EN 60947-3:2009

SLOVENSKI STANDARD
01-september-2009
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SIST EN 60947-3:2000/A1:2002
SIST EN 60947-3:2000/A2:2006
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Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-
disconnectors and fuse-combination units (IEC 60947-3:2008)
Niederspannungsschaltgeräte - Teil 3: Lastschalter, Trennschalter, Lasttrennschalter und
Schalter-Sicherungs-Einheiten (IEC 60947-3:2008)
Appareillage à basse tension - Partie 3: Interrupteurs, sectionneurs, interrupteurs-
sectionneurs et combinés-fusibles (CEI 60947-3:2008)
Ta slovenski standard je istoveten z: EN 60947-3:2009
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 60947-3
NORME EUROPÉENNE
June 2009
EUROPÄISCHE NORM
ICS 29.120.40; 29.130.20 Supersedes EN 60947-3:1999 + A1:2001 + A2:2005

English version
Low-voltage switchgear and controlgear -
Part 3: Switches, disconnectors, switch-disconnectors
and fuse-combination units
(IEC 60947-3:2008)
Appareillage à basse tension -  Niederspannungsschaltgeräte -
Partie 3: Interrupteurs, sectionneurs, Teil 3: Lastschalter, Trennschalter,
interrupteurs-sectionneurs Lasttrennschalter
et combinés-fusibles und Schalter-Sicherungs-Einheiten
(CEI 60947-3:2008) (IEC 60947-3:2008)

This European Standard was approved by CENELEC on 2009-05-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

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

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

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

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

Central Secretariat: Avenue Marnix 17, B - 1000 Brussels

© 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60947-3:2009 E
Foreword
The text of document 17B/1601/FDIS, future edition 3 of IEC 60947-3, prepared by SC 17B, Low-voltage
switchgear and controlgear, of IEC TC 17, Switchgear and controlgear, was submitted to the
IEC-CENELEC parallel vote and was approved by CENELEC as EN 60947-3 on 2009-05-01.
This European Standard supersedes EN 60947-3:1999 + A1:2001 + A2:2005.
– alignment with EN 60947-1:2007;
– a switching operation without current allowed between making and breaking operation (Table 3);
– increased number of operations for AC-23 allowed with agreement of the manufacturer (Table 3);
– simplified test procedure amended, f) added to 8.3.2.1.3;
– temperature rise test shall be made at the rated operational current Ie instead of the conventional
enclosed thermal current Ithe (8.3.3.1).
This part is to be used in conjunction with EN 60947-1.The numbering of the subclauses is sometimes not
continuous because it is based on EN 60947-1.
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) 2010-02-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2012-05-01
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of
EC Directive EMC (2004/108/EC). See Annex ZZ.
Annexes ZA and ZZ have been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60947-3:2008 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60447 NOTE  Harmonized as EN 60447:2004 (not modified).
__________
- 3 - EN 60947-3:2009
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

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

IEC 60050-441 1984 International Electrotechnical Vocabulary - -
A1 2000 (IEV) -
Chapter 441: Switchgear, controlgear and
fuses
IEC 60269 (mod) Series Low-voltage fuses EN/HD 60269 Series

IEC 60410 1973 Sampling plans and procedures - -
for inspection by attributes
IEC 60417 Data- Graphical symbols for use on equipment - -
base
IEC 60947-1 2007 Low-voltage switchgear and controlgear - EN 60947-1 2007
Part 1: General rules
IEC 60947-2 2006 Low-voltage switchgear and controlgear - EN 60947-2 2006
Part 2: Circuit-breakers
IEC 60947-4-1 2000 Low-voltage switchgear and controlgear - EN 60947-4-1 2001
A1 2002 Part 4-1: Contactors and motor-starters - A1 2002
A2 2005 Electromechanical contactors and motor- A2 2005
starters
IEC 60947-5-1 2003 Low-voltage switchgear and controlgear - EN 60947-5-1 2004
Part 5-1: Control circuit devices and switching + corr. July 2005
elements - Electromechanical control circuit
devices
1)
IEC 61000-4-2 1995 Electromagnetic compatibility (EMC) - EN 61000-4-2 1995
A1 1998 Part 4-2: Testing and measurement A1 1998
A2 2000 techniques - Electrostatic discharge A2 2001
immunity test
IEC 61000-4-3 2006 Electromagnetic compatibility (EMC) - EN 61000-4-3 2006
A1 2007 Part 4-3: Testing and measurement A1 2008
techniques - Radiated, radio-frequency, + IS1 2009
electromagnetic field immunity test

