IEC 60947-3:2020

Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units

IEC 60947-3:2020 applies to switches, disconnectors, switch-disconnectors and fuse-combination units and their dedicated accessories to be used in distribution circuits and motor circuits of which the rated voltage does not exceed 1 000 V AC or 1 500 V DC. This fourth edition cancels and replaces the third edition published in 2008, Amendment 1:2012 and Amendment 2:2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
- addition of critical load current tests for DC switches (see 9.3.9);
- addition of requirements for a conditional short-circuit rating for disconnectors, switches, and switch-disconnectors protected by circuit-breakers (see 9.3.7.2);
- addition of new categories for high-efficiency motors switching (see Annex A);
- addition of new Annex E for connection to aluminium conductors;
- addition of new Annex F for power losses measurement.
The contents of the corrigendum of October 2021 have been included in this copy.

Appareillage à basse tension - Partie 3: Interrupteurs, sectionneurs, interrupteurs-sectionneurs et combinés-fusibles

L’IEC 60947-3:2020 s’applique à l’appareillage suivant: interrupteurs, sectionneurs, interrupteurs-sectionneurs, combinés-fusibles et leurs accessoires dédiés, destinés à être insérés dans des circuits de distribution et des circuits de moteurs dont la tension assignée est inférieure ou égale à 1 000 V en courant alternatif ou à 1 500 V en courant continu. Cette quatrième édition annule et remplace la troisième édition parue en 2008, l’Amendement 1:2012 et l’Amendement 2:2015. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente:
- ajout d'essais de courant critique de charge pour interrupteurs à courant continu (voir 9.3.9);
- ajout d’exigences relatives à la caractéristique assignée de court-circuit conditionnel pour les sectionneurs, les interrupteurs et les interrupteurs-sectionneurs protégés par des disjoncteurs (voir 9.3.7.2);
- ajout de nouvelles catégories pour commande de moteurs à haut rendement (voir Annexe A);
- ajout d’une nouvelle Annexe E pour le raccordement à des conducteurs en aluminium;
- ajout d’une nouvelle Annexe F pour la mesure des puissances dissipées.
Le contenu du corrigendum d’octobre 2021 a été pris en considération dans cet exemplaire.

General Information

• Status: Published
• Publication Date: 24-Apr-2025
• ICS: 29.120.40 - Switches
• ICS: 29.130.20 - Low voltage switchgear and controlgear
• Technical Committee: SC 121A - Low-voltage switchgear and controlgear
• Drafting Committee: MT 6 - TC 121/SC 121A/MT 6
• Current Stage: PPUB - Publication issued
• Start Date: 22-Apr-2020
• Completion Date: 15-May-2020

Relations

• Amended By: IEC 60947-3:2020/AMD1:2025 - Amendment 1 - Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units
• Effective Date: 05-Sep-2023
• Corrected By: IEC 60947-3:2020/COR1:2021 - Corrigendum 1 - Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units
• Effective Date: 05-Sep-2023
• Revises: IEC 60947-3:2008/AMD1:2012 - Amendment 1 - Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units
• Effective Date: 05-Sep-2023
• Revises: IEC 60947-3:2008/AMD2:2015 - Amendment 2 - Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units
• Effective Date: 05-Sep-2023
• Revises: IEC 60947-3:2008 - Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units
• Effective Date: 05-Sep-2023
• Revises: IEC 60947-3:2008/AMD1:2012/COR1:2013 - Amendment 1 - Corrigendum 1 - Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units
• Effective Date: 05-Sep-2023

Overview

IEC 60947-3:2020 (Edition 4) is the international standard for low-voltage switchgear and controlgear - Part 3: switches, disconnectors, switch-disconnectors and fuse-combination units. It applies to equipment and dedicated accessories used in distribution and motor circuits with rated voltages up to 1 000 V AC or 1 500 V DC. This fourth edition cancels and replaces the third edition (2008) and its amendments, and introduces technical revisions that reflect modern switching needs for AC and DC systems.

