EN 62271-109:2006

SLOVENSKI STANDARD
01-november-2007
9LVRNRQDSHWRVWQHVWLNDOQHLQNUPLOQHQDSUDYH±GHO6WLNDOD]]DSRUHGQLPL
NRQGHQ]DWRUMLQDL]PHQLþQLWRN,(&
High-voltage switchgear and controlgear -- Part 109: Alternating-current series capacitor
by-pass switches (IEC 62271-109:2006)
Hochspannungs-Schaltgeräte und -Schaltanlagen -- Teil 109: Wechselstrom-
Überbrückungsschalter für Reihenkondensatoren (IEC 62271-109:2006)
Appareillage a haute tension -- Partie 109: Interrupteurs de contournement pour
condensateurs série a courant alternatif (IEC 62271-109:2006)
Ta slovenski standard je istoveten z: EN 62271-109:2006
ICS:
29.130.10 Visokonapetostne stikalne in High voltage switchgear and
krmilne naprave controlgear
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 62271-109
NORME EUROPÉENNE
December 2006
EUROPÄISCHE NORM
ICS 29.130.10
English version
High-voltage switchgear and controlgear
Part 109: Alternating-current series capacitor by-pass switches
(IEC 62271-109:2006)
Appareillage à haute tension Hochspannungs-Schaltgeräte
Partie 109: Interrupteurs de und -Schaltanlagen
contournement pour condensateurs Teil 109: Wechselstrom-
série à courant alternatif Überbrückungsschalter
(CEI 62271-109:2006) für Reihenkondensatoren
(IEC 62271-109:2006)
This European Standard was approved by CENELEC on 2006-11-01. 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, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

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

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

© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62271-109:2006 E
Foreword
The text of document 17A/759/FDIS, future edition 1 of IEC 62271-109, 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 62271-109 on 2006-11-01.
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) 2007-08-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2009-11-01
This standard should be read in conjunction with EN 62271-100:2001 and EN 60694:1996, to which it
refers and which is 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 60694.
Amendments to these clauses and subclauses are given under the same numbering, whilst additional
subclauses are numbered from 101.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62271-109:2006 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60071-1 NOTE  Harmonized as EN 60071-1:1995 (not modified).
IEC 60071-2 NOTE  Harmonized as EN 60071-2:1997 (not modified).
IEC 61166 NOTE  Harmonized as EN 61166:1993 (not modified).
IEC 62271-200 NOTE  Harmonized as EN 62271-200:2004 (not modified).
IEC 62271-203 NOTE  Harmonized as EN 62271-203:2004 (not modified).
__________
- 3 - EN 62271-109:2006
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

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

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

IEC 60050-151 2001 International Electrotechnical Vocabulary - -
(IEV)
Part 151: Electrical and magnetic devices

IEC 60050-436 1990 International Electrotechnical Vocabulary - -
(IEV)
Chapter 436: Power capacitors
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 60060 Series High-voltage test techniques EN 60060 Series

IEC 60137 2003 Insulated bushings for alternating voltages EN 60137 2003
above 1 000 V
IEC 60143-1 2004 Series capacitors for power systems EN 60143-1 2004
Part 1: General
IEC 60143-2 1994 Series capacitors for power systems EN 60143-2 1994
Part 2: Protective equipment for series
capacitor banks
IEC 60296 2003 Fluids for electrotechnical applications - EN 60296 2004
Unused mineral insulating oils for + corr. September 2004
transformers and switchgear
IEC 60376 2005 Specification of technical grade sulfur EN 60376 2005
hexafluoride (SF ) for use in electrical
equipment
1)
IEC 60427 2000 Synthetic testing of high-voltage alternating EN 60427 2000
current circuit-breakers
IEC 60480 2004 Guidelines for the checking and treatment of EN 60480 2004
sulphur hexafluoride (SF ) taken from
electrical equipment and specification for its
re-use
1)
EN 60427 is superseded by EN 62271-101:2006, which is based on IEC 62271-101:2006.

