EN 60934:2001

SLOVENSKI STANDARD
01-marec-2003
1DGRPHãþD
SIST EN 60934:1996
SIST EN 60934:1996/A11:1999
SIST EN 60934:1996/A2:1997
Odklopniki za opremo (CBE) (IEC 60934:2000)
Circuit-breakers for equipment (CBE)
Geräteschutzschalter (GS)
Disjoncteurs pour équipement (DPE)
Ta slovenski standard je istoveten z: EN 60934:2001
ICS:
29.120.40 Stikala Switches
29.120.50 9DURYDONHLQGUXJD Fuses and other overcurrent
PHGWRNRYQD]DãþLWD protection devices
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60934
NORME EUROPÉENNE
EUROPÄISCHE NORM January 2001
ICS 29.120.40;29.120.50 Supersedes EN 60934:1994 + A1:1994 + A2:1997 + A11:1998
English version
Circuit-breakers for equipment (CBE)
(IEC 60934:2000)
Disjoncteurs pour équipement (DPE) Geräteschutzschalter (GS)
(CEI 60934:2000) (IEC 60934:2000)
This European Standard was approved by CENELEC on 2000-11-01. CENELEC members are bound
to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,
Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60934:2001 E
Foreword
The text of document 23E/430/FDIS, future edition 3 of IEC 60934, prepared by SC 23E,
Circuit-breakers and similar equipment for household use, of IEC TC 23, Electrical accessories, was
submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60934 on
2000-11-01.
This European Standard supersedes EN 60934:1994 + A1:1994 + A2:1997 + A11:1998.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2001-08-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2003-11-01
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annexes A, B, C, D, E, G, H, J, K and ZA are normative and annex F is informative.
Annex ZA has been added by CENELEC.
In this standard the following print types are used:
- requirements: in roman type;
- test specifications: in italic type;
- notes: in smaller roman type.
__________
Endorsement notice
The text of the International Standard IEC 60934:2000 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 60934:2001
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of
any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
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 60050-151 1978 International Electrotechnical Vocabulary--
(IEV)
Chapter 151: Electrical and magnetic
devices
IEC 60050-441 1984 Chapter 441: Switchgear, controlgear and--
fuses
IEC 60050-604 1987 Chapter 604: Generation, transmission--
and distribution of electricity - Operation
IEC 60050-826 1982 Chapter 826: Electrical installations of
buildings
+ A1 1990
+ A2 1995
+ A3 1999 HD 384.2 S2 2001
IEC 60060-1 1989 High-voltage test techniques HD 588.1 S1 1991
+ corr. March 1990 Part 1: General definitions and test
requirements
1)
IEC 60068-2-20 1979 Basic environmental testing procedures HD 323.2.20 S3 1988
Part 2: Tests - Test T: Soldering
IEC 60099-1 1991 Surge arresters EN 60099-1 1994
Part 1: Non-linear resistor type gapped
surge arresters for a.c. systems
2)
IEC 60227 Series Polyvinyl chloride insulated cables of HD 21 Series
rated voltages up to and including
450/750 V
IEC 60269 Series Low-voltage fuses EN 60269 Series

1)
HD 323.2.20 S3 includes A2:1987 to IEC 60068-2-20.
2)
The HD 21 series is related to but not equivalent to the IEC 60227 series.

