IEC 62271-112:2021

IEC 62271-112 ®
Edition 2.0 2021-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
High-voltage switchgear and controlgear –
Part 112: Alternating current high-speed earthing switches for secondary arc
extinction on transmission lines

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IEC 62271-112 ®
Edition 2.0 2021-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
High-voltage switchgear and controlgear –
Part 112: Alternating current high-speed earthing switches for secondary arc
extinction on transmission lines
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.130.10; 29.130.99 ISBN 978-2-8322-5282-6

– 2 – IEC 62271-112:2021 RLV  IEC 2021
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Normal and special service conditions . 8
5 Ratings . 8
6 Design and construction . 11
7 Type tests . 13
8 Routine tests . 17
9 Guide to the selection of HSESs (informative) . 17
10 Information to be given with enquiries, tenders and orders (informative) . 17
10 Rules for transport, storage, installation, operation and maintenance .
11 Transport, storage, installation, operating instructions and maintenance. 17
12 Safety . 18
Annex A (informative) Background information on the use of HSESs . 19
Annex B (informative) Induced current and voltage conditions for other cases . 25
Bibliography . 30

Figure 1 – Explanation of a multi-phase auto-reclosing scheme . 7
Figure 2 – Timing chart of HSES and circuit-breakers . 10
Figure A.1 – Single-line diagram of a power system . 20
Figure A.2 – Timing chart of the HSESs in relation to the transmission line circuit-
breakers . 20
Figure A.3 – Typical timing chart showing the time between fault initiation and a
successful re-close of the transmission line circuit-breakers . 22
Figure B.1 – System condition to explain successive fault . 26
Figure B.2 – Example of waveforms of delayed current zero phenomena . 26
Figure B.3 – Typical test circuit for electromagnetic coupling test-duty of a HSES with
delayed current zero crossings . 28
Figure B.4 – Typical test circuit for electrostatic coupling test-duty of HSES with
delayed current zero crossings . 28

Table 1 – Standardized values of rated induced currents and voltages .
Table 2 – Items to be listed on nameplate of a HSES .
Table 1 – Nameplate information . 12
Table 2 – Standard values of rated induced currents and voltages . 15
Table A.1 – Comparison of earthing switches . 23
Table A.2 – Comparison of a four-legged reactor and HSES . 24
Table B.1 – Preferred values for single-phase earth fault with delayed current zero
phenomena in the presence of a successive fault . 27
Table B.2 – Preferred values for multi-phase earth faults in a double-circuit system . 29
Table B.3 – Preferred values for covering the cases of categories 0 and 1 . 29

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 112: Alternating current high-speed earthing switches
for secondary arc extinction on transmission lines

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes made to
the previous edition IEC 62271-112:2013. A vertical bar appears in the margin wherever a change
has been made. Additions are in green text, deletions are in strikethrough red text.

– 4 – IEC 62271-112:2021 RLV  IEC 2021
IEC 62271-112 has been prepared by subcommittee 17A: Switching devices, of IEC technical
committee 17: High-voltage switchgear and controlgear. It is an International Standard.
This second edition cancels and replaces the first edition published in 2013. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
The document has been updated to the second edition of IEC 62271-1:2017.
The text of this International Standard is based on the following documents:
FDIS Report on voting
17A/1311/FDIS 17A/1314/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
This International Standard should be read in conjunction with IEC 62271-1:2017, 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 62271-1:2017. Amendments 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 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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 112: Alternating current high-speed earthing switches
for secondary arc extinction on transmission lines

