EN IEC 62271-201:2026
(Main)High-voltage switchgear and controlgear - Part 201: AC solid-insulation enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV
General Information
- Abstract
This part of IEC 62271 is applicable to prefabricated solid-insulation enclosed switchgear and controlgear assemblies designed for:
– alternating current;
– rated voltages above 1 kV and up to and including 52 kV;
– service frequencies up to and including 60 Hz;
– indoor installation;
– areas limited to authorized personnel.
The assembly can include either air-insulated or fluid-filled compartments, or both. For components installed in a solid-insulation enclosed switchgear and controlgear, this
document supplements or even replaces in some cases, the requirements as stated by the individual product standards.
The list of components which can be inside the solid-insulation enclosed switchgear and controlgear is not limited to the ones explicitly cited in this document.
- Status
- Published
- Publication Date
- 17-Sep-2026
- Technical Committee
- CLC/TC 17AC - High-voltage switchgear and controlgear
- Drafting Committee
- IEC/SC 17C - IEC_SC_17C
- Current Stage
- 6060 - Document made available - Publishing
- Start Date
- 18-Sep-2026
- Due Date
- 29-Mar-2024
- Completion Date
- 18-Sep-2026
Overview
EN IEC 62271-201:2026 specifies requirements for prefabricated, AC solid-insulation enclosed switchgear and controlgear for use at rated voltages above 1 kV and up to and including 52 kV. Developed by CLC and the International Electrotechnical Commission (IEC), this standard addresses assemblies designed for indoor installation and service frequencies up to 60 Hz, aiming to ensure safety, reliability, and performance in high-voltage electrical distribution systems.
This third edition aligns closely with related standards in the EN IEC 62271 series, reflecting technical and structural updates to harmonize with current industry best practices. The document applies to assemblies used in environments limited to authorized personnel and covers both three-phase and single-/two-phase systems, supporting a broad range of high-voltage applications in modern power distribution networks.
Key Topics
Scope and Definitions
EN IEC 62271-201 covers assemblies built with solid insulation, addressing the requirements for design, construction, ratings, testing, and operation. It introduces precise terminology for key concepts such as normal operating conditions, assemblies, and earthing circuits.Design and Construction Requirements
The standard outlines criteria for the use of solid insulation enclosures, requirements for air-insulated and fluid-filled compartments, as well as provisions for safety against internal arc faults, dielectric strength, fire hazards, corrosion resistance, and electromagnetic compatibility (EMC).Testing Procedures
It specifies procedures for type and routine tests including:- Dielectric tests
- Resistance and EMC tests
- Mechanical operation evaluations
- Pressure and tightness assessment for liquid/gas compartments
- Internal arc and partial discharge tests
- Verification of thermal stability and protection levels
Service Conditions and Ratings
Provides guidance on normal and special service conditions, rated voltage, insulation levels, current ratings, frequency, and auxiliary circuit requirements. The document includes criteria for reliable operation in a variety of indoor environmental conditions.Safety and Environmental Aspects
The standard incorporates robust guidelines to ensure personnel safety (especially regarding internal arc faults), protection from dangerous electrical effects, and environmental considerations throughout the switchgear's lifecycle.
Applications
EN IEC 62271-201:2026 is essential for stakeholders involved in the design, manufacturing, specification, installation, and maintenance of high-voltage switchgear and controlgear. Typical applications include:
Medium- and High-Voltage Distribution
Used by utilities, industrial and commercial facilities to manage and protect electrical power distribution at voltages from above 1 kV up to 52 kV.Indoor Electrical Installations
Designed primarily for indoor use in substations, control centers, or any areas accessible only to trained personnel.Infrastructure Projects
Suitable for critical infrastructure, data centers, and transportation hubs requiring reliable, high-performance electrical distribution and circuit protection.Retrofitting and Upgrades
Provides a reference framework for updating or replacing existing switchgear to meet current safety and performance standards.