Publication Year Title EN/HD Year
IEC 60417-1 1998 Graphical symbols for use on equipment EN 60417-1 1999
Part 1: Overview and application
IEC 60529 1989 Degrees of protection provided by EN 60529 1991
enclosures (IP Code) + corr May 1993
IEC 60664 Series Insulation coordination for equipment--
within low-voltage systems
IEC 60664-1 1992 Part 1: Principles, requirements and tests HD 625.1 S1 1996
(mod) + corr. November 1996
IEC 60664-3 1992 Part 3: Use of coatings to achieve HD 625.3 S1 1997
insulation coordination of printed board
assemblies
3)
IEC 60695-2-1/X Series Fire hazard testing EN 60695-2-1/X Series
Part 2: Test methods - Section 1: Glow-
wire test methods
4)
IEC 60898 1995 Electrical accessories - Circuit-breakers--
for overcurrent protection for household
and similar installations
IEC 60947-1 1999 Low-voltage switchgear and controlgear EN 60947-1 1999
(mod) Part 1: General rules + corr. October 1999
IEC 60950 (mod) 1999 Safety of information technology EN 60950 2000
+ corr. January 2000 equipment
IEC 61000-4-2 1995 Electromagnetic compatibility (EMC) EN 61000-4-2 1995
Part 4-2: Testing and measurement
techniques - Electrostatic discharge
immunity test
IEC 61000-4-3
1995 Part 4-3: Testing and measurement EN 61000-4-3 1996
(mod)
techniques - Radiated, radio-frequency,
electromagnetic field immunity test
IEC 61000-4-4 1995 Part 4-4: Testing and measurement EN 61000-4-4 1995
techniques - Electrical fast transient/burst
immunity test
IEC 61000-4-5 1995 Part 4-5: Testing and measurement EN 61000-4-5 1995
techniques - Surge immunity test
CISPR 22 (mod) 1997 Information technology equipment - Radio EN 55022 1998
disturbance characteristics - Limits and + corr. August 1999
methods of measurement
3)
EN 60695-2-1/X:1996 are superseded by EN 60695-2-10:2001 to EN 60695-2-13:2001, which are based on
IEC 60695-2-10:2000 to IEC 60685-2-13:2000.
4)
IEC 60898:1987 + corrigendum May 1988 + A2:1990 + A3:1990 + corrigendum August 1990, mod., are harmonized as
EN 60898:1991. This European Standard applies with its corrigendum October 1991 and its amendments A1:1991
(IEC/A1:1989) and A11:1994 up to A19:2000.

NORME CEI
INTERNATIONALE IEC
INTERNATIONAL
Troisième édition
STANDARD
Third edition
2000-10
Disjoncteurs pour équipement (DPE)
Circuit-breakers for equipment (CBE)
 IEC 2000 Droits de reproduction réservés  Copyright - all rights reserved
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60934  IEC:2000 – 3 –
CONTENTS
Page
FOREWORD .11
Clause
1 Scope and object . 15
2 Normative references. 15
3 Definitions. 19
3.1 Definitions related to protection and switching devices. 19
3.2 General terms. 21
3.3 Definitions related to current . 23
3.4 Definitions related to voltage. 25
3.5 Definitions related to constructional elements of a CBE . 27
3.6 Definitions related to releases in CBEs . 29
3.7 Definitions related to insulation and clearances in a CBE. 31
3.8 Definitions related to operation of CBEs. 35
3.9 Definitions related to the operating characteristic of CBEs . 39
3.10 Definitions related to characteristic quantities . 39
3.11 Definitions concerning coordination of CBEs and SCPDs associated
in the same circuit. 41
3.12 Definitions related to terminals and terminations. 43
3.13 Definitions related to tests . 49
4 Classification .49
4.1 Quantity of poles. 49
4.2 Method of mounting . 49
4.3 Method of connection. 49
4.4 Method of operation. 51
4.5 Mode of tripping. 51
4.6 Influence of the ambient temperature. 51
4.7 Trip-free behaviour . 53
4.8 Influence of the mounting position. 53
4.9 Electrical performance . 53
5 Characteristics of CBEs . 53
5.1 List of characteristics . 53
5.2 Rated quantities. 53
5.3 Standard and preferred values. 57
6 Marking and other product information . 59
7 Standard conditions for operation in service. 61
7.1 Ambient air temperature . 61
7.2 Altitude . 61
7.3 Atmospheric conditions. 63
8 Requirements for construction and operation . 63
8.1 Mechanical design . 63
8.2 Protection against electric shock. 87
8.3 Temperature-rise . 87
8.4 Dielectric properties. 89
8.5 Conditions for automatic operation. 91
8.6 Electrical performance . 95