1 General
1 Scope
This part of IEC 62271 applies to AC high-speed earthing switches (hereinafter termed HSES)
designed for indoor and outdoor installation and for operation at service frequencies of 50 Hz
and 60 Hz on systems having rated voltages of 550 kV and above.
HSESs described in this document are intended to extinguish the secondary arc remaining after
clearing faults on transmission lines by the circuit-breakers.
For more detailed information on HSESs, refer to Annex A.
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 62271-1:20072017, High-voltage switchgear and controlgear – Part 1: Common
specifications for alternating current switchgear and controlgear
IEC 62271-100:20082021, High-voltage switchgear and controlgear – Part 100: Alternating
current circuit-breakers
IEC 62271-102:20012018, High-voltage switchgear and controlgear – Part 102: Alternating
current disconnectors and earthing switches
IEC 62271-200:2011, High-voltage switchgear and controlgear – Part 200: AC metal-enclosed
switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV
IEC 62271-203:2011, High-voltage switchgear and controlgear – Part 203: Gas-insulated metal-
enclosed switchgear for rated voltages above 52 kV
3 Terms and definitions
For the purposes of this document, the terms and definitions given in Clause 3 of
IEC 62271-1:20112017, as well as the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
– 6 – IEC 62271-112:2021 RLV  IEC 2021
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
Additional terms and definitions are classified so as to be aligned with the classification used
in IEC 60050-441.
3.1 General terms and definitions
3.1.101
secondary arc
arc that remains at the faulted point after interruption of the short-circuit current fed by the
network
Note 1 to entry: This secondary arc is supplied by electrostatic or electromagnetic induction from the adjacent
healthy live phases.
3.1.102
single-phase auto-reclosing scheme
auto-reclosing scheme in which a faulted phase circuit is opened and automatically re-closed
independently from the other phases
3.1.103
multi-phase auto-reclosing scheme
auto-reclosing scheme applied to double circuit overhead lines in which all faulted phase circuits
are opened and re-closed independently provided that at least two different phases remain un-
faulted
Note 1 to entry: An example of multi-phase auto-reclosing scheme is indicated in Figure 1.

Key
1) Up to 4 phases have a fault Closed circuit-breaker

2) Only the faulted phases have been tripped Open circuit-breaker

3) All circuit-breakers at both ends re-closed Re-closed circuit-breaker

Figure 1 – Explanation of a multi-phase auto-reclosing scheme
Note 2 to entry: Other than the scheme described in 3.1.102 and 3.1.103, a three-phase auto-reclosing scheme is
commonly applied. In this scheme, all three phases of one circuit are tripped and re-closed at both ends even if a
fault occurred in one phase. So far high-speed earthing switches are rarely applied with this scheme.
3.1.104
successive fault
additional earth fault that occurs in the adjacent phase circuit(s) during the time interval between
a single-phase earth fault and the opening of the high-speed earthing switch(es)
3.2 Assemblies of switchgear and controlgear
No particular definitions.
– 8 – IEC 62271-112:2021 RLV  IEC 2021
3.3 Parts of assemblies
No particular definitions.
3.4 Switching devices
3.4.101
high-speed earthing switch
HSES
earthing switch that has the capability to:
– make, carry and interrupt the induced current;
– withstand the recovery voltage caused by electromagnetic and/or by electrostatic couplings
prior to circuit re-closure;
– make and carry the rated short-circuit current
Note 1 to entry: The high-speed operation applies normally to both closing and opening.
Note 2 to entry: A high-speed earthing switch is not intended to be used as a maintenance earthing switch.
3.4.103.1102
high-speed earthing switch class M0
high-speed earthing switch having a normal mechanical endurance of 1 000 operation cycles
3.4.103.2
high-speed earthing switch class M1
high-speed earthing switch having an extended mechanical endurance of 2 000 operation
cycles for special requirements
3.5 Parts of switchgear and controlgear
No particular definitions.
3.6 Operational characteristics of switchgear and controlgear
No particular definitions.
3.7 Characteristics quantities
No particular definitions.
24 Normal and special service conditions
Clause 2 of IEC 62271-1:2007 is applicable.
Clause 4 of IEC 62271-1:2017 is applicable.
45 Ratings
5.1 General
Clause 4 of IEC 62271-1:2007 is applicable with the following additions.
Clause 5 of IEC 62271-1:2017 is applicable with the following additions.
NOTE Categories corresponding to the fault modes are explained in Annex B.

