SIST EN 62271-110:2006

High-voltage switchgear and controlgear -- Part 110: Inductive load switching

This International Standard is applicable to a.c. circuit-breakers designed for indoor or outdoor installation, for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 1000 V and applied for inductive current switching with or without additional short-circuit current breaking duties. The standard is applicable to circuit-breakers in accordance with IEC 62271-100 that are used to switch high-voltage motor currents and shunt reactor currents and also to high-voltage contactors used to switch high-voltage motor currents [1] 1. Switching unloaded transformers, i.e. breaking transformer magnetizing current, is not considered in this standard. The reasons for this are as follows: a) due to the non-linearity of the transformer core, it is not possible to correctly model the switching of transformer magnetizing current using linear components in a test laboratory. Tests conducted using an available transformer, such as a test transformer, will only be valid for the transformer tested and cannot be representative for other transformers; b) as detailed in the guide for application of IEC 62271-100 and IEC 60694 (hereafter referred to as the guide [2]), the characteristics of this duty are usually less severe than any other inductive current switching duty. It should be noted that such a duty may produce severe overvoltages within the transformer winding(s) depending on the circuitbreaker re-ignition behaviour and transformer winding resonance frequencies. Short-line faults, out-of-phase current making and breaking and capacitive current switching are not applicable to circuit-breakers applied to switch shunt reactors or motors. These duties are therefore not included in this standard. Subclause 1.1 of IEC 62271-100 is otherwise applicable.

Hochspannungs-Schaltgeräte und -Schaltanlagen -- Teil 110: Schalten induktiver Lasten

Appareillage à haute tension -- Partie 110: Manoeuvre de charges inductives

Applicable aux disjoncteurs à courant alternatif conçus pour une installation à l'intérieur ou à l'extérieur, et pour fonctionner à des fréquences de 50 Hz à 60 Hz, sur des réseaux de tensions supérieures à 1 000 V et prévus pour l'établissement et la coupure de courants inductifs avec ou sans pouvoir de coupure de court-circuit additionnel. Cette norme est applicable aux disjoncteurs selon EN 62271-100 et qui sont utilisés pour l'établissement et la coupure de courants de moteurs à haute tension et de réactances shunt, et aussi aux contacteurs à haute tension utilisés pour l'établissement et la coupure de courants de moteurs à haute tension. La manoeuvre de transformateurs à vide, c'est-à-dire la coupure de courant magnétisant de transformateur, n'est pas prise en compte dans cette norme. Les raisons pour cela sont les suivantes: a) à cause du comportement non linéaire du circuit magnétique du transformateur, il n'est pas possible de modéliser correctement l'établissement et la coupure d'un courant magnétisant en utilisant des composants linéaires dans un laboratoire d'essais. Les essais effectués en utilisant un transformateur à disposition, tel qu'un transformateur d'essais, seront valables seulement pour le transformateur essayé et ne peuvent pas être représentatifs pour d'autres transformateurs; b) ainsi qu'il est détaillé dans le Guide d'application des EN 62271-100 et 60694, les caractéristiques de cette manoeuvre sont habituellement moins sévères que les autres manoeuvres d'établissement et de coupure de courants inductifs. Il convient de noter que cette manoeuvre peut produire des surtensions sévères dans le ou les bobinages d'un transformateur en fonction de la caractéristique de réallumage du disjoncteur et des fréquences de résonances du bobinage du transformateur. L'établissement et la coupure de défaut en ligne, courant de discordance de phases et courants capacitifs ne sont pas applicables aux disjoncteurs pour la manoeuvre de réactances shunt ou de

Visokonapetostne stikalne in krmilne naprave - 110. del: Preklapljanje induktivnega bremena (IEC 62271-110:2005)

General Information

• Status: Withdrawn
• Publication Date: 30-Nov-2006
• Withdrawal Date: 12-May-2009
• ICS: 29.130.10 - High voltage switchgear and controlgear
• Technical Committee: SKA - Switchgear and control gear
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 13-May-2009
• Due Date: 05-Jun-2009
• Completion Date: 13-May-2009
• Ref Project: EN 62271-110:2005 - High-voltage switchgear and controlgear - Part 110: Inductive load switching