Key topics and technical requirements

• Scope & classification: Definitions, equipment types, utilization categories and suitability for isolation for switches, disconnectors, switch-disconnectors and fuse-combination units.
• Rated and limiting values: Rated voltages, currents, frequency, duty and short-circuit characteristics for main, auxiliary and control circuits.
• Performance requirements and tests:
  • Making/breaking ability under no‑load, normal load and overload.
  • Short-circuit performance tests, operational endurance, temperature-rise and dielectric properties.
  • New tests added: critical load current tests for DC switches (9.3.9) and conditional short-circuit rating tests for equipment protected by circuit‑breakers (9.3.7.2).
  • EMC immunity and emission requirements.
• New or expanded annexes:
  • Annex A - new categories for high-efficiency motor switching.
  • Annex D - PV DC applications (photovoltaic DC switch requirements).
  • Annex E - requirements for connection to aluminium conductors.
  • Annex F - procedures for power losses measurement.
• Product information & marking: required documentation, marking, installation and maintenance instructions.

Practical applications

IEC 60947-3 is essential for:

• Designing and certifying low-voltage switchgear used in industrial distribution boards, motor control centers and machinery.
• Specifying and testing DC switches and PV DC isolators in renewable energy systems.
• Ensuring safe isolation, coordination with short-circuit protective devices, and reliable switching of modern high‑efficiency motors.
• Addressing specific installation needs such as aluminium conductor connections and verifying power losses for efficiency and thermal planning.

Who uses this standard

• Manufacturers of switches, disconnectors, switch‑disconnectors and fuse-combination units
• Test laboratories and certification bodies
• Electrical engineers, panel builders and system integrators
• Specifiers, procurement teams and compliance officers in industrial, commercial and renewable energy sectors

Related standards

• Other parts of the IEC 60947 series (general rules and related product parts) provide complementary requirements and should be consulted alongside IEC 60947-3 for complete low-voltage switchgear compliance.

Keywords: IEC 60947-3, low-voltage switchgear, switches and disconnectors, switch-disconnectors, fuse-combination units, DC switches, conditional short-circuit rating, aluminium conductors, power losses measurement, PV DC, motor circuits.

Standards Content (Sample)

IEC 60947-3 ®
Edition 4.1 2025-04
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
Low-voltage switchgear and controlgear –
Part 3: Switches, disconnectors, switch-disconnectors and fuse combination
units
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 Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
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 corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews, graphical symbols and the glossary.
committee, …). It also gives information on projects, replaced With a subscription you will always have access to up to date
and withdrawn publications. content tailored to your needs.

IEC Just Published - webstore.iec.ch/justpublished
Electropedia - www.electropedia.org
Stay up to date on all new IEC publications. Just Published
The world's leading online dictionary on electrotechnology,
details all new publications released. Available online and once
containing more than 22 500 terminological entries in English
a month by email.
and French, with equivalent terms in 25 additional languages.

Also known as the International Electrotechnical Vocabulary
IEC Customer Service Centre - webstore.iec.ch/csc
(IEV) online.
If you wish to give us your feedback on this publication or need