60934  IEC:2000 – 5 –
Clause Page
8.7 Performance under conditional short-circuit current conditions. 95
8.8 Resistance to mechanical shock and impact . 95
8.9 Resistance to heat . 95
8.10 Resistance to abnormal heat and to fire. 95
8.11 Resistance to tracking . 95
8.12 Resistance to rusting . 97
9 Tests . 99
9.1 Type tests and sequences . 99
9.2 Test conditions . 101
9.3 Test of indelibility of marking . 103
9.4 Test of reliability of terminals, current-carrying parts and connections. 103
9.5 Test of reliability of terminals for external conductors (see 3.12.15) . 109
9.6 Test of protection against electric shock . 113
9.7 Test of dielectric properties. 113
9.8 Test of temperature-rise. 121
9.9 28-day test. 123
9.10 Test of tripping characteristics . 123
9.11 Verification of electrical operational capability. 125
9.12 Conditional short-circuit tests. 133
9.13 Test of resistance to mechanical shock and impact. 139
9.14 Tests of resistance to heat. 139
9.15 Test of resistance to abnormal heat and to fire . 141
9.16 Test of resistance to tracking . 141
9.17 Test of resistance to rusting. 143
Annex A (normative) Time-current zone . 155
Annex B (normative) Determination of clearances and creepage distances . 157
Annex C (normative) Test sequences and number of samples to be submitted
for certification purposes . 161
Annex D (normative) Correspondence between ISO and AWG copper conductors. 167
Annex E (normative) Examples of terminals . 169
Annex F (informative) Coordination between a CBE and a short-circuit protective
device (SCPD) associated in the same circuit. 187
Annex G (normative) Electromagnetic behaviour of CBEs . 213
Annex H (normative) Correlation between nominal voltage of the supply systems and
the line-to-neutral voltage relevant for determining the rated impulse voltage. 217
Annex J (normative) Routine or statistical tests . 219
Annex K (normative) Additional requirements for electrical performance
of CBE-switches.223
Bibliography . 225

60934  IEC:2000 – 7 –
Page
Figure 1 – Thread-forming screw. 145
Figure 2 – Thread-cutting screw . 145
Figures 3 to 6 – Test circuits for overcurrent tests . 147
Figure 7 – Standard test finger . 149
Figure 8 – Ball pressure apparatus. 151
Figure 9 – Arrangements and dimensions of the electrodes for the tracking test . 151
Figures 10 to 13 – Test circuits for verification of the conditional short-circuit current. 153
Figures A.1 to A.4 .155
Figures B.1 to B.10 . 159
Figure E.1 – Examples of pillar terminals . 169
Figure E.2 – Examples of screw terminals and stud terminals. 171
Figure E.3 – Examples of saddle terminals. 173
Figure E.4 – Examples of lug terminals . 173
Figure E.5 – Examples of screwless terminals with clamping means . 175
Figure E.6 – Dimensions of male tabs . 177
Figure E.7 – Dimensions of round dimple detents of male tabs (see figure E.6). 179
Figure E.8 – Dimensions of rectangular dimple detents of male tabs . 179
Figure E.9 – Dimensions of hole detents of male tabs . 179
Figure E.10 – Dimensions of male tabs . 181
Figure E.11 – Dimensions of male tabs . 181
Figure E.12 – Dimensions of male tabs . 181
Figure E.13 – Dimensions of male tabs for two different sizes of female connectors . 183
Figure E.14 – Dimensions of female connectors for male tabs. 185
Figure F.1 – Thermal only CBE, backed up by thermal magnetic circuit-breaker. 199
Figure F.2 – Thermal only CBE, backed up by a fuse . 201
Figure F.3 – Thermal-magnetic CBE backed up by thermal-magnetic circuit-breaker. 203
Figure F.4 – Hydraulic-magnetic CBE backed up by thermal-magnetic circuit-breaker . 205
Figure F.5 – Thermal CBE backed up by a hydraulic-magnetic circuit-breaker. 205
Figure F.6 – Energy-limiting CBE, backed up by thermal-magnetic circuit-breaker. 207
Figure F.7 – Energy-limiting CBE, backed up by a fuse . 209
Figure F.8 – Examples illustrating proper and improper coordination. 211
Table 1 – Minimum clearances for basic and reinforced insulation. 67
Table 2 – Minimum creepage distances. 71
Table 3 – Connectable cross-sectional areas of external copper conductors
for screw type and screwless terminals . 75

