IEC 62271-104:2020

IEC 62271-104 ®
Edition 3.0 2020-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –
Part 104: Alternating current switches for rated voltages higher than 52 kV

Appareillage à haute tension –
Partie 104: Interrupteurs à courant alternatif pour tensions assignées
supérieures à 52 kV
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IEC 62271-104 ®
Edition 3.0 2020-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –

Part 104: Alternating current switches for rated voltages higher than 52 kV

Appareillage à haute tension –

Partie 104: Interrupteurs à courant alternatif pour tensions assignées

supérieures à 52 kV
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.130.10; 29.130.99 ISBN 978-2-8322-8609-8

– 2 – IEC 62271-104:2020 © IEC 2020
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
3.1 General terms and definitions . 8
3.2 Assemblies . 8
3.3 Parts of assemblies . 9
3.4 Switching devices . 9
3.5 Parts of switches . 10
3.6 Operational characteristics of switches . 10
3.7 Characteristic quantities . 10
4 Normal and special service conditions . 12
5 Ratings . 12
5.1 General . 12
5.2 Rated voltage (U ) . 12
r
5.3 Rated insulation level (U , U , U ) . 12
d p s
5.4 Rated frequency (f ) . 12
r
5.5 Rated continuous current (I ) . 12
r
5.6 Rated short-time withstand current (I ) . 12
k
5.7 Rated peak withstand current (I ) . 13
p
5.8 Rated duration of short-circuit (t ) . 13
k
5.9 Rated supply voltage of auxiliary and control circuits (U ) . 13
a
5.10 Rated supply frequency of auxiliary and control circuits . 13
5.11 Rated pressure of compressed gas supply for controlled pressure systems . 13
5.101 Rated earth fault breaking current . 13
5.102 Rated short-circuit making current . 13
5.103 Rated mainly active load-breaking current . 13
5.104 Rated closed-loop breaking current . 13
5.105 Rated capacitive switching currents . 13
5.106 Inductive load switching . 14
5.107 Rated static mechanical terminal load . 15
5.108 Coordination of rated values for a general purpose switch . 15
5.109 Coordination of rated values for limited purpose and special purpose
switches . 15
6 Design and construction . 16
6.1 Requirements for liquids in high-voltage switches . 16
6.2 Requirements for gases in high-voltage switches . 16
6.3 Earthing of high-voltage switches . 16
6.4 Auxiliary and control equipment and circuits . 16
6.5 Dependent power operation . 16
6.6 Stored energy operation . 16
6.7 Independent unlatched operation (independent manual or power operation) . 16
6.8 Manually operated actuators . 16
6.9 Operation of releases . 16
6.10 Pressure/level indication . 16
6.11 Nameplates. 16

6.12 Locking devices . 17
6.13 Position indication . 18
6.14 Degree of protection provided by enclosures . 18
6.15 Creepage distances for outdoor insulators . 18
6.16 Gas and vacuum tightness . 18
6.17 Tightness for liquid systems . 18
6.18 Fire hazard (flammability) . 18
6.19 Electromagnetic compatibility (EMC) . 18
6.20 X-ray emission . 18
6.21 Corrosion . 18
6.22 Filling levels for insulation, switching and/or operation . 18
6.101 Closing mechanism . 18
6.102 Mechanical strength . 18
6.103 Position of the movable contact system and its indicating or signalling device . 18
7 Type tests . 19
7.1 General . 19
7.2 Dielectric tests . 20
7.3 Radio interference voltage (RIV) tests . 21
7.4 Resistance measurement . 21
7.5 Continuous current tests . 21
7.6 Short-time withstand current and peak withstand current tests . 21
7.7 Verification of the protection . 21
7.8 Tightness tests . 21
7.9 Electromagnetic compatibility tests (EMC) . 21
7.10 Additional tests on auxiliary and control circuits . 21
7.11 X-radiation test for vacuum interrupters . 21
7.101 Mechanical operation tests . 22
7.102 Miscellaneous provision for making and breaking tests . 24
7.103 Test circuits for making and breaking tests . 26
7.104 Test quantities . 36
7.105 Capacitive current tests . 40
7.106 Inductive load switching (test duties TD and TD ) . 43
notr shunt
7.107 Tests for general purpose switches . 43
7.108 Tests for limited purpose switches . 44
7.109 Tests for special purpose switches . 44
7.110 Type test reports . 45
8 Routine tests . 46
8.1 General . 46
8.2 Dielectric tests on the main circuit . 46
8.3 Tests on auxiliary and control circuits . 46
8.4 Measurement of the resistance of the main circuit . 46
8.5 Tightness test . 46
8.6 Design and visual checks . 46
8.101 Mechanical operating tests . 46
9 Guide to the selection of high-voltage switches (informative) . 47
9.1 General . 47
9.2 Selection of rated values . 47
9.3 Cable-interface considerations . 47
9.4 Continuous or temporary overload due to changed service conditions . 47

