IEC 62271-203:2022

High-voltage switchgear and controlgear - Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above 52 kV

IEC 62271-203:2022 specifies requirements for gas-insulated metal-enclosed switchgear in which the insulation is obtained, at least partly, by an insulating gas or gas mixture other than air at atmospheric pressure, for alternating current of rated voltages above 52 kV, for indoor and outdoor installation, and for service frequencies up to and including 60 Hz. This third edition cancels and replaces the second edition published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- the document has been aligned with IEC 62271-1:2017;
- beside SF6 also alternative gases have been implemented where needed;
- the terms and definitions have been updated and terms not used have been removed;
- Subclause 6.16 “Gas and vacuum tightness” has been updated;
- Subclause 6.16.3 “Closed pressure systems”: Two classes of gas has been introduced:
- GWP ≤ 1 000
- GWP > 1 000
and the tightness requirements for type tests for gasses with GWP > 1 000 has been reduced from 0,5 % to 0,1 % per year per gas compartment;
- Subclause 6.108 “Interfaces”: Typical maximum pressures in service for interfaces connected to GIS have been defined;
- Subclauses 7.102 through 7.108 have been restructured;
- Subclause 7.107 “Corrosion test on earthing connections” has been updated;
- Subclause 7.108 “Corrosion tests on sealing systems of enclosures and auxiliary equipment” has been updated;
- Annex F ‘Service Continuity’ has been modified and aligned with the recommendations of CIGRE WG B3.51.

Appareillage à haute tension - Partie 203: Appareillage sous enveloppe métallique à isolation gazeuse et à courant alternatif de tensions assignées supérieures à 52 kV

L'IEC 62271-203:2022 spécifie les exigences pour l'appareillage sous enveloppe métallique à isolation gazeuse dont l'isolation est réalisée, au moins partiellement, par un gaz isolant ou un mélange de gaz autre que l'air à la pression atmosphérique, pour courant alternatif de tensions assignées supérieures à 52 kV, pour l'installation à l'intérieur et à l'extérieur, et pour des fréquences de service inférieures ou égales à 60 Hz. Cette troisième édition annule et remplace la deuxième édition parue en 2011. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- le document a été aligné sur l’IEC 62271-1:2017;
- outre le SF6, des gaz alternatifs ont également été mis en œuvre lorsque nécessaire;
- les termes et définitions ont été actualisés et les termes non employés ont été supprimés;
- le paragraphe 6.16 “Étanchéité au gaz et au vide” a été actualisé;
- paragraphe 6.16.3 ‘’Systèmes à pression autonome’’: Deux classes de gaz ont été présentées:
- PRC ≤ 1 000
- PRC > 1 000
et les exigences d'étanchéité relatives aux essais de type pour des gaz avec PRC > 1 000 ont été réduites de 0,5 % à 0,1 % par an et par compartiment de gaz;
- paragraphe 6.108 “Interfaces”: des pressions maximales types en service pour les interfaces reliées au PSEM ont été définies;
- les paragraphes 7.102 à 7.108 ont été restructurés;
- le paragraphe 7.107 “Essai de corrosion sur les connexions de terre” a été actualisé;
- le paragraphe 7.108 ‘’Essais de corrosion sur les systèmes d'étanchéité des enveloppes et des équipements auxiliaires’’ a été actualisé;
- l’Annexe F ‘’Continuité de service’’ a été modifiée et alignée sur les recommandations du groupe de travail B3.51 du CIGRE.

General Information

• Status: Published
• Publication Date: 29-May-2022
• ICS: 29.130.10 - High voltage switchgear and controlgear
• Technical Committee: SC 17C - Assemblies
• Drafting Committee: MT 16 - TC 17/SC 17C/MT 16
• Current Stage: PPUB - Publication issued
• Start Date: 30-May-2022
• Completion Date: 13-May-2022

Relations

• Revises: IEC 62271-203:2011 - High-voltage switchgear and controlgear - Part 203: Gas-insulated metal-enclosed switchgear for rated voltages above 52 kV
• Effective Date: 05-Sep-2023
• Revises: IEC 62271-203:2011/COR1:2013 - Corrigendum 1 - High-voltage switchgear and controlgear - Part 203: Gas-insulated metal-enclosed switchgear for rated voltages above 52 kV
• Effective Date: 05-Sep-2023

Overview

IEC 62271-203:2022 is the international standard for AC gas‑insulated metal‑enclosed switchgear (GIS) for rated voltages above 52 kV. It covers indoor and outdoor GIS for alternating current systems up to 60 Hz, specifying design, construction, testing and operational requirements where insulation is provided partly or wholly by an insulating gas or gas mixture (e.g., SF6 and alternative gases). Edition 3.0 (2022) is a technical revision that replaces the 2011 edition and aligns the document with IEC 62271‑1:2017.

Key topics and technical requirements

• Scope and definitions: Updated terms and removed unused definitions to harmonize with IEC 62271‑1:2017.
• Design & construction: Requirements for gas compartments, enclosures, interfaces and pressure coordination for GIS components.
• Gas and vacuum tightness: Revised Subclause 6.16 and updated criteria for leak tightness and pressure management.
• Closed pressure systems & GWP classes: Two gas classes introduced:
  • GWP ≤ 1 000
  • GWP > 1 000 Tightness requirements for gases with GWP > 1 000 have been tightened for type tests (leakage criteria reduced from 0.5% to 0.1% per year per gas compartment).
• Interfaces & pressures: Typical maximum in‑service pressures for interfaces connected to GIS are defined (Subclause 6.108).
• Type and routine tests: Detailed requirements for dielectric, partial discharge, arcing, corrosion and sealing tests (Subclauses 7.x and 8).
• Corrosion testing: Updated tests for earthing connections and sealing systems (7.107, 7.108).
• Service continuity: Annex F revised and aligned with CIGRE WG B3.51 recommendations for partitioning, maintenance strategies and minimizing outage impact.
• Supporting material: Informative annexes on site testing, pressure-rise calculations, specification checklists and insulation levels up to ultra‑high voltages.

Applications and users

IEC 62271‑203 is used by:

• GIS manufacturers for design verification and type testing.
• Electric utilities and grid operators for procurement specifications and operation of high‑voltage substations.
• Testing laboratories and certification bodies for conformity assessment.
• Consulting engineers and project managers for system integration, maintenance planning and service continuity strategies.
• Environmental and regulatory teams evaluating SF6 alternatives and GWP compliance.

Practical uses include preparing tenders, defining routine and type tests, determining pressure coordination and leak tightness specifications, and ensuring safe installation, transport and maintenance of high‑voltage GIS.

Related standards

• IEC 62271‑1:2017 (general rules for high‑voltage switchgear and controlgear)
• Other parts of the IEC 62271 series for component‑level requirements and testing

Keywords: IEC 62271‑203, gas‑insulated switchgear, GIS, high‑voltage switchgear, SF6 alternatives, GWP, type tests, service continuity.