60934  IEC:2000 – 9 –
Page
Table 4 – Minimum distance between clamping screw and the end of conductor
when fully inserted . 79
Table 5 – Dimensions of tabs in millimetres –
Dimensions A, B, C, D, E, F, J, M, N, P and Q. 83
Table 6 – Dimensions of tabs in millimetres –
Dimensions H, I, T, K, R, G, L, S and U. 85
Table 7 – Dimensions in millimetres of combined male tabs for two different sizes
of female connectors .85
Table 8 – Temperature-rise values for CBEs for different reference
ambient air temperatures (T) . 89
Table 9 – Time-current operating characteristics . 91
Table 10 – Operating limits of undervoltage and zero-voltage releases (for a.c. and d.c.). 93
Table 11 – Test conditions for electrical performance for CBEs intended for general use,
including inductive circuits.97
Table 12 – Test conditions for electrical performance of CBEs used in essentially
resistive circuits only. 99
Table 13 – List of type tests . 99
Table 14 – Standard cross-sections of copper conductors corresponding to
the rated currents. 101
Table 15 – Screw-thread diameter and applied torques . 105
Table 16 – Insertion and withdrawal forces. 107
Table 17 – Push/pull force. 109
Table 18 – Pulling forces. 111
Table 19 – Make-up of conductors for the test of 9.5.3 . 111
Table 20 – Test voltages . 117
Table 21 – Impulse withstand test voltages for verification of insulation coordination . 121
Table 22 – Power factor and time constant of test circuit. 133
Table C.1 – Test sequences. 161
Table C.2 – Number of samples for full test procedure . 163
Table C.3 – Reduction of samples for simplified test procedure. 165
Table D.1 – Correspondence between ISO and AWG conductor cross-sections . 167
Table G.2.2 – Minimum EMC immunity performances of CBEs . 215
Table H.1 – Nominal voltages and corresponding rated impulse voltages . 217

60934  IEC:2000 – 11 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
CIRCUIT-BREAKERS FOR EQUIPMENT (CBE)
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60934 has been prepared by subcommittee 23E: Circuit-breakers
and similar equipment for household use, of IEC technical committee 23: Electrical
accessories.
This third edition cancels and replaces the second edition published in 1993 and its
amendments 1 (1994) and 2 (1997), and constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
23E/430/FDIS 23E/441/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 3.
Annexes A, B, C, D, E, G, H, J and K form an integral part of this standard.
Annex F is for information only.