IEC 61000-4-4 2004 Electromagnetic compatibility (EMC) - EN 61000-4-4 2004
Part 4-4: Testing and measurement
techniques - Electrical fast transient/burst
immunity test
IEC 61000-4-5 2005 Electromagnetic compatibility (EMC) - EN 61000-4-5 2006
Part 4-5: Testing and measurement
techniques - Surge immunity test

1)
EN 61000-4-2 is superseded by EN 61000-4-2:2009, which is based on IEC 61000-4-2:2008.

Publication Year Title EN/HD Year

IEC 61000-4-6 2003 Electromagnetic compatibility (EMC) -
+ A1 2004 Part 4-6: Testing and measurement
2)
+ A2 2006 techniques - Immunity to conducted EN 61000-4-6 2007
disturbances, induced by radio-frequency + corr. August 2007
fields + IS1 2009
CISPR 11 (mod) 2003 Industrial scientific and medical (ISM)
+ A1 (mod) 2004 radio-frequency equipment - EN 55011 2007
A2 2006 Electromagnetic disturbance characteristics - A2 2007
Limits and methods of measurement

CISPR 22 (mod) 2005 Information technology equipment - Radio EN 55022 2006
A1 2005 disturbance characteristics - Limits and A1 2007
3)
A2 (mod) 2006 methods of measurement A2 200X

2)
EN 61000-4-6 is superseded by EN 61000-4-6:2009, which is based on IEC 61000-4-6:2008.
3)
At draft stage.
- 5 - EN 60947-3:2009
Annex ZZ
(informative)
Coverage of Essential Requirements of EC Directives
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and within its scope the standard covers all
relevant essential requirements as given in Article 1 of Annex I of the EC Directive 2004/108/EC.
Compliance with this standard provides one means of conformity with the specified essential
requirements of the Directive concerned.
WARNING: Other requirements and other EC Directives may be applicable to the products falling within
the scope of this standard.
__________
IEC 60947-3
Edition 3.0 2008-08
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
PRICE CODE
INTERNATIONALE
XA
CODE PRIX
ICS 29.120.40; 29.130.20 ISBN 2-8318-9965-6
– 2 – 60947-3 © IEC:2008
CONTENTS
FOREWORD.4
1 General .6
1.1 Scope and object.6
1.2 Normative references .7
2 Terms and definitions .8
3 Classification .11
3.1 According to the utilization category.11
3.2 According to the method of operation of manually operated equipment.11
3.3 According to suitability for isolation .11
3.4 According to the degree of protection provided.11
4 Characteristics.12
4.1 Summary of characteristics.12
4.2 Type of equipment .12
4.3 Rated and limiting values for the main circuit .12
4.4 Utilization category .14
4.5 Control circuits .15
4.6 Auxiliary circuits .15
4.7 Relays and releases .15
5 Product information.15
5.1 Nature of information .15
5.2 Marking .16
5.3 Instructions for installation, operation and maintenance.17
6 Normal service, mounting and transport conditions.17
7 Constructional and performance requirements .17
7.1 Constructional requirements .17
7.2 Performance requirements.19
7.3 Electromagnetic compatibility.22
8 Tests .24
8.1 Kind of tests .24
8.2 Type tests for constructional requirements .25
8.3 Performance.29
8.4 Electromagnetic compatibility tests .45
8.5 Special tests.46
Annex A (normative) Equipment for direct switching of a single motor.47
Annex B (informative) Items subject to agreement between manufacturer and user.53
Annex C (normative) Single pole operated three pole switches .54
Bibliography .57