Publication Year Title EN/HD Year
IEC 60529 1989 Degrees of protection provided by enclosures EN 60529 1991
(IP Code) + corr. May 1993
IEC 60694 1996 Common specifications for high-voltage EN 60694 1996
switchgear and controlgear standards + corr. May 1999

IEC/TS 61634 1995 High-voltage switchgear and controlgear - - -
Use and handling of sulphur hexafluoride
(SF ) in high-voltage switchgear and
controlgear
IEC 62271-100 2001 High-voltage switchgear and controlgear EN 62271-100 2001
Part 100: High-voltage alternating-current
circuit-breakers
IEC 62271-102 2001 High-voltage switchgear and controlgear
+ corr. April 2002 Part 102: Alternating current disconnectors EN 62271-102 2002
+ corr. May 2003 and earthing switches + corr. March 2005

NORME CEI
INTERNATIONALE
IEC
62271-109
INTERNATIONAL
Première édition
STANDARD
First edition
2006-08
Appareillage à haute tension –
Partie 109:
Interrupteurs de contournement pour
condensateurs série à courant alternatif

High-voltage switchgear and controlgear –
Part 109:
Alternating-current series capacitor
by-pass switches
 IEC 2006 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: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
CODE PRIX
XF
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

62271-109  IEC:2006 – 3 –
CONTENTS
FOREWORD.13
1 General .17
1.1 Scope.17
1.2 Normative references .17
2 Normal and special service conditions .19
3 Terms and definitions .19
3.1 General terms.19
3.2 Assemblies .23
3.3 Parts of assemblies .23
3.4 Switching devices .23
3.5 Parts of by-pass switches .27
3.6 Operation .31
3.7 Characteristic quantities .33
3.8 Definitions related to series capacitor banks.43
3.9 Index of definitions .49
4 Ratings.55
4.1 Rated voltage (U ) .55
r
4.2 Rated insulation level.57
4.3 Rated frequency (f ).57
r
4.4 Rated normal current (I ) and temperature rise .57
r
4.5 Rated short-time withstand current (I ) .57
k
4.6 Rated peak withstand current (I ) .57
p
4.7 Rated duration of short circuit (t ).57
k
4.8 Rated supply voltage of closing and opening devices and of auxiliary and
control circuits (U ) .59
a
4.9 Rated supply frequency of closing and opening devices and auxiliary
circuits.59
4.10 Rated pressures of compressed gas supply for insulation, operation and/or
by-passing and insertion.59
4.101 Rated operating sequence .59
4.102 Rated by-pass making current (IBP) .59
4.104 Rated reinsertion voltage (UINS) .61
4.105 Rated time quantities.63
4.106 Number of mechanical operations.63
5 Design and construction .63
5.1 Requirements for liquids in by-pass switches.63
5.2 Requirements for gases in by-pass switches.63
5.3 Earthing of by-pass switches .65
5.4 Auxiliary equipment .65
5.5 Dependent power operation.67
5.6 Stored energy operation .67
5.7 Independent manual operation.67
5.8 Operation of releases .67
5.9 Low- and high-pressure interlocking devices.69
5.10 Nameplates .69

62271-109  IEC:2006 – 5 –
5.11 Interlocking devices.73
5.12 Position indication.73
5.13 Degrees of protection by enclosures.73
5.14 Creepage distances.73
5.15 Gas and vacuum tightness.73
5.16 Liquid tightness.73
5.17 Flammability .73
5.18 Electromagnetic compatibility.75
5.101 Requirements for simultaneity within a pole .75
5.102 General requirement for operation .75
5.103 Pressure limits of fluids for operation.75
5.104 Vent outlets.75
6 Type tests .77
6.1 General .79
6.2 Dielectric tests.79
6.3 Radio interference voltage (r.i.v.) tests .87
6.4 Measurement of the resistance of the main circuit .87
6.5 Temperature-rise tests.87
6.6 Short-time withstand current and peak withstand current tests.89
6.7 Verification of the degree of protection .89
6.8 Tightness tests.89
6.9 Electromagnetic compatibility (EMC) tests .89
6.101 Mechanical and environmental tests .89
6.102 Miscellaneous provisions for by-pass making and insertion tests .111
6.103 Invalid tests.127
6.104 Sequence of the tests .127
6.105 By-pass making current test-duty.129
6.106 Insertion current test-duty.131
6.107 Criteria to pass the test duties .137
7 Routine tests .137
7.1 Dielectric test on the main circuit .137
7.2 Dielectric test on auxiliary and control circuits .139
7.3 Measurement of the resistance of the main circuit .139
7.4 Tightness test.139
7.5 Design and visual checks .139
7.101 Mechanical operating tests .139
8 Guide to the selection of by-pass switches for service .143
9 Information to be given with enquiries, tenders and orders .143
9.101 Information to be given with enquiries and orders .143
9.102 Information to be given with tenders .145
10 Rules for transport, storage, installation, operation and maintenance .149
10.1 Conditions during transport, storage and installation .149
10.2 Installation .149
10.3 Operation .163
10.4 Maintenance.163
11 Safety.163