4.4 Rated normal current and temperature rise
Subclause 4.4 of IEC 62271-1:2007 is not applicable.
5.5 Rated continuous current (I )
r
Subclause 5.5 of IEC 62271-1:2017 is not applicable.
45.101 Rated short-circuit making current (I )
ma
Subclause 4.101 of IEC 62271-102:2001 is applicable.
Subclause 5.101 of IEC 62271-102:2018 is applicable.
45.102 Rated operating sequence
The rated characteristics of the HSES are referred to the rated operating sequence.
a) C – t – O,
i1
or
b) C – t – O – t – C – t – O
i1 i2 i1
Where
– t is a time that is longer than the time required for secondary arc extinction and for dielectric
i1
recovery of air insulation at the faulted point. t is determined by users considering system
i1
stability. The preferred value of t is 0,15 s;
i1
– t is the intermediate time that is given by the system protection. t includes the closing
i2 i2
time of the circuit-breakers after the HSESs open, the duration of a new line fault and the
break-time of the circuit-breakers. Following this time t , the HSES can be reclosed. The
i2
preferred value of t is 0,5 s.
i2
In this case the HSES shall be able to operate without intentional time delay.
NOTE t and t are set by system control scheme and a HSES itself is to be operated according to its own operating
i1 i2
time.
Figure 2 shows the time chart for the rated operating sequence of C – t – O – t – C – t – O.
i1 i2 i1
– 10 – IEC 62271-112:2021 RLV  IEC 2021