Standards Content (Sample)

IEC 62271-203 ®
Edition 3.0 2022-05
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
High-voltage switchgear and controlgear –
Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above
52 kV
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IEC 62271-203 ®
Edition 3.0 2022-05
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
High-voltage switchgear and controlgear –
Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above
52 kV
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.130.10 ISBN 978-2-8322-3800-4
– 2 – IEC 62271-203:2022 CMV  IEC 2022
CONTENTS 1
FOREWORD .4
1 General .
1 Scope .7
2 Normative references .7
3 Terms and definitions .9
4 Normal and special service conditions . 12
5 Ratings . 13
6 Design and construction . 16
7 Type tests . 32
8 Routine tests . 49
9 Guide to the selection of switchgear and controlgear (informative) . 51
10 Information to be given with enquiries, tenders and orders (informative) . 52
11 Transport, storage, installation, operation operating instructions and maintenance . 52
12 Safety . 58
13 Influence of the product on the environment . 58
Annex A (normative) Test procedure for dielectric test on three-phase encapsulated
GIS, range II (above 245 kV) . 59
Annex B (normative) Methods for testing gas-insulated metal-enclosed switchgear
under conditions of arcing due to an internal fault . 60
Annex C (informative) Technical and practical considerations of site testing. 63
Annex D (informative) Calculation of pressure rise due to an internal fault . 68
Annex E (informative) Information to be given with enquiries, tenders and orders . 69
Annex F (informative) Service continuity . 75
Annex G (informative) Insulation levels for GIS with rated voltages higher than 800 kV .
Annex G (informative) List of notes concerning certain countries . 94
Bibliography . 95
List of comments .98
Figure 1 – Pressure coordination . 23
Figure 2 – Example of arrangement of enclosures and gas compartments . 29
Figure F.1 – Impact due to the removal of common partition between busbar-
disconnector .
Figure F.2 – Impact of GIS partitioning on service continuity .
Figure F.3 – Single line diagram with gas partitioning scheme .
Figure F.4 – Localisation and isolation .
Figure F.5 – Removal of busbar disconnector in SECTION-1 .
Figure F.6 – Removal of busbar disconnector in SECTION-3 .
Figure F.7 – Extension .
Figure F.8 – On-site dielectric test .
Figure F.1 – MRE1X (e.g. repair of disconnector to busbar) . 88
Figure F.2 – MRE00 (e.g. during visual inspection) . 88
Figure F.3 – MRE01 (e.g. repair of circuit-breaker) . 89

Figure F.4 – MRE11 (e.g. repair of disconnector) . 89
Figure F.5 – MRE11 (e.g. extension of switchgear with a feeder bay). 90
Figure F.6 – MRE13 (e.g. repair of disconnector) . 90
Figure F.7 – MRE2X (e.g. on-site dielectric test of busbar section A) . 91
Figure F.8 – MRE2X (e.g. on-site dielectric test of busbar section 1). 91
Figure F.9 – MRE00 (e.g. repair of circuit-breaker) . 92

Table 1 – Reference table of service conditions relevant to GIS . 13
Table 2 – Rated insulation levels for rated voltages for equipment of range I (245 kV
and below) . 14
Table 3 – Rated insulation levels for rated voltages for equipment of range II (above
245 kV) . 15
Table 4 – Performance criteria . 25
Table 5 – Example of grouping of Type tests . 34
Table 6 – Test voltage for measuring PD intensity . 38
Table 7 – On-site test voltages . 55
Table A.1 – Switching impulse test conditions above 245 kV . 59
Table E.1 – Normal and special service conditions . 69
Table E.2 – Ratings . 70
Table E.3 – Design and construction . 71
Table E.4 – Bus ducts . 72
Table E.5 – Bushing . 72
Table E.6 – Cable connection . 73
Table E.7 – Transformer connection . 73
Table E.8 – Current transformer . 73
Table E.9 – Inductive voltage transformer . 73
Table E.10 – Documentation for enquiries and tenders . 74
Table G.1 – Insulation levels used for GIS with rated voltages higher than 800 kV in
different countries .

– 4 – IEC 62271-203:2022 CMV  IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 203: AC gas-insulated metal-enclosed switchgear
for rated voltages above 52 kV

FOREWORD
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This commented version (CMV) of the official standard IEC 62271-203:2022 edition 3.0
allows the user to identify the changes made to the previous IEC 62271-203:2011 edition
2.0. Furthermore, comments from IEC SC 17C experts are provided to explain the reasons
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A vertical bar appears in the margin wherever a change has been made. Additions are in
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This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.

IEC 62271-203 has been prepared by subcommittee 17C: Assemblies, of IEC technical
committee 17: High-voltage switchgear and controlgear. It is an International Standard.
This third edition cancels and replaces the second edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition: 2
a) the document has been aligned with IEC 62271-1:2017;
b) beside SF also alternative gases have been implemented where needed;
c) the terms and definitions have been updated and terms not used have been removed;
d) Subclause 6.16 “Gas and vacuum tightness” has been updated;
e) Subclause 6.16.3 “Closed pressure systems”: Two classes of gas has been introduced:
1) GWP ≤ 1 000
2) GWP > 1 000
and the tightness requirements for type tests for gasses with GWP > 1 000 has been reduced
from 0,5 % to 0,1 % per year per gas compartment;
f) Subclause 6.108 “Interfaces”: Typical maximum pressures in service for interfaces
connected to GIS have been defined;
g) Subclauses 7.2 through 7.8 have been restructured;
h) Subclause 7.107 “Corrosion test on earthing connections” has been updated;
i) Subclause 7.108 “Corrosion tests on sealing systems of enclosures and auxiliary
equipment” has been updated;
j) Annex F ‘Service Continuity’ has been modified and aligned with the recommendations of
CIGRE WG B3.51.
The text of this International Standard is based on the following documents:
Draft Report on voting
17C/835/FDIS 17C/844/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.

– 6 – IEC 62271-203:2022 CMV  IEC 2022
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HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 203: AC gas-insulated metal-enclosed switchgear
for rated voltages above 52 kV 3

1 General
1 Scope
This part of IEC 62271 specifies requirements for gas-insulated metal-enclosed switchgear in
which the insulation is obtained, at least partly, by an insulating gas or gas mixture 4 other
than air at atmospheric pressure, for alternating current of rated voltages above 52 kV, for
indoor and outdoor installation, and for service frequencies up to and including 60 Hz.
For the purpose of this document, the terms “GIS” and “switchgear” are used for “gas-insulated
metal-enclosed switchgear”.
The gas-insulated metal-enclosed switchgear covered by this document consists of individual
components intended to be directly connected together and able to operate only in this manner.
This document completes and amends, if necessary applicable, the various relevant standards
applying to the individual components constituting GIS.
2 Normative references 5
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 60044-1:1996, Instrument transformers – Part 1: Current transformers
IEC 60044-2:1997, Instrument transformers – Part 2: Inductive voltage transformers
IEC 60068-2-11, Basic environmental testing procedures Environmental testing – Part 2-11:
Tests – Test Ka: Salt mist
IEC 60068-2-17, Basic environmental testing procedures – Part 2-17: Tests – Test Q: Sealing
IEC 60085:2007, Electrical insulation – Thermal evaluation and designation
IEC 60099-4:2014, Surge arresters – Part 4: Metal-oxide surge arresters without gaps for a.c.
systems
IEC 60137:20082017, Insulating Insulated bushings for alternating voltages above 1 000 V
IEC 60141-1, Tests on oil-filled and gas-pressure cables and their accessories – Part 1:
Oil-filled, paper or polypropylene paper laminate insulated, metal-sheathed cables and
accessories for alternating voltages up to and including 400 500 kV
IEC 60270, High-voltage test techniques – Partial discharge measurements