62271-109  IEC:2006 – 7 –
Annex A (normative) Tolerances on test quantities during type tests.199
Annex B (normative) Records and reports of type tests.207
Annex C (informative) List of symbols and abbreviations used .213
Annex D (informative) Examples of by-pass switch ratings.217
Annex E (informative) By-pass switches used as the primary by-passing devices .231
Annex F (informative) Explanatory note regarding transient recovery voltage during
reinsertion .233

Bibliography.255

Figure 1 – By-pass switch – Opening and closing operations .165
Figure 2 – By-pass switch – Close-open cycle .167
Figure 3 – By-pass switch – Open-close cycle .169
Figure 4 – Test sequences for low and high temperature tests.171
Figure 5 – Static terminal load forces.173
Figure 6 – Directions for static terminal load tests.175
Figure 7 – Reference mechanical travel characteristics (idealized curve) .177
Figure 8 – Reference mechanical travel characteristics (idealized curve) with the
prescribed envelopes centred over the reference curve (±5 %), contact separation in
this example at time t = 20 ms .177
Figure 9 – Reference mechanical travel characteristics (idealized curve) with the
+10
prescribed envelopes fully displaced upward from the reference curve ( %),
contact separation in this example at time t = 20 ms .179
Figure 10 – Reference mechanical travel characteristics (idealized curve) with the
prescribed envelopes fully displaced downward from the reference curve ( %),
−10
contact separation in this example at time t = 20 ms .179
Figure 11 – Equivalent testing set-up for unit testing of by-pass switches with more
than one separate by-pass units .181
Figure 12 – Typical test circuit for the by-pass making current test-duty .183
Figure 13 – Oscillogram obtained from the typical test circuit for the by-pass making
current test-duty .185
Figure 14 – Typical LC test circuit for the insertion current test-duty .187
Figure 15 – Oscillogram obtained from the typical LC test circuit for the insertion
current test-duty .189
Figure 16 – Typical test circuit for the insertion current test-duty (mainly for high rated
insertion current) .191
Figure 17 – Oscillogram obtained from the typical test circuit shown in Figure 16 for
the insertion current test-duty .193
Figure 18 – Typical direct test circuit for the insertion current test-duty.195

62271-109  IEC:2006 – 9 –
Figure 19 – Oscillogram obtained from the typical direct test circuit for the insertion
current test-duty .197
Figure E.1 – Typical components layout for by-pass switches used as the primary by-
passing device.231
Figure F.1 – Typical example of the transient reinsertion voltage across a by-switch
for a low compensation factor scheme (k = 0,2) and for a power swing of 1,8 p.u. .247
Figure F.2 – Typical example of the transient reinsertion voltage across a by-switch
for an high compensation factor scheme (k = 0,5) and for a power swing of 1,8 p.u. .247
Figure F.3 – Comparison of the calculated transient reinsertion voltage examples and
possible testing envelopes for 50 Hz systems .249
Figure F.4 – Comparison of the calculated transient reinsertion voltage examples and
possible testing envelopes for 60 Hz systems .251