Related Standards
EN IEC 62271-201 is part of a comprehensive set of standards governing high-voltage switchgear and controlgear:
- IEC 62271-1: Common specifications for AC switchgear and controlgear
- IEC 62271-100: AC circuit-breakers
- IEC 62271-102: Disconnectors and earthing switches
- IEC 62271-200: Metal-enclosed switchgear and controlgear assemblies
- IEC 62271-103 / 105 / 106 / 107: Covering switches, switch-fuse combinations, contactors, and fused circuit-switchers
- IEC/IEEE 62271-37-013: Generator circuit-breakers
- IEC 60050, 60270, 60529, 62262: Vocabulary, test techniques, and protection (IP/IK Codes)
Adhering to EN IEC 62271-201:2026 helps ensure operational safety, equipment durability, and regulatory compliance in high-voltage electrical systems. Its alignment with other key IEC standards offers a consistent foundation for specifying, testing, and installing high-voltage switchgear worldwide.
Relations
- Effective Date
- 21-Oct-2021
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Refers
EN IEC 60270:2025 - High-voltage test techniques - Charge-based measurement of partial discharges - Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
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Frequently Asked Questions
EN IEC 62271-201:2026 is a standard published by CLC. Its full title is "High-voltage switchgear and controlgear - Part 201: AC solid-insulation enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV". This standard covers: This part of IEC 62271 is applicable to prefabricated solid-insulation enclosed switchgear and controlgear assemblies designed for: – alternating current; – rated voltages above 1 kV and up to and including 52 kV; – service frequencies up to and including 60 Hz; – indoor installation; – areas limited to authorized personnel. The assembly can include either air-insulated or fluid-filled compartments, or both. For components installed in a solid-insulation enclosed switchgear and controlgear, this document supplements or even replaces in some cases, the requirements as stated by the individual product standards. The list of components which can be inside the solid-insulation enclosed switchgear and controlgear is not limited to the ones explicitly cited in this document.
This part of IEC 62271 is applicable to prefabricated solid-insulation enclosed switchgear and controlgear assemblies designed for: – alternating current; – rated voltages above 1 kV and up to and including 52 kV; – service frequencies up to and including 60 Hz; – indoor installation; – areas limited to authorized personnel. The assembly can include either air-insulated or fluid-filled compartments, or both. For components installed in a solid-insulation enclosed switchgear and controlgear, this document supplements or even replaces in some cases, the requirements as stated by the individual product standards. The list of components which can be inside the solid-insulation enclosed switchgear and controlgear is not limited to the ones explicitly cited in this document.
EN IEC 62271-201:2026 is classified under the following ICS (International Classification for Standards) categories: 29.130.10 - High voltage switchgear and controlgear. The ICS classification helps identify the subject area and facilitates finding related standards.
EN IEC 62271-201:2026 has the following relationships with other standards: It is inter standard links to EN 62271-201:2014, EN 60529:1991/A2:2013, EN ISO 4126-2:2019, EN IEC 62271-100:2021/A1:2024, EN IEC 60270:2025, EN 62271-1:2017, EN IEC 62271-105:2023, EN IEC 62271-106:2021, EN IEC 62271-102:2018/A1:2022, EN 60529:1991/A1:2000, EN IEC 62271-107:2019, EN IEC 62271-102:2018, EN 60529:1991, EN 62262:2002, EN IEC 62271-103:2023. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN IEC 62271-201:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2026