– 8 – IEC 62271-203:2022 CMV  IEC 2022
IEC 60376, Specification of technical grade sulphur hexafluoride (SF ) and complementary
gases to be used in its mixtures for use in electrical equipment
the checking and treatment of sulfur hexafluoride (SF ) taken from
IEC 60480, Guidelines for
electrical equipment and specification for its re-use Specifications for the re-use of sulphur
hexafluoride (SF ) and its mixtures in electrical equipment
IEC 60840, Power cables with extruded insulation and their accessories for rated voltages
above 30 kV (U = 36 kV) up to 150 kV (U = 170 kV) – Test methods and requirements
m m
IEC/TR 61639:1996, Direct connection between power transformers and gas-insulated metal-
enclosed switchgear for rated voltages of 72,5 kV and above
IEC 61869-1, Instrument transformers – Part 1: General requirements
IEC 61869-2, Instrument transformers – Part 2: Additional requirements for current transformers
IEC 61869-3, Instrument transformers – Part 3: Additional requirements for inductive voltage
transformers
IEC 62067, Power cables with extruded insulation and their accessories for rated voltages
above 150 kV (U = 170 kV) up to 500 kV (U = 550 kV) – Test methods and requirements
m m
IEC 62271-1:20072017, High-voltage switchgear and controlgear – Part 1: Common
specifications for alternating current switchgear and controlgear
IEC 62271-4, High-voltage switchgear and controlgear – Part 4: Handling procedures for
sulphur hexafluoride (SF ) and its mixtures
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 62271-209:20072019, High-voltage switchgear and controlgear – Part 209: Cable
connections for gas-insulated metal-enclosed switchgear for rated voltages above 52 kV –
Fluid-filled and extruded insulation cables – Fluid-filled and dry-type cable-terminations
IEC 62271-211:2014, High-voltage switchgear and controlgear – Part 211: Direct connection
between power transformers and gas-insulated metal-enclosed switchgear for rated voltages
above 52 kV
IEC/TR 62271-303, High-voltage switchgear and controlgear – Part 303: Use and handling of
sulphur hexafluoride (SF )
ISO 3231, Paints and varnishes – Determination of resistance to humid atmospheres containing
sulfur dioxide
ISO 22479, Corrosion of metals and alloys – Sulfur dioxide test in a humid atmosphere (fixed
gas method)
3 Terms and definitions 6
For the purposes of this document, the terms and definitions given in IEC 62271-1:2017 and
the following, apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEC Electropedia: available at http://www.electropedia.org/
3.101
metal-enclosed switchgear and controlgear
switchgear and controlgear assemblies with an external metal enclosure intended to be earthed,
and complete except for external connections
[SOURCE: IEC 60050-441:1984, 441-12-04, modified – The note was deleted.]
3.102
gas-insulated metal-enclosed switchgear
metal-enclosed switchgear in which the insulation is obtained, at least partly, by an insulating
gas or gas mixture other than air at atmospheric pressure
Note 1 to entry: This term generally applies to high-voltage switchgear and controlgear.
Note 2 to entry: Three-phase enclosed gas-insulated switchgear applies to switchgear with the three phases
enclosed in a common enclosure.
Note 3 to entry: Single-phase enclosed gas-insulated switchgear applies to switchgear with each phase enclosed
in a single independent enclosure.
[SOURCE: IEC 60050-441:1984, 441-12-05, modified – "or gas mixture” has been added in the
definition, and Note 2 and 3 to entry have been added.]
3.103
gas-insulated switchgear enclosure
part of gas-insulated metal-enclosed switchgear retaining the insulating gas under the
prescribed conditions necessary to maintain safely the highest insulation level, protecting the
equipment against external influences and providing a high degree of protection to personnel
Note 1 to entry: The enclosure can be single-phase or three-phase.
3.104
isolating link 7
part of the conductor which can easily be opened or removed in order to isolate two parts of the
GIS from each other
Note 1 to entry: The open gap is designed to withstand the test voltages across isolating distance according Table 2
and Table 3.
Note 2 to entry: The purpose of an isolating link is to ensure electrical isolation between sections of a GIS e.g.
during maintenance and repair work.
3.105
removable link 8
part of the conductor which can easily be opened or removed in order to isolate separate two
parts of the GIS from each other
Note 1 to entry: The open gap is designed to withstand the phase-to-earth test voltages according to Table 2 and
Table 3.
– 10 – IEC 62271-203:2022 CMV  IEC 2022
Note 2 to entry: The purpose of a removable link is to ensure electrical separation between sections of a GIS, where
the equipment is separated from the rest of the GIS, e.g. in front of voltage transformers, surge arresters, cable
connections and transformer connections during high voltage testing of GIS or testing of the components.
3.106
compartment
part of gas-insulated metal-enclosed switchgear, totally enclosed except for openings
necessary for interconnection and control which is gastight and enclosed
Note 1 to entry: A compartment may can be designated by the main component contained therein, e.g. circuit-
breaker compartment, busbar compartment.
3.107
component
essential part of the main or earthing circuits of gas-insulated metal-enclosed switchgear which
serves a specific function (for example circuit-breaker, disconnector, switch, fuse, instrument
transformer, bushing, busbar, etc.)
3.108
support insulator
internal insulator supporting one or more conductors
3.109
partition
gas tight support insulator of gas-insulated metal-enclosed switchgear separating one
compartment from other compartments two adjacent compartments
3.110
bushing
a device that enables one or several conductors to pass through a partition such as a wall or a
tank, an enclosure and insulate the conductors from it
NOTE The means of attachment (flange or fixing device) to the partition form part of the bushing.
[SOURCE: IEC 60050-471:2007, 471-02-01, modified – “an enclosure” inserted after “pass
through” and “a partition such as a wall or a tank” deleted. Notes 1 and 2 were deleted.]
3.111
main circuit
all the conductive parts of gas-insulated metal-enclosed switchgear included in a circuit which
is intended to transmit electrical energy
[SOURCE: IEC 60050-441:1984, 441-13-02, modified – “gas-insulated metal-enclosed
switchgear” inserted after “parts of” and “an assembly” deleted]
3.112
auxiliary circuit
all the conductive parts of gas-insulated metal-enclosed switchgear included in a circuit (other
than the main circuit) intended to control, measure, signal and regulate
Note 1 to entry: The auxiliary circuits of gas-insulated metal-enclosed switchgear include the control and auxiliary
circuits of the switching devices.
3.113
enclosure design temperature of enclosures
maximum temperature that the enclosures can reach under specified maximum service
conditions
3.114
enclosure design pressure of enclosures
relative pressure used to determine the design of the enclosure
Note 1 to entry: It is at least equal to the maximum pressure in the enclosure at the highest temperature that the
gas used for insulation can reach under specified maximum service conditions.
Note 2 to entry: The transient pressure occurring during and after a breaking operation (e.g. circuit-breaker) is not
to be considered in the determination of the design pressure.
3.115
partition design pressure of partitions
relative pressure across the partition used to determine the design of the partition
Note 1 to entry: It is at least equal to the maximum relative differential pressure across the partition during
maintenance activities.
Note 2 to entry: The transient pressure occurring during and after a breaking operation (e.g. circuit-breaker) is not
to be considered in the determination of the design pressure.
3.116
operating pressure
relative pressure chosen for the opening operation of pressure relief
devices
3.117
routine test pressure
relative pressure to which all enclosures and partitions are
subjected after manufacturing
3.118
type test pressure
relative pressure to which enclosures and partitions are subjected
for type test
3.119
fragmentation
damage to enclosure due to pressure rise with projection of solid material
NOTE The term “no fragmentation of the enclosure” is interpreted as follows:
– no explosion of the compartment;
– no solid parts flying off from the compartment.
Exceptions are:
– parts of the pressure relief device, if their ejection is directed;
– glowing particles and molten material resulting from burn-through of the enclosure. 9
3.120
disruptive discharge
phenomena 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 almost zero
3.120
service period
time until a maintenance, including opening of the gas compartments, is required