Key
Circuit- Transmission line circuit-breakers that
3 Contact touch of HSESs
breaker interrupt the fault
HSES High-speed earthing switches 4 Energizing of the opening release of the HSESs
1 Energizing of the closing circuit of the 5 Contact separation of HSESs
HSESs
2 Current start in HSESs 6 Arc extinction in HSESs
t , t Times defined in 45.102 7 Fully open position of HSESs
i1 i2
NOTE 1 A common value for the re-closing time of the circuit-breaker is 1 s to guarantee system stability.
NOTE 2 t is normally within the range of 0,15 s to 0,5 s.
i1
NOTE 3 t is normally within the range of 0,5 s to 1 s.
i2
NOTE 4 The operating sequence b) is for system stability requirements to cover cases where another fault occurs
on the same phase.
NOTE 5 The HSES closing time is normally less than 0,2 s.
Figure 2 – Timing chart of HSES and circuit-breakers
4.103 Standard values for interruption
Standard values for HSES are given in Table 1.
Table 1 – Standardized values of rated induced currents and voltages
Rated Electromagnetic coupling Electrostatic coupling
voltage U
r
Rated Rated First TRV Time to first Rated induced Rated induced
induced power peak peak current voltage
current frequency
+10 +10 +10 +10
% % % %
( ) ( ) ( )
recovery -0 -0 -0 -0
+10
( )
( % )
voltage
-0
+10
%
( )
-0
kV A (rms) kV (rms) kV ms A (rms) kV (rms)
550 6 800 240 580 0,6 120 115
800 6 800 240 580 0,6 170 170
1 100 to 6 800 240 580 0,6 230 235
1 200
NOTE 1 For Table 1 the rated induced voltages by electrostatic recovery voltage have a 1-cos wave shape.
NOTE 2 For networks with up to two faults (category 0 and 1 as described in B.2) the corresponding values are
presented in Table B.3.
For networks with delayed current zero crossing occurrence (category 3 as described in B.2),
the corresponding values are presented in Table B.1.
For networks with multi-phase faults (category 4 as described in B.2) the corresponding values
are presented in Table B.2.
56 Design and construction
Clause 5 of IEC 62271-1:2007 is applicable with the following modifications.
Clause 6 of IEC 62271-1:2017 is applicable with the following modifications.
56.5 Dependent power operation
Subclause 5.5 of IEC 62271-1:2007 is not applicable.
Subclause 6.5 of IEC 62271-1:2017 is not applicable.
5.7 Independent manual operation power operation (independent unlatched operation)
Subclause 5.7 of IEC 62271-1:2007 is not applicable.
6.7 Independent unlatched operation (independent manual or power operation)
Subclause 6.7 of IEC 62271-1:2017 is not applicable.
5.106.11 Nameplates
The designation of the equipment is specified as HSES.
Items to be indicated on the nameplate are listed in Table 2 Table 1.
Table 2 – Items to be listed on nameplate of a HSES
Item
Manufacturer
Designation of type
Serial number
Year of manufacture
Rated voltage
Rated lightning impulse withstand voltage
Rated switching impulse withstand voltage
Rated power-frequency withstand voltage
Rated short-time withstand and peak withstand current
Rated duration of short-circuit
Rated filling pressure for insulation and /or operation
Rated supply voltage of auxiliary circuit
Rated frequency
Mechanical endurance class
Mass (including fluid)
Operating sequence
– 12 – IEC 62271-112:2021 RLV  IEC 2021
Table 1 – Nameplate information
Item Abbreviation Unit
Name of manufacturer
Type designation
Serial number
Year of manufacture
Rated voltage U kV
r
Rated lightning impulse withstand voltage U kV
p
Rated switching impulse withstand voltage U kV
s
Rated power-frequency withstand voltage U kV
d
Rated short-time withstand current I kA
k
Rate peak withstand current I kA
p
t
Rated duration of short-circuit s
k
Rated short-circuit making current I kA
ma
Filling pressure for insulation P MPa
re
Filling pressure for operation P MPa
rm
U
Rated supply voltage(s) of auxiliary and control circuits V
a
Specify DC/AC (with rated frequency)
f
Rated frequency Hz
r
Mechanical endurance class M /M
1 2
Electrical endurance class E /E
1 2
Type and mass fluid (liquid or gas) for insulation M kg
f
Mass (including fluid) M kg
Operating sequence C-t -O or
r1
C-t -O-t -C-t -O
r1 r2 r1
(t , t )
r1 r2
Minimum and maximum ambient temperature °C
a
Category (option)
a
Category is to refer to Clause B.2

5.11 Interlocking devices
Subclause 5.11 of IEC 62271-1:2007 is not applicable.
6.12 Locking devices
Subclause 6.12 of IEC 62271-1:2017 is not applicable.
56.101 Anti-pumping device
Anti-pumping device shall be provided for pneumatic and hydraulic operating mechanism.

56.102 Special requirements for HSES
A HSES shall be able to earth transmission lines and re-open to achieve their full voltage
withstand within the dead time of the auto-reclosing duty cycle of the transmission line circuit-
breakers. The dead time is defined by system stability and is normally set around 1 s enabling
dielectric recovery of insulation capability at the fault location. Fast operating capability for both
making and breaking is required.
The HSES shall have a capability to by-pass secondary arc current on the transmission lines.
The HSES shall have a capability to break induced current by electromagnetic and/or
electrostatic coupling on transmission lines with a transient recovery voltage specified in Table
1 Table 2.
The HSES shall have a capability to withstand transient recovery voltage after interruption and
rated power frequency voltage to earth (U /√3) in open position.
r
The HSES shall be single-pole operated, unless otherwise specified.
67 Type tests
7.1 General
Clause 6 of IEC 62271-1:2007 is applicable with the following additions.
Clause 7 of IEC 62271-1:2017 is applicable with the following additions.
The dielectric performance shall be verified for phase-to-earth in the open position only in
accordance with IEC 62271-1:20072017.
6.1.1 Grouping of tests
Subclause 6.1.1 of IEC 62271-1:2007 is not applicable.
67.3 Radio interference voltage (RIV) test
Subclause 6.3 of 62271-1:2007 is applicable.
In case of metal enclosed type, 6.3 of CEI 62271-203:2011 is applicable.
Subclause 7.3 of IEC 62271-1:2017 is applicable for open position only.
6.5 Temperature-rise tests
Subclause 6.5 of IEC62271-1:2007 is not applicable.
7.5 Continuous current tests
Subclause 7.5 of IEC 62271-1:2017 is not applicable.
67.101 Tests to prove the short-circuit making performance
Subclause 6.101 of IEC 62271-102:2001 is applicable.
Subclause 7.101 of IEC 62271-102:2018 is applicable.