– 4 – IEC 62271-104:2020 © IEC 2020
9.5 Environmental aspects . 47
9.101 General . 47
9.102 Conditions affecting application . 47
9.103 Insulation coordination . 47
10 Information to be given with enquiries, tenders and orders (informative) . 48
11 Transport, storage, installation, operating instructions and maintenance. 48
12 Safety . 48
13 Influence of the product on the environment . 48
Annex A (normative) Tolerances on test quantities during tests . 49
Bibliography . 52

Figure 1 – Single-phase test circuit for mainly active load current switching for test
duties TD and TD . 27
load1 load2
Figure 2 – Single-phase test circuit for transmission line closed-loop and parallel
transformer current switching test, for test duties TD and TD . 27
loop pptr
Figure 3 – Three-phase test circuit for mainly active load current switching, for test
duties TD and TD . 28
load1 load2
Figure 4 – Supply and load side transient for mainly active load current switching tests
(see Table 4) . 29
Figure 5 – Three-phase test circuit for transmission line closed-loop and parallel
transformer current switching test for test duties TD and TD . 30
loop pptr
Figure 6 – Illustration of the transient associated with transmission line closed-loop
current breaking tests (see Table 5) . 32
Figure 7 – Three-phase test circuit for short circuit making current test
for test duty TD . 35
ma
Figure 8 – Single-phase test circuit for short circuit making current test for test duty
TD . 35
ma
Table 1 – Preferred values of line- and cable-charging breaking currents for a general
purpose switch . 15
Table 2 – Nameplate information . 17
Table 3 – Type tests . 20
Table 4 – Supply circuit TRV parameters for mainly active load current breaking tests . 29
Table 5 – TRV parameters for transmission line closed-loop current breaking tests . 31
Table 6 – Test duties for single-phase tests on three-pole switches having a non-

simultaneity between poles of 0,25 cycle or less . 32
Table 7 – Test duties for single-phase tests on three-pole switches having more than
0,25 cycle non-simultaneity and switches operated pole after pole . 33
Table 8 – TRV parameters for parallel transformer current breaking tests . 34
Table 9 – Test duties for three-phase tests on three-pole switches . 37
Table A.1 – Tolerances on test quantities during type tests (1 of 3) . 49

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 104: Alternating current switches
for rated voltages higher than 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
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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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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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
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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 62271-104 has been prepared by subcommittee 17A: Switching
devices, of IEC technical committee 17: High-voltage switchgear and controlgear.
This third edition replaces and cancels the second edition published in 2015. It constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– new numbering, following IEC 62271-1:2017.

– 6 – IEC 62271-104:2020 © IEC 2020
The text of this document is based on the following documents:
FDIS Report on voting
17A/1273/FDIS 17A/1278/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This standard is to be read in conjunction with IEC 62271-1:2017, IEC 62271-100: ,
IEC 62271-102:2018 and IEC 62271-110:2017. In order to simplify the indication of
corresponding requirements, the same numbering of clauses and subclauses is used as in
IEC 62271-1. Modifications to these clauses and subclauses are given under the same
numbering, whilst additional subclauses are numbered from 101.
A list of all parts in the IEC 62271 series, published 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 document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
___________
Under preparation. Stage at the time of publication: IEC CCDV 62271-100:2020.

HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 104: Alternating current switches
for rated voltages higher than 52 kV

1 Scope
This part of IEC 62271 is applicable to three-pole alternating current switches for rated
voltages higher than 52 kV, having making and breaking current ratings, for indoor and
outdoor installations, and for rated frequencies up to and including 60 Hz.
This document is also applicable to the operating devices of these switches and to their
auxiliary equipment.
NOTE 1 Switches for gas insulated switchgear are covered by this document.
NOTE 2 Switches having a disconnecting function and called switch-disconnectors are also covered by
IEC 62271-102.
NOTE 3 Earthing switches are not covered by this document. Earthing switches forming an integral part of a
switch are covered by IEC 62271-102.
The main object of this document is to establish requirements for switches used in
transmission and distribution systems. General purpose switches for this application are
designed to comply with the following service applications:
– carrying rated continuous current;
– carrying short-circuit currents for a specified time;
– switching of mainly active loads;
– switching of no-load transformers;
– switching of the charging current of unloaded cables, overhead lines or busbars;
– switching of closed-loop circuits;
– making short-circuit currents.
A further object of this document is to establish requirements for limited purpose and special
purpose switches used in transmission and distribution systems.
Limited purpose switches comply with one or more of the service applications indicated above.
Special purpose switches may comply with one or more of the service applications indicated
above and, in addition, are suitable for one or more of the following applications:
– switching single capacitor banks;
– switching back-to-back capacitor banks;
– switching shunt reactors including secondary or tertiary reactors switched from the primary
side of the transformer;
– applications requiring an increased number of operating cycles;
– switching under earth fault conditions in non-effectively earthed neutral systems.

– 8 – IEC 62271-104:2020 © IEC 2020
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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) – Part 441: Switchgear,
controlgear and fuses
IEC 60050-441:1984/AMD1:2000
IEC 60071 (all parts), Insulation co-ordination
IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60270, High-voltage test techniques – Partial discharge measurements
IEC 62271-1:2017, High-voltage switchgear and controlgear – Part 1: Common specifications
for alternating current switchgear and controlgear
IEC 62271-100: , High-voltage switchgear and controlgear – Part 100: Alternating current
circuit-breakers
IEC 62271-101, High-voltage switchgear and controlgear – Part 101: Synthetic testing
IEC 62271-102:2018, High-voltage switchgear and controlgear – Part 102: Alternating current
disconnectors and earthing switches
IEC 62271-110:2017, High-voltage switchgear and controlgear – Part 110: Inductive load
switching
3 Terms and definitions
For the purposes of this document, the terms and definitions given in Clause 3 of IEC 62271-
1:2017, IEC 60050-441 and IEC 60071-1, and the following apply.
NOTE Some definitions of IEC 60050-441 and IEC 60071-1 are recalled here for easier use.
Additional terms and definitions are classified so as to be aligned with the classification used in IEC 60050-441.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 General terms and definitions
Subclause 3.1 of IEC 62271-1:2017 is applicable.
3.2 Assemblies
Subclause 3.2 of IEC 62271-1:2017 is applicable.
___________
Under preparation. Stage at the time of publication: IEC CCDV 62271-100:2020.

3.3 Parts of assemblies
Subclause 3.2 of IEC 62271-1:2017 is applicable.
3.4 Switching devices
Subclause 3.4 of IEC 62271-1:2017 is applicable, with the following additions.
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 short
circuit
[SOURCE: IEC 60050-441:2000, 441-14-10, modified – deletion of the word "mechanical" in
the term and in the definition, and deletion of the note.]
3.4.102
switch-disconnector
switch which, in the open position, satisfies the isolating requirements specified for a
disconnector
[SOURCE: IEC 60050-441:2000, 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; capable of carrying and making short-circuit
currents
Note 1 to entry: Refer to 5.108 for specific ratings of a general purpose switch.
3.4.104
limited purpose switch
switch which complies with one or more, but not with all, service applications of a general
purpose switch
3.4.105
special purpose switch
switch suitable for switching requirements other than those specified for a general purpose
switch
Note 1 to entry: Examples of such requirements are capacitor bank switching, shunt reactor switching, switching
under earth fault conditions, and a capability of an increased number of operating cycles.
3.4.106
class C1 switch
special purpose switch with low probability of restrike during capacitive current breaking as
demonstrated by specific type tests
3.4.107
class C2 switch
special purpose switch with very low probability of restrike during capacitive current breaking
as demonstrated by specific type tests