Figure 1 – Actuator applied force F.28
Figure C.1 – Typical arrangements.55

Table 1 – Summary of equipment definitions .11
Table 2 – Utilization categories.15
Table 3 – Verification of rated making and breaking capacities (see 8.3.3.3) –
Conditions for making and breaking corresponding to the various utilization categories.20

60947-3 © IEC:2008 – 3 –
Table 4 – Verification of operational performance – Number of operating cycles
corresponding to the rated operational current.21
Table 5 – Test circuit parameters for Table 4.21
Table 6 − Immunity tests .23
Table 7 − Emission limits.23
Table 8 – Actuator test forces.27
Table 9 – List of type tests applicable to a given equipment .29
Table 10 – Overall scheme of test sequences.30
Table 11 – Test sequence I: general performance characteristics .34
Table 12 – Temperature-rise limits for terminals and accessible parts.37
Table 13 – Test sequence II: operational performance capability .37
Table 14 – Test sequence III: short-circuit performance capability .39
Table 15 – Test sequence IV: conditional short-circuit current.43
Table 16 – Test sequence V: overload performance capability .45
Table A.1 – Utilization categories .48
Table A.2 – Rated making and breaking capacity conditions corresponding to several
utilization categories .48
Table A.3 – Relationship between current broken I and off-time for the verification of
c
the rated making and breaking capacities .49
Table A.4 – Operational performance – Conditions for making and breaking
corresponding to several utilization categories.49
Table A.5 – Verification of the number of on-load operating cycles – Conditions for
making and breaking corresponding to several utilization categories.52