– 12 – IEC 62271-203:2022 CMV  IEC 2022
3.121
transport unit
part of gas-insulated metal-enclosed switchgear suitable for shipment without being dismantled
3.122
functional unit 10
part of metal-enclosed switchgear and controlgear comprising all the components of the main
circuits and auxiliary circuits that contribute to the fulfilment of a single function
Note 1 to entry: Functional units can be distinguished according to the function for which they are intended, for
example complete single-phase or three-phase bay or functional parts of a bay like complete circuit-breaker,
disconnector, earthing switch, voltage transformer, current transformer, operating mechanism, enclosure, etc.
[SOURCE: IEC 60050-441:1984, 441-13-04, modified – In the definition, “metal-enclosed”
inserted after “part of” and “an assembly of” deleted. In the note the examples have been
exchanged with examples relevant for GIS.]
4 Normal and special service conditions
Clause 2 of IEC 62271-1 is applicable with the following additions:
At any altitude the dielectric characteristics of the internal insulation are identical with those
measured at sea-level. For this internal insulation, therefore, no specific requirements
concerning the altitude are applicable.
Some items of a GIS such as pressure relief devices and pressure and density monitoring
devices may be affected by altitude. The manufacturer shall take appropriate measures if
necessary. 11
4.1 Normal service conditions
Subclause 4.1 of IEC 62271-1:2017 is applicable, taking into account the recommended values
presented in Table 1 of this document.
4.2 Special service conditions
Subclause 4.2 of IEC 62271-1:2017 is applicable, taking into account the recommended values
presented in Table 1 of this document.
In the cases where higher than (>) is used in Table 1, the values shall be specified by the user
as described in IEC 62271-1:2017.

4.101 General
Table 1 – Reference table of service conditions relevant to GIS
Normal Special
Item
Indoor Outdoor Indoor Outdoor
Ambient air temperature:
Minimum (°C) –5 or –25 –25 or –40 –25 –50
Maximum (°C) +40 +40 +50 +50
Not applicable 1 000 Not applicable >1 000
Solar radiation (W/m )
Altitude (m) 1 000 1 000 >1 000 >1 000
a
Not applicable c c, d or e d or e
Site pollution severity
Ice coating (mm) Not applicable 1, 10 or 20 Not applicable >20
Wind (m/s) Not applicable 34 Not applicable >34
Average humidity over 24 h (%) 95 100 98 100
Condensation or precipitation Occasional Yes Yes Yes
Vibration class Not applicable Not applicable IEC 62271-207 IEC 62271-207
IEC/TR 62271- IEC/TR 62271-
300 300
Abnormal vibrations, shock or tilting Not applicable Not applicable Applicable Applicable
NOTE The user’s specification may can use any combination of normal or special service conditions above.
a 1
Site pollution severity c, d or e according to IEC TS 60815-1:2008, 8.3 [5]

At any altitude the dielectric characteristics of the internal insulation are identical with those
measured at sea-level. For this internal insulation no specific requirements concerning the
altitude are applicable.
Some items of a GIS such as pressure relief devices and pressure and density monitoring
devices can be affected by altitude. The manufacturer shall take appropriate measures if
necessary. 12
5 Ratings
5.1 General
Subclause 5.1 of IEC 62271-1:2017 is applicable with the following modifications:
e) rated short-time withstand current (I ) (for main and earthing circuits);
k
f) rated peak withstand current (I ) (for main and earthing circuits);
p
and with the following addition:
lk) rated values of the components forming part of gas-insulated metal-enclosed switchgear,
including their operating devices and auxiliary equipment.
5.2 Rated voltage (U )
r
Subclause 5.2 of IEC 62271-1:2017 is applicable with the following addition:
___________
Numbers in square brackets refer to the Bibliography.

– 14 – IEC 62271-203:2022 CMV  IEC 2022
NOTE Components forming part of the GIS may can have individual values of rated voltage for
equipment in accordance with the relevant standards.
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:
Tables 1, 2, 3 and 4 in Subclause 5.3 of IEC 62271-1:2017 are replaced with Table 2 and
Table 3 below.
For rated voltages above 800 kV, see Annex G.
NOTE 1 The higher values for GIS in IEC 62271-203 compared to the values in IEC 62271-1 were introduced with
revision 1 in 2003. They have now been established as standard values.
The GIS comprises components having a definite insulation level. Although internal faults can
largely be avoided by the choice of a suitable insulation level, measures to limit external
overvoltages (e.g. surge arresters,) should be considered.
NOTE 1 According to CIGRE studies the natural ratio between the withstand voltages under standard tests, for SF gas
insulation is U / U = 0,45 and U / U = 0,75. The values U shown in Table 3 are calculated with these factors. 13
d p s p d
NOTE 2 Regarding the external parts of bushings (if any), see to IEC 60137:2017.
NOTE 3 The waveforms are standardized lightning impulse and switching impulse shapes, pending the results of
studies on the ability of this equipment to withstand other types of impulses.
NOTE 4 The choice between alternative insulation levels for a particular rated voltage for equipment should can be
based on insulation coordination studies, taking into account also the self-generated transient overvoltages due
to switching.
Table 2 – Rated insulation levels for rated voltages
for equipment of range I (245 kV and below)
Rated short-duration power-frequency Rated lightning impulse
withstand voltage
withstand voltage
U U
d p
Rated voltage for
equipment kV (RMS value) kV (peak value)
U
r
Phase-to-earth, Phase-to-earth,
across open Across across open Across
kV (RMS value)
switching device the isolating switching device the isolating
and between distance and between distance
phases phases
(1) (2) (3) (4) (5)
72,5 140 160 325 375
100 185 210 450 520
123 230 265 550 630
145 275 315 650 750
170 325 375 750 860
245 460 530 1 050 1 200
NOTE Values in column (2) are applicable:
a) for type tests, phase-to-earth and between phases;
b) for routine tests, phase-to-earth, phase-to-phase, and across the open switching device.
Values in columns (3), (4) and (5) are applicable for type tests only.

Table 3 – Rated insulation levels for rated voltages for equipment of range II
(above 245 kV)
Rated short-duration Rated lightning
Rated switching impulse
power-frequency impulse
withstand voltage
withstand voltage withstand voltage
U
s
U U
d p
Rated
kV (peak value)
voltage for
kV (RMS value) kV (peak value)
equipment
Phase-to- Across Phase-to- Between Across Phase-to- Across open
U
r
earth and open earth and phases isolating earth and switching
between switching across (Notes 3 distance between device
kV (RMS
phases device open and 4) (Notes 1, 2 phases and/or
value)
(Notes 3 and/or switching and 3) (Note 5) isolating
and 5) isolating device distance
distance (Note 5) (Notes 2
(Note 3) and 3)
(1) (2) (3) (4) (5) (6) (7) (8)
300 460 595 850 1 275 700 ([phone] (+170)
362 520 675 950 1 425 800 ([phone] (+205)
420 650 815 1 050 1 575 900 ([phone] (+240)
550 710 925 1 175 1 760 900 ([phone] (+315)
800 960 1 270 1 425 2 420 1 100 ([phone] (+455)
1 100 1 550 2 635 1 550 +(900) 2 250 2 250 + (630)
1 100
1 100 14
1 100
1 800 2 880 1 675 +(900) 2 400 2 400 + (630)
+(635)
1 200 1 800 2 970 2 400 2 400 + (685)
1 200 1 200 1 675 +(980)
1 200
1 950 3 120 2 550 2 550 + (685)
+(695)
NOTE 1 Column (6) is also applicable to some circuit-breakers, see IEC 62271-100:2021.
2 / 3
NOTE 2 In column (6), values in brackets are the peak values of the power-frequency voltage U applied
r
to the opposite terminal (combined voltage).
In column (8), values in brackets are the peak values of the power-frequency voltage 0,7 U 2 / 3 applied to
r
the opposite terminal (combined voltage).
NOTE 3 Values in column (2) are applicable:
a) for type tests, phase-to-earth and between phases;
b) for routine tests, phase-to-earth, phase-to-phase, and across the open switching device.
Values in columns (3), (4), (5), (6), (7) and (8) are applicable for type tests only.
NOTE 4 These values are derived using the multiplying factors stated in Table 3 of IEC 60071-1:20062019 [4].
NOTE 5 For earthing switches only phase-to-earth tests according column (2), (4) and (7) are applicable.