60934  IEC:2000 – 13 –
In this standard, the following print types are used:
– Requirements proper: in roman type
– Test specifications: in italic type
– Explanatory matter: in smaller roman type.
The committee has decided that the contents of this publication will remain unchanged until
2005-06. At this date, the publication will be
 reconfirmed;
 withdrawn;
 replaced by a revised edition, or
 amended.
60934  IEC:2000 – 15 –
CIRCUIT-BREAKERS FOR EQUIPMENT (CBE)
1 Scope and object
This International Standard is applicable to mechanical switching devices designed as "circuit-
breakers for equipment" (CBE) intended to provide protection to circuits within electrical
equipment.
NOTE 1 The term "equipment" includes appliances.
NOTE 2 The protected components are usually motors, transformers, internal wiring, etc.
CBEs may have a rated short-circuit capacity higher than that required for overload conditions
and may, in addition, have a conditional short-circuit current rating in association with a
specified short-circuit protective device (SCPD).
This standard is also applicable to switching devices for protection of electrical equipment in
case of undervoltage and/or overvoltage.
It is applicable for a.c. not exceeding 440 V and/or d.c. not exceeding 250 V and a rated
current not exceeding 125 A.
This standard covers CBEs which are intended for
– automatic interruption and non-automatic or automatic resetting;
– automatic interruption and non-automatic or automatic resetting and manual switching
operation.
It also covers CBE-switches, in which the means for automatic interruption are inhibited or not
present by construction (see 3.1.3).
NOTE 3 This standard may be used as a guiding document for voltages up to 630 V a.c.
NOTE 4 Requirements for CBEs suitable for isolation are under consideration.
This standard contains all the requirements necessary to ensure compliance with the
operational characteristics required for these devices by type tests.
It also contains the details relative to test requirements and methods of testing necessary to
ensure reproducibility of test results.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this International Standard. For dated references, subsequent
amendments to, or revisions of, any of these publications do not apply. However, parties to
agreements based on this International Standard are encouraged to investigate the possibility
of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO
and IEC maintain registers of currently valid International Standards.

60934  IEC:2000 – 17 –
IEC 60050(151):1978, International Electrotechnical Vocabulary (IEV) – Chapter 151:
Electrical and magnetic devices
IEC 60050(441):1984, International Electrotechnical Vocabulary (IEV) – Chapter 441:
Switchgear, controlgear and fuses
IEC 60050(604):1987, International Electrotechnical Vocabulary (IEV) – Chapter 604:
Generation, transmission and distribution of electricity – Operation
IEC 60050(826):1982, International Electrotechnical Vocabulary (IEV) – Chapter 826:
Electrical installations of buildings
Amendment 1 (1990)
Amendment 2 (1995)
Amendment 3 (1999)
IEC 60060-1:1989, High-voltage test techniques – Part 1: General definitions and test
requirements
IEC 60068-2-20:1979, Environmental testing – Part 2: Tests – Test T: Soldering
IEC 60099-1:1991, Surge arresters – Part 1: Non-linear resistor type gapped arresters for a.c.
1)
systems
IEC 60227 (all parts), Polyvinyl chloride insulated cables of rated voltages up to and including
450/750 V
IEC 60269 (all parts), Low-voltage fuses
IEC 60417-1:1998, Graphical symbols for use on equipment – Part 1: Overview and
application
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60664 (all parts), Insulation coordination for equipment within low-voltage systems
IEC 60664-1:1992, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60664-3:1992, Insulation coordination for equipment within low-voltage systems – Part 3:
Use of coatings to achieve insulation coordination of printed board assemblies
IEC 60695-2-1 (all sheets), Fire hazard testing – Part 2: Test methods – Section 1: Glow-wire
test methods
IEC 60898:1995, Electrical accessories – Circuit-breakers for overcurrent protection for
household and similar installations
IEC 60947-1:1999, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60950:1999, Safety of information technology equipment
———————
1)
There is a consolidated edition 3.1 (1999) that includes IEC 60099-1 (1991) and its amendment 1 (1999).