further assistance, please contact the Customer Service
Centre: [e-mail].
IEC 60947-3 ®
Edition 4.1 2025-04
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
Low-voltage switchgear and controlgear –
Part 3: Switches, disconnectors, switch-disconnectors and fuse combination
units
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.40, 29.130.20 ISBN 978-2-8327-0405-9
REDLINE VERSION – 2 – IEC 60947-3:2020+AMD1:2025 CSV
© IEC 2025
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 11
2 Normative references . 12
3 Terms, definitions and index of terms . 13
3.1 General . 13
3.2 Alphabetical index of terms . 13
3.3 General terms . 14
4 Classification . 17
4.1 According to the utilization category . 17
4.2 According to the method of operation . 17
4.2.1 Manually operated equipment . 17
4.2.2 Remotely operated equipment . 17
4.3 According to suitability for isolation . 17
4.4 According to the degree of protection provided . 17
4.5 Summary of symbols for equipment types . 17
5 Characteristics . 18
5.1 Summary of characteristics . 18
5.2 Type of equipment . 18
5.3 Rated and limiting values for the main circuit . 18
5.3.1 General . 18
5.3.2 Rated voltages . 18
5.3.3 Currents . 19
5.3.4 Rated frequency . 19
5.3.5 Rated duty . 19
5.3.6 Normal load and overload characteristics . 19
5.3.7 Short-circuit characteristics . 20
5.4 Utilization category . 20
5.5 Control circuits . 21
5.6 Auxiliary circuits . 21
5.7 Relays and releases . 21
5.8 Co-ordination with short-circuit protective devices (SCPD) . 21
5.9 Remote operation . 22
6 Product information . 22
6.1 Nature of information . 22
6.2 Marking . 22
6.3 Instructions for installation, operation and maintenance, decommissioning
and dismantling. 24
7 Normal service, mounting and transport conditions . 24
8 Constructional and performance requirements . 24
8.1 Constructional requirements . 24
8.1.1 General . 24
8.1.7 Additional requirements for equipment suitable for isolation . 25
8.1.9 Additional requirements for equipment provided with a neutral pole . 25
8.1.10 Additional requirements for remotely operated equipment . 25
8.2 Performance requirements . 25

© IEC 2025
8.2.1 Operating conditions . 25
8.2.2 Temperature-rise . 27
8.2.3 Dielectric properties . 27
8.2.4 Ability to make and break under no-load, normal load and
overload conditions . 27
8.2.5 Ability to make, break or withstand short-circuit currents . 30
8.2.6 Void . 30
8.2.7 Additional performance requirements for equipment suitable for
isolation . 30
8.2.8 Critical load current performance: DC equipment . 30
8.2.9 Overload requirements for equipment incorporating fuses. 30
8.3 Electromagnetic compatibility (EMC) . 30
8.3.1 General . 30
8.3.2 Immunity . 30
8.3.3 Emission . 31
9 Tests . 32
9.1 Kinds of test . 32
9.1.1 General . 32
9.1.2 Type tests . 32
9.1.3 Routine tests . 32
9.1.4 Sampling tests . 33
9.1.5 Special tests . 33
9.2 Compliance with constructional requirements . 33
9.2.1 General . 33
9.3 Performance . 34
9.3.1 General . 34
9.3.2 Test sequences . 34
9.3.3 General test conditions . 35
9.3.4 Test sequence I: general performance characteristics . 38
9.3.5 Test sequence II: operational performance capability . 42
9.3.6 Test sequence III: short-circuit performance capability. 45
9.3.7 Test sequence IV: conditional short-circuit current . 48
9.3.8 Test sequence V: overload performance capability . 52
9.3.9 Test sequence VI: critical load current performance of equipment with a
DC rating . 53
9.4 Electromagnetic compatibility tests . 55
9.4.1 General . 55
9.4.2 Immunity . 56
9.4.3 Emission . 56
9.5 Special tests . 56
9.5.1 Mechanical and electrical durability . 56
9.5.2 Mechanical durability . 56
9.5.3 Electrical durability . 56
9.5.4 Damp heat, salt mist, vibration and shock . 57
Annex A (normative) Equipment for direct switching of a single motor . 58
A.1 General . 58
A.2 Rated . 58
A.2.1 Intermittent periodic duty or intermittent duty . 58
A.2.2 Temporary duty . 58