5.4 Rated frequency (f )
r
Subclause 5.4 of IEC 62271-1:2017 is applicable.
4.4 Rated normal current and temperature rise
5.5 Rated normal continuous current (I )
r
Subclause 5.5 of IEC 62271-1:2017 is applicable with the following addition:

– 16 – IEC 62271-203:2022 CMV  IEC 2022
Some main circuits of GIS (e.g. busbars, feeder circuits, etc.) may can have different values of
rated normal continuous current. However, these values should also be selected from R10
series.
4.4.2 Temperature rise
Subclause 4.4.2 of IEC 62271-1 is applicable with the following addition:
The temperature rise of components contained in the GIS which are subject to standards not
covered by the scope of IEC 62271-1 shall not exceed the temperature-rise limits permitted in
the relevant standard for those components.
NOTE When applying a temperature rise equal to or higher than 65 K for parts of the enclosure not accessible to
the operator, every precaution should be taken to ensure that no damage is caused to the surrounding insulating
materials.
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 with the following addition.
NOTE In principle, the rated short-time withstand current and the rated peak withstand current of a main circuit
cannot exceed the corresponding rated values of the weakest of its series connected components.
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 closing and opening devices and of auxiliary and control
circuits (U )
a
Subclause 5.9 of IEC 62271-1:2017 is applicable.
5.10 Rated supply frequency of closing and opening devices and of auxiliary and
control circuits
Subclause 5.10 of IEC 62271-1:2017 is applicable.
5.11 Rated pressure of compressed gas supply for controlled pressure systems
Subclause 5.11 of IEC 62271-1:2017 is applicable.
4.11 Rated filling levels for insulation and/or operation
Subclause 4.11 of IEC 62271-1 is applicable.
6 Design and construction
GIS shall be designed so that normal service, inspection and maintenance operations, earthing
of connected cables, locating of cable faults, voltage tests on connected cables or other
apparatus and the elimination of dangerous electrostatic charges, can be carried out safely,
including the checking of phase sequence after installation and extension.

The design of the equipment shall be such that the agreed permitted movement of foundations
and mechanical or thermal effects do not impair the assigned performance of the equipment.
All components of the same rating and construction which may need to be replaced shall be
interchangeable.
The various components contained within the enclosure are subject to their relevant standards
except where modified by this standard. 15
6.1 Requirements for liquids in switchgear and controlgear
Subclause 6.1 of IEC 62271-1:2017 is not applicable.
6.2 Requirements for gases in switchgear and controlgear
Subclause 6.2 of IEC 62271-1:2017 is applicable with the following addition.
Recommendation for dew-point measurements and adequate corrections shall be supplied by
the manufacturer. Refer to E.4
6.3 Earthing of switchgear and controlgear
Subclause 6.3 of IEC 62271-1:2017 is applicable.
6.3.101 Earthing of the main circuit
To ensure safety during maintenance work, all parts of the main circuit to which access is
required or provided shall be capable of being earthed.
Earthing may can be made by:
a) earthing switches with a making capacity equal to the rated peak withstand current, if there
is still a possibility that the circuit connected is live energised;
b) earthing switches without a making capacity or with a making capacity lower than the rated
peak withstand current, if there is certainty that the circuit connected is not live energised.
Furthermore, it shall be possible, after opening the enclosure, to connect removable
earthing devices for the duration of the work on a circuit element previously earthed via
an earthing switch. The removable earthing device shall have the relevant short-circuit
withstand capability and/or induced current withstand capability.
The earthing circuit may can be degraded after being subjected to the rated short-circuit current.
After such event, earthing circuit may can need to be replaced.
6.3.102 Earthing of the enclosure
The enclosures shall be connected to earth. All metal parts which do not belong to a main or
an auxiliary circuit shall be earthed. For the interconnection of enclosures, frames, etc.,
fastening (e.g. bo
...

IEC 62271-203 ®
Edition 3.0 2022-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –
Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above
52 kV
Appareillage à haute tension –
Partie 203: Appareillage sous enveloppe métallique à isolation gazeuse et à
courant alternatif de tensions assignées supérieures à 52 kV

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IEC 62271-203 ®
Edition 3.0 2022-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –
Part 203: AC gas-insulated metal-enclosed switchgear for rated voltages above
52 kV
Appareillage à haute tension –
Partie 203: Appareillage sous enveloppe métallique à isolation gazeuse et à
courant alternatif de tensions assignées supérieures à 52 kV
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.130.10 ISBN 978-2-8322-3799-1
– 2 – IEC 62271-203:2022  IEC 2022
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Normal and special service conditions . 10
5 Ratings . 11
6 Design and construction . 14
7 Type tests . 27
8 Routine tests . 41
9 Guide to the selection of switchgear and controlgear (informative) . 44
10 Information to be given with enquiries, tenders and orders (informative) . 44
11 Transport, storage, installation, operating instructions and maintenance. 44
12 Safety . 50
13 Influence of the product on the environment . 51
Annex A (normative) Test procedure for dielectric test on three-phase encapsulated
GIS, range II (above 245 kV) . 52
Annex B (normative) Methods for testing gas-insulated metal-enclosed switchgear
under conditions of arcing due to an internal fault . 53
Annex C (informative) Technical and practical considerations of site testing . 56
Annex D (informative) Calculation of pressure rise due to an internal fault . 61
Annex E (informative) Information to be given with enquiries, tenders and orders . 62
Annex F (informative) Service continuity . 68
Annex G (informative) List of notes concerning certain countries . 76
Bibliography . 77

Figure 1 – Pressure coordination . 19
Figure 2 – Example of arrangement of enclosures and gas compartments . 24
Figure F.1 – MRE1X (e.g. repair of disconnector to busbar) . 71
Figure F.2 – MRE00 (e.g. during visual inspection) . 71
Figure F.3 – MRE01 (e.g. repair of circuit-breaker) . 72
Figure F.4 – MRE11 (e.g. repair of disconnector) . 72
Figure F.5 – MRE11 (e.g. extension of switchgear with a feeder bay) . 73
Figure F.6 – MRE13 (e.g. repair of disconnector) . 73
Figure F.7 – MRE2X (e.g. on-site dielectric test of busbar section A) . 74
Figure F.8 – MRE2X (e.g. on-site dielectric test of busbar section 1) . 74
Figure F.9 – MRE00 (e.g. repair of circuit-breaker) . 75

Table 1 – Reference table of service conditions relevant to GIS . 11
Table 2 – Rated insulation levels for rated voltages for equipment of range I (245 kV
and below) . 12
Table 3 – Rated insulation levels for rated voltages for equipment of range II (above
245 kV) . 13

Table 4 – Performance criteria . 20
Table 5 – Type tests . 28
Table 6 – Test voltage for measuring PD intensity . 31
Table 7 – On-site test voltages . 48
Table A.1 – Switching impulse test conditions above 245 kV . 52
Table E.1 – Normal and special service conditions . 62
Table E.2 – Ratings . 63
Table E.3 – Design and construction . 64
Table E.4 – Bus ducts . 65
Table E.5 – Bushing. 65
Table E.6 – Cable connection . 66
Table E.7 – Transformer connection . 66
Table E.8 – Current transformer . 66
Table E.9 – Inductive voltage transformer . 66
Table E.10 – Documentation for enquiries and tenders . 67