Nadomešča:
SIST EN 62271-201:2014
Visokonapetostne stikalne in krmilne naprave - 201. del: Izolacijsko obdane
izmenične stikalne in krmilne naprave za napetosti nad 1 kV in do vključno 52 kV
(IEC 62271-201:2026)
High-voltage switchgear and controlgear - Part 201: AC solid-insulation enclosed
switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV
(IEC 62271-201:2026)
Hochspannungs-Schaltgeräte und -Schaltanlagen - Teil 201: Isolierstoffgekapselte
Wechselstrom-Schaltanlagen für Bemessungsspannungen über 1 kV bis einschließlich
52 kV (IEC 62271-201:2026)
Appareillage à haute tension - Partie 201: Appareillage sous enveloppe isolante solide
pour courant alternatif de tensions assignées supérieures à 1 kV et inférieures ou égales
à 52 kV (IEC 62271-201:2026)
Ta slovenski standard je istoveten z: EN IEC 62271-201:2026
ICS:
29.130.10 Visokonapetostne stikalne in High voltage switchgear and
krmilne naprave controlgear
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 62271-201
NORME EUROPÉENNE
EUROPÄISCHE NORM September 2026
ICS 29.130.10 Supersedes EN 62271-201:2014
English Version
High-voltage switchgear and controlgear - Part 201: AC solid-
insulation enclosed switchgear and controlgear for rated
voltages above 1 kV and up to and including 52 kV
(IEC 62271-201:2026)
Appareillage à haute tension - Partie 201: Appareillage Hochspannungs-Schaltgeräte und -Schaltanlagen - Teil
sous enveloppe isolante solide pour courant alternatif de 201: Isolierstoffgekapselte Wechselstrom-Schaltanlagen für
tensions assignées supérieures à 1 kV et inférieures ou Bemessungsspannungen über 1 kV bis einschließlich 52 kV
égales à 52 kV (IEC 62271-201:2026)
(IEC 62271-201:2026)
This European Standard was approved by CENELEC on 2026-08-26. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62271-201:2026 E
European foreword
The text of document 17C/980/FDIS, future edition 3 of IEC 62271-201, prepared by SC 17C
"Assemblies" of IEC/TC 17 "High-voltage switchgear and controlgear" was submitted to the IEC-
CENELEC parallel vote and approved by CENELEC as EN IEC 62271-201:2026.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-09-30
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-09-30
document have to be withdrawn
This document supersedes EN 62271-201:2014 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document is read in conjunction with EN 62271-1:2017 and EN 62271-1:2017/A1:2021.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 62271-201:2026 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 62271-200:2021 NOTE Approved as EN IEC 62271-200:2021 (not modified)
IEC 62271-
NOTE Approved as EN IEC 62271-200:2021/A1:2024 (not modified)
200:2021/AMD1:2024
IEC 60059:1999 NOTE Approved as EN 60059:1999 (not modified)
IEC 62271-4 NOTE Approved as EN IEC 62271-4
IEC 62271-213 NOTE Approved as EN IEC 62271-213
IEC 62271-215 NOTE Approved as EN IEC 62271-215
IEC 60243-1:2013 NOTE Approved as EN 60243-1:2013 (not modified)
Approved as EN IEC 61936-1:2021 (not modified)
IEC 61936-1:2021 NOTE
+A11:2025
IEC 60909-0:2016 NOTE Approved as EN 60909-0:2016 (not modified)
IEC 60507:2013 NOTE Approved as EN 60507:2014 (not modified)
IEC 60050 (series) NOTE Approved as prEN IEC 60050 (series) to be published
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-151 - International Electrotechnical Vocabulary - - -
Part 151: Electrical and magnetic devices
IEC 60050-441 - International Electrotechnical Vocabulary. - -
Switchgear, controlgear and fuses
IEC 60060-1 2025 High-voltage test techniques - Part 1: EN IEC 60060-1 2025
General terminology and test requirements
IEC 60270 - High-voltage test techniques - Charge- EN IEC 60270 -
based measurement of partial discharges
IEC 60529 1989 Degrees of protection provided by EN 60529 1991