REDLINE VERSION – 4 – IEC 60947-3:2020+AMD1:2025 CSV
© IEC 2025
A.3 Making and breaking capacities . 58
A.4 Utilization category . 58
A.5 Operational performance . 61
A.6 Mechanical durability . 62
A.7 Electrical durability . 62
A.8 Verification of making and breaking capacities . 62
A.9 Operational performance test . 62
A.10 Special tests . 62
A.10.1 General . 62
A.10.2 Mechanical durability test . 63
A.10.3 Electrical durability test. 63
A.11 Critical load current performance for DC equipment . 64
Annex B (informative) Items subject to agreement between manufacturer and user . 65
Annex C (normative) Single pole operated three-pole switches . 66
C.1 General . 66
C.2 Tests . 67
C.3 Test set-up and sequence . 67
C.3.1 Making and breaking capacities ( 9.3.4.4) and operational performance
(9.3.5.2) . 67
C.3.2 Fuse protected short-circuit test (9.3.7.3) . 67
C.3.3 Short circuit making test for switches and switch-disconnectors . 67
C.4 Condition of equipment after tests . 67
C.5 Instructions for use . 67
Annex D (normative) Switches, disconnectors, switch-disconnectors and fuse-
combination units for use in photovoltaic (PV) DC applications . 68
D.1 General . 68
D.1.1 Background . 68
D.1.2 Object . 68
D.2 Normative references . 68
D.3 Terms and definitions . 68
D.4 Classification . 69
D.4.1 According to the utilization category . 69
D.5 Characteristics . 69
D.6 Product information . 70
D.7 Normal service, mounting and transport conditions . 70
D.8 Constructional and performance requirements . 70
D.9 Tests . 74
Annex E (normative) Additional requirements for LV switchgear intended for
connection of aluminium conductors . 80
E.1 Object . 80
E.2 Normative references . 80
E.3 Terms, definitions and index of terms . 80
E.4 Classification . 81
E.5 Characteristics . 81
E.6 Product information . 81
E.6.1 Nature of information . 81
E.6.2 Marking . 81
E.6.3 Instructions for installation, operation and maintenance,
decommissioning and dismantling . 81

© IEC 2025
E.7 Normal service, mounting and transport conditions . 82
E.8 Constructional and performance requirements . 82
E.9 Tests . 82
E.9.1 General . 82
E.9.2 Current cycling test. 83
E.9.3 Mechanical properties of terminals . 88
E.9.4 Test for insertability of unprepared round aluminium conductors having
the maximum cross-section . 89
Annex F (informative) Power loss. 92
F.1 General . 92
F.2 Test methods . 92
F.2.1 General . 92
F.2.2 General case for AC switches and/or disconnectors . 92
F.2.3 General case for AC fused combination units and fuse disconnectors . 93
F.2.4 Switches and/or disconnectors of rated current not exceeding 400 A . 93
F.2.5 Fused combination units and fuse disconnectors of rated current not
exceeding 400 A . 93
F.3 Test procedure . 94
Annex G (normative) DC disconnectors, switch-disconnectors and fuse-combination
units for use with battery power supplies (BPS) DC applications . 97
G.1 General . 97
G.2 Vacant . 97
G.3 Vacant . 97
G.4 Classification . 97
G.5 Characteristics . 98
G.6 Product information . 98
G.7 Normal service, mounting and transport conditions . 98
G.8 Constructional and performance requirements . 99
G.9 Tests . 103
Bibliography . 109

Figure C.1 – Typical arrangements . 66
Figure E.1 – General test arrangement . 84
Figure E.2 – Mounting of terminals for the current cycling test . 84
Figure F.1 – Example of power loss measurement according to F.2.2 . 95
Figure F.2 – Example of power loss measurement according to F.2.3 . 95
Figure F.3 – Example of power loss measurement according to F.2.4 . 96
Figure F.4 – Example of power loss measurement according to F.2.5 . 96

Table 1 – Summary of equipment definitions . 17
Table 2 – Utilization categories . 21
Table 3 – Product information . 22
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 . 28
Table 5 – Verification of operational performance – Number of operating cycles
corresponding to the rated operational current . 29
Table 6 – Test circuit parameters for Table 5 . 29
a
Table 7 – Immunity tests . 31