– 4 – IEC 62271-203:2022  IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 203: AC gas-insulated metal-enclosed switchgear
for rated voltages above 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
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6) All users should ensure that they have the latest edition of this publication.
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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.
IEC 62271-203 has been prepared by subcommittee 17C: Assemblies, of IEC technical
committee 17: High-voltage switchgear and controlgear. It is an International Standard.
This third edition cancels and replaces the second edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the document has been aligned with IEC 62271-1:2017;
b) beside SF also alternative gases have been implemented where needed;
c) the terms and definitions have been updated and terms not used have been removed;
d) Subclause 6.16 “Gas and vacuum tightness” has been updated;

e) Subclause 6.16.3 “Closed pressure systems”: Two classes of gas has been introduced:
1) GWP ≤ 1 000
2) GWP > 1 000
and the tightness requirements for type tests for gasses with GWP > 1 000 has been reduced
from 0,5 % to 0,1 % per year per gas compartment;
f) Subclause 6.108 “Interfaces”: Typical maximum pressures in service for interfaces
connected to GIS have been defined;
g) Subclauses 7.2 through 7.8 have been restructured;
h) Subclause 7.107 “Corrosion test on earthing connections” has been updated;
i) Subclause 7.108 “Corrosion tests on sealing systems of enclosures and auxiliary
equipment” has been updated;
j) Annex F ‘Service Continuity’ has been modified and aligned with the recommendations of
CIGRE WG B3.51.
The text of this International Standard is based on the following documents:
Draft Report on voting
17C/835/FDIS 17C/844/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.
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.
– 6 – IEC 62271-203:2022  IEC 2022
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 203: AC gas-insulated metal-enclosed switchgear
for rated voltages above 52 kV

1 Scope
This part of IEC 62271 specifies requirements for gas-insulated metal-enclosed switchgear in
which the insulation is obtained, at least partly, by an insulating gas or gas mixture other than
air at atmospheric pressure, for alternating current of rated voltages above 52 kV, for indoor
and outdoor installation, and for service frequencies up to and including 60 Hz.
For the purpose of this document, the terms “GIS” and “switchgear” are used for “gas-insulated
metal-enclosed switchgear”.
The gas-insulated metal-enclosed switchgear covered by this document consists of individual
components intended to be directly connected together and able to operate only in this manner.
This document completes and amends, if applicable, the various relevant standards applying to
the individual components constituting GIS.
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 60068-2-11, Environmental testing – Part 2-11: Tests – Test Ka: Salt mist
IEC 60068-2-17, Basic environmental testing procedures – Part 2-17: Tests – Test Q: Sealing
IEC 60085:2007, Electrical insulation – Thermal evaluation and designation
IEC 60099-4:2014, Surge arresters – Part 4: Metal-oxide surge arresters without gaps for a.c.
systems
IEC 60137:2017, Insulated bushings for alternating voltages above 1 000 V
IEC 60141-1, Tests on oil-filled and gas-pressure cables and their accessories – Part 1:
Oil-filled, paper or polypropylene paper laminate insulated, metal-sheathed cables and
accessories for alternating voltages up to and including 500 kV
IEC 60270, High-voltage test techniques – Partial discharge measurements
IEC 60376, Specification of technical grade sulphur hexafluoride (SF ) and complementary
gases to be used in its mixtures for use in electrical equipment
IEC 60480, Specifications for the re-use of sulphur hexafluoride (SF ) and its mixtures in
electrical equipment
IEC 60840, Power cables with extruded insulation and their accessories for rated voltages
above 30 kV (U = 36 kV) up to 150 kV (U = 170 kV) – Test methods and requirements
m m
IEC 61869-1, Instrument transformers – Part 1: General requirements
IEC 61869-2, Instrument transformers – Part 2: Additional requirements for current transformers
IEC 61869-3, Instrument transformers – Part 3: Additional requirements for inductive voltage
transformers
IEC 62067, Power cables with extruded insulation and their accessories for rated voltages
above 150 kV (U = 170 kV) up to 500 kV (U = 550 kV) – Test methods and requirements
m m
IEC 62271-1:2017, High-voltage switchgear and controlgear – Part 1: Common specifications
for alternating current switchgear and controlgear
IEC 62271-4, High-voltage switchgear and controlgear – Part 4: Handling procedures for
sulphur hexafluoride (SF ) and its mixtures
IEC 62271-100:2021, High-voltage switchgear and controlgear – Part 100: Alternating current
circuit-breakers
IEC 62271-102:2018, High-voltage switchgear and controlgear – Part 102: Alternating current
disconnectors and earthing switches
IEC 62271-209:2019, High-voltage switchgear and controlgear – Part 209: Cable connections
for gas-insulated metal-enclosed switchgear for rated voltages above 52 kV – Fluid-filled and
extruded insulation cables – Fluid-filled and dry-type cable-terminations
IEC 62271-211:2014, High-voltage switchgear and controlgear – Part 211: Direct connection
between power transformers and gas-insulated metal-enclosed switchgear for rated voltages
above 52 kV
ISO 22479, Corrosion of metals and alloys – Sulfur dioxide test in a humid atmosphere (fixed
gas method)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62271-1:2017 and
the following, apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEC Electropedia: available at http://www.electropedia.org/
3.101
metal-enclosed switchgear and controlgear
switchgear and controlgear assemblies with an external metal enclosure intended to be earthed,
and complete except for external connections
[SOURCE: IEC 60050-441:1984, 441-12-04, modified – The note was deleted.]

– 8 – IEC 62271-203:2022  IEC 2022
3.102
gas-insulated metal-enclosed switchgear
metal-enclosed switchgear in which the insulation is obtained, at least partly, by an insulating
gas or gas mixture other than air at atmospheric pressure
Note 1 to entry: This term generally applies to high-voltage switchgear and controlgear.
Note 2 to entry: Three-phase enclosed gas-insulated switchgear applies to switchgear with the three phases
enclosed in a common enclosure.
Note 3 to entry: Single-phase enclosed gas-insulated switchgear applies to switchgear with each phase enclosed
in a single independent enclosure.
[SOURCE: IEC 60050-441:1984, 441-12-05, modified – "or gas mixture” has been added in the
definition, and Note 2 and 3 to entry have been added.]
3.103
gas-insulated switchgear enclosure
part of gas-insulated metal-enclosed switchgear retaining the insulating gas under the
prescribed conditions necessary to maintain safely the highest insulation level, protecting the
equipment against external influences and providing a high degree of protection to personnel
Note 1 to entry: The enclosure can be single-phase or three-phase.
3.104
isolating link
part of the conductor which can easily be opened or removed in order to isolate two parts of the
GIS from each other
Note 1 to entry: The open gap is designed to withstand the test voltages across isolating distance according Table 2
and Table 3.
Note 2 to entry: The purpose of an isolating link is to ensure electrical isolation between sections of a GIS e.g.
during maintenance and repair work.
3.105
removable link
part of the conductor which can easily be opened or removed in order to separate two parts of
the GIS from each other
Note 1 to entry: The open gap is designed to withstand the phase-to-earth test voltages according to Table 2 and
Table 3.
Note 2 to entry: The purpose of a removable link is to ensure electrical separation between sections of a GIS, where
the equipment is separated from the rest of the GIS, e.g. in front of voltage transformers, surge arresters, cable
connections and transformer connections during high voltage testing of GIS or testing of the components.
3.106
compartment
part of gas-insulated metal-enclosed switchgear, which is gastight and enclosed
Note 1 to entry: A compartment can be designated by the main component contained therein, e.g. circuit-breaker
compartment, busbar compartment.
3.107
component
essential part of the main or earthing circuits of gas-insulated metal-enclosed switchgear which
serves a specific function (for example circuit-breaker, disconnector, switch, fuse, instrument
transformer, bushing, busbar, etc.)
3.108
support insulator
internal insulator supporting one or more conductors