– 14 – IEC 62271-112:2021 RLV  IEC 2021
67.102 Operating and mechanical endurance tests
Subclause 6.102 of IEC 62271-102:2001 is applicable.
Subclause 7.102 of IEC 62271-102:2018 is applicable with the following modifications.
The rated operating sequence shall be verified during mechanical operation.
The mechanical operating sequence for class M0 shall be one of the following:
a) A HSES with a specified duty cycle required C – t – O:
i1
– 1 000 C – t – O operations.
i1
b) A HSES with a specified duty cycle C – t – O – t – C – t – O
i1 i2 i1
– 500 C – t – O operations, plus
i1
– 250 C – t – O – t – C – t – O operations.
i1 i2 i1
For class M1, the number of operations shall be twice the sequence specified.
Mechanical travel characteristics shall be recorded and acceptance criteria are referred to
6.101.1.1 of IEC 62271-100:2008 7.102.4.1 of IEC 62271-100:2021 with the modification of the
+0
+20 +10
total tolerance to 20 % (for example % , % or % ).
-0 -10 -20
67.103 Operation under severe ice conditions
Subclause 6.103 of 62271-102:2001 is applicable.
Subclause 7.103 of 62271-102:2018 is applicable.
6.104 Operation at the temperature limits
Subclause 6.104 of 62271-102:2001 is applicable.
7.104 Low- and high-temperature tests
Subclause 7.104 of 62271-102:2018 is applicable.
67.105 Tests to prove the induced current making and breaking performance of HSES
67.105.1 General test conditions
Tests shall be performed in accordance with the standard condition values for HSES specified
in Table 1 Table 2.
Table 2 – Standard values of rated induced currents and voltages
Rated Electromagnetic coupling Electrostatic coupling
voltage U
r
Rated Rated First TRV Time to first Rated induced Rated induced
induced power- peak peak current voltage
current frequency
+10 +10 +10 +10
% % % %
( ) ( ) ( ) ( )
recovery
+10 -0 -0 -0 -0
( % )
voltage
-0
+10
( % )
-0
kV(RMS) A (RMS) kV (RMS) kV(peak) ms A (RMS) kV (RMS)
550 6 800 240 580 0,6 120 115
800 6 800 240 580 0,6 170 170
1 100 / 6 800 240 580 0,6 230 235
1 200
NOTE 1 For Table 2, the rated induced voltages by electrostatic recovery voltage have a “1-cos” wave shape based
on the applied power frequency voltage.
NOTE 2 For networks with up to two faults (categories 0 and 1 as described in Clause B.2), the corresponding
values are presented in Table B.3.
NOTE 3 For networks with delayed current zero crossing occurrence (category 3 as described in Clause B.2), the
corresponding values are presented in Table B.1.
NOTE 4 For networks with multi-phase faults (category 4 as described in Clause B.2), the corresponding values
are presented in Table B.2.
NOTE 5 The prospective TRV wave shape for electromagnetic coupling may be of a triangular or “1-cos” form. The
time to peak is valid for either wave shape type.
Subclause C.6.105 of IEC 62271-102:2001 7.107 of IEC 62271-102:2018 is applicable with the
following additions and modifications.
Number of tests both for electromagnetic and electrostatic coupling:
– 10 times C and O.
Measurement of travel characteristics shall be in accordance with subclause 6.101.1.1 of
IEC 62271-100:2008 7.102.4.1 of IEC 62271-100:2021.
Test circuits are those shown in Figures C.1 and C.2 of IEC 62271-102:2001 Figure 12 and
Figure 13 of IEC 62271-102:2018.
For electrostatic induced current test independent of the rated voltage of the HSES, the test
circuit parameters shall be:
– capacitance value C = 1,56 µF;
– surge impedance: 245 Ω;
– line length 200 km.
NOTE 6 This test condition corresponds to line length 200 km.
The HSES shall preferably be tested at rated frequency; however, for convenience of testing,
tests at 50 Hz cover the requirement for 60 Hz and vice versa.
These tests cover the classes of A and B described in Annex C of IEC 62271-102:2001 5.109
of IEC 62271-102:2018.
– 16 – IEC 62271-112:2021 RLV  IEC 2021
67.105.2 Induced current switching details
Type tests for HSES having a rated induced current making and breaking capability shall include
tests to prove the electromagnetically and/or electrostatically induced current making and
breaking capability under minimum control voltage.
+10
%
The test currents shall be within a tolerance of ( ) of the rated induced currents as shown
-0
in Table 1 Table 2.
For convenience of testing, the control voltage of the HSES can be either the rated or maximum
of the auxiliary supply voltage if the control voltage does not affect the making and breaking
capability of HSES. This condition is considered to be satisfied if the travel characteristics of
+5
that condition are within a range of ( % ) of those obtained with a minimum control voltage.
-5
Induced current making and breaking tests shall be conducted without maintenance.
67.105.3 Arrangement of the HSES before the test
The HSES under test shall be completely mounted on its own support or on a mechanically
equivalent test support. Its operating device shall be operated in the manner prescribed and, in
particular, if it is electrically, hydraulically or pneumatically operated, it shall be operated either
at the minimum supply voltage or at the minimum functional pressure for operation, respectively.
Before commencing making and breaking tests, no-load operations shall be made and details
of the operating characteristics of the HSES, such as travel characteristics, closing time and
opening time, shall be recorded.
If applicable, tests shall be performed at the minimum functional pressure for interruption and
insulation.
67.105.4 Behaviour of the HSES during the test
The HSES shall perform successfully without undue mechanical or electrical distress.
During tests, the HSES shall not
– show signs of distress;
– show harmful interaction with adjacent laboratory equipment;
– exhibit behaviour which could endanger an operator.
Outward emission of gases, flames or metallic particles from the switch during operation is
permitted, if this does not impair the insulation level of the earthing switch or prove to be harmful
to an operator or other person in the vicinity, or prove to be harmful to an operator or other
person in the vicinity.
Should doubt exist after an operation, the testing is to be continued or repeated with indicators
as specified in IEC 62271-200:2011 mounted in the most onerous position likely for personnel
to stand during the operation of the HSES.
67.105.5 Condition after the test
Comparison of mechanical characteristics before and after the test shall be done according to
subclause 6.102 7.102.3.2 of IEC 62271-102:2018.
Subclause C.6.105.9 of IEC 62271-102:2001 7.108.9 of IEC 62271-102:2018 is applicable.

