IEC 62271-108:2020

High-voltage switchgear and controlgear - Part 108: High-voltage alternating current disconnecting circuit-breakers for rated voltages above 52 kV

IEC 62271-108:2020 applies to high-voltage alternating current disconnecting circuit-breakers for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 52 kV.
This second edition cancels and replaces the first edition published in 2005. This edition contains the following significant technical changes with respect to the previous edition:
- The document has been restructured according to IEC 62271-1:2017.
- The document has been adapted to some of the changes introduced in IEC 62271-100:–[1].
- The document has been adapted to some of the changes introduced in IEC 62271-102:2018.
- References have been reviewed and updated.
- Some definitions have been reviewed and adapted to the latest IEV editions.
- Rated static terminal load and static terminal load test have been removed and a design requirement for static mechanical loads has been included.
- Additional type tests for auxiliary and control circuits have been included.
- X-radiation test procedure for vacuum interrupters has been included.
- Type test for testing of interlocking device and type test for testing of temporary mechanical locking devices have been included.
- Special requirements for making and breaking tests on class E2 disconnecting circuit-breakers have been removed.
[1] Under preparation. Stage at the time of publication: IEC CDV 62271-100:2020.

Appareillage à haute tension - Partie 108: Disjoncteurs-sectionneurs à courant alternatif à haute tension de tensions assignées supérieures ou égales à 52 kV

L'IEC 62271-108:2020 s'applique aux disjoncteurs-sectionneurs à courant alternatif à haute tension fonctionnant à des fréquences de 50 Hz et 60 Hz sur des systèmes de tensions assignées supérieures à 52 kV.
Cette deuxième édition annule et remplace la première édition parue en 2005. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- le document a été restructuré conformément à l'IEC 62271-1:2017;
- le document a été adapté à certaines des modifications introduites dans
- l'IEC 62271‑100:–[1];
- le document a été adapté à certaines des modifications introduites dans l'IEC 62271‑102:2018;
- les références ont été révisées et mises à jour;
- certaines définitions ont été révisées et adaptées aux dernières éditions de l'IEV;
- l'effort statique assigné sur les bornes et l'essai d'efforts statiques sur les bornes ont été supprimés et une exigence de conception pour les charges mécaniques statiques a été ajoutée;
- des essais de type complémentaires ont été ajoutés pour les circuits auxiliaires et de commande;
- une procédure d'essai de rayonnement X a été ajoutée pour les interrupteurs à vide;
- des essais de type ont été ajoutés pour le dispositif de verrouillage et les dispositifs de verrouillage mécanique temporaire;
- les exigences spéciales pour les essais d'établissement et de coupure des disjoncteurs‑sectionneurs de classe E2 ont été supprimées.
[1] En cours d'élaboration. Stade au moment de la publication: IEC CDV 62271-100:2020.

General Information

• Status: Published
• Publication Date: 08-Jul-2020
• ICS: 29.130.10 - High voltage switchgear and controlgear
• Technical Committee: SC 17A - Switching devices
• Drafting Committee: MT 31 - TC 17/SC 17A/MT 31
• Current Stage: PPUB - Publication issued
• Start Date: 17-Jul-2020
• Completion Date: 09-Jul-2020

Relations

• Revises: IEC 62271-108:2005 - High-voltage switchgear and controlgear - Part 108: High-voltage alternating current disconnecting circuit-breakers for rated voltages of 72,5 kV and above
• Effective Date: 05-Sep-2023

Overview

IEC 62271-108