– 10 – IEC 62271-104:2020 © IEC 2020
3.4.108
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
3.4.109
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 bus or supply side of the switch, up to its rated back-
to-back capacitor bank breaking current
3.4.110
shunt reactor switch
special purpose switch intended for switching a shunt reactor, including secondary or tertiary
reactors switched from the primary side of the transformer
3.5 Parts of switches
Subclause 3.5 of IEC 62271-1:2017 is applicable.
3.6 Operational characteristics of switches
Subclause 3.6 of IEC 62271-1:2017 is applicable.
3.7 Characteristic quantities
Subclause 3.7 of IEC 62271-1:2017 is applicable, with the following additions.
3.7.101
breaking capacity (of a switching device or a fuse)
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 to entry: The voltage to be stated and the conditions to be prescribed are dealt with in the relevant
publications.
Note 2 to entry: 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.
[SOURCE: IEC 60050-441:2000, 441-17-08]
3.7.102
mainly active load breaking capacity
breaking capacity when opening a mainly active load circuit 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 no-load transformer circuit
3.7.104
closed-loop breaking capacity
breaking capacity when opening a closed transmission line loop circuit, or a transformer in
parallel with one or more transformers, i.e. a circuit in which both sides of the switch remain
energized after breaking, and in which the voltage appearing across the terminals is
substantially less than the system voltage

3.7.105
cable-charging breaking capacity
breaking capacity when opening a cable circuit at no load
3.7.106
line-charging breaking capacity
breaking capacity when opening an overhead line circuit at no load
3.7.107
busbar charging breaking capacity
breaking capacity when opening a busbar circuit at no load
3.7.108
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
3.7.109
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
3.7.110
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
Note 1 to entry: The frequency and magnitude of the inrush current depend upon the values of capacitance and
the values of the inductance between the capacitor banks.
3.7.111
shunt reactor breaking capacity
breaking capacity when opening a shunt reactor circuit, including secondary or tertiary
reactors switched from the primary side of the transformer
3.7.112
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
3.7.113
line- and cable-charging breaking capacity under earth fault conditions
breaking capacity in the sound phases of an effectively earthed neutral or non-effectively
earthed neutral system when switching off an overhead line or an unloaded cable, with an
earth fault on the supply side of the switch
3.7.114
breaking current (of a switching device or a fuse)
current in a pole of a switching device or in a fuse at the instant of initiation of the arc during a
breaking process
[SOURCE: IEC 60050-441:2000, 441-17-07]
3.7.115
making current
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

– 12 – IEC 62271-104:2020 © IEC 2020
Note 1 to entry: The 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 to entry: Where, for a polyphase circuit, a single value of (peak) making current is referred to, it is, unless
otherwise stated, the highest value in any phase.
3.7.116
short-circuit making capacity
making capacity for which the prescribed conditions include a short-circuit at the terminals of
the switching device
[SOURCE: IEC 60050-441:2000, 441-17-10]
3.7.117
simultaneity between poles
maximum difference between the instant of contact touch in the first pole and the last pole
when closing and the maximum time difference between the instant of contact separation
between the first pole and the last pole when opening
4 Normal and special service conditions
Clause 4 of IEC 62271-1:2017 is applicable.
5 Ratings
Clause 5 of IEC 62271-1:2017 is applicable with the following additions.
5.1 General
Subclause 5.1 of IEC 62271-1:2017 is applicable.
5.2 Rated voltage (U )
r
Subclause 5.2 of IEC 62271-1:2017 is applicable with the following addition:
The 1 100 kV and 1 200 kV voltage ratings do not apply to switches.
5.3 Rated insulation level (U , U , U )
d p s
Subclause 5.3 of IEC 62271-1:2017 is applicable with the following addition:
The rated insulation levels given in Table 3 of IEC 62271-1:2017 for 1 100 kV and 1 200 kV
voltage ratings do not apply to switches.
5.4 Rated frequency (f )
r
Subclause 5.4 of IEC 62271-1:2017 is applicable.
5.5 Rated continuous current (I )
r
Subclause 5.5 of IEC 62271-1:2017 is applicable.
5.6 Rated short-time withstand current (I )
k
Subclause 5.6 of IEC 62271-1:2017 is applicable.