60934  IEC:2000 – 19 –
IEC 61000-4-2:1995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
2)
techniques – Section 2: Electrostatic discharge immunity test – Basic EMC Publication
IEC 61000-4-3:1995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 3: Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-4:1995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 4: Electrical fast transient/burst immunity test – Basic EMC Publication
IEC 61000-4-5:1995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 5: Surge immunity test
CISPR 22:1997, Information technology equipment – Radio disturbance characteristics –
Limits and methods of measurement
3 Definitions
For the purposes if this International standard, the following definitions apply.
3.1 Definitions related to protection and switching devices
3.1.1
circuit-breaker
mechanical switching device, capable of making, carrying and breaking currents under normal
circuit conditions and also making, carrying for a specified time and breaking currents under
specified abnormal conditions such as those of short circuit [IEV 441-14-20]
3.1.2
circuit-breaker for equipment (CBE)
circuit-breaker specifically designed for the protection of equipment
3.1.3
CBE-switch
CBE without overcurrent releases, equipped or not with releases tripping by voltage or by
mechanical means
NOTE The relevant specific requirements are given in annex K.
3.1.4
fuse
device that, by the fusing of one or more of its specially designed and proportioned
components, opens the circuit in which it is inserted by breaking the current when this
exceeds a given value for a sufficient time. The fuse comprises all of the parts that form the
complete device [IEV 441-18-01]
3.1.5
switching device
device designed to make or break the current in one or more electric circuits [IEV 441-14-01]
———————
2)
There is a consolidated edition 1.1 (1999) that includes IEC 61000-4-2 (1995) and its amendment 1 (1998).

60934  IEC:2000 – 21 –
3.1.6
mechanical switching device
switching device designed to close and open one or more electric circuits by means of
separable contacts [IEV 441-14-02]
3.1.7
switch (mechanical)
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 [IEV 441-14-10]
3.1.8
disconnector
mechanical switching device which in the open position complies with the requirements
specified for the isolating function [IEV 441-14-05, modified]
3.1.9
disconnection
interruption of an electrical circuit in a pole so as to provide insulation between the supply and
those parts intended to be disconnected from the supply
3.1.10
full-disconnection
disconnection that provides the equivalent of basic insulation by contact separation
3.1.11
micro-disconnection
disconnection that provides compliance of performance by contact separation
3.1.12
isolation (isolating function)
function intended to cut off the supply from all or a discrete section of the installation by
separating the installation from every source of electrical energy for reasons of safety
3.2 General terms
3.2.1
ambient air temperature
temperature, determined under prescribed conditions, of the air surrounding the complete
CBE (for example, for an enclosed CBE, it is the air outside the enclosure) [IEV 441-11-13,
modified]
3.2.2
applied voltage
voltage which exists across the terminals of a pole of a CBE just before the making of the
current. In the case of a.c., it is the r.m.s. value [IEV 441-17-24, modified]
3.2.3
main circuit (of a CBE)
all the conductive parts of a CBE included in the circuit which it is designed to close and to
open [IEV 441-15-02, modified]
3.2.4
control circuit (of a CBE)
circuit (other than a path of the main circuit) intended for the closing operation or opening
operation, or both, of a CBE [IEV 441-15-03, modified]

60934  IEC:2000 – 23 –
3.2.5
auxiliary circuit (of a CBE)
all the conductive parts of a CBE intended to be included in a circuit other than the main
circuit and the control circuit of the CBE [IEV 441-15-04, modified]
3.2.6
pole (of a CBE)
that part of a CBE associated exclusively with one, electrically separated, conducting path of
its main circuit provided with contacts intended to connect and disconnect the main circuit
itself and excluding those portions which provide a means for mounting and operating the
poles together [IEV 441-15-01, modified]
3.2.7
protected pole
pole provided with an overcurrent release (see 3.6.2)
3.2.8
unprotected pole
pole without overcurrent release (see 3.6.2) but otherwise generally capable of the same
performance as a protected pole of the same CBE
3.2.9
neutral conductor (symbol N)
conductor connected to the neutral point of a system and capable of contributing to the
transmission of electrical energy [IEV 826-01-03]
3.2.10
closed position
position in which the predetermined continuity of the main circuit of a CBE is secured
[IEV 441-16-22, modified]
3.2.11
open position
position in which the predetermined clearance between open contacts in the main circuit of a
CBE is provided [IEV 441-16-23, modified]
3.2.12
incorporated mounting
method of mounting where the user provides in his equipment a cavity to fix the CBE in its
position
3.3 Definitions related to current
3.3.1
current
flow of electric charge through a conductor
3.3.2
rated current
current assigned by the manufacturer for a specified operating condition of the CBE
3.3.3
overcurrent
current exceeding the rated current [IEV 441-11-06]