– 4 – 60947-3 © IEC:2008
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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60947-3 has been prepared by subcommittee 17B: Low-voltage
switchgear and controlgear, of IEC technical committee 17: Switchgear and controlgear.
This third edition cancels and replaces the second edition published in 1999, Amendment 1
(2001) and Amendment 2 (2005). This edition constitutes a technical revision.
The document 17B/1601/FDIS, circulated to the National Committees as amendment 3, led to
the publication of the new edition.
This edition includes the following significant technical changes with respect to the previous
edition:
– alignment with the fifth edition of IEC 60947-1;
– a switching operation without current allowed between making and breaking operation
(Table 3);
– increased number of operations for AC-23 allowed with agreement of the manufacturer
(Table 3);
60947-3 © IEC:2008 – 5 –
– simplified test procedure amended, f) added to 8.3.2.1.3;
– temperature rise test shall be made at the rated operational current I instead of the
e
conventional enclosed thermal current I (8.3.3.1).
the
The text of this standard is based on the first edition, its amendment 1, amendment 2 and the
following documents:
FDIS Report on voting
17B/1601/FDIS 17B/1608/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60947 series can be found, under the general title Low-voltage
switchgear and controlgear, on the IEC website.
This part is to be used in conjunction with IEC 60947-1.The numbering of the subclauses is
sometimes not continuous because it is based on IEC 60947-1.
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition; or
• amended.
– 6 – 60947-3 © IEC:2008
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 3: Switches, disconnectors, switch-disconnectors
and fuse-combination units
1 General
The provisions of the general rules dealt with in IEC 60947-1 are applicable to this part, where
specifically called for. Clauses and subclauses, tables, figures and appendices of the general
rules thus applicable are identified by reference IEC 60947-1, e.g., 4.3.4.1 of IEC 60947-1,
Table 4 of IEC 60947-1, or Annex A of IEC 60947-1.
1.1 Scope and object
This part of IEC 60947 applies to switches, disconnectors, switch-disconnectors and fuse-
combination units to be used in distribution circuits and motor circuits of which the rated
voltage does not exceed 1 000 V a.c. or 1 500 V d.c.
The manufacturer shall specify the type, ratings and characteristics according to the relevant
standard of any incorporated fuses.
This part does not apply to equipment coming within the scope of IEC 60947-2, IEC 60947-4-1 and
IEC 60947-5-1; however, when switches and fuse-combination units coming into the scope of
this part are normally used to start, accelerate and/or stop an individual motor they shall also
comply with the additional requirements given in Annex A.
The requirements for single pole operated three pole switches are included in Annex C.
Auxiliary switches fitted to equipment within the scope of this part shall comply with the
requirements of IEC 60947-5-1.
This part does not include the additional requirements necessary for electrical apparatus for
explosive gas atmospheres.
NOTE 1 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 2 In this part, 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 3 In general, throughout this part switches, disconnectors, switch-disconnectors and fuse-combination units
will be referred to as "equipment".
The object of this part is to state
a) the characteristics of the equipment;
b) the conditions with which the equipment shall comply 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 to be
adopted for these tests;
60947-3 © IEC:2008 – 7 –
d) the information to be marked on the equipment or made available by the manufacturer, e.g.
in the catalogue.
1.2 Normative references
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For undated references, the latest edition of
the referenced document (including any amendments) applies.
IEC 60050-441:1984, International Electrotechnical Vocabulary (IEV) – Chapter 441:
Switchgear, controlgear and fuses
Amendment 1 (2000)
IEC 60269 (all parts), Low-voltage fuses
IEC 60410:1973, Sampling plans and procedures for inspection by attributes
IEC 60417-DB:2000 , Graphical symbols for use on equipment
IEC 60947-1:2007, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-2:2006, Low-voltage switchgear and controlgear – Part 2: Circuit-breakers
IEC 60947-4-1:2000, Low-voltage switchgear and controlgear – Part 4-1: Contactors and
motor-starters – Electromechanical contactors and motor-starters
Amendment 1 (2002)
Amendment 2 (2005)
IEC 60947-5-1:2003, Low-voltage switchgear and controlgear – Part 5-1: Control circuit
devices and switching elements – Electromechanical control circuit devices
IEC 61000-4-2:1995, Electromagnetic compatibility (EMC) – Part 4-2: Testing and
measurement techniques – Electrostatic discharge immunity test
Amendment 1 (1998)
Amendment 2 (20È00)
IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and
measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test
Amendment 1 (2007)
IEC 61000-4-4:2004, Electromagnetic compatibility (EMC) – Part 4-4: Testing and
measurement techniques – Electrical fast transient/burst immunity test
IEC 61000-4-5:2005, Electromagnetic compatibility (EMC) – Part 4-5: Testing and
measurement techniques – Surge immunity test
IEC 61000-4-6:2003, Electromagnetic compatibility (EMC) – Part 4-6: Testing and
measurement techniques – Immunity to conducted disturbances, induced by radio-frequency
fields
Amendment 1 (2004)
Amendment 2 (2006)
CISPR 11:2003, Industrial, scientific and medical (ISM) radio-frequency equipment –
Electromagnetic disturbance characteristics – Limits and methods of measurement
___________
“DB” refers to the IEC on-line database.

– 8 – 60947-3 © IEC:2008
Amendment 1 (2004)
Amendment 2 (2006)
CISPR 22:2005, Information technology equipment – Radio disturbance characteristics – Limits
and methods of measurement
Amendment 1 (2005)
Amendment 2 (2006)
2 Terms and definitions
For the purposes of this part of IEC 60947, the terms and definitions given in IEC 60050-441,
IEC 60947-1 and the following apply.
Reference
D
Dependent manual operation (of a mechanical switching device). 2.13
Disconnector. 2.2
Disconnector-fuse. 2.7

F
Fuse-combination unit . 2.4
Fuse-disconnector. 2.8
Fuse-switch. 2.6
Fuse-switch-disconnector. 2.10

I
Independent manual operation (of a mechanical switching device). 2.14

M
Multiple tip contact system . 2.12

S
Semi-independent manual operation. 2.15
Single pole operated three pole switch. 2.11
Stored energy operation (of a mechanical switching device). 2.16
Switch (mechanical). 2.1
Switch-disconnector. 2.3
Switch-disconnector-fuse. 2.9
Switch-fuse. 2.5
2.1
(mechanical) switch
mechanical switching device capable of making, carrying and breaking currents under normal
circuit conditions which may include specified operating overload conditions and also carrying
for a specified time currents under specified abnormal circuit conditions such as those of short-
circuit
NOTE A switch may be capable of making, but not breaking, short-circuit currents.
[IEV 441-14-10]
2.2
disconnector
mechanical switching device which, in the open position, complies with the requirements
specified for the isolating function
[IEV 441-14-05, modified]
NOTE 1 This definition differs from IEV 441-14-05 by referring to isolating function instead of isolating distance.

