EN 60947-2:2006

SLOVENSKI SIST EN 60947-2:2006

STANDARD
december 2006
Nizkonapetostne stikalne naprave – 2. del: Odklopniki (IEC 60947-2:2006)
Low-voltage switchgear and controlgear – Part 2: Circuit-breakers (IEC 60947-
2:2006)
ICS 5HIHUHQþQDãWHYLOND
29.130.20
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EUROPEAN STANDARD
EN 60947-2
NORME EUROPÉENNE
August 2006
EUROPÄISCHE NORM
ICS 29.130.20 Supersedes EN 60947-2:2003

English version
Low-voltage switchgear and controlgear
Part 2: Circuit-breakers
(IEC 60947-2:2006)
Appareillage à basse tension  Niederspannungsschaltgeräte
Partie 2: Disjoncteurs Teil 2: Leistungsschalter
(CEI 60947-2:2006) (IEC 60947-2:2006)

This European Standard was approved by CENELEC on 2006-07-01. 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, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

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

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

© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60947-2:2006 E
Foreword
The text of document 17B/1455/FDIS, future edition 4 of IEC 60947-2, 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 60947-2 on 2006-07-01.
This European Standard supersedes EN 60947-2:2003.
The main changes introduced in EN 60947-2:2006 are an amendment to the verification of dielectric
properties, the improvement of EMC clauses in Annexes B, F, J and M, and the addition of a new Annex
O regarding instantaneous trip circuit-breakers.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2007-04-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2009-07-01
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 (89/336/CEE). See Annex ZZ.
Annexes ZA and ZZ have been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60947-2:2006 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60112 NOTE  Harmonized as EN 60112:2003 (not modified).
IEC 60269-1 NOTE  Harmonized as EN 60269-1:1998 (not modified), new edition at draft stage.
IEC 60269-2-1 NOTE  Harmonized as HD 60269-2-1:2005 (not modified).
IEC 60269-3 NOTE  Harmonized as EN 60269-3:1995 (not modified), new edition at draft stage.
IEC 60439 NOTE  Harmonized as EN 60439 (Series) (not modified).
IEC 60947-3 NOTE  Harmonized as EN 60947-3:1999 (not modified).
IEC 60947-5-1 NOTE  Harmonized as EN 60947-5-1:2004 (not modified).
__________
- 3 - EN 60947-2:2006
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 60051 Series Direct acting indicating analogue electrical EN 60051 Series
measuring instruments and their accessories

IEC 60068-2-14 1984 Environmental testing
+ A1 1986 Part 2: Tests - Test N: Change of temperature EN 60068-2-14 1999

IEC 60068-2-30 2005 Environmental testing EN 60068-2-30 2005
Part 2-30: Tests - Test Db: Damp heat, cyclic
(12 h + 12 h cycle)
IEC 60364 Series Low-voltage electrical installations - -

IEC 60364-4-41 2001 Electrical installations of buildings - -
Part 4-41: Protection for safety - Protection
against elctric shock
IEC 60695-2-10 2000 Fire hazard testing EN 60695-2-10 2001
Part 2-10: Glowing/hot-wire based test
methods - Glow-wire apparatus and common
test procedure
IEC 60695-2-11 2000 Fire hazard testing EN 60695-2-11 2001
Part 2-11: Glowing/hot-wire based test
methods - Glow-wire flammability test method
for end-products
IEC 60695-2-12 2000 Fire hazard testing EN 60695-2-12 2001
Part 2-12: Glowing/hot-wire based test
methods - Glow-wire flammability test method
for materials
IEC 60695-2-13 2000 Fire hazard testing EN 60695-2-13 2001
Part 2-13: Glowing/hot-wire based test
methods - Glow-wire ignitability test method
for materials
IEC/TR 60755 1983 General requirements for residual current - -
A1 1988 operated protective devices - -
A2 1992 - -
Publication Year Title EN/HD Year
IEC 60898 Series Electrical accessories - Circuit-breakers for EN 60898 Series
(mod) overcurrent protection for household and
similar installations
1) 2)
IEC 60934 - Circuit-breakers for equipment (CBE) EN 60934 2001

IEC 60947-1 2004 Low-voltage switchgear and controlgear EN 60947-1 2004
Part 1: General rules + corr. November 2004