Relations

• Replaced By: SIST EN 62271-110:2009 - High-voltage switchgear and controlgear - Part 110: Inductive load switching (IEC 62271-110:2009)
• Effective Date: 13-May-2010
• Replaced By: SIST EN 62271-110:2009 - High-voltage switchgear and controlgear - Part 110: Inductive load switching (IEC 62271-110:2009)
• Effective Date: 29-Jan-2023
• Replaced By: SIST EN 62271-110:2009 - High-voltage switchgear and controlgear - Part 110: Inductive load switching (IEC 62271-110:2009)
• Effective Date: 01-Jul-2009

Standards Content (Sample)

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---------------------- Page: 1 ----------------------

EUROPEAN STANDARD EN 62271-110
NORME EUROPÉENNE
EUROPÄISCHE NORM October 2005

ICS 33.100.10; 33.100.20


English version


High-voltage switchgear and controlgear
Part 110: Inductive load switching
(IEC 62271-110:2005)


Appareillage à haute tension Hochspannungs-Schaltgeräte und
Partie 110: Manoeuvre de charges -Schaltanlagen
inductives Teil 110: Schalten induktiver Lasten
(CEI 62271-110:2005) (IEC 62271-110:2005)





This European Standard was approved by CENELEC on 2005-10-01. 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, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, 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


© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 62271-110:2005 E

---------------------- Page: 2 ----------------------

EN 62271-110:2005 - 2 -
Foreword
The text of document 17A/729/FDIS, future edition 1 of IEC 62271-110, prepared by SC 17A, High-
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 62271-110 on 2005-10-01.
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) 2006-07-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-10-01
This European Standard should be read in conjunction with EN 62271-100:2001 and EN 60694:1996,
to which it refers and which are applicable, unless otherwise specified. In order to simplify the
indication of corresponding requirements, the same numbering of clauses and subclauses is used as
in EN 62271-100 and EN 60694. Additional subclauses are numbered from 101.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62271-110:2005 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60470 NOTE Harmonized as EN 60470:2000 (not modified).
__________

---------------------- Page: 3 ----------------------

- 3 - EN 62271-110:2005
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 Where an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 62271-100 2001 High-voltage switchgear and controlgear EN 62271-100 2001
Part 100: High-voltage alternating-current
circuit-breakers

---------------------- Page: 4 ----------------------

NORME CEI
INTERNATIONALE
IEC



62271-110
INTERNATIONAL


Première édition
STANDARD

First edition

2005-06


Appareillage à haute tension –
Partie 110:
Manœuvre de charges inductives

High-voltage switchgear and controlgear –
Part 110:
Inductive load switching

 IEC 2005 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
CODE PRIX
U
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

---------------------- Page: 5 ----------------------

62271-110  IEC:2005 – 3 –
CONTENTS
FOREWORD.7

1 General .11
1.1 Scope.11
1.2 Normative references .11
2 Normal and special service conditions .13
3 Definitions .13
4 Ratings.13
4.1 Rated voltage (U ) .13
r
4.2 Rated insulation level .13
4.3 Rated frequency (f ) .13
r
4.4 Rated normal current (I ) and temperature rise .13
r
4.5 Rated short-time withstand current (I ) .13
k
4.6 Rated peak withstand current (I ) .13
p
4.7 Rated duration of short-circuit (t ) .13
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 auxiliary circuits .15
4.10 Rated pressure of compressed gas supply for insulation, operation and/or
interruption.15
5 Design and construction .15
6 Type tests .15
6.1 General .15
6.2 Dielectric test .17
6.3 Radio interference voltage (r.i.v.) tests .17
6.4 Measurement of the resistance of the main circuit .17
6.5 Temperature-rise tests .17
6.6 Short-time withstand current and peak withstand current tests .17
6.7 Verification of protection.17
6.8 Tightness tests .17
6.9 Electromagnetic compatibility (EMC) tests.17
6.101 Mechanical and environmental tests .17
6.102 Miscellaneous provisions for making and breaking tests .17
6.103 Test circuits for short-circuit making and breaking tests .19
6.104 Short-circuit test quantities .19
6.105 Short-circuit test procedures .19
6.106 Basic short-circuit test duties .19
6.107 Critical current tests.19
6.108 Single-phase and double-earth fault tests .19
6.114  High-voltage motor current switching tests .19
6.115  Shunt reactor current switching tests.29
7 Routine tests .39
8 Guide to selection of circuit-breakers for service .39