60947-3 © IEC:2008 – 9 –
NOTE 2 A disconnector is capable of opening and closing a circuit when either a negligible current is broken or
made, or when no significant change in the voltage across the terminals of each of the poles of the disconnector
occurs. It is also capable of carrying currents under normal circuit conditions and carrying for a specified time
currents under abnormal conditions such as those of short circuit.
2.3
switch-disconnector
switch which, in the open position, satisfies the isolating requirements specified for a
disconnector
[IEV 441-14-12]
2.4
fuse-combination unit
combination of a mechanical switching device and one or more fuses in a composite unit,
assembled by the manufacturer or in accordance with his instructions
[IEV 441-14-04]
NOTE (Not included in IEV 441-14-04.) This is a general term for fuse switching devices (see also from 2.5 to 2.10
and Table 1).
2.5
switch-fuse
switch in which one or more poles have a fuse in series in a composite unit
[IEV 441-14-14]
2.6
fuse-switch
switch in which a fuse-link or a fuse-carrier with fuse-link forms the moving contact
[IEV 441-14-17]
2.7
disconnector-fuse
disconnector in which one or more poles have a fuse in series in a composite unit
[IEV 441-14-15]
2.8
fuse-disconnector
disconnector in which a fuse-link or fuse-carrier with fuse-link forms the moving contact
[IEV 441-14-18]
2.9
switch-disconnector-fuse
switch-disconnector in which one or more poles have a fuse in series in a composite unit
[IEV 441-14-16]
2.10
fuse-switch-disconnector
switch-disconnector in which a fuse-link or a fuse-carrier with fuse-link forms the moving
contact
[IEV 441-14-19]
– 10 – 60947-3 © IEC:2008
2.11
single pole operated three pole switch
device consisting of three individually operable single pole switch disconnecting devices
according to this part, rated as a complete unit for use in a three-phase system
NOTE These devices are intended for power distribution systems where switching and/or isolation of an individual
phase may be necessary and they should not be used for the switching of the primary circuit of three-phase
equipment.
2.12
multiple tip contact system
system that consists of more than one contact gap per pole, which can be switched, in series
and/or in parallel
2.13
dependent manual operation (of a mechanical switching device)
operation solely by means of directly applied manual energy such that the speed and force of
the operation are dependent upon the action of the operator
[IEV 441-16-13]
2.14
independent manual operation (of a mechanical switching device)
stored energy operation where the energy originates from manual power, stored and released
in one continuous operation, such that the speed and force of the operation are independent of
the action of the operator
[IEV 441-16-16]
2.15
semi-independent manual operation
operation solely by means of directly applied manual energy such that the manual force is
increased up to a threshold value beyond which the independent switching operation is
achieved unless deliberately delayed by the operator
2.16
stored energy operation (of a mechanical switching device)
operation by means of energy stored in the mechanism itself prior to the completion of the
operation and sufficient to complete it under predetermined conditions
NOTE This kind of operation may be subdivided according to
a) the manner of storing the energy (spring, weight, etc.);
b) the origin of the energy (manual, electric, etc.);
c) the manner of releasing the energy (manual, electric, etc.).
[IEV 441-16-15]
A summary of equipment definitions is given in Table 1.