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
Electromechanical contactors and motor-
starters
3)
IEC 61000-3-2 2000 Electromagnetic compatibility (EMC) EN 61000-3-2 2000
(mod) Part 3-2: Limits - Limits for harmonic current
A1 2001 emissions (equipment input current up to and

+ A2 2004 including 16 A per phase) A2 2005

IEC 61000-3-3 1994 Electromagnetic compatibility (EMC) EN 61000-3-3 1995
Part 3-3: Limits - Limitation of voltage + corr. July 1997
A1 2001 changes, voltage fluctuations and flicker in A1 2001
public low-voltage supply systems, for
equipment with rated current ≤ 16 A per
phase and not subject to conditional
connection
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 immunity A2 2001
test
4)
IEC 61000-4-3 2002 Electromagnetic compatibility (EMC) EN 61000-4-3 2002

A1 2002 Part 4-3: Testing and measurement A1 2002
techniques - Radiated, radio-frequency,
electromagnetic field immunity test

5)
IEC 61000-4-4 1995 Electromagnetic compatibility (EMC) EN 61000-4-4 1995
A1 2000 Part 4-4: Testing and measurement A1 2001

A2 2001 techniques - Electrical fast transient/burst A2 2001
immunity test
IEC 61000-4-5 1995 Electromagnetic compatibility (EMC) EN 61000-4-5 1995
A1 2000 Part 4-5: Testing and measurement A1 2001
techniques - Surge immunity test

IEC 61000-4-6 2003 Electromagnetic compatibility (EMC) - -
A1 2004 Part 4-6: Testing and measurement - -
techniques - Immunity to conducted
disturbances, induced by radio-frequency
fields
1)
Undated reference.
2)
Valid edition at date of issue.
3)
EN 61000-3-2 + A2 are superseded by EN 61000-3-2:2006, which is based on IEC 61000-3-2:2005.
4)
EN 61000-4-3 + A1 are superseded by EN 61000-4-3:2006, which is based on IEC 61000-4-3:2006.
5)
EN 61000-4-4 + A1 + A2 are superseded by EN 61000-4-4:2004, which is based on IEC 61000-4-4:2004.

- 5 - EN 60947-2:2006
Publication Year Title EN/HD Year
IEC 61000-4-11 2004 Electromagnetic compatibility (EMC) EN 61000-4-11 2004
Part 4-11: Testing and measurement
techniques - Voltage dips, short interruptions
and voltage variations immunity tests

IEC 61000-4-13 2002 Electromagnetic compatibility (EMC) EN 61000-4-13 2002
Part 4-13: Testing and measurement
techniques - Harmonics and interharmonics
including mains signalling at a.c. power port,
low frequency immunity tests
IEC 61000-5-2 1997 Electromagnetic compatibility (EMC) - -
Part 5: Installation and mitigation guidelines -
Section 2: Earthing and cabling

IEC 61008-1 (mod) 1996 Residual current operated circuit-breakers
+ A1 (mod) 2002 without integral overcurrent protection for EN 61008-1 2004
household and similar uses (RCCB's)
Part 1: General rules
IEC 61009-1 1996 Residual current operated circuit-breakers
+ corr. May 2003 with integral overcurrent protection for
+ A1 (mod) 2002 household and similar uses (RCBO's) EN 61009-1 2004
Part 1: General rules + corr. July 2006

CISPR 11 (mod) 2003 Industrial scientific and medical (ISM) radio- - -
6)
+A1 (mod) 2004 frequency equipment - Electromagnetic EN 55011 200X
disturbance characteristics - Limits and
methods of measurement
6)
CISPR 22 (mod) 2005 Information technology equipment - Radio EN 55022 200X
A1 2005 disturbance characteristics - Limits and - -
methods of measurement
6)
To be published.
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 4 of the EC Directive 89/336/EEC.
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.
INTERNATIONAL IEC
STANDARD 60947-2
Fourth edition
2006-05
Low-voltage switchgear and controlgear –
Part 2:
Circuit-breakers
 IEC 2006 Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
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60947-2  IEC:2006 – 3 –
CONTENTS
FOREWORD.13