REDLINE VERSION – 6 – IEC 60947-3:2020+AMD1:2025 CSV
© IEC 2025
Table 8 – Emission limits . 31
Table 9 – List of type tests applicable to a given equipment . 34
Table 10 – Overall scheme of test sequences . 35
Table 11 – Test sequence I: general performance characteristics . 39
Table 12 – Temperature-rise limits for terminals and accessible parts . 42
Table 13 – Test sequence II: operational performance capability . 43
Table 14 – Test sequence III: short-circuit performance capability . 45
Table 15 – Test sequence IV: conditional short-circuit current – circuit-breaker
protected . 49
Table 16 – Test sequence IV: conditional short-circuit current – fuse protected . 51
Table 17 – Test sequence V: overload performance capability . 53
Table 18 – Number of operating cycles corresponding to the critical load current . 55
Table 19 – Test circuit parameters for Table 18 . 55
Table 20 – Test sequence VI: critical load current performance of equipment with a DC
rating . 55
Table A.1 – Utilization categories . 59
Table A.2 – Rated making and breaking capacity conditions corresponding to several
utilization categories . 60
Table A.3 – Relationship between current broken I and off-time for the verification of
c
the rated making and breaking capacities . 61
Table A.4 – Operational performance – Conditions for making and breaking
corresponding to several utilization categories . 61
Table A.5 – Verification of the number of on-load operating cycles – Conditions for
making and breaking corresponding to several utilization categories . 64
Table D.1 – Utilization categories . 69
Table D.2 – Service arrangements . 70
Table D.3 – Environmental conditions . 70
Table D.4 – Rated impulse withstand levels for PV switches, PV disconnectors, PV
switch-disconnectors or PV fuse-combination units . 71
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 . 72
Table D.6 – Number of operating cycles . 73
Table D.7 – Test circuit parameters for Table D.6 . 73
Table D.8 – Overall scheme of test sequences . 75
Table D.9 – Number of operating cycles corresponding to the critical load current . 77
Table D.10 – Test circuit parameters for Table D.9 . 77
a
Table E.1 – List of tests for terminal connections with aluminium cables . 83
Table E.2 – Conductor length for current cycling test as per conductor cross-section . 85
Table E.3 – Equalizer dimensions . 85
Table E.4 – Starting test current for the current cycling test . 87
Table E.5 – Example of stability factor calculation . 88
Table E.6 – Test values for flexion and pull-out test for cables . 89
a, d
Table E.7 – Test aluminium cable for test currents up to 800 A . 90
a, f
Table E.8 – Test aluminium bars for test currents above 150 A and up to 3 150 A . 91
Table G.1 – Utilization categories . 98
Table G.2 – Service arrangements . 98

© IEC 2025
Table G.3 – Environmental conditions . 99
Table G.4 – Rated impulse withstand levels for BPS disconnectors,
BPS switch-disconnectors or BPS fuse-combination units . 100
Table G.5 – Verification of rated making and breaking capacities (see 9.3.4.4) –
Conditions for making and breaking corresponding to the DC-BPS category . 101
Table G.6 – Number of operating cycles . 101
Table G.7 – Test parameters for Table G.6 . 102
Table G.8 – Overall scheme of test sequences . 103
Table G.9 – Number of operating cycles corresponding to the critical load current . 106
Table G.10 – Test circuit parameters for Table G.9 . 106