60947-3 © IEC:2008 – 11 –
Table 1 – Summary of equipment definitions
Functions
Making and breaking current Isolating Making, breaking and isolating

Switch
Disconnector Switch-disconnector
2.1 2.2 2.3
Fuse-combination units 2.4
Switch-fuse Disconnector-fuse Switch-disconnector-fuse
2.5 2.7 2.9
a a a
Fuse-switch Fuse-disconnector Fuse-switch-disconnector
2.6 2.8 2.10
NOTE 1  All equipment may be single-break or multi-break.
NOTE 2  Numbers are subclause references of the relevant definitions.
NOTE 3  Symbols are based on IEC 60617-7.
a
The fuse may be on either side of or in a stationary position between the contacts of the equipment.

3 Classification
3.1 According to the utilization category
See 4.4.
3.2 According to the method of operation of manually operated equipment
– dependent manual operation (see 2.13);
– independent manual operation (see 2.14);
– semi-independent manual operation (see 2.15).
NOTE The method of operation on closing may be different from the method for opening.
3.3 According to suitability for isolation
– suitable for isolation (see 7.1.7 of IEC 60947-1 and 7.1.7.1);
– not suitable for isolation.
3.4 According to the degree of protection provided
See 7.1.12 of IEC 60947-1.
– 12 – 60947-3 © IEC:2008
4 Characteristics
4.1 Summary of characteristics
The characteristics of the equipment shall be stated in terms of the following as applicable:
– type of equipment (see 4.2);
– rated and limiting values for the main circuit (see 4.3);
– utilization category (see 4.4);
– control circuits (see 4.5);
– auxiliary circuits (see 4.6);
4.2 Type of equipment
The following shall be stated.
4.2.1 Number of poles
4.2.2 Kind of current
Kind of current (a.c. or d.c.) and, in the case of a.c., number of phases and rated frequency.
4.2.3 Number of positions of the main contacts
(if more than two)
4.3 Rated and limiting values for the main circuit
Rated values are assigned by the manufacturer. They shall be stated in accordance with 4.3.1
to 4.3.6.4 but it may not be necessary to establish all the rated values listed.
4.3.1 Rated voltages
An equipment is defined by the following rated voltages.
4.3.1.1 Rated operational voltage (U )
e
Subclause 4.3.1.1 of IEC 60947-1 applies.
4.3.1.2 Rated insulation voltage (U )
i
Subclause 4.3.1.2 of IEC 60947-1 applies.
4.3.1.3 Rated impulse withstand voltage (U )
imp
Subclause 4.3.1.3 of IEC 60947-1 applies.
4.3.2 Currents
An equipment is defined by the following currents.
4.3.2.1 Conventional free air thermal current (I )
th
Subclause 4.3.2.1 of IEC 60947-1 applies.
4.3.2.2 Conventional enclosed thermal current (I )
the
Subclause 4.3.2.2 of IEC 60947-1 applies.

60947-3 © IEC:2008 – 13 –
4.3.2.3 Rated operational currents (I ) (or rated operational powers)
e
Subclause 4.3.2.3 of IEC 60947-1 applies.
4.3.2.4 Rated uninterrupted current (I )
u
Subclause 4.3.2.4 of IEC 60947-1 applies.
4.3.3 Rated frequency
Subclause 4.3.3 of IEC 60947-1 applies.
4.3.4 Rated duty
The rated duties considered as normal are as follows.
4.3.4.1 Eight-hour duty
Subclause 4.3.4.1 of IEC 60947-1 applies.
4.3.4.2 Uninterrupted duty
Subclause 4.3.4.2 of IEC 60947-1 applies.
4.3.5 Normal load and overload characteristics
4.3.5.1 Ability to withstand motor switching overload currents
See Annex A.
4.3.5.2 Rated making capacity
Subclause 4.3.5.2 of IEC 60947-1 applies with the following additions.
The rated making capacity is stated by reference to the rated operational voltage and rated
operational current and to the utilization category according to Table 3.
Not applicable to AC-20 or DC-20 equipment.
4.3.5.3 Rated breaking capacity
Subclause 4.3.5.3 of IEC 60947-1 applies with the following additions.
The rated breaking capacity is stated by reference to the rated operational voltage and rated
operational current and to the utilization category according to Table 3.
Not applicable to AC-20 or DC-20 equipment.
4.3.6 Short-circuit characteristics
4.3.6.1 Rated short-time withstand current (I )
cw
The rated short-time withstand current of a switch, a disconnector or a switch-disconnector is
the value of short-time withstand current, assigned by the manufacturer, that the equipment
can carry without any damage under the test conditions of 8.3.5.1.
The value of the rated short-time withstand current shall be not less than twelve times the
maximum rated operational current and, unless otherwise stated by the manufacturer, the
duration of the current shall be 1 s.