1 General .17
1.1 Scope and object.17
1.2 Normative references .19
2 Definitions .23
3 Classification .29
4 Characteristics of circuit-breakers.31
4.1 Summary of characteristics.31
4.2 Type of circuit-breaker.33
4.3 Rated and limiting values of the main circuit.33
4.4 Utilization categories .41
4.5 Control circuits .41
4.6 Auxiliary circuits .43
4.7 Releases .43
4.8 Integral fuses (integrally fused circuit-breakers) .45
5 Product information.45
5.1 Nature of the information .45
5.2 Marking .47
5.3 Instructions for installation, operation and maintenance.49
6 Normal service, mounting and transport conditions.49
7 Constructional and performance requirements .49
7.1 Constructional requirements .49
7.2 Performance requirements.53
7.3 Electromagnetic compatibility (EMC) .65
8 Tests .65
8.1 Kind of tests .65
8.2 Compliance with constructional requirements.67
8.3 Type tests .67
8.4 Routine tests . 121

Annex A (normative)  Co-ordination under short-circuit conditions between a circuit-
breaker and another short-circuit protective device associated in the same circuit. 131
Annex B (normative)  Circuit-breakers incorporating residual current protection . 149
Annex C (normative)  Individual pole short-circuit test sequence. 213
Annex D Vacant . 215
Annex E (informative)  Items subject to agreement between manufacturer and user. 217
Annex F (normative)  Additional tests for circuit-breakers with electronic over-current
protection. 219
Annex G (normative)  Power loss . 279
Annex H (normative)  Test sequence for circuit-breakers for IT systems . 285

60947-2  IEC:2006 – 5 –
Annex J (normative)  Electromagnetic compatibility (EMC) – Requirements and test
methods for circuit-breakers. 289
Annex K (informative) Glossary of symbols related to products covered by this standard. 317
Annex L (normative)  Circuit-breakers not fulfilling the requirements for overcurrent
protection. 321
Annex M (normative)  Modular residual current devices (without integral current
breaking device). 331
Annex N (normative)  Electromagnetic compatibility (EMC) – Additional requirements
and test methods for devices not covered by Annexes B, F and M . 421
Annex O  Instantaneous trip circuit-breakers (ICB) . 429

Bibliography . 435

Figure 1 – Test arrangement (connecting cables not shown) for short-circuit tests . 129
Figure A.1 – Over-current co-ordination between a circuit-breaker and a fuse or back-up
protection by a fuse: operating characteristics . 141
Figure A.2 Figure A.3. 143
Total discrimination between two circuit-breakers . 143
Figure A.4 Figure A.5. 145
Back-up protection by a circuit-breaker – Operating characteristics. 145
Figure A.6 – Example of test circuit for conditional short-circuit breaking capacity tests
showing cable connections for a 3-pole circuit-breaker (C ). 147
Figure B.1 – Test circuit for the verification of the operating characteristic (see B.8.2) . 197
Figure B.2 – Test circuit for the verification of the limiting value of the non-operating
current under over-current conditions (see B.8.5) . 199
Figure B.3 – Test circuit for the verification of the behaviour of CBRs classified under
B.3.1.2.2 (see B.8.9) . 201
Figure B.4 – Current ring wave 0,5 µs/100 kHz . 203
Figure B.5 – Example of test circuit for the verification of resistance to unwanted
tripping . 205
Figure B.6 – Surge current wave 8/20 µs . 205
Figure B.7 – Test circuit for the verification of resistance to unwanted tripping in case of
flashover without follow-on current (B.8.6.2) . 207
Figure B.8 – Test circuit for the verification of the correct operation of CBRs, in the case
of residual pulsating direct currents (see B.8.7.2.1, B.8.7.2.2 and B.8.7.2.3) . 209
Figure B.9 – Test circuit for the verification of the correct operation of CBRs, in the case
of a residual pulsating direct current superimposed by a smooth direct residual current
(see B.8.7.2.4) . 211
Figure F.1 – Representation of test current produced by back-to-back thyristors in
accordance with F.4.1 . 237
Figure F.2 – Test circuit for immunity and emission tests in accordance with F.4.1.3,
F.4.2, F.4.3, F.4.6, F.4.7.1, F.5.4 and F.6.2 – Two phase poles in series. 239
Figure F.3 – Test circuit for immunity and emission tests in accordance with F.4.1.3,
F.4.2, F.4.3, F.4.6, F.4.7.1, F.5.4 and F.6.2 – Three phase poles in series . 241