REDLINE VERSION – 8 – IEC 60947-3:2020+AMD1:2025 CSV
© IEC 2025
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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s),
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
https://patents.iec.ch. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 60947-3 edition 4.1 contains the fourth edition (2020-04) [documents 121A/340/FDIS
and 121A/354/RVD], its corrigendum 1 (2021-10) and its amendment 1 (2025-04)
[documents 121A/645/FDIS and 121A/675/RVD].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
© IEC 2025
International Standard IEC 60947-3 has been prepared by subcommittee 121A: Low-voltage
switchgear and controlgear, of IEC technical committee 121: Switchgear and controlgear and
their assemblies for low voltage.
This fourth edition cancels and replaces the third edition published in 2008,
Amendment 1:2012 and Amendment 2:2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
• addition of critical load current tests for DC switches (see 9.3.9);
• addition of requirements for a conditional short-circuit rating for disconnectors, switches,
and switch-disconnectors protected by circuit-breakers (see 9.3.7.2);
• addition of new categories for high-efficiency motors switching (see Annex A);
• addition of new Annex E for connection to aluminium conductors;
• addition of new Annex F for power losses measurement.
The text of this International Standard is based on the following documents:
FDIS Report on voting
121A/340/FDIS 121A/354/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.
A list of all parts in the IEC 60947 series, published under the general title Low-voltage
switchgear and controlgear, can be found on the IEC website.
This part is to be used in conjunction with the sixth edition of IEC 60947-1:2020 The
numbering of the subclauses is sometimes not continuous because it is based on
IEC 60947-1:2020.
The committee has decided that the contents of this document and its amendment will remain
unchanged until the stability date indicated on the IEC website under webstore.iec.ch in the
data related to the specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
REDLINE VERSION – 10 – IEC 60947-3:2020+AMD1:2025 CSV
© IEC 2025
INTRODUCTION
The provisions of the general rules dealt with in IEC 60947-1 are applicable to this document,
where specifically called for. Clauses and subclauses, tables, figures and annexes of the
general rules thus applicable are identified by reference to the sixth edition of
IEC 60947-1:2020, for example, 5.3.4.1 of IEC 60947-1:2020, Table 4 of IEC 60947-1:2020,
or Annex A of IEC 60947-1:2020.

© IEC 2025
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 3: Switches, disconnectors, switch-disconnectors and
fuse-combination units
1 Scope
This part of IEC 60947 applies to switches, disconnectors, switch-disconnectors and fuse-
combination units and their dedicated accessories to be used in distribution circuits and motor
circuits of which the rated voltage does not exceed 1 000 V AC or 1 500 V DC.
NOTE 1 Accessories are interconnecting units, extended terminals, internal coils, auxiliary contacts, motor
operator, etc. offered as options with the basic unit.
This document does not apply to equipment coming within the scope of IEC 60947-2, IEC 60947-4-
1 and IEC 60947-5-1.
Particular requirements for switches, disconnectors, switch-disconnectors and fuse-
combination units for use in photovoltaic (PV) DC applications are given in Annex D.
Specific requirements for LV switchgear intended for the connections of aluminium conductors
are given in Annex E.
Guidance on measurement of power loss is provided in Annex F.
This document does not include the additional requirements necessary for electrical
apparatus for explosive gas atmospheres.
NOTE 2 Depending on its design, a switch (or disconnector) can be referred to as "a rotary switch
(disconnector)", "cam-operated switch (disconnector)", "knife-switch (disconnector)", etc.
NOTE 3 In this document, the word "switch" also applies to the apparatus referred to in French as
"commutateurs", intended to modify the connections between several circuits and inter alia to substitute a part of a
circuit for another.
NOTE 4 In general, throughout this document, switches, disconnectors, switch-disconnectors and fuse-
combination units will be referred to as "equipment".
The object of this document is to state:
a) the characteristics of the equipment;
b) the conditions that apply to the equipment with reference to:
1) operation and behaviour in normal service;
2) operation and behaviour in case of specified abnormal conditions, e.g. short-circuit;
3) dielectric properties;
c) the tests for confirming that these conditions have been met and the methods that are
adopted for these tests;
d) the information relevant to the marking of the equipment or made available by the
manufacturer, e.g. in the catalogue.
Specific items requiring agreement between the user and the manufacturer are identified in
Annex B.
REDLINE VERSION – 12 – IEC 60947-3:2020+AMD1:2025 CSV
© IEC 2025
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 60050-441, International Electrotechnical Vocabulary – Part 441: Switchgear, controlgear
and fuses (available at http://www.electropedia.org)
IEC 60034-12:2016, Rotating electrical machines – Part 12: Starting performance of single-
speed three-phase cage induction motors
IEC 60034-30-1:2014, Rotating electrical machines – Part 30-1: Efficiency classes of line
operated AC motors (IE code)
IEC 60068-2-14:2023, Environmental testing – Part 2-14: Tests – Test N: Change of
temperature
IEC 62208:2023, Empty enclosures for low-voltage switchgear and controlgear assemblies –
General requirements
IEC 60228:2004, Conductors of insulated cable
IEC 60269 (all parts), Low-voltage fuses
IEC 60417, Graphical symbols for use on equipment (available at http://www.graphical-
symbols.info/equipment)
IEC 60695-2-11:2014, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods –
Glow-wire flammability test method for end-products (GWEPT)
IEC 60947-1:2020, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-5-1:2016, Low-voltage switchgear and controlgear – Part 5-1: Control circuit
devices and switching elements – Electromechanical control circuit devices
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and
measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-3:2006/AMD1:2007
IEC 61000-4-3:2006/AMD2:2010
IEC 61000-4-4:2012, Electromagnetic compatibility (EMC) – Part 4-4: Testing and
measurement techniques – Electrical fast transient/burst immunity test
IEC 61000-4-5:2014, Electromagnetic compatibility (EMC) – Part 4-5: Testing and
measurement techniques – Surge immunity test
IEC 61000-4-5:2014/AMD1:2017
IEC 61000-4-6:2013, Electromagnetic compatibility (EMC) – Part 4-6: Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
© IEC 2025
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 switchgear and controlgear assemblies –
General requirements
IEC 62475:2010, High-current test techniques – Definitions and requirements for test currents
and measuring
...