– 14 – 60947-3 © IEC:2008
For a.c., the value of the current is the r.m.s. value of the a.c. component and it is assumed
that the highest peak value likely to occur does not exceed n times this r.m.s. value, the factor
n being given by Table 16 of IEC 60947-1.
4.3.6.2 Rated short-circuit making capacity (I )
cm
The rated short-circuit making capacity of a switch or a switch-disconnector is the value of
short-circuit making capacity assigned to the equipment by the manufacturer for the rated
operational voltage, at rated frequency (if any) and at a specified power-factor (or time-
constant). It is expressed as the maximum prospective peak current.
For a.c., the relationship between power-factor, prospective peak current and r.m.s. current
shall be in accordance with Table 16 of IEC 60947-1.
Not applicable to AC-20 or DC-20 equipment.
4.3.6.3 Vacant
4.3.6.4 Rated conditional short-circuit current
Subclause 4.3.6.4 of IEC 60947-1 applies.
4.4 Utilization category
The utilization categories define the intended applications and are given in Table 2.
Each utilization category is characterized by the values of the currents and voltages, expressed
as multiples of the rated operational current and the rated operational voltage, as well as the
power-factors or time-constants of the circuit. The conditions for making and breaking given in
Table 3 correspond in principle to the applications listed in Table 2.
The designation of utilization categories is completed by the suffix A or B according to whether
the intended applications require frequent or infrequent operations (see Table 4).
Utilization categories with suffix B are appropriate for devices which, due to design or
application, are only intended for infrequent operation. This could apply, for example, to
disconnectors normally only operated to provide isolation for maintenance work or switching
devices where the fuse-link blade forms the moving contact.
The distinction between frequent and infrequent operation is based on the manufacturer’s rated
operation and the number of operating cycles used as a test criterion in Table 4.
, a device will be designated for frequent use
For a particular rated operational current I
e
(category A) if the manufacturer’s rated operating life is more than the number of operating
cycles indicated in columns 3, 4 or 5 of Table 4.

60947-3 © IEC:2008 – 15 –
Table 2 – Utilization categories
Utilization categories
Nature of current
Typical applications
Category A Category B
a a
AC-20A AC-20B – Connecting and disconnecting under
no-load conditions
AC-21A AC-21B – Switching of resistive loads including
moderate overloads
Alternating current
AC-22A AC-22B – Switching of mixed resistive and inductive
loads, including moderate overloads
AC-23A AC-23B – Switching of motor loads or other highly
inductive loads
a a
DC-20A DC-20B – Connecting and disconnecting under no-
load conditions
DC-21A DC-21B – Switching of resistive loads including

moderate overloads
Direct current
DC-22A DC-22B – Switching of mixed resistive and inductive
loads, including moderate overloads
(e.g. shunt motors)
DC-23A DC-23B – Switching of highly inductive loads
(e.g. series motors)
a
The use of these utilization categories is not permitted in the USA.

Category AC-23 includes occasional switching of individual motors. The switching of capacitors
or of tungsten filament lamps shall be subject to agreement between manufacturer and user.
The utilization categories referred to in Tables 2 and 3 do not apply to an equipment normally
used to start, accelerate and/or stop individual motors. The utilization categories for such an
equipment are dealt with in Annex A.
4.5 Control circuits
Subclause 4.5 of IEC 60947-1 applies.
4.6 Auxiliary circuits
Subclause 4.6 of IEC 60947-1 applies.
4.7
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