enclosures (IP Code)
- - + corrigendum May 1993
+ A1 1999 + A1 2000
+ A2 2013 + A2 2013
IEC 62262 2002 Degrees of protection provided by EN 62262 2002
enclosures for electrical equipment against
external mechanical impacts (IK code)
IEC 62271-1 2017 High-voltage switchgear and controlgear - EN 62271-1 2017
Part 1: Common specifications for
alternating current switchgear and
controlgear
+ AMD1 2021 + A1 2021
IEC 62271-100 2021 High-voltage switchgear and controlgear - EN IEC 62271-100 2021
Part 100: Alternating-current circuit-
breakers
+ AMD1 2024 + A1 2024
IEC 62271-102 2018 High-voltage switchgear and controlgear - EN IEC 62271-102 2018
Part 102: Alternating current disconnectors
and earthing switches
+ AMD1 2022 + A1 2022
IEC 62271-103 2021 High-voltage switchgear and controlgear - EN IEC 62271-103 2023
Part 103: Switches for rated voltages
above 1 kV up to and including 52 kV
IEC 62271-105 2021 High-voltage switchgear and controlgear - EN IEC 62271-105 2023
Part 105: Alternating current switch-fuse
combinations for rated voltages above 1 kV
up to and including 52 kV
IEC 62271-106 2021 High-voltage switchgear and controlgear - EN IEC 62271-106 2021
Part 106: Alternating current contactors,
contactor-based controllers and motor-
starters
IEC 62271-107 2019 High-voltage switchgear and controlgear - EN IEC 62271-107 2019
Part 107: Alternating current fused circuit-
switchers for rated voltages above 1 kV up
to and including 52 kV
IEC/IEEE 62271-37- 2021 High-voltage switchgear and controlgear -
013 Part 37-013: Alternating current generator
circuit-breakers
ISO 4126-2 - EN ISO 4126-2 -
IEC 62271-201 ®
Edition 3.0 2026-07
INTERNATIONAL
STANDARD
High-voltage switchgear and controlgear -
Part 201: AC solid-insulation enclosed switchgear and controlgear for rated
voltages above 1 kV and up to and including 52 kV
ICS 29.130.10 ISBN 978-2-8327-1300-6
IEC 62271-201:2026-07(en)
IEC 62271-201:2026 © IEC 2026
CONTENTS
FOREWORD . 8
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 12
3 Terms and definitions . 13
3.1 General terms and definitions . 13
3.2 Assemblies of switchgear and controlgear . 15
3.3 Parts of assemblies . 15
3.4 Switching devices . 15
3.5 Parts of switchgear and controlgear . 15
3.6 Operational characteristics of switchgear and controlgear . 19
3.7 Characteristic quantities . 21
3.8 Index of definitions . 22
4 Normal and special service conditions . 23
5 Ratings . 24
5.1 General . 24
5.2 Rated voltage (U ) . 24
r
5.3 Rated insulation level (U , U , U ) . 24
d p s
5.4 Rated frequency (f ) . 24
r
5.5 Rated continuous current (I ) . 24
r
5.6 Rated short-time withstand current (I , I ) . 25
k ke
5.6.101 Rated short-time withstand current (I ) . 25
k
5.6.102 Rated short-time phase to earth withstand current (I ) . 25
ke
5.7 Rated peak withstand current (I , I ) . 25
p pe
5.7.101 Rated peak withstand current (I ) . 25
p
5.7.102 Rated peak phase-to-earth withstand current (I ) . 25
pe
5.8 Rated durations of short-circuit (t , t ) . 26
k ke
5.8.101 Rated duration of short-circuit (t ) . 26
k
5.8.102 Rated duration of phase-to-earth short-circuit (t ) . 26
ke
5.9 Rated supply voltage of auxiliary and control circuits (U ) . 26
a
5.10 Rated supply frequency of auxiliary circuits . 26
5.11 Rated pressure of compressed gas supply for controlled pressure systems . 26
5.101 Classification of earthing function through main switching device . 26
5.102 Rated cable test voltages (U , U ) . 26
ct (AC) ct (DC)
5.102.1 General . 26
5.102.2 Rated power-frequency cable test voltage U . 27
ct (AC)
5.102.3 Rated DC cable test voltage U with rated duration t . 27
ct (DC) ct (DC)
5.103 Ratings of the internal arc classification (IAC) . 27
5.103.1 General . 27
5.103.2 Types of accessibility . 27
5.103.3 Classified sides . 27
5.103.4 Rated arc fault currents (I , I ) . 28
A Ae