60947-2  IEC:2006 – 7 –
Figure F.4 – Test circuit for immunity and emission tests in accordance with F.4.1.3,
F.4.2, F.4.3, F.4.6, F.4.7.1, F.5.4 and F.6.2 – Three-phase connection . 243
Figure F.5 – Test current for the verification of the influence of the current dips and
interruptions in accordance with F.4.7.1. 245
Figure F.6 – Circuit for electrical fast transients/bursts (EFT/B) immunity test in
accordance with F.4.4 – Two phase poles in series. 247
Figure F.7 – Circuit for electrical fast transients/bursts (EFT/B) immunity test in
accordance with F.4.4 – Three phase poles in series . 249
Figure F.8 – Circuit for electrical fast transients/bursts (EFT/B) immunity test in
accordance with F.4.4 – Three-phase connection . 251
Figure F.9 – Test circuit for the verification of the influence of surges in the main circuit
(line-to-earth) in accordance with F.4.5 – Two phase poles in series . 253
Figure F.10 – Test circuit for the verification of the influence of surges in the main
circuit (line-to-earth) in accordance with F.4.5 – Three phase poles in series . 255
Figure F.11 – Test circuit for the verification of the influence of surges in the main
circuit (line-to-earth) in accordance with F.4.5 – Three-phase connection. 257
Figure F.12 – Test circuit for the verification of the influence of current surges in the
main circuit in accordance with F.4.5 – Two phase poles in series . 259
Figure F.13 – Test circuit for the verification of the influence of current surges in the
main circuit in accordance with F.4.5 – Three phase poles in series. 259
Figure F.14 – Test circuit for the verification of the influence of current surges in the
main circuit in accordance with F.4.5 – Three-phase connection . 261
Figure F.15 – Temperature variation cycles at a specified rate of change in accordance
with F.9.1. 261
Figure F.16 – General test set up for immunity tests . 263
Figure F.17 – Test set up for the verification of immunity to radiated r.f.
electromagnetic fields . 265
Figure F.18 – Test set up for the verification of immunity to electrical fast
transients/bursts (EFT/B) on power lines . 267
Figure F.19 – Test set up for verification of immunity to electrical fast transients/bursts
(EFT/B) on signal lines.269
Figure F.20 – General test set-up for the verification of immunity to conducted
disturbances induced by r.f. fields (common mode) . 271
Figure F.21 – Arrangement of connections for the verification of immunity to conducted
disturbances induced by r.f. fields - Two phase poles in series configuration. 273
Figure F.22 – Arrangement of connections for the verification of immunity to conducted
disturbances induced by r.f. fields - Three phase poles in series configuration . 275
Figure F.23 – Arrangement of connections for the verification of immunity to conducted
disturbances induced by r.f. fields – Three-phase configuration . 277
Figure G.1 – Example of power loss measurement according to G.2.1 . 283
Figure G.2 – Example of power loss measurement according to G.2.2 and G.2.3 . 283
Figure J.1 – EUT mounted in a metallic enclosure . 305
Figure J.2 – Test set up for the measurement of radiated r.f. emissions. 307
Figure J.3 – Test set up for the verification of immunity to electrostatic discharges . 309