78 Routine tests
Clause 7 of IEC 62271-1:2007 is applicable with the following additions.
Clause 8 of IEC 62271-1:2017 is applicable with the following additions.
For mechanical operating test, refer to subclause 7.101 of IEC 62271-100:2008 8.101 of
IEC 62271-100:2021.
Mechanical travel characteristics shall be recorded and acceptance criteria are referred to
subclause 6.101.1.1 of IEC 62271-100:2008 7.102.4.1 of IEC 62271-100:2021 with the
modification of the tolerance to
+20 +10 +0
20 % (for example % or % or % ).
-0 -10 -20
Timing test of close and open with rated and minimum conditions of auxiliary supply shall be
verified.
89 Guide to the selection of HSESs (informative)
For the selection of HSESs described in Table 1 Table 2 and also in Table B.1 and Table B.2 if
necessary, the following conditions and requirements at site shall should be considered:
– existing fault conditions;
– number of circuits;
– auto-reclosing scheme (single or multi auto-reclosing scheme);
– required operating sequence (the operating sequence is linked to circuit-breaker operating
sequence);
– the operating sequence is linked to circuit-breaker operating sequence;
– consideration on successive faults and other special conditions such as delayed current
zero phenomena during HSES operations;
– required operational performance (mechanical endurance);
– switching requirements (fault making capability making and short-circuit breaking
capability);
– class M1 is mainly for applications where the HSES is operated in special requirement where
frequent lightning strokes occur.
910 Information to be given with enquiries, tenders and orders (informative)
Clause 9 of IEC 62271-1:2007 is applicable.
Clause 10 of IEC 62271-1:2017 is applicable.
10 Rules for Transport, storage, installation, operation and maintenance
Clause 10 of IEC 62271-1:2007 is applicable.
11 Transport, storage, installation, operating instructions and maintenance
Clause 11 of IEC 62271-1:2017 is applicable.