IEC 62271-201:2026 © IEC 2026
5.103.5 Rated arc fault duration (t , t ) . 28
A Ae
6 Design and construction . 28
6.1 Requirements for liquids in switchgear and controlgear . 28
6.2 Requirements for gases in switchgear and controlgear . 28
6.3 Earthing of switchgear and controlgear . 28
6.3.101 Earthing of the high-voltage conductive parts . 28
6.3.102 Earthing of enclosure(s) . 29
6.3.103 Earthing of withdrawable and removable parts . 29
6.3.104 Earthing circuit . 29
6.4 Auxiliary and control equipment . 30
6.5 Dependent power operation . 30
6.6 Stored energy operation. 30
6.7 Independent unlatched operation (independent manual or power operation) . 30
6.8 Manually operated actuators . 30
6.9 Operation of releases. 30
6.10 Pressure/level indication . 30
6.11 Nameplates . 31
6.12 Locking devices . 33
6.13 Position indication . 34
6.14 Degrees of protection provided by enclosures . 34
6.14.1 General . 34
6.14.2 Protection of persons against access to hazardous parts and protection
of the equipment against ingress of solid foreign objects (IP coding) . 34
6.14.3 Protection against ingress of water (IP coding) . 34
6.14.4 Protection of equipment against mechanical impact under normal
service conditions (IK coding) . 34
6.15 Creepage distances for outdoor insulators . 34
6.16 Gas and vacuum tightness . 34
6.17 Tightness for liquid systems . 34
6.18 Fire hazard (flammability) . 34
6.19 Electromagnetic compatibility (EMC) . 34
6.20 X-ray emission . 34
6.21 Corrosion . 35
6.22 Filling levels for insulation, switching and/or operation . 35
6.101 General requirements for assemblies . 35
6.102 Solid insulating enclosure . 36
6.102.1 General . 36
6.102.2 Covers and doors . 36
6.102.3 Partition or shutter being part of the enclosure . 37
6.102.4 Inspection windows . 37
6.102.5 Ventilating openings, vent outlets . 37
6.102.6 Protection category of the solid insulating enclosure against electric
shock . 38
6.102.7 Requirements for protection categories . 38
6.103 High-voltage compartments . 39
6.103.1 General . 39
6.103.2 Fluid-filled compartments (gas or liquid) . 40
6.103.3 Partitions and shutters . 41
6.104 Removable parts . 42
IEC 62271-201:2026 © IEC 2026
6.105 Provisions for dielectric tests on cables . 43
6.106 Internal arc fault . 43
7 Type tests . 43
7.1 General . 43
7.1.1 Basics . 43
7.1.2 Information for identification of specimens . 44
7.1.3 Information to be included in type-test reports . 44
7.2 Dielectric tests . 44
7.2.1 General . 44
7.2.2 Ambient air conditions during tests . 45
7.2.3 Wet test procedure . 45
7.2.4 Conditions of switchgear and controlgear during dielectric tests . 45
7.2.5 Criteria to pass the test . 45
7.2.6 Application of the test voltage and test conditions . 45
7.2.7 Tests of switchgear and controlgear of U ≤ 245 kV . 46
r
7.2.8 Tests of switchgear and controlgear of U >245 kV . 47
r
7.2.9 Artificial pollution tests for outdoor insulators . 48
7.2.10 Partial discharge tests . 48
7.2.11 Dielectric tests on auxiliary and control circuits . 48
7.2.12 Voltage test as condition check . 48
7.2.101 Dielectric tests on cable testing circuits . 49
7.3 Radio interference voltage (RIV) test . 49
7.4 Resistance measurement . 49
7.4.1 Measurement of the resistance of auxiliary contacts class 1 and class 2 . 49
7.4.2 Measurement of the resistance of auxiliary contacts class 3 . 49
7.4.3 Electrical continuity of earthed metallic parts test . 49
7.4.4 Resistance measurement of contacts and connections in the main
circuit as a condition check . 49
7.4.101 Requirement for protection category PB2. 49
7.5 Continuous current tests . 50
7.5.1 Condition of the test object . 50
7.5.2 Arrangement of the equipment . 50
7.5.3 Test current and duration . 50
7.5.4 Temperature measurement during test . 50
7.5.5 Resistance of the main circuit . 51
7.5.6 Criteria to pass the test . 51