5.7 Rated peak withstand current (I )
p
Subclause 5.7 of IEC 62271-1:2017 is applicable.
5.8 Rated duration of short-circuit (t )
k
Subclause 5.8 of IEC 62271-1:2017 is applicable.
5.9 Rated supply voltage of auxiliary and control circuits (U )
a
Subclause 5.9 of IEC 62271-1:2017 is applicable.
5.10 Rated supply frequency of auxiliary and control circuits
Subclause 5.10 of IEC 62271-1:2017 is applicable, with the following additions.
5.11 Rated pressure of compressed gas supply for controlled pressure systems
Subclause 5.11 of IEC 62271-1:2017 is applicable.
5.101 Rated earth fault breaking current
The rated earth fault breaking current, for a non-effectively earthed neutral system is the
maximum earth fault current in the faulted phase that the switch shall be capable of breaking
at its rated voltage.
NOTE The TRV (transient recovery voltage) of an isolated neutral system is more severe than the TRV of a
resonant earthed system, even if detuned.
5.102 Rated short-circuit making current
The rated short-circuit making current is the maximum peak prospective current that the
switch shall be capable of making at its rated voltage.
5.103 Rated mainly active load-breaking current
The rated mainly active load-breaking current is the maximum mainly active load current that
the switch shall be capable of breaking at its rated voltage.
5.104 Rated closed-loop breaking current
The rated closed-loop breaking current is the maximum closed-loop current the switch shall
be capable of breaking. Separate ratings for transmission line loop current and parallel
transformer current may be assigned.
5.105 Rated capacitive switching currents
5.105.1 Rated line-charging breaking current
The rated line-charging breaking current is the maximum line-charging current that the switch
shall be capable of breaking at its rated voltage.
5.105.2 Rated cable-charging breaking current
The rated cable-charging breaking current is the maximum cable-charging current that the
switch shall be capable of breaking at its rated voltage.

– 14 – IEC 62271-104:2020 © IEC 2020
5.105.3 Rated single capacitor bank breaking current
The rated capacitor bank breaking current is the maximum capacitor current the switch shall
be capable of breaking at the rated voltage under the conditions of use and behaviour
prescribed in this document. The breaking current refers to the switching of a shunt capacitor
bank where no shunt capacitors are connected to the source side of the switch.
5.105.4 Rated back-to-back capacitor bank breaking current
The rated back-to-back capacitor bank breaking current is the maximum capacitor bank
breaking current that the switch shall be capable of breaking at its rated voltage with one or
more capacitor banks connected on the supply side of the switch adjacent to the bank being
switched, such as to produce the rated capacitor bank inrush making current.
NOTE Similar conditions could apply for switching at substations with cables.
5.105.5 Single capacitor bank inrush making current
No rating or preferred values are defined. This is because inrush currents associated with
single capacitor banks are not considered critical.
5.105.6 Rated back-to-back capacitor bank inrush making current
The rated back-to-back capacitor bank inrush making current is the peak value of the current
that the switch shall be capable of making at its rated voltage and with a frequency of the
inrush current appropriate to the service conditions (see Table 1 of IEC 62271-100:).
The back-to-back capacitor bank making performance is covered when
– the tested peak inrush making current is equal to or greater than the rated value, and
– the tested frequency of the inrush making current is between 3 400 Hz and 6 000 Hz.
5.105.7 Rated and line- and cable-charging breaking current under earth fault
conditions
The rated line- and cable-charging breaking current under earth fault conditions, for a non-
effectively earthed neutral system is the current in the sound phases that the switch shall be
capable of breaking at its rated voltage.
The maximum line- and cable-charging current under fault conditions is √3
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