 51

– 6 – IEC 60947-3:2020 © IEC 2020
Table 20 – Test sequence VI: critical load current performance of equipment with a DC
rating . 51
Table A.1 – Utilization categories . 55
Table A.2 – Rated making and breaking capacity conditions corresponding to several
utilization categories . 56
Table A.3 – Relationship between current broken I and off-time for the verification of
c
the rated making and breaking capacities . 57
Table A.4 – Operational performance – Conditions for making and breaking
corresponding to several utilization categories . 57
Table A.5 – Verification of the number of on-load operating cycles – Conditions for
making and breaking corresponding to several utilization categories . 60
Table D.1 – Utilization categories . 65
Table D.2 – Service arrangements . 66
Table D.3 – Environmental conditions . 66
Table D.4 – Rated impulse withstand levels for PV switches, PV disconnectors, PV
switch-disconnectors or PV fuse-combination units . 67
Table D.5 – Verification of rated making and breaking capacities (see 9.3.4.4) –
Conditions for making and breaking corresponding to the DC-PV category . 68
Table D.6 – Number of operating cycles . 69
Table D.7 – Test circuit parameters for Table D.6 . 69
Table D.8 – Overall scheme of test sequences . 71
Table D.9 – Number of operating cycles corresponding to the critical load current . 73
Table D.10 – Test circuit parameters for Table D.9 . 73
Table E.1 – List of tests for terminal connections with aluminium cables . 78
Table E.2 – Conductor length for current cycling test as per conductor cross-section . 81
Table E.3 – Equalizer dimensions . 81
Table E.4 – Starting test current for the current cycling test . 83
Table E.5 – Example of stability factor calculation . 84
Table E.6 – Test values for flexion and pull-out test for cables . 85
Table E.7 – Test aluminium cable for test currents up to 800 A . 86
Table E.8 – Test aluminium bars for test currents above 150 A and up to 3 150 A . 87

IEC 60947-3:2020 © IEC 2020 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 3: Switches, disconnectors, switch-disconnectors
and fuse-combination units
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 60947-3 has been prepared by subco
...