Table 1 – Nameplate information .71
Table 2 – Type tests .79
Table 3 – Number of operating sequences .99
Table 4 – Examples of static horizontal and vertical forces for static terminal load test .111
Table 5 – Invalid tests.127
Table 6 – Application of voltage for dielectric test on the main circuit.139
Table A.1 – Tolerances on test quantities for type tests .201
Table D.1 – Typical ratings for a series capacitor bank by-pass switch – Cases 1 to 6.219
Table D.2 – Typical series capacitor bank by-pass switch ratings – Cases 7 to 12 .223
Table D.3 – Typical series capacitor bank by-pass switch ratings – Cases 13 to 18 .227
Table F.1 – Typical examples of transient reinsertion voltages for systems not having
power swing nor emergency overload, I = 1,0 p.u; U = 2,2 p.u.; β = 0,85 and f =
load PL
50 Hz.235
Table F.2 – Typical examples of transient reinsertion voltages for systems not having
power swing but with an emergency overload, I = 1,2 p.u; U = 2,2 p.u.; β = 0,85
load PL
and f = 50 Hz .235
Table F.3 – Typical examples of transient reinsertion voltages for systems not having
power swing but with an emergency overload, I = 1,4 p.u; U = 2,2 p.u.; β = 0,85
load PL
and f = 50 Hz .237
Table F.4 – Typical examples of transient reinsertion voltages for systems not having
power swing but with an emergency overload, I = 1,6 p.u; U = 2,2 p.u.; β = 0,85
load PL
and f = 50 Hz .237
Table F.5 – Typical examples of transient reinsertion voltages for systems having
power swing, I = 1,8 p.u; U = 2,2 p.u.; β = 0,85 and f = 50 Hz .237
load PL
62271-109  IEC:2006 – 11 –
Table F.6 – Typical examples of transient reinsertion voltages for systems having
power swing, I = 2,0 p.u; U = 2,2 p.u.; β = 0,85 and f = 50 Hz .239
load PL
Table F.7 – Typical examples of transient reinsertion voltages for systems having
power swing, I = 2,3 p.u; U = 2,2 p.u.; β = 0,85 and f = 50 Hz .239
load PL
Table F.8 – Typical examples of transient reinsertion voltages for systems having
power swing, I = 2,5 p.u; U = 2,2 p.u.; β = 0,85 and f = 50 Hz .239
load PL
Table F.9 – Typical examples of transient reinsertion voltages for systems not having
power swing nor emergency overload, I = 1,0 p.u; U = 2,2 p.u.; β = 0,85 and f =
load PL
60 Hz.241
Table F.10 – Typical examples of transient reinsertion voltages for systems not having
power swing but with an emergency overload, I = 1,2 p.u; U = 2,2 p.u.; β = 0,85
load PL
and f = 60 Hz .241
Table F.11 – Typical examples of transient reinsertion voltages for systems not having
power swing but with an emergency overload, I = 1,4 p.u; U = 2,2 p.u.; β = 0,85
load PL
and f = 60 Hz .241
Table F.12 – Typical examples of transient reinsertion voltages for systems not having
power swing but with an emergency overload, I = 1,6 p.u; U = 2,2 p.u.; β = 0,85
load PL
and f = 60 Hz .243
Table F.13 – Typical examples of transient reinsertion voltages for systems having
power swing, I = 1,8 p.u; U = 2,2 p.u.; β = 0,85 and f = 60 Hz .243
load PL
Table F.14 – Typical examples of transient reinsertion voltages for systems having
power swing, I = 2,0 p.u; U = 2,2 p.u.; β = 0,85 and f = 50 Hz .243
load PL
Table F.15 – Typical examples of transient reinsertion voltages for systems having
power swing, I = 2,3 p.u; U = 2,2 p.u.; β = 0,85 and f = 60 Hz .245
load PL
Table F.16 – Typical examples of reinsertion recovery voltages for systems having
power swing, I = 2,5 p.u; U = 2,2 p.u.; β = 0,85 and f = 60 Hz .245
load PL
62271-109  IEC:2006 – 13 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 109: Alternating-current series capacitor
by-pass switches
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 62271-109 has been prepared by subcommittee 17A: High-voltage
switchgear and controlgear, of IEC technical committee 17: Switchgear and controlgear.
This standard cancels and replaces IEC/PAS 62271-109 published in 2002. This first edition
constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
17A/759/FDIS 17A/762/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.