---------------------- Page: 6 ----------------------

62271-110  IEC:2005 – 5 –
9 Information to be given with enquiries, tenders and orders .41
10 Rules for transport, storage, installation, operation and maintenance .41
11 Safety.41

Bibliography.53

Figure 1 – Motor switching test circuit and summary of parameters.43
Figure 2 – Illustration of transient voltages at interruption of inductive current for first
phase clearing in a three-phase non-solidly earthed circuit .45
Figure 3 – Reactor switching test − Basic layout of three-phase test circuit.47
Figure 4 – Reactor switching test − Basic layout of single-phase test circuit .49
Figure 5 – Illustration of transient voltages at interruption of inductive current for a
single-phase test .51

Table 1 – Test duties at motor current switching tests.25
Table 2 – Prospective transient voltage of load circuit including connection to the
circuit-breaker.33
Table 3 – Load circuit 1 test currents .33
Table 4 – Load circuit 2 test currents .35
Table 5 – Test duties for reactor current switching tests .37

---------------------- Page: 7 ----------------------

62271-110  IEC:2005 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 110: Inductive load switching



FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62271-110 has been prepared by subcommittee 17A: High-voltage
switchgear and controlgear, of IEC technical committee 17: Switchgear and controlgear.
This first edition cancels and replaces IEC 61233 TS (1994) and constitutes a technical
revision. The main changes from IEC 61233 are as follows: Sections 1, 2, 3 and 4 have been
retained and revised to conform to IEC 60694 and 62271-100 in terms of numbering and
format. Section 5 and all annexes have been removed and are now included in Cigre
Brochure “CIGRE Guide for application of IEC 60694 and IEC 62271-100”.

---------------------- Page: 8 ----------------------

62271-110  IEC:2005 – 9 –
The text of this standard is based on the following documents:
FDIS Report on voting
17A/729/FDIS 17A/734/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 62271-100, first edition, published in 2001,
and with IEC 60694, second edition, published in 1996, to which it refers and which are
applicable, unless otherwise specified. In order to simplify the indication of corresponding
requirements, the same numbering of clauses and subclauses is used as in IEC 62271-100
and IEC 60694. Additional subclauses are numbered from 101.
The following standards belong to the same IEC 62271 series, under the general title High-
voltage switchgear and controlgear:
Part 102: Alternating current disconnectors and earthing switches
Part 105: Alternating current switch-fuse combinations
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.

---------------------- Page: 9 ----------------------

62271-110  IEC:2005 – 11 –
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 110: Inductive load switching



1 General
1.1 Scope
This International Standard is applicable to a.c. circuit-breakers designed for indoor or
outdoor installation, for operation at frequencies of 50 Hz and 60 Hz on systems having
voltages above 1000 V and applied for inductive current switching with or without additional
short-circuit current breaking duties. The standard is applicable to circuit-breakers in
accordance with IEC 62271-100 that are used to switch high-voltage motor currents and shunt
reactor currents and also to high-voltage contactors used to switch high-voltage motor
1
currents [1] .
Switching unloaded transformers, i.e. breaking transformer magnetizing current, is not
considered in this standard. The reasons for this are as follows:
a) due to the non-linearity of the transformer core, it is not possible to correctly model the
switching of transformer magnetizing current using linear components in a test laboratory.
Tests conducted using an available transformer, such as a test transformer, will only be
valid for the transformer tested and cannot be representative for other transformers;
b) as detailed in the guide for application of IEC 62271-100 and IEC 60694 (hereafter
referred to as the guide [2]), the characteristics of this duty are usually less severe than
any other inductive current switching duty. It should be noted that such a duty may
produce severe overvoltages within the transformer winding(s) depending on the circuit-
breaker re-ignition behaviour and transformer winding resonance frequencies.
Short-line faults, out-of-phase current making and breaking and capacitive current switching
are not applicable to circuit-breakers applied to switch shunt reactors or motors. These duties
are therefore not included in this standard.
Subclause 1.1 of IEC 62271-100 is otherwise applicable.
1.2 Normative references
Subclause 1.2 of IEC 62271-100 is applicable with the following addition:
IEC 62271-100:2001, High-voltage switchgear and controlgear – Part 100: High-voltage
2
alternating-current circuit-breakers
___________
1
Figures in square brackets refer to the bibliography.
2
A consolidated edition is available (2003).