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
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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
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 corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

need further assistance, please contact the Customer Service

Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC - Electropedia - www.electropedia.org
webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au
La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en
en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans
comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire
projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.

IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary
Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais
Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et Définitions des
Disponible en ligne et une fois par mois par email. publications IEC parues depuis 2002. Plus certaines entrées
antérieures extraites des publications des CE 37, 77, 86 et
Service Clients - webstore.iec.ch/csc CISPR de l'IEC.

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
[e-mail].
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

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

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

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 subcommittee 121A: Low-voltage
switchgear and controlgear, of IEC technical committee 121: Switchgear and controlgear and
their assemblies for low voltage.
This fourth edition cancels and replaces the third edition published in 2008,
Amendment 1:2012 and Amendment 2:2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
• addition of critical load current tests for DC switches (see 9.3.9);
• addition of requirements for a conditional short-circuit rating for disconnectors, switches,
and switch-disconnectors protected by circuit-breakers (see 9.3.7.2);
• addition of new categories for high-efficiency motors switching (see Annex A);

– 8 – IEC 60947-3:2020 © IEC 2020
• addition of new Annex E for connection to aluminium conductors;
• addition of new Annex F for power losses measurement.
The text of this International Standard is based on the following documents:
FDIS Report on voting
121A/340/FDIS 121A/354/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.
A list of all parts in the IEC 60947 series, published under the general title Low-voltage
switchgear and controlgear, can be found on the IEC website.
This part is to be used in conjunction with the sixth edition of IEC 60947-1:2020 The
numbering of the subclauses is sometimes not continuous because it is based on
IEC 60947-1:2020.
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.
INTRODUCTION
The provisions of the general rules dealt with in IEC 60947-1 are applicable to this document,
where specifically called for. Clauses and subclauses, tables, figures and annexes of the
general rules thus applicable are identified by reference to the sixth edition of
IEC 60947-1:2020, for example, 5.3.4.1 of IEC 60947-1:2020, Table 4 of IEC 60947-1:2020,
or Annex A of IEC 60947-1:2020.