62271-109  IEC:2006 – 15 –
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 (2001) and IEC 60694, second
edition, published in 1996, to which it refers and which is 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 60694. Amendments to these clauses
and subclauses are numbered from 101.
The following standards belong to the same IEC 62271 series, under the title High-voltage
switchgear and controlgear:
Part 1: Common specifications
Part 100: High-voltage alternating-current circuit-breakers
Part 101: Synthetic testing
Part 102: Alternating current disconnectors and earthing switches
Part 104: Alternating current switches for rated voltages of 52 kV and above
Part 105: Alternating current switch-fuse combinations
Part 107: Alternating current fused circuit-switchers for rated voltages above 1 kV up to and
including 52 kV
Part 108: High voltage alternating current disconnecting circuit-breakers for rated voltages
of 72,5 kV and above
Part 109: Alternating-current series capacitor by-pass switches
Part 110: Inductive load switching
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.
___________
Some of these parts are still in the process of being developed.

62271-109  IEC:2006 – 17 –
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 109: Alternating-current series capacitor
by-pass switches
1 General
1.1 Scope
This International Standard is applicable to a.c. series capacitor by-pass switches designed
for outdoor installation and for operation at frequencies of 50 Hz and 60 Hz on systems
having voltages above 52 kV.
It is only applicable to by-pass switches for use in three-phase systems.
This standard is also applicable to the operating devices of by-pass switches and to their
auxiliary equipment.
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(151):2001, International Electrotechnical Vocabulary (IEV) – Chapter 151:
Electrical and magnetic devices
IEC 60050(436):1990, International Electrotechnical Vocabulary (IEV) – Chapter 436: Power
capacitors
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 60060 (all parts), High-voltage test techniques
IEC 60137:2003, Insulated bushings for alternating voltages above 1 000 V
IEC 60143-1:2004, Series capacitors for power systems – Part 1: General
IEC 60143-2:1994, Series capacitors for power systems – Part 2: Protective equipment for
series capacitor banks
IEC 60296:2003, Fluids for electrotchnical applications – Unused mineral insulating oils for
transformers and switchgear
62271-109  IEC:2006 – 19 –
IEC 60376:2005, Specification of technical grade sulphur hexafluoride (SF ) for use in
electrical equipment
IEC 60427:2000, Synthetic testing of high-voltage alternating current circuit-breakers
IEC 60480:2004, Guide for the checking and treatment of sulphur hexafluoride (SF ) taken
from electrical equipment and specification for its re-use
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60694:1996, Common specifications for high-voltage switchgear and controlgear
standards
IEC 61634:1995, High-voltage switchgear and controlgear – Use and handling of sulphur
hexafluoride (SF ) in high-voltage switchgear and controlgear
IEC 62271-100:2001, High-voltage switchgear and controlgear – Part 100: High-voltage
alternating current circuit-breakers
IEC 62271-102:2001, High-voltage switchgear and controlgear – Part 102: Alternating current
disconnectors and earthing switches
2 Normal and special service conditions
Clause 2 of IEC 60694 is applicable.
3 Terms and definitions
For the purposes of this document, the terms and definitions of IEC 60050(151),
IEC 60050(436), IEC 60050(441), IEC 60050(604), IEC 60143-1, IEC 60143-2 and IEC 60694
apply. Some of them are recalled here for ease of reference.
Additional definitions are classified so as to be aligned with the classification used in
IEC 60050(441).
3.1 General terms
3.1.101
switchgear and controlgear
[IEV 441-11-01]
3.1.102
outdoor switchgear and controlgear
[IEV 441-11-05]
3.1.103
short-circuit current
[IEV 441-11-07]
3.1.104
ambient air temperature
[IEV 441-11-13]
62271-109  IEC:2006 – 21 –
3.1.105
temperature rise (of a part of a by-pass switch)
difference between the temperature of the part and the ambient air temperature
3.1.106
overvoltage (in a system)
any voltage between one phase and earth or between phases having a peak value or values
exceeding the corresponding peak of the highest voltage for equipment
[IEV 604-03-09, modified]
3.1.107
unit test
test made on a by-passing or insertion unit or group of units at the by-pass making current or
the insertion current, specified for the test on the complete pole of a by-pass switch and at the
appropriate fraction of the applied voltage, or the transient recovery voltage, specified for the
test on the complete pole of the by-pass switch
3.1.108
external insulation
distances in air and the surfaces in contact with open air of solid insulation of the equipment,
which are subject to dielectric stresses and to the effects of atmospheric and other external
conditions such as pollution, humidity, vermin, etc.
[IEV 604-03-02, modified]
3.1.109
internal insulation
internal solid, liquid or gaseous parts of the insulation of equipment, which are protected from
the effects of atmospheric and other external conditions
[IEV 604-03-03]
3.1.110
self-restoring insulation
insulation which completely recovers its insulating properties after a disruptive discharge
[IEV 604-03-04]
3.1.111
non-self restoring insulation
insulation which loses its insulating properties, or does not recover them completely, after a
disruptive discharge
[IEV 604-03-05]
3.1.112
disruptive discharge
phenomenon associated with the failure of insulation under electric stress, in which the
discharge completely bridges the insulation under test, reducing the voltage between the
electrodes to zero or nearly to zero
NOTE 1 This term applies to discharges in solid, liquid and gaseous dielectrics and to combinations of these.
NOTE 2 A disruptive discharge in a solid dielectric produces permanent loss of dielectric strength (non-self-
restoring insulation); in a liquid or gaseous dielectric, the loss may be only temporary (self-restoring insulation).