60947-2  IEC:2006 – 9 –
Figure J.4 – Test set up for the verification of immunity to radiated r.f. electromagnetic
fields. 311
Figure J.5 – Test set up for the verification of immunity to electrical fast
transients/bursts (EFT/B) on power lines . 313
Figure J.6 – Test set up for the verification of immunity to electrical fast
transients/bursts (EFT/B) on signal lines . 315
Figure K.1 – Relationship between symbols and tripping characteristics. 319
Figure M.1 – Test circuits for the verification of operation in the case of a steady
increase of residual current . 379
Figure M.2 – Test circuits for the verification of operation in the case of a sudden
appearance of residual current (with breaking device) . 381
Figure M.3 – Test circuits for the verification of operation in the case of a sudden
appearance of residual current (without breaking device). 383
Figure M.4 – Test circuits for the verification of the limiting value of non-operating
current under overcurrent conditions . 385
Figure M.5 – Test circuits for the verification of the resistance to unwanted tripping in
the case of loading of the network capacitance. 387
Figure M.6 – Test circuit for the verification of the resistance to unwanted tripping in the
case of flashover without follow-on current . 389
Figure M.7 – Test circuits for the verification of operation in the case of a continuous
rise of a residual pulsating direct current . 391
Figure M.8 – Test circuits for the verification of operation in the case of a sudden
appearance of residual pulsating direct current (without breaking device) . 393
Figure M.9 – Test circuits for the verification of operation in the case of a sudden
appearance of residual pulsating direct current (with breaking device) . 395
Figure M.10 – Test circuits for the verification of operation in the case of a residual
pulsating direct current superimposed by smooth direct current of 6 mA . 397
Figure M.11 – Test circuits for the verification of operation in the case of a slowly rising
residual smooth direct current . 399
Figure M.12 – Test circuits for the verification of operation in the case of a sudden
appearance of residual smooth direct current (without breaking device) . 401
Figure M.13 – Test circuits for the verification of operation in the case of a sudden
appearance of residual smooth direct current (with breaking device). 403
Figure M.14 – Test circuits for the verification of operation in the case of a slowly rising
residual current resulting from a fault in a circuit fed by a three-pulse star or a six-pulse
bridge connection. 405
Figure M.15 – Test circuits for the verification of operation in the case of a slowly rising
residual current resulting from a fault in a circuit fed by a two-pulse bridge connection
line-to-line. 407
Figure M.16 – Test circuit for the verification of the behaviour of MRCDs with separate
sensing means in the case of a failure of the sensor means connection . 409
Figure M.17 − Test circuit for the verification of the behaviour of MRCD with separate
sensing means under short-circuit conditions . 411
Figure M.18 − Test circuit for the verification of the behaviour of MRCD with integral
sensing means under short-circuit conditions . 413

60947-2  IEC:2006 – 11 –
Figure M.19 − Test circuit for the verification of the behaviour of terminal type MRCD
under short-circuit conditions. 415
Figure M.20 – Verification of immunity to radiated r.f. electromagnetic fields - Test set-
up for MRCD with separate sensing means (additional to the test of Annex B) . 417
Figure M.21 – Verification of immunity to electrical fast transients/bursts (EFT/B) on the
sensing means connection of an MRCD with separate sensing means (additional to the
test of Annex B) . 419
Figure M.22 – Verification of immunity to conducted disturbances induced by r.f. fields -
Test set up for MRCD with separate sensing means (additional to the test of Annex B) . 419

Table 1 – Standard ratios between I and I .37
cs cu
Table 2 – Ratio n between short-circuit making capacity and short-circuit breaking
capacity and related power factor (for a.c. circuit-breakers) .39
Table 3 – Minimum values of rated short-time withstand current .39
Table 4 – Utilization categories.41
Table 5 – Preferred values of the rated control supply voltage, if different from that of
the main circuit .41
Table 6 – Characteristics of the opening operation of inverse time-delay over-current
opening releases at the reference temperature.57
Table 7 – Temperature-rise limits for terminals and accessible parts .61
Table 8 – Number of operating cycles.63
a
Table 9 – Overall schema of test sequences .71
Table 9a – Applicability of test sequences according to the relationship between I , I
cs cu
and I .73
cw
Table 10 – Number of samples for test .79
Table 11 – Values of power factors and time constants corresponding to test currents.83
Table 12 – Test circuit characteristics for overload performance . 105
Table B.1 – Operating characteristic for non-time-delay type. 159
Table B.2 – Operating characteristic for time-delay-type having a limiting non-actuating
time of 0,06 s . 161
Table B.3 – Requirements for CBRs functionally dependent on line voltage . 169
Table B.4 – Additional test sequences . 175
Table B.5 – Tripping current range for CBRs in case of an earth fault comprising a d.c.
component. 185
Table F.1 – Test parameters for current dips and interruptions . 229
Table J.1 − EMC − Immunity tests . 293
Table J.2 – Reference data for immunity test specifications . 295
Table J.3 − EMC − Emission tests . 301
Table J.4 – Reference data for emission test specifications . 301
Table M.1 – Product information. 343
Table M.2 – Requirements for MRCDs with voltage source . 347
Table M.3 – Test sequences . 351