– 18 – IEC 62271-112:2021 RLV  IEC 2021
1112 Safety
Clause 11 of IEC 62271-1:2007 is applicable.
Clause 12 of IEC 62271-1:2017 is applicable.

A.1 General
Single-phase or multi-phase auto-reclosing schemes are generally applied for high-voltage
transmission systems to enhance system reliability. When on an overhead line a fault involving
earth occurs, circuit-breakers located at both ends of the line open to clear the fault. In case of
high-voltage overhead lines (especially for system voltages equal to or higher than 550 kV),
where the conductors are located in the vicinity of each other and transmission systems are
single phase operated, a lower current may can remain at the fault point after interruption of
the short-circuit current. This current is called secondary arc current and is caused by the
electrostatic or electromagnetic coupling with the other adjacent live conductors, and this
secondary arc current is difficult to self-extinguish in a short time. From a system stability point
of view it is preferable to apply auto-reclosing scheme with a reclosing time in the order of 1 s
maximum. To achieve auto-reclosing in due time some means are necessary to extinguish the
secondary arc before re-closing circuit-breakers.
Especially for short distance lines without shunt reactors or for double circuit systems with multi-
phase auto-reclosing scheme, where 4 legged reactors are not suitable, one of the useful and
important means is to apply a special earthing switch for the purpose of secondary arc extinction.
This earthing switch is generally designed for high-speed operation to ensure that the required
switching performance is met and is called high-speed earthing switch (acronym HSES).
The secondary arc extinction performance will be influenced by the recovery voltage and
secondary arc current at the fault location, both of which will be influenced by the following:
– tower configuration, e.g. single or double circuit lines (i.e. several circuits mounted on one
tower), distance between phases and circuits, height of lines above ground level, etc.;
– transposition of the transmission lines (untransposed or transposed);
– occurrence of successive earth faults on the other line.
Therefore, the time duration between the duty cycles is specified by the user.
NOTE This HSES is distinguished from a fast acting earthing switch. Refer to Table A.1.
The operating sequence of a HSES is determined by the time to maintain system stability, high-
speed auto reclosing sequence of the circuit-breaker, dielectric recovery characteristics of fault
point on the transmission line and time coordination with protection relays including the time for
confirming the condition of circuit-breaker and HSES, e.g. open/close condition.
A.2 Typical operating sequence
Figure A.1 shows a single line diagram of a power system. A fault has occurred on one phase
of the transmission line. The circuit-breakers at the both ends of the line open in order to
interrupt the fault current. 0,2 s after completion of the interruption by the circuit-breaker, the
HSESs will close and remain in the closed position for several hundred milliseconds. In this
period secondary arc current shall be extinguished and the insulation re-established. Opening
of the HSESs takes typically 0,1 s after initiation of opening signal to the HSESs. The preceding
interrupting HSES will interrupt electromagnetic induced current and the later interrupting HSES
will interrupt electrostatic induced current. The circuit-breaker will re-close after completion of
the opening operation of the HSESs.