3.109
partition
gas tight support insulator of gas-insulated metal-enclosed switchgear separating two adjacent
compartments
3.110
bushing
a device that enables one or several conductors to pass through an enclosure and insulate the
conductors from it
[SOURCE: IEC 60050-471:2007, 471-02-01, modified – “an enclosure” inserted after “pass
through” and “a partition such as a wall or a tank” deleted. Notes 1 and 2 were deleted.]
3.111
main circuit
all the conductive parts of gas-insulated metal-enclosed switchgear included in a circuit which
is intended to transmit electrical energy
[SOURCE: IEC 60050-441:1984, 441-13-02, modified – “gas-insulated metal-enclosed
switchgear” inserted after “parts of” and “an assembly” deleted]
3.112
auxiliary circuit
all the conductive parts of gas-insulated metal-enclosed switchgear included in a circuit
intended to control, measure, signal and regulate
Note 1 to entry: The auxiliary circuits of gas-insulated metal-enclosed switchgear include the control and auxiliary
circuits of the switching devices.
3.113
enclosure design temperature
maximum temperature that the enclosures can reach under specified maximum service
conditions
3.114
enclosure design pressure
relative pressure used to determine the design of the enclosure
Note 1 to entry: It is at least equal to the maximum pressure in the enclosure at the highest temperature that the
gas used for insulation can reach under specified maximum service conditions.
Note 2 to entry: The transient pressure occurring during and after a breaking operation (e.g. circuit-breaker) is not
considered in the determination of the design pressure.
3.115
partition design pressure
relative pressure across the partition used to determine the design of the partition
Note 1 to entry: It is at least equal to the maximum differential pressure across the partition during maintenance
activities.
Note 2 to entry: The transient pressure occurring during and after a breaking operation (e.g. circuit-breaker) is not
considered in the determination of the design pressure.
3.116
operating pressure
relative pressure chosen for the opening operation of pressure relief
devices
– 10 – IEC 62271-203:2022  IEC 2022
3.117
routine test pressure
relative pressure to which all enclosures and partitions are
subjected after manufacturing
3.118
type test pressure
relative pressure to which enclosures and partitions are subjected
for type test
3.119
fragmentation
damage to enclosure due to pressure rise with projection of solid material
3.120
disruptive discharge
phenomena 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 almost zero
3.121
transport unit
part of gas-insulated metal-enclosed switchgear suitable for shipment without being dismantled
3.122
functional unit
part of metal-enclosed switchgear and controlgear comprising all the components of the main
circuits and auxiliary circuits that contribute to the fulfilment of a single function
Note 1 to entry: Functional units can be distinguished according to the function for which they are intended, for
example complete single-phase or three-phase bay or functional parts of a bay like complete circuit-breaker,
disconnector, earthing switch, voltage transformer, current transformer, operating mechanism, enclosure, etc.
[SOURCE: IEC 60050-441:1984, 441-13-04, modified – In the definition, “metal-enclosed”
inserted after “part of” and “an assembly of” deleted. In the note the examples have been
exchanged with examples relevant for GIS.]
4 Normal and special service conditions
4.1 Normal service conditions
Subclause 4.1 of IEC 62271-1:2017 is applicable, taking into account the recommended values
presented in Table 1 of this document.
4.2 Special service conditions
Subclause 4.2 of IEC 62271-1:2017 is applicable, taking into account the recommended values
presented in Table 1 of this document.
In the cases where higher than (>) is used in Table 1, the values shall be specified by the user
as described in IEC 62271-1:2017.

4.101 General
Table 1 – Reference table of service conditions relevant to GIS
Normal Special
Item
Indoor Outdoor Indoor Outdoor
Ambient air temperature:
Minimum (°C) –5 –25 –25 –50
Maximum (°C) +40 +40 +50 +50
Not applicable 1 000 Not applicable >1 000
Solar radiation (W/m )
Altitude (m) 1 000 1 000 >1 000 >1 000
a
Not applicable c c, d or e d or e
Site pollution severity
Ice coating (mm) Not applicable 20 Not applicable >20
Wind (m/s) Not applicable 34 Not applicable >34
Average humidity over 24 h (%) 95 100 98 100
Condensation or precipitation Occasional Yes Yes Yes
Abnormal vibrations, shock or tilting Not applicable Not applicable Applicable Applicable
NOTE The user’s specification can use any combination of normal or special service conditions above.
a 1
Site pollution severity c, d or e according to IEC TS 60815-1:2008, 8.3 [5]
At any altitude the dielectric characteristics of the internal insulation are identical with those
measured at sea-level. For this internal insulation no specific requirements concerning the
altitude are applicable.
Some items of a GIS such as pressure relief devices and pressure and density monitoring
devices can be affected by altitude. The manufacturer shall take appropriate measures if
necessary.
5 Ratings
5.1 General
Subclause 5.1 of IEC 62271-1:2017 is applicable with the following modifications:
e) rated short-time withstand current (I ) (for main and earthing circuits);
k
f) rated peak withstand current (I ) (for main and earthing circuits);
p
and with the following addition:
k) rated values of the components forming part of gas-insulated metal-enclosed switchgear,
including their operating devices and auxiliary equipment.
5.2 Rated voltage (U )
r
Subclause 5.2 of IEC 62271-1:2017 is applicable with the following addition:
Components forming part of the GIS can have individual values of rated for equipment in
accordance with the relevant standards.
___________
Numbers in square brackets refer to the Bibliography.

– 12 – IEC 62271-203:2022  IEC 2022

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:
Tables 1, 2, 3 and 4 in Subclause 5.3 of IEC 62271-1:2017 are replaced with Table 2 and
Table 3 below.
NOTE 1 The higher values for GIS in IEC 62271-203 compared to the values in IEC 62271-1 were introduced with
revision 1 in 2003. They have now been established as standard values.
The GIS comprises components having a definite insulation level. Although internal faults can
largely be avoided by the choice of a suitable insulation level, measures to limit external
overvoltages (e.g. surge arresters,) should be considered.
NOTE 2 Regarding the external parts of bushings (if any), see to IEC 60137:2017.
NOTE 3 The waveforms are standardized lightning impulse and switching impulse shapes, pending the results of
studies on the ability of this equipment to withstand other types of impulses.
NOTE 4 The choice between alternative insulation levels for a particular rated voltage for equipment can be based
on insulation coordination studies, taking into account also the self-generated transient overvoltages due
to switching.
Table 2 – Rated insulation levels for rated voltages
for equipment of range I (245 kV and below)
Rated short-duration power-frequency Rated lightning impulse
withstand voltage withstand voltage
U U
d p
Rated voltage for
equipment
kV (RMS value) kV (peak value)
U
r
Phase-to-earth, Phase-to-earth,
across open Across across open Across
kV (RMS value)
switching device the isolating switching device the isolating
and between distance and between distance
phases phases
(1) (2) (3) (4) (5)
72,5 140 160 325 375
100 185 210 450 520
123 230 265 550 630
145 275 315 650 750
170 325 375 750 860
245 460 530 1 050 1 200
NOTE Values in column (2) are applicable:
a) for type tests, phase-to-earth and between phases;
b) for routine tests, phase-to-earth, phase-to-phase, and across the open switching device.
Values in columns (3), (4) and (5) are applicable for type tests only.