60947-2  IEC:2006 – 13 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 2: Circuit-breakers
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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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 60947-2 has been prepared by subcommittee 17B: Low-voltage
switchgear and controlgear, of IEC technical committee 17: Switchgear and controlgear.
This fourth edition of IEC 60947-2 cancels and replaces the third edition published in 2003.
The main changes introduced in this new edition are an amendment to the verification of
dielectric properties, the improvement of EMC clauses in Annexes B, F, J and M, and the
addition of a new Annex O regarding instantaneous trip circuit-breakers.

60947-2  IEC:2006 – 15 –
The text of this standard is based on the third edition and the following documents:
FDIS Report on voting
17B/1455/FDIS 17B/1463/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.
The IEC 60947 series comprises the following parts under the general title Low-voltage
switchgear and controlgear:
Part 1: General rules
Part 2: Circuit-breakers
Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units
Part 4: Contactors and motor-starters
Part 5: Control circuit devices and switching elements
Part 6: Multiple function equipment
Part 7: Ancillary equipment
Part 8: Control units for built-in thermal protection (PTC) for rotating electrical machines
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.
60947-2  IEC:2006 – 17 –
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 2: Circuit-breakers
1 General
The provisions of the general rules dealt with in IEC 60947-1 are applicable to this standard,
where specifically called for. Clauses and subclauses, tables, figures and annexes of the
general rules thus applicable are identified by reference to IEC 60947-1, for example, 1.2.3 of
IEC 60947-1, Table 4 of IEC 60947-1, or Annex A of IEC 60947-1.
1.1 Scope and object
This standard applies to circuit-breakers, the main contacts of which are intended to be
connected to circuits, the rated voltage of which does not exceed 1 000 V a.c. or 1 500 V d.c.;
it also contains additional requirements for integrally fused circuit-breakers.
It applies whatever the rated currents, the method of construction or the proposed applications
of the circuit-breakers may be.
The requirements for circuit-breakers which are also intended to provide earth-leakage
protection are contained in Annex B.
The additional requirements for circuit-breakers with electronic over-current protection are
contained in Annex F.
The additional requirements for circuit-breakers for IT systems are contained in Annex H.
The requirements and test methods for electromagnetic compatibility of circuit-breakers are
contained in Annex J.
The requirements for circuit-breakers not fulfilling the requirements for over-current protection
are contained in Annex L.
The requirements for modular residual current devices (without integral current breaking
device) are contained in Annex M.
The requirements and test methods for electromagnetic compatibility of circuit-breaker
auxiliaries are contained in Annex N.
Supplementary requirements for circuit-breakers used as direct-on-line starters are given in
IEC 60947-4-1, applicable to low-voltage contactors and starters.
The requirements for circuit-breakers for the protection of wiring installations in buildings and
similar applications, and designed for use by uninstructed persons, are contained in
IEC 60898.
The requirements for circuit-breakers for equipment (for example electrical appliances) are
contained in IEC 60934.
60947-2  IEC:2006 – 19 –
For certain specific applications (for example traction, rolling mills, marine service) particular or
additional requirements may be necessary.
NOTE Circuit-breakers which are dealt with in this standard may be provided with devices for automatic opening
under predetermined conditions other than those of over-current and undervoltage as, for example, reversal of
power or current. This standard does not deal with the verification of operation under such pre-determined
conditions.
The object of this standard is to state:
a) the characteristics of circuit-breakers;
b) the conditions with which circuit-breakers shall comply with reference to:
1) operation and behaviour in normal service;
2) operation and behaviour in case of overload and operation and behaviour in case of
short-circuit, including co-ordination in service (discrimination and back-up protection);
3) dielectric properties;
c) tests intended for confirming that these conditions have been met and the methods to be
adopted for these tests;
d) information to be marked on or given with the apparatus.
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 60051 (all parts) Direct acting indicating analogue electrical measuring instruments and
their accessories
IEC 60068-2-14:1984, Environmental testing – Part 2: Tests. Test N: Change of temperature
Amendme
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