– 10 – IEC 60947-3:2020 © IEC 2020
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 3: Switches, disconnectors, switch-disconnectors
and fuse-combination units
1 Scope
This part of IEC 60947 applies to switches, disconnectors, switch-disconnectors and fuse-
combination units and their dedicated accessories to be used in distribution circuits and motor
circuits of which the rated voltage does not exceed 1 000 V AC or 1 500 V DC.
NOTE 1 Accessories are interconnecting units, extended terminals, internal coils, auxiliary contacts, motor
operator, etc. offered as options with the basic unit.
This document does not apply to equipment coming within the scope of IEC 60947-2, IEC 60947-4-
1 and IEC 60947-5-1.
Particular requirements for switches, disconnectors, switch-disconnectors and fuse-
combination units for use in photovoltaic (PV) DC applications are given in Annex D.
Specific requirements for LV switchgear intended for the connections of aluminium conductors
are given in Annex E.
Guidance on measurement of power loss is provided in Annex F.
This document does not include the additional requirements necessary for electrical
apparatus for explosive gas atmospheres.
NOTE 2 Depending on its design, a switch (or disconnector) can be referred to as "a rotary switch
(disconnector)", "cam-operated switch (disconnector)", "knife-switch (disconnector)", etc.
NOTE 3 In this document, the word "switch" also applies to the apparatus referred to in French as
"commutateurs", intended to modify the connections between several circuits and inter alia to substitute a part of a
circuit for another.
NOTE 4 In general, throughout this document, switches, disconnectors, switch-disconnectors and fuse-
combination units will be referred to as "equipment".
The object of this document is to state:
a) the characteristics of the equipment;
b) the conditions that apply to the equipment with reference to:
1) operation and behaviour in normal service;
2) operation and behaviour in case of specified abnormal conditions, e.g. short-circuit;
3) dielectric properties;
c) the tests for confirming that these conditions have been met and the methods that are
adopted for these tests;
d) the information relevant to the marking of the equipment or made available by the
manufacturer, e.g. in the catalogue.
Specific items requiring agreement between the user and the manufacturer are identified in
Annex B.
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 60050-441, International Electrotechnical Vocabulary – Part 441: Switchgear, controlgear
and fuses (available at http://www.electropedia.org)
IEC 60034-12:2016, Rotating electrical machines – Part 12: Starting performance of single-
speed three-phase cage induction motors
IEC 60034-30-1:2014, Rotating electrical machines – Part 30-1: Efficiency classes of line
operated AC motors (IE code)
IEC 60228:2004, Conductors of insulated cable
IEC 60269 (all parts), Low-voltage fuses
IEC 60417, Graphical symbols for use on equipment (available at http://www.graphical-
symbols.info/equipment)
IEC 60695-2-11:2014, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods –
Glow-wire flammability test method for end-products (GWEPT)
IEC 60947-1:2020, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-5-1:2016, Low-voltage switchgear and controlgear – Part 5-1: Control circuit
devices and switching elements – Electromechanical control circuit devices
IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and
measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-3:2006/AMD1:2007
IEC 61000-4-3:2006/AMD2:2010
IEC 61000-4-4:2012, Electromagnetic compatibility (EMC) – Part 4-4: Testing and
measurement techniques – Electrical fast transient/burst immunity test
IEC 61000-4-5:2014, Electromagnetic compatibility (EMC) – Part 4-5: Testing and
measurement techniques – Surge immunity test
IEC 61000-4-5:2014/AMD1:2017
IEC 61000-4-6:2013, Electromagnetic compatibility (EMC) – Part 4-6: Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
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 switchgear and controlgear assemblies –
General requirements
– 12 – IEC 60947-3:2020 © IEC 2020
IEC 62475:2010, High-current test techniques – Definitions and requirements for test currents
and measuring systems
ISO 2859-1:1999, Sampling procedures for inspection by attributes – Part 1: Sampling
schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
ISO 2859-1:1999/AMD1:2011
CISPR 11:2015, Industrial, scientific and medical equipment – Radio-frequency disturbance
characteristics – Limits and methods of measurement
CISPR 11:2015/AMD1:2016
CISPR 32:2015, Electromagnetic compatibility of multimedia equipment – Emission
requirements
3 Terms, definitions and index of terms
3.1 General
For the purposes of this document, the terms and definitions given in IEC 60050-441 and
IEC 60947-1 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
3.2 Alphabetical index of terms
References
D
Disconnector . 3.3.1
Disconnector-fuse . 3.3.5
Disconnector-fuse single opening . 3.3.5.1
Disconnector-fuse double opening . 3.3.5.2
F
Fuse-combination unit . 3.3.2
Fuse-disconnector . 3.3.6
Fuse-disconnector single opening . 3.3.6.1
Fuse-disconnector double opening .
...