---------------------- Page: 10 ----------------------

62271-110  IEC:2005 – 13 –
2 Normal and special service conditions
Clause 2 of IEC 60694 is applicable.
3 Definitions
For the purposes of this document, the definitions of IEC 60050(441) and IEC 60694 apply.
4 Ratings
Clause 4 of IEC 62271-100 is applicable except for the references to short-line faults, out-of-
phase making and breaking, capacitive current switching and as noted in specific subclauses
below.
4.1 Rated voltage (U )
r
Subclause 4.1 of IEC 60694 is applicable.
4.2 Rated insulation level
Subclause 4.2 of IEC 60694 is applicable with the following addition:
The rated values stated in Tables 1a and 1b and Tables 2a and 2b of IEC 60694 are
applicable with the exception of column (8) in the latter two tables.
NOTE 1 The reason for this exception is the passive nature of the shunt reactor load circuit.
NOTE 2 In some cases (high chopping overvoltage levels, or where a neutral reactor is present or in cases of
shunt reactors with isolated neutral), it may be necessary to specify an appropriate insulation level which is higher
than the rated values given in Tables 1a, 1b, 2a and 2b.
4.3 Rated frequency (f )
r
Subclause 4.3 of IEC 60694 is applicable with the following addition:
The standard values for the rated frequency of high voltage circuit-breakers are 50 Hz and
60 Hz.
4.4 Rated normal current (I ) and temperature rise
r
Subclause 4.4 of IEC 60694 is applicable.
4.5 Rated short-time withstand current (I )
k
Subclause 4.5 of IEC 62271-100 is applicable.
4.6 Rated peak withstand current (I )
p
Subclause 4.6 of IEC 62271-100 is applicable.
4.7 Rated duration of short-circuit (t )
k
Subclause 4.7 of IEC 62271-100 is applicable.

---------------------- Page: 11 ----------------------

62271-110  IEC:2005 – 15 –
4.8 Rated supply voltage of closing and opening devices and of auxiliary and control
circuits (U )
a
Subclause 4.8 of IEC 60694 is applicable.
4.9 Rated supply frequency of closing and opening devices and auxiliary circuits
Subclause 4.9 of IEC 60694 is applicable.
4.10 Rated pressure of compressed gas supply for insulation, operation and/or
interruption
Subclause 4.10 of IEC 60694 is applicable.
4.101 Rated short-circuit breaking current (I )
sc
Subclause 4.101 of IEC 62271-100 is applicable.
4.102 Transient recovery voltage related to the rated short-circuit breaking current
Subclause 4.102 of IEC 62271-100 is applicable.
4.103 Rated short-circuit making current
Subclause 4.103 of IEC 62271-100 is applicable.
4.104 Rated operating sequence
Subclause 4.104 of IEC 62271-100 is applicable.
4.108 Inductive load switching
This standard is applicable thereby replacing IEC 61233.
4.109 Rated time quantities
Subclause 4.109 of IEC 62271-100 is applicable.
4.110 Number of mechanical operations
Subclause 4.110 of IEC 62271-100 is applicable.
5 Design and construction
Clause 5 of IEC 62271-100 is applicable.
6 Type tests
6.1 General
Subclause 6.1 of IEC 62271-100 is applicable with the following addition:
Inductive current switching tests performed for a given current rating and type of application
may be considered valid for another current rating and same type of application as detailed
below:

---------------------- Page: 12 ----------------------

62271-110  IEC:2005 – 17 –
a) for high-voltage shunt reactor switching at rated voltage 52 kV and above, tests at a
particular current rating are to be considered valid for applications up to the tested current
value +20 %;
b) for shunt reactor switching at rated voltage below 52 kV, no type testing is required and
reference should be made to the guide [2];
c) for high-voltage motor switching, no further type testing is considered necessary for
stalled motor currents between 100 A and 300 A or for stalled motor currents between
300 A and the current associated with the short-circuit current of test duty T10 according
to 6.106.1 of IEC 62271-100.
6.2 Dielectric test
Subclause 6.2 of IEC 62271-100 is applicable with the following addition:
Refer to 4.2 of this standard.
6.3 Radio interference voltage (r.i.v.) tests
Subclause 6.3 of IEC 60694 is applicable.
6.4 Measurement of the resistance of the main circuit
Subclause 6.4 of IEC 60694 is applicable.
6.5 Temperature-rise tests
Subclause 6.5 of IEC 60694 is applicable.
6.6 Short-time withstand current and peak withstand current tests
Subclause 6.6 of IEC 60694 is applicable.
6.7 Verification of protection
Subclause 6.7 of IEC 60694 is applicable.
6.8 Tightness tests
Subclause 6.8 of IEC 60694 is applicable.
6.9 Electromagnetic compatibility (EMC) tests
Subclause 6.9 of IEC 60694 is applicable.
6.101 Mechanical and environmental tests
Subclause 6.101 of IEC 62271-100 is applicable.
6.102 Miscellaneous provisions for making and breaking tests
Subclause 6.102 of IEC 62271-100 is applicable with the following addition:

---------------------- Page: 13 ----------------------

62271-110  IEC:2005 – 19 –
High-voltage motor current and shunt reactor switching tests shall be performed at rated
auxiliary and control voltage or, where necessary, at maximum auxiliary and control voltage to
facilitate consistent control of the opening and closing operation according to 6.102.3.1 of
IEC 62271-100 and at rated functional pressure for interruption and insulation. For gas circuit-
breakers shunt reactor switching tests shall also be performed at the minimum functional
pressure for interruption and insulation.
6.103 Test circuits for short-circuit making and breaking tests
Subclause 6.103 of IEC 62271-100 is applicable.
6.104 Short-circuit test quantities
Subclause 6.104 of IEC 62271-100 is applicable.
6.105 Short-circuit test procedures
Subclause 6.105 of IEC 62271-100 is applicable.
6.106 Basic short-circuit test duties
Subclause 6.106 of IEC 62271-100 is applicable.
6.107 Critical current tests
Subclause 6.107 of IEC 62271-100 is applicable.
6.108 Single-phase and double-earth fault tests
Subclause 6.108 of IEC 62271-100 is applicable.
NOTE Subclauses 6.109 to 6.112 of IEC 62271-100 are not applicable to this standard.
6.114 High-voltage motor current switching tests
6.114.1 Applicability
This subclause is applicable to three-phase alternating current circuit-breakers having rated
voltages above 1 kV and up to 17,5 kV, which are used for switching high-voltage motors.
Tests may be carried out at 50 Hz with a relative tolerance of ±10 % or 60 Hz with a relative
tolerance of ±10 %, both frequencies being considered equivalent.
Motor switching tests are applicable to all three-pole circuit-breakers having rated voltages
equal to or less than 17,5 kV, which may be used for the switching of three-phase
asynchronous squirrel-cage or slip-ring motors. The circuit-breaker may be of a higher rated
voltage than the motor when connected to the motor through a stepdown transformer.
However, the more usual application is a direct cable connection between circuit-breaker and
motor. When tests are required, they shall be made in accordance with 6.114.2 to 6.114.9.
No limits to the overvoltages are given as the overvoltages are only relevant to the specific
application. Overvoltages between phases may be as significant as phase-to-earth over-
voltages.

---------------------- Page: 14 ----------------------

62271-110  IEC:2005 – 21 –
6.114.2 General
The switching tests can be either field tests or laboratory tests. As regards overvoltages, the
switching of the current of a starting or stalled motor is usually the more severe operation.
Due to the non-linear behaviour of the motor iron core it is not possible to exactly model the
switching of motor current using linear components in a test station. Tests using linear
components to simulate the motors can be considered to be more conservative than switching
actual motors.
For laboratory tests a standardized circuit simulating the stalled condition of a motor is
specified (refer to Figure 1). The parameters of this test circuit have been chosen to represent
a relatively severe case with respect to overvoltages and will cover the majority of service
applications.
The laboratory tests are performed to prove the ability of a circuit-breaker to switch motors
and to establish its behaviour with respect to switching overvoltages, re-ignitions and current
chopping. These characteristics may serve as a basis for estimates of the circuit-breaker
performance in other motor circuits. Tests performed with the test currents defined in 6.114.3
and 6.114.4 demonstrate the capability of the switching device to switch high-voltage motors
up to its rated interrupting current.
For field tests, actual circuits are used with a supply system on the source side and a cable
and motor on the load side. There may be a transformer between the circuit-breaker and
motor. However, the results of such field tests are only valid for circuit-breakers working in
circuits similar to those during the tests.
The apparatus under test includes the circuit-breaker with overvoltage protection devices if
they are normally fitted.
NOTE 1 Overvoltages may be produced when switching running motors. This condition is not represented by the
substitute circ
...