62271-109  IEC:2006 – 23 –
NOTE 3 The term "sparkover" is used when a disruptive discharge occurs in a gaseous or liquid dielectric. The
term "flashover" is used when a disruptive discharge occurs over the surface of a solid dielectric in a gaseous or
liquid medium. The term "puncture" is used when a disruptive discharge occurs through a solid dielectric.
3.1.113
restrike performance
expected probability of restrike during insertion current test-duty as demonstrated by specified
type test
NOTE Specific numeric probabilities cannot be applied throughout a by-pass switch service life.
3.2 Assemblies
No particular definitions.
3.3 Parts of assemblies
No particular definitions.
3.4 Switching devices
3.4.101
switching device
[IEV 441-14-01]
3.4.102
mechanical switching device
[IEV 441-14-02]
3.4.103
by-pass switch
three-phase switching device used in parallel with a series capacitor and its overvoltage
protector to shunt line current of a specified level for a specified time, or continuously.
By-pass switches may be three-pole or single-pole operated
NOTE 1 Besides by-passing the capacitor, this device normally has the capability to insert the capacitor into a
circuit that carries a specified level of current.
NOTE 2 By-pass switches are normally used in conjunction with a fast by-passing device for example spark-gap
(for special applications without the use of a fast by-passing device, see Annex E).
Examples of series capacitor layouts using a fast by-passing device in parallel with the by-
pass switch (see IEC 60143-1)are shown below:

62271-109  IEC:2006 – 25 –
C
D
G G
S
IEC  1425/06
Single gap
C
D
G
G G
S
IEC  1426/06
Dual gap
C
NLR
D
G G
S
IEC  1427/06
Non-linear resistor with by-pass gap
Key
C series capacitor
D damping circuit
G spark-gap
S by-pass switch
NLR non linear resistor
62271-109  IEC:2006 – 27 –
3.4.104
by-pass switch class M1
by-pass switch with normal mechanical endurance (mechanically type tested for 2 000
operating sequences) not falling into the category of class M2 as defined in 3.4.105
3.4.105
by-pass switch class M2
frequently operated by-pass switch for special service requirements and designed so as to
require only limited maintenance as demonstrated by specific type tests (by-pass switch with
extended mechanical endurance, mechanically type tested for 10 000 operating sequences).
This type of by-pass switch is normally used on multi-segmented capacitors where the control
of the capacitor impedance is
...