Table 3 – Rated insulation levels for rated voltages for equipment of range II
(above 245 kV)
Rated short-duration Rated lightning
Rated switching impulse
power-frequency impulse
withstand voltage
withstand voltage withstand voltage
U
s
U U
d p
Rated
kV (peak value)
voltage for
kV (RMS value) kV (peak value)
equipment
Between Across Phase-to- Across open
Phase-to- Across Phase-to-
U
r
earth and open earth and phases isolating earth and switching
between switching across (Notes 3 distance between device
kV (RMS
phases device open and 4) (Notes 1, 2 phases and/or
value)
(Notes 3 and/or switching and 3) (Note 5) isolating
and 5) isolating device distance
distance (Note 5) (Notes 2
(Note 3) and 3)
(1) (2) (3) (4) (5) (6) (7) (8)
300 460 595 850 1 275 700 ([phone] (+170)
362 520 675 950 1 425 800 ([phone] (+205)
420 650 815 1 050 1 575 900 ([phone] (+240)
550 710 925 1 175 1 760 900 ([phone] (+315)
800 960 1 270 1 425 2 420 1 100 ([phone] (+455)
1 100 1 550 2 635 1 550 +(900) 2 250 2 250 + (630)
1 100 1 100
1 100
1 800 2 880 1 675 +(900) 2 400 2 400 + (630)
+(635)
1 200 1 800 2 970 2 400 2 400 + (685)
1 200 1 200 1 675 +(980)
1 200
1 950 3 120 2 550 2 550 + (685)
+(695)
NOTE 1 Column (6) is also applicable to some circuit-breakers, see IEC 62271-100:2021.
NOTE 2 In column (6), values in brackets are the peak values of the power-frequency voltage U
2 / 3 applied
r
to the opposite terminal (combined voltage).
In column (8), values in brackets are the peak values of the power-frequency voltage 0,7 U 2 / 3 applied to
r
the opposite terminal (combined voltage).
NOTE 3 Values in column (2) are applicable:
a) for type tests, phase-to-earth and between phases;
b) for routine tests, phase-to-earth, phase-to-phase, and across the open switching device.
Values in columns (3), (4), (5), (6), (7) and (8) are applicable for type tests only.
NOTE 4 These values are derived using the multiplying factors stated in Table 3 of IEC 60071-1:2019 [4].
NOTE 5 For earthing switches only phase-to-earth tests according column (2), (4) and (7) are applicable.
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 with the following addition:
Some main circuits of GIS (e.g. busbars, feeder circuits, etc.) can have different values of rated
continuous current. However, these values should also be selected from R10 series.

– 14 – IEC 62271-203:2022  IEC 2022
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.
5.11 Rated pressure of compressed gas supply for controlled pressure systems
Subclause 5.11 of IEC 62271-1:2017 is applicable.
6 Design and construction
6.1 Requirements for liquids in switchgear and controlgear
Subclause 6.1 of IEC 62271-1:2017 is applicable.
6.2 Requirements for gases in switchgear and controlgear
Subclause 6.2 of IEC 62271-1:2017 is applicable.
6.3 Earthing of switchgear and controlgear
Subclause 6.3 of IEC 62271-1:2017 is applicable.
6.3.101 Earthing of the main circuit
To ensure safety during maintenance work, all parts of the main circuit to which access is
required or provided shall be capable of being earthed.
Earthing can be made by:
a) earthing switches with a making capacity equal to the rated peak withstand current, if there
is still a possibility that the circuit connected is energised;
b) earthing switches without a making capacity or with a making capacity lower than the rated
peak withstand current, if there is certainty that the circuit connected is not energised.
Furthermore, it shall be possible, after opening the enclosure, to connect removable
earthing devices for the duration of the work on a circuit element previously earthed via
an earthing switch. The removable earthing device shall have the relevant short-circuit
withstand capability and/or induced current withstand capability.
The earthing circuit can be degraded after being subjected to the short-circuit current. After
such event, earthing circuit can need to be replaced.

6.3.102 Earthing of the enclosure
The enclosures shall be connected to earth. All metal parts which do not belong to a main or
an auxiliary circuit shall be earthed. For the interconnection of enclosures, frames, etc.,
fastening (e.g. bolting or welding) is acceptable for providing electrical continuity.
The continuity of the earthing circuits shall be ensured taking into account the thermal and
electrical stresses caused by the current they can have to carry.
If using single-phase enclosed switchgear, a looping circuit, i.e. an interconnection between the
enclosures of the three phases, should be installed for the induced current. Each of these
looping circuits should be linked as directly as possible to the general earthing grid by a
conductor capable to carry the short-circuit current.
NOTE The looping circuits are intended to avoid induced currents in the enclosures from flowing in the earthing
circuits and earthing grid. They are usually dimensioned for the rated continuous current and located at the
appropriate location according to the layout of the GIS installation.
6.4 Auxiliary and control equipment and circuits
Subclause 6.4 of IEC 62271-1:2017 and IEC 62271-1:2017/AMD1:2021 is applicable.
6.5 Dependent power operation
Subclause 6.5 of IEC 62271-1:2017 is applicable.
6.6 Stored energy operation
Subclause 6.6 of IEC 62271-1:2017 is applicable.
6.7 Independent unlatched operation (independent manual or power operation)
Subclause 6.7 of IEC 62271-1:2017 is applicable.
6.8 Manually operated actuators
Subclause 6.8 of IEC 62271-1:2017 is applicable.
6.9 Operation of releases
Subclause 6.9 of IEC 62271-1:2017 is applicable.
6.10 Pressure/level indication
Subclause 6.10 of IEC 62271-1:2017 is applicable with the following addition:
The performance of the GIS is depending on the gas density of the pure gas or the gas mixtures.
For GIS it is not sufficient to monitor the gas pressure without temperature compensation.
The gas density or temperature compensated gas pressure in each compartment shall be
continuously monitored. The monitoring device shall provide at least two alarm levels for
pressure or density (alarm and minimum functional pressure or density). The correct functioning
of gas monitoring devices shall be able to be checked with the high-voltage equipment in
service.
NOTE 1 When the filling density differs between adjacent compartments, an additional alarm indicating over
pressure or density can be used, if it is applicable for the GIS design.

– 16 – IEC 62271-203:2022  IEC 2022
NOTE 2 Tolerances of the monitoring device, as well as possible differences in temperature (e.g. inside/outside of
a building) between the monitoring device and the volume of gas being monitored, can be considered.
NOTE 3 Checking of gas monitoring can initiate wrong alarms which can initiate or inhibit switching operations.
NOTE 4 It is preferable for gas monitoring devices to be placed as close as possible to the gas compartment which
is being monitored to ensure measuring accuracy and minimum leakage, however consideration can be given to
safety and accessibility when choosing the location.
NOTE 5 The preferred solution for checking the gas monitoring device is to isolate the density monitor from the gas
compartment without mechanically removing it from the GIS, in order to minimize gas losses.
6.11 Nameplates
Subclause 6.11 of IEC 62271-1:2017 is applicable with the following addition:
A common nameplate shall be provided to identify the GIS. It shall, as a minimum, detail the
ratings listed in Clause 5 of this document. The common nameplate shall be clearly readable
from the position of local operation side.
For each individual device a nameplate according to its relevant standard is required where
ratings are not detailed on the common nameplate.
The nameplates shall be durable and clearly legible for the lifetime of the GIS.
The manufacturer shall give information of the type, volume and mass of the gas contained in
each gas compartment as well as the total mass for the entire GIS installation either on the
nameplate or on a label placed in a visible location. If required, more information shall be
provided in the instruction manual.
6.12 Locking devices
Subclause 6.12 of IEC 62271-1:2017 is applicable with the following addition:
The following provisions are mandatory for apparatus installed in main circuits which are used
as isolating distance and earthing:
– apparatus installed in main circuits, which are used for ensuring isolating distances during
maintenance work, shall be provided with visible locking devices to prevent closing (e.g.
padlock);
...