7.5.101 Test report . 51
7.6 Short-time withstand current and peak withstand current tests . 51
7.6.1 General . 51
7.6.2 Arrangement of the equipment and of the test circuit . 52
7.6.3 Test current and duration . 53
7.6.4 Condition of test object after test . 53
7.7 Verification of the protection . 54
7.7.1 Verification of the IP coding . 54
7.7.2 Verification of the IK coding . 54
7.8 Tightness tests . 54
7.9 Electromagnetic compatibility tests (EMC) . 54
7.10 Additional tests on auxiliary and control circuits . 54
7.10.1 General . 54
IEC 62271-201:2026 © IEC 2026
7.10.2 Functional tests . 55
7.10.3 Verification of the operational characteristics of auxiliary contacts . 55
7.10.4 Environmental tests . 55
7.10.5 Dielectric test . 55
7.11 X-radiation test procedures for vacuum interrupters . 55
7.101 Verification of making and breaking capacities . 55
7.101.1 General . 55
7.101.2 Test requirements for main switching devices . 56
7.101.3 Test requirements for earthing function . 56
7.102 Mechanical operation tests . 56
7.102.1 Switching devices and removable parts . 56
7.102.2 Mechanical and electromechanical interlocks and locking devices . 57
7.103 Pressure withstand test for gas-filled compartments . 59
7.103.1 Pressure withstand test for gas-filled compartments with pressure relief
devices . 59
7.103.2 Pressure withstand test for gas-filled compartments without pressure
relief devices . 60
7.104 Tests to verify the protection of persons against dangerous electrical effects . 60
7.104.1 General . 60
7.104.2 Dielectric tests . 60
7.104.3 Measurements of leakage currents . 61
7.105 Internal arc test . 61
7.105.1 General . 61
7.105.2 Test conditions . 62
7.105.3 Arrangement of the equipment . 63
7.105.4 Test procedure . 63
7.105.5 Criteria to pass the test . 63
7.105.6 Test report . 64
7.105.7 Extension of validity of test results . 65
7.106 Thermal stability test . 65
7.107 Humidity test . 66
8 Routine tests . 66
8.1 General . 66
8.2 Dielectric test on the main circuit . 66
8.3 Tests on auxiliary and control circuits . 66
8.3.1 Inspection of auxiliary and control circuits, and verification of conformity
to the circuit diagrams and wiring diagrams . 66
8.3.2 Functional tests . 67
8.3.3 Verification of protection against electrical shock . 67
8.3.4 Dielectric tests . 67
8.4 Measurement of the resistance of the main circuit . 67
8.5 Tightness test . 67
8.6 Design and visual checks . 67
8.101 Partial discharge measurement . 67
8.102 Mechanical operation tests . 68
8.103 Pressure tests of gas-filled compartments . 68
8.104 Tests after erection on site. 68
8.105 Measurement of fluid condition after filling on site . 69
9 Guide to the selection of switchgear and controlgear (informative) . 69
IEC 62271-201:2026 © IEC 2026
9.1 General . 69
9.2 Selection of rated values . 69
9.3 Cable-interface considerations . 70
9.4 Continuous or temporary overload due to changed service conditions . 70
9.5 Environmental aspects . 70
9.101 Selection of design and construction . 70
9.101.1 General . 70
9.101.2 Architecture and accessibility to high-voltage compartments . 71
9.101.3 Service continuity of the switchgear and controlgear . 72
9.102 Ratings related to earthing circuits . 74
9.103 Internal arc fault . 74
9.103.1 General . 74
9.103.2 Causes and preventive measures . 75
9.103.3 Supplementary protective measures . 75
9.103.4 Considerations for the selection and installation . 76
9.103.5 Internal arc test . 77
9.103.6 IAC classification . 78
9.104 Summary of technical requirements, ratings and optional tests . 79
10 Information to be given with enquiries, tenders and orders (informative) . 81
10.1 General . 81
10.2 Information with enquiries and orders . 81
10.3 Information with tenders . 82
11 Transport, storage, installation, operating instructions and maintenance . 83