60934  IEC:2000 – 25 –
3.3.4
overload current
overcurrent that occurs in an electrically undamaged circuit
3.3.5
short-circuit current
overcurrent resulting from a fault of negligible impedance between points intended to be at
different potentials in normal service [IEV 441-11-07, modified]
NOTE A short-circuit current may result from a fault or from an incorrect connection.
3.3.6
conventional tripping current I
t
specified value of current which causes a CBE to operate within a specified time
(conventional time)
3.3.7
conventional non-tripping current I
nt
specified value of current which a CBE is capable of carrying for a specified time (conventional
time) without tripping
3.3.8
instantaneous tripping current I
i
value of current for which a CBE will operate automatically (without intentional time delay)
within a time less than 0,1 s
3.3.9
instantaneous non-tripping current I
ni
value of current for which a CBE will not operate automatically without intentional time delay
within a time equal to or less than 0,1 s
3.4 Definitions related to voltage
3.4.1
rated voltage
value of voltage assigned by the manufacturer to a CBE or to its components and to which
operation and performance characteristics are referred
NOTE A CBE may have more than one rated voltage value or may have a rated voltage range.
3.4.2
working voltage
highest value of the a.c. or d.c. voltage across any particular insulation which can occur when
a CBE is supplied at rated voltage
NOTE 1 Transients are disregarded.
NOTE 2 Both open-circuit and normal operating conditions are taken into account.
3.4.3
overvoltage
any voltage having a peak value exceeding the corresponding peak value of maximum
steady-state voltage at normal operating conditions
3.4.4
temporary overvoltage
overvoltage at power frequency of relatively long duration

60934  IEC:2000 – 27 –
3.4.5
transient overvoltage
short-duration overvoltage of a few milliseconds or less, oscillatory or non-oscillatory, usually
highly damped [IEV 604-03-13]
3.4.6
temporary withstand voltage
highest value of a temporary overvoltage which does not cause breakdown of insulation under
specified conditions
3.5 Definitions related to constructional elements of a CBE
3.5.1
accessible part
part which can be touched in normal use
3.5.2
conductive part
part which is capable of conducting current although it may not necessarily be used for
carrying service current [IEV 441-11-09]
3.5.3
exposed conductive part
conductive part which can readily be touched and which is not normally alive, but which may
become alive under fault conditions [IEV 441-11-10]
NOTE Typical exposed conductive parts are walls of metal enclosures, metal operating handles, etc.
3.5.4
live part
conductor or conductive part intended to be energized in normal use, including a neutral
conductor, but, by convention, not a PEN conductor [IEV 826-03-01]
NOTE This term does not necessarily imply a risk of electric shock.
3.5.5
detachable part
part which can be removed without the aid of a general purpose tool
3.5.6
main contact
contact included in the main circuit of a CBE, intended to carry, in the closed position, the
current of the main circuit [IEV 441-15-07, modified]
3.5.7
auxiliary contact
contact included in an auxiliary circuit of a CBE and mechanically operated by the CBE
[IEV 441-15-10, modified]
3.5.8
control contact
contact included in a control circuit of a CBE and mechanically operated by the CBE
[IEV 441-15-09, modified]
60934  IEC:2000 – 29 –
3.5.9
form A contact (make contact)
control or auxiliary contact which is closed when the main contacts of a CBE are closed and
open when they are open [IEV 441-15-12, modified]
3.5.10
form B contact (break contact)
control or auxiliary contact which is open when the main contacts of a CBE are closed and
closed when they are open [IEV 441-15-13, modified]
3.5.11
form C contact (ma
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