– 20 – IEC 62271-112:2021 RLV  IEC 2021

Key
CB , CB Transmission line circuit-breakers
1 2
HSES , HSES High-speed earthing switches
1 2
Figure A.1 – Single-line diagram of a power system
A typical timing chart of the relationship between the transmission line circuit-breakers that
interrupt the fault and the HSESs is shown in Figure A.2. This figure shows the first O – C
operation of the circuit-breakers and the first C – O operation of the HSESs.

Key
Circuit- Transmission line circuit-breakers 3 Contact touch of HSESs
breaker that interrupt the fault
HSES High-speed earthing switches 4 Energizing of the opening release of the
HSESs
1 Energizing of the closing circuit of the 5 Contact separation of HSESs
HSESs
2 Current start in HSESs 6 Arc extinction in HSESs

Figure A.2 – Timing chart of the HSESs in relation
to the transmission line circuit-breakers

0 100 200 300 400 500 600 700 800 900 1 000
Time
(ms)
First
fault
Circuit
breaker
Protection
relay
4 12
5 6
HSES
Successive
fault occurs
A
in the
B
adjacent
Phase/lines
C
IEC  1899/13
Key
A There may be successive faults. However these successive faults do not affect on the HSESs interruption
since the successive faults on the other phases/ lines will have been cleared by CBs prior to the HSESs
opening.
B Successive fault may affect on HSESs interruption. Common value of break time is up to 100 ms.
C Arcing time may be longer in case delayed current zero phenomena occurs.
1 CB , CB open 9 HSES , HSES arcing time
1 2 1 2
2 Confirmation of CB and CB in open position 10 HSES , HSES open
1 2
1 2
3 Main relay function recovery 11 Confirmation of HSES , HSES in open position
1 2
4 Confirmation of re-close condition 12 Confirmation of CB ,CB re-close condition
1 2
5 HSES , HSES close command 13 CB , CB close command
1 2 1 2
6 HSES , HSES close 14 CB , CB re-close at 1 s
1 2 1 2
7 HSES , HSES open command 15 CB , CB remain open
1 2 1 2
8 HSES , HSES opening time 16 HSES , HSES remain close
1 2 1 2
– 22 – IEC 62271-112:2021 RLV  IEC 2021

Key
A There may be successive faults. However, these successive faults do not affect the HSESs interruption
since the successive faults on the other phases/ lines will have been cleared by CBs prior to the HSESs
opening.
B Successive fault may affect HSESs interruption. Common value of break-time is up to 100 ms.
C Arcing time may be longer in case delayed current zero phenomena occurs.
1 CB , CB open 10 HSES , HSES arcing time
1 2 1 2
2 Confirmation of CB and CB in open position 11 HSES , HSES instant of arc extinction
1 2 1 2
3 Main relay function recovery 12 Confirmation of HSES , HSES in open position
1 2
4 Confirmation of re-close condition 13 Confirmation of CB ,CB re-close condition
1 2
5 HSES , HSES instant of initiation of closing 14 CB , CB close command
1 2 1 2
operation
6 Instant of current flow 15 CB , CB re-close at 1 s
1 2
7 HSES , HSES instant of contact touch 16 CB , CB remain open
1 2 1 2
8 HSES , HSES instant of initiation of opening 17 HSES , HSES remain close
1 2 1 2
operation
9 HSES , HSES opening time
1 2
CB , CB , HSES and HSES are explained in Figure A.1
...