11.1 General . 83
11.2 Conditions during transport, storage and installation . 83
11.3 Installation . 83
11.4 Operating instructions . 83
11.5 Maintenance . 84
12 Safety . 84
12.101 Procedures . 84
12.102 Internal arc aspects . 84
13 Influence of the product on the environment . 84
Annex A (normative) Internal arc fault – Method to verify the internal arc classification
(IAC) . 85
A.1 Room simulation . 85
A.2 Indicators (for assessing the thermal effects of the gases) . 87
A.2.1 General . 87
A.2.2 Arrangement of indicators . 87
A.3 Tolerances for geometrical dimensions of test arrangements . 88
A.4 Test parameters . 88
A.4.1 General . 88
A.4.2 Voltage . 88
A.4.3 Current . 88
A.4.4 Frequency . 89
A.5 Test procedure. 89
A.5.1 Supply circuit . 89
A.5.2 Arc initiation . 90
Annex B (normative) Partial discharge measurement . 99
IEC 62271-201:2026 © IEC 2026
B.1 General . 99
B.2 Application . 99
B.3 Test circuits and measuring instruments . 100
B.4 Test procedure. 100
Annex C (informative) Regional deviations . 105
Annex D (normative) Humidity test . 106
D.1 General . 106
D.2 Test procedure and test conditions . 106
D.2.1 Test cycle and its duration . 106
D.2.2 Generation of fog . 107
D.2.3 High air temperature period . 107
D.2.4 Test chamber . 107
D.2.5 Test object. 107
D.2.6 Test voltage and voltage supply. 108
D.2.7 Total test duration. 108
D.3 Test criteria and evaluation . 108
D.3.1 Criterion during the test . 108
D.3.2 Criterion after the test . 108
D.3.3 Evaluation of the test . 108
Annex E (informative) Protection categories . 110
E.1 Protection category PA . 110
E.2 Protection categories PB. 111
Annex F (informative) List of symbols and abbreviations used in IEC 62271-201 . 112
Annex G (normative) Flowchart categorisation procedure LSC for a given functional
unit FU1 with connection compartment . 113
Annex H (informative) Pressure coordination chart for gas-filled compartments . 114
Bibliography . 115
Figure 1 – LSC1. 73
Figure 2 – LSC2. 73
Figure 3 – LSC2. 73
Figure 4 – LSC2. 74
Figure 5 – LSC2A . 74
Figure 6 – LSC2B . 74
Figure 7 – LSC2B . 74
Figure 8 – No LSC assigned . 74
Figure 9 – No LSC assigned . 74
Figure A.1 – Mounting frame for vertical indicators . 92
Figure A.2 – Horizontal indicator . 92
Figure A.3 – Position of the indicators. 93
Figure A.4 – Room simulation and indicator positioning for accessibility A, classified
rear side, ceiling above 2 000 mm, functional unit of any height . 94
Figure A.5 – Ceiling height stated from the floor or false floor level where the
switchgear is actually placed . 96
Figure A.6 – Indicator positioning in case of protrusion at < 2 000 mm height, at
classified side . 97
IEC 62271-201:2026 © IEC 2026
Figure A.7 – Indicator positioning in case a bottom exhaust duct belonging to the
assembly is defined as a walkable integrated part of the false floor . 97
Figure A.8 – Room simulation and indicator positioning for accessibility type A, non-
accessible rear side, ceiling at 2 000 mm, so functional unit ≤ 1 800 mm high . 98
Figure B.1 – Partial discharge test circuit (three-phase arrangement) . 103
Figure B.2 – Partial discharge test circuit (system without earthed neutral) . 104
Figure D.1 – Test cycle . 109
Figure D.2 – Test chamber . 109
Figure E.1 – Possible designs for protection category PA . 110
Figure E.2 – Possible designs for protection category PB . 111
Figure G.1 – Flowchart categorisation procedure LSC for a given functional unit FU1
with connection compartment . 113
Figure H.1 – Example of pressure coordination chart . 114
Table 1 – Nameplate information . 31
Table 2 – Locations, causes and examples of measures to decrease the probability of
internal arc faults . 76
Table 3 – Single-phase-to-earth arc fault current depending on the network neutral
earthing .
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