IEC 62271-103:2011

IEC 62271-103 ®
Edition 1.0 2011-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –
Part 103: Switches for rated voltages above 1 kV up to and including 52 kV

Appareillage à haute tension –
Partie 103: Interrupteurs pour tensions assignées supérieures à 1 kV et
inférieures ou égales à 52 kV
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by
any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or
IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

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

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: inmail@iec.ch
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
 Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
 IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
 Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
 Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: csc@iec.ch
Tel.: +41 22 919 02 11
Fax: +41 22 919 03 00
A propos de la CEI
La Commission Electrotechnique Internationale (CEI) est la première organisation mondiale qui élabore et publie des
normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.
 Catalogue des publications de la CEI: www.iec.ch/searchpub/cur_fut-f.htm
Le Catalogue en-ligne de la CEI vous permet d’effectuer des recherches en utilisant différents critères (numéro de référence,
texte, comité d’études,…). Il donne aussi des informations sur les projets et les publications retirées ou remplacées.
 Just Published CEI: www.iec.ch/online_news/justpub
Restez informé sur les nouvelles publications de la CEI. Just Published détaille deux fois par mois les nouvelles
publications parues. Disponible en-ligne et aussi par email.
 Electropedia: www.electropedia.org
Le premier dictionnaire en ligne au monde de termes électroniques et électriques. Il contient plus de 20 000 termes et
définitions en anglais et en français, ainsi que les termes équivalents dans les langues additionnelles. Egalement appelé
Vocabulaire Electrotechnique International en ligne.
 Service Clients: www.iec.ch/webstore/custserv/custserv_entry-f.htm
Si vous désirez nous donner des commentaires sur cette publication ou si vous avez des questions, visitez le FAQ du
Service clients ou contactez-nous:
Email: csc@iec.ch
Tél.: +41 22 919 02 11
Fax: +41 22 919 03 00
IEC 62271-103 ®
Edition 1.0 2011-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –
Part 103: Switches for rated voltages above 1 kV up to and including 52 kV

Appareillage à haute tension –
Partie 103: Interrupteurs pour tensions assignées supérieures à 1 kV et
inférieures ou égales à 52 kV
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XB
ICS 29.130.10 ISBN 978-2-88912-534-0

– 2 – 62271-103  IEC:2011
CONTENTS
FOREWORD . 6
1 General . 8
1.1 Scope . 8
1.2 Normative references . 8
2 Normal and special service conditions . 9
3 Terms and definitions . 9
3.1 General terms . 9
3.2 Assemblies of switchgear and controlgear . 9
3.3 Parts of assemblies . 9
3.4 Switching devices . 9
3.5 Parts of switchgear and controlgear . 11
3.6 Operation . 11
3.7 Characteristic quantities . 11
3.8 Index of definitions . 13
4 Ratings . 14
4.1 Rated voltage (U ) . 14
r
4.2 Rated insulation level . 15
4.3 Rated frequency (f ) . 15
r
4.4 Rated normal current and temperature rise . 15
4.5 Rated short-time withstand current (I ) . 15
k
4.6 Rated peak withstand current (I ) . 15
p
4.7 Rated duration of short-circuit (t ) . 15
k
4.8 Rated supply voltage of closing and opening devices and of auxiliary and
control circuits (U ) . 15
a
4.9 Rated supply frequency of closing and opening devices and of auxiliary
circuits . 15
4.10 Rated pressure of compressed gas supply for controlled pressure systems . 15
4.11 Rated filling levels for insulation and/or operation . 15
4.101 Rated mainly active load-breaking current (I ) . 15
load
4.102 Rated closed-loop breaking current (I and I ). 16

loop pptr
4.103 Rated cable-charging breaking current (I ) . 16
cc
4.104 Rated line-charging breaking current (I ) . 16
lc
4.105 Rated single capacitor bank breaking current for special purpose switches
(I ) . 16
sb
4.106 Rated back-to-back capacitor bank breaking current for special purpose
) . 16
switches (I
bb
4.107 Rated back-to-back capacitor bank inrush making current for special
purpose switches (I ) . 16
in
4.108 Rated earth fault breaking current (I ) . 16
ef1
4.109 Rated cable- and line-charging breaking current under earth fault
conditions (I ) . 17
ef2
4.110 Rated motor breaking current for special purpose switches (I ) . 17
mot
4.111 Rated short-circuit making current (I ) . 17
ma
4.112 Rated breaking and making currents for a general purpose switch . 17
4.113 Ratings for limited purpose switches . 18
4.114 Ratings for special purpose switches . 18
4.115 Ratings for switches backed by fuses . 18

62271-103  IEC:2011 – 3 –
4.116 Type and classes for general purpose, limited purpose and special purpose
switches . 18
5 Design and construction . 19
5.1 Requirements for liquids in switchgear and controlgear . 19
5.2 Requirements for gases in switchgear and controlgear . 19
5.3 Earthing of switchgear and controlgear . 19
5.4 Auxiliary and control equipment . 19
5.5 Dependent power operation . 19
5.6 Stored energy operation . 19
5.7 Independent manual or power operation (independent unlatched operation) . 19
5.8 Operation of releases . 19
5.9 Low- and high-pressure interlocking and monitoring devices . 19
5.10 Nameplates . 19
5.11 Interlocking devices . 21
5.12 Position indication . 21
5.13 Degrees of protection provided by enclosures . 21
5.14 Creepage distances for outdoor insulators . 21
5.15 Gas and vacuum tightness . 21
5.16 Liquid tightness . 21
5.17 Fire hazard (flammability) . 22
5.18 Electromagnetic compatibility (EMC) . 22
5.19 X-ray emission . 22
5.20 Corrosion . 22
5.101 Making and breaking operations . 22
5.102 Requirements for switch-disconnectors . 22
5.103 Mechanical strength. 22
5.104 Securing the position . 22
5.105 Auxiliary contacts for signalling . 22
5.106 No-load transformer breaking . 23
6 Type tests . 23
6.1 General . 23
6.1.1 Grouping of tests . 23
6.1.2 Information for identification of specimens . 24
6.1.3 Information to be included in the type-test reports . 24
6.1.101Reference no-load test . 24
6.2 Dielectric tests . 24
6.3 Radio interference voltage (r.i.v.) test . 24
6.4 Measurement of the resistance of circuits . 24
6.5 Temperature-rise tests . 24
6.6 Short-time withstand current and peak withstand current tests . 24
6.7 Verification of the protection . 25
6.8 Tightness tests . 25
6.9 Electromagnetic compatibility (EMC) tests . 25
6.10 Additional tests on auxiliary and control circuits . 25
6.10.1 General . 25
6.10.2 Functional tests . 25
6.10.3 Electrical continuity of earthed metallic parts test . 25
6.10.4 Verification of the operational characteristics of auxiliary contacts . 25
6.10.5 Environmental tests . 25

– 4 – 62271-103  IEC:2011
6.10.6 Dielectric test . 25
6.11 X-radiation test procedure for vacuum interrupters . 25
6.101 Making and breaking tests . 26
6.101.1 Test duties for general purpose switches . 26
6.101.2 Test duties for limited purpose switches . 28
6.101.3 Test duties for special purpose switches . 28
6.101.4 Arrangement of the switch for tests . 30
6.101.5 Earthing of test circuit and switch . 30
6.101.6 Test parameters . 31
6.101.7 Test circuits . 33
6.101.8 Behaviour of switch during breaking tests . 46
6.101.9 Condition of switch after breaking tests and short-circuit making
tests . 47
6.101.10 Type-test reports . 48
6.102 Mechanical and environmental tests . 49
6.102.1 Miscellaneous provisions for mechanical and environmental tests . 49
6.102.2 Mechanical operation test at ambient air temperature . 51
6.102.3 Low and high temperature tests . 52
6.102.4 Humidity test on auxiliary and control circuits . 52
6.102.5 Operation under severe ice conditions . 58
6.102.6 Tests to verify the proper functioning of the position indicating
device . 58
7 Routine tests . 59
7.101 Mechanical operating tests . 59
8 Guide to the selection of switchgear and controlgear . 60
8.101 General . 60
8.102 Conditions affecting application . 60
8.103 Insulation coordination . 60
8.104 Selection of class of switch . 60
8.104.1 General purpose switch . 60
8.104.2 Limited purpose switch . 61
8.104.3 Special purpose switch . 61
8.105 Tests for special applications . 61
9 Information to be given with inquiries, tenders and orders . 61
9.1 Information to be given with inquiries and orders . 61
9.2 Information to be given with tenders . 62
10 Transport, storage, installation, operation and maintenance . 63
11 Safety . 63
12 Influence of the product on the environment . 63
Annex A (normative) Tolerances on test quantities for type tests . 64
Bibliography . 66

Figure 1 – Three-phase test circuit for mainly active load current switching for test
duty TD . 34
load
Figure 2 – Single-phase test circuit for mainly active load current switching for test
duty TD . 35
load
Figure 3 – Three-phase test circuit for distribution line closed-loop and parallel
transformer current switching test for test duties TD and TD . 37
loop pptr
62271-103  IEC:2011 – 5 –
Figure 4 – Single-phase test circuit for distribution line closed-loop and parallel
transformer current switching test, for test duties TD and TD . 37
loop pptr
Figure 5 – General test circuit for three- and single-phase capacitive switching tests . 42
Figure 6 – Prospective TRV parameter limits for capacitor bank current breaking tests . 44
Figure 7 – Three-phase test circuit for earth fault breaking current tests, for test duty
TD . 45
ef1
Figure 8 – Three-phase test circuit for cable-charging breaking current tests under
earth fault conditions, for test duty TD . 45
ef2
Figure 9 – Three-phase test circuit for short-circuit making current test for test duty
TD . 46
ma
Figure 10 – Single-phase test circuit for short-circuit making current test for test duty
TD . 46
ma
Figure 11 – Test sequences for low and high temperature tests . 53
Figure 12 – Humidity test . 57

Table 1 – Preferred values of rated line- and cable-charging breaking currents for
general purpose switch . 17
Table 2 – Product information . 20
Table 3 – Test duties for general purpose switches – Test duties for three-phase tests
on three-pole operated, switches . 26
Table 4 – Test duties for general purpose switches – Single phase tests on three-pole
switches operated pole-after-pole and single-pole switches applied on three-phase
systems . 27
Table 5 – Test duties for special purpose switches – Three-phase tests on three-pole
operated, switches . 29
Table 6 – Test duties for special purpose switches – Single phase tests on three-pole
switches operated pole-after-pole and single-pole switches applied on three-phase
systems . 29
a
Table 7 – Supply circuit TRV parameters for mainly active load current breaking tests . 36
Table 8 – TRV parameters for distribution line closed loop breaking tests . 38
Table 9 – TRV parameters for parallel power transformer current breaking tests . 39
Table 10 – Prospective recovery voltage parameter limits for capacitor bank current
breaking tests . 43
Table A.1 – Tolerances on test quantities for type tests . 64

– 6 – 62271-103  IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 103: Switches for rated voltages above 1 kV
up to and including 52 kV
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62271-103 has been prepared by subcommittee 17A: High-voltage
switchgear and controlgear, of IEC technical committee 17: Switchgear and controlgear.
This standard cancels and replaces the third edition of IEC 60265-1, published in 1998. It
constitutes a technical revision.
This edition includes the following significant technical changes with respect to
IEC 60265-1:1998:
– the rated voltage of 52 kV is now included;
– the document is aligned with IEC 62271-1 and IEC 62271-100;
– addition of a test procedure for short-circuit making tests;
– introduction of notion of NSDD (non-sustained disruptive discharge) as defined in
IEC 62271-1 and restrikes;
– new classes C1 and C2 for capacitive switching;

62271-103  IEC:2011 – 7 –
– new Annex A defining tolerances.
The text of this standard is based on the following documents:
FDIS Report on voting
17A/961/FDIS 17A/966/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.
This standard is to be read in conjunction with IEC 62271-1:2007, to which it refers and which
is applicable unless otherwise specified in this standard. In order to simplify the indication of
corresponding requirements, the same numbering of clauses and subclauses is used as in
IEC 62271-1. Amendments to these clauses and subclauses are given under the same
references whilst additional subclauses are numbered from 101.
The list of all parts of the IEC 62271 series under the general title, High-voltage switchgear
and controlgear, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability 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.
The contents of the corrigendum of October 2013 have been included in this copy.

– 8 – 62271-103  IEC:2011
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 103: Switches for rated voltages above 1 kV
up to and including 52 kV
1 General
1.1 Scope
This part of IEC 62271 is applicable to three-phase, alternating current switches and switch-
disconnectors for their switching function, having making and breaking current ratings, for
indoor and outdoor installations, for rated voltages above 1 kV up to and including 52 kV and
for rated frequencies from 16 /3 Hz up to and including 60 Hz. This standard is also applicable
to single-pole switches used on three phase systems.
This standard is also applicable to the operating devices of these switches and to their
auxiliary equipment.
Switch-disconnectors are also covered by IEC 62271-102 for their disconnecting function.
Devices that require a dependent manual operation are not covered by this standard.
General principles and provisions of this standard may also be applicable to single pole
switches intended for application in single-phase systems. The requirements for dielectric
tests and making and breaking tests should be in accordance with the requirements of the
specific application.
This standard establishes requirements for general, limited and special purpose switches
used in distribution systems.
It is assumed that opening and closing operations are performed according to the
manufacturer's instructions. A making operation may immediately follow a breaking operation
but a breaking operation should not immediately follow a making operation since the current
to be broken may then exceed the rated breaking current of the switch.
NOTE 1 Except where special clarification is required, the term “switch” is used to refer to all kinds of switches
and switch-disconnectors within the scope of this standard.
NOTE 2 Earthing switches are not covered by this standard. Earthing switches forming an integral part of a switch
are covered by IEC 62271-102.
NOTE 3 This standard is not applicable to switching devices attached as an accessory to a high-voltage fuse
assembly or its mounting and operated by opening and closing the fuse assembly.
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
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 62271-1:2007, High-voltage switchgear and controlgear – Part 1: Common specifications

62271-103  IEC:2011 – 9 –
IEC 62271-100:2008, High-voltage switchgear and controlgear – Part 100: Alternating-current
circuit-breakers
IEC 62271-102:2001, High-voltage switchgear and controlgear – Part 102: Alternating current
disconnectors and earthing switches
IEC 62271-110:2009, High-voltage switchgear and controlgear – Part 110: Inductive load
switching
2 Normal and special service conditions
Clause 2 of IEC 62271-1 is applicable.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-441 and
IEC 62271-1, as well as the following apply.
NOTE 1 Some terms and definitions are recalled hereunder for easier use or for the necessity of some precision
or adaptation for the interpretation of this standard.
NOTE 2 The terms and definitions given below are classified in accordance with IEC 60050-441. The additional
terms and definitions are classified so as to be aligned with the classification used in IEC 60050-441.
3.1 General terms
Subclause 3.1 of IEC 62271-1 is applicable with the following additions.
3.1.101
effectively earthed neutral system
system earthed through a sufficiently low impedance such that for all system conditions the
ratio of the zero-sequence reactance to the positive-sequence reactance (X /X ) is positive
0 1
and less than 3, and the ratio of the zero-sequence resistance to the positive-sequence
reactance (R /X ) is positive and less than 1. Normally such systems are solidly earthed
0 1
(neutral) systems or low impedance earthed (neutral) systems
NOTE For the correct assessment of the earthing conditions not only the physical earthing conditions around the
relevant location but the total system is to be considered.
3.1.102
non-effectively earthed neutral system
system other than effectively earthed neutral system, not meeting the conditions given in
3.1.101. Normally such systems are isolated neutral systems, high impedance earthed
(neutral) systems or resonant earthed (neutral) systems
NOTE For the correct assessment of the earthing conditions not only the physical earthing conditions around the
relevant location but the total system is to be considered.
3.2 Assemblies of switchgear and controlgear
Subclause 3.2 of IEC 62271-1 applies.
3.3 Parts of assemblies
Subclause 3.3 of IEC 62271-1 applies.
3.4 Switching devices
Subclause 3.4 of IEC 62271-1 applies with the following addition.

– 10 – 62271-103  IEC:2011
3.4.101
switch
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 a short-
circuit
[IEC 60050-441:1984, 441-14-10, modified]
3.4.102
switch-disconnector
switch which, in the open position, satisfies the isolating requirements specified for a
disconnector
[IEC 60050-441:1984, 441-14-12]
3.4.103
general purpose switch
switch capable of performing, with currents up to its rated breaking currents, all making and
breaking operations which may normally occur in distribution systems. The switch is also
capable of carrying and making short-circuit currents
3.4.103.1
class E1 general purpose switch
general purpose switch capable of performing a basic electrical endurance of load breaking
currents and short-circuit makings
NOTE This class is typically adequate for applications where infrequent switching operations are performed or
where appropriate inspection and replacement of switching parts is permissible.
3.4.103.2
class E2 general purpose switch
general purpose switch capable of performing a medium electrical endurance of lo ad breaking
currents and short-circuit makings
NOTE This class is typically adequate for applications where infrequent switching operations are performed but
where inspection and replacement of switching parts is not permissible or possible.
3.4.103.3
class E3 general purpose switch
general purpose switch capable of performing a high electrical endurance of load breaking
currents and short-circuit makings
NOTE This class is typically adequate for applications where frequent switching operations are performed and
inspection and replacement of switching parts is not permissible or possible.
3.4.103.4
class M1 switch
switch suitable for applications requiring a mechanical endurance of 1 000 operations
3.4.103.5
class M2 switch
switch suitable for special service applications and for frequent operation having an extended
mechanical endurance of 5 000 operations
3.4.103.6
class C1 switch
switch with capability of capacitive current breaking as demonstrated by specific type tests
(test duties I , I , I and I )
cc lc sb bb
3.4.103.7
class C2 switch
switch with very low probability of restrike during capacitive current breaking as demonstrated
by specific type tests (test duties I , I , I and I )
cc lc sb bb
62271-103  IEC:2011 – 11 –
3.4.104
limited purpose switch
switch which has a rated normal current, a rated short-time withstand current, and one or
more but not all switching capabilities of a general purpose switch
3.4.105
special purpose switch
general purpose switch or limited purpose switch suitable for one or more of the following
applications:
– switching single capacitor banks;
– switching back-to-back capacitor banks;
– switching of closed-loop circuits consisting of large power transformers in parallel;
– switching of motors under steady-state and stalled conditions
3.4.105.1
single capacitor bank switch
special purpose switch intended for switching of a single capacitor bank with charging
currents up to its rated single capacitor bank breaking current
3.4.105.2
back-to-back capacitor bank switch
special purpose switch intended for breaking capacitor bank charging currents with one or
more capacitor banks connected to the supply side of the switch up to its rated back-to-back
capacitor bank breaking current. The switch is capable of making the associated inrush
current up to its rated capacitor bank inrush making current
3.4.105.3
motor switch
special purpose switch intended for switching of motors under steady-state and stalled
conditions
3.4.105.4
parallel power transformer closed-loop switch
special purpose switch intended for switching a closed-loop circuit consisting of large power
transformers in parallel
NOTE The switch is typically applied as a medium voltage tie switch on the transformer secondary circuit such
that the breaking current is high and the transient recovery voltage (TRV) conditions are severe
3.5 Parts of switchgear and controlgear
Subclause 3.5 of IEC 62271-1 applies.
3.6 Operation
Subclause 3.6 of IEC 62271-1 applies.
3.7 Characteristic quantities
Subclause 3.7 of IEC 62271-1 applies with the following addition.
3.7.101
breaking capacity
value of prospective current that a switching device or a fuse is capable of breaking at a
stated voltage under prescribed conditions of use and behaviour
NOTE 1 The voltage to be stated and the conditions to be prescribed are dealt with in the relevant publications.
NOTE 2 For switching devices, the breaking capacity may be termed according to the kind of current included in
the prescribed conditions, e.g. line-charging breaking capacity, cable charging breaking capacity, single capacitor
bank breaking capacity, etc.
– 12 – 62271-103  IEC:2011
[IEC 60050-441:1984, 441-17-08, modified]
3.7.102
mainly active load-breaking capacity
breaking capacity when opening a mainly active load circuit, the power factor of which is at
least 0,75, in which the load can be represented by resistors and reactors in parallel
3.7.103
no-load transformer breaking capacity
breaking capacity when opening a transformer circuit under no-load conditions
3.7.104
closed-loop breaking capacity
breaking capacity when opening a closed-loop distribution line circuit, or a power transformer
in parallel with one or more power transformers, i.e., a circuit in which both sides of the switch
remain energized after breaking
3.7.105
cable-charging breaking capacity
breaking capacity when opening a cable circuit under no-load conditions
3.7.106
line-charging breaking capacity
breaking capacity when opening an overhead line circuit under no-load conditions
3.7.107
single capacitor bank breaking capacity
breaking capacity when opening a single capacitor bank circuit connected to a supply that
does not include another capacitor bank adjacent to the bank being switched
3.7.108
back-to-back capacitor bank breaking capacity
breaking capacity when opening a capacitor bank circuit connected to a supply that includes
one or more capacitor banks adjacent to the bank being switched
3.7.109
back-to-back capacitor bank inrush making current
high-frequency and high-magnitude current occurring when closing a capacitor bank circuit
onto a supply including one or more capacitor banks adjacent to the bank being switched
3.7.110
motor breaking capacity
breaking capacity when opening a motor under steady-state and stalled conditions
3.7.111
earth fault breaking capacity
breaking capacity in the faulty phase of a non-effectively earthed neutral system when
clearing an earth fault on an unloaded cable or overhead line on the load side of the switch
3.7.112
cable- and line-charging breaking capacity under earth fault conditions
breaking capacity in the sound phases of a non-effectively earthed neutral system when
switching off an unloaded cable or overhead line, with an earth fault on the supply side of the
switch
62271-103  IEC:2011 – 13 –
3.7.113
breaking current
current in a pole of a switching device or in a fuse at the instant of initiation of the arc during a
breaking process
[IEC 60050-441:1984, 441-17-07]
3.7.114
(peak) making current
peak value of the first major loop of the current in a pole of a switch during the transient
period following the initiation of current during a making operation
NOTE 1 Peak value may differ from one pole to another and from one operation to another as it depends on the
instant of current initiation relative to the wave of the applied voltage.
NOTE 2 Where, for a three-phase circuit, a single value of (peak) making current is referred to, it is, unless
otherwise stated, the highest value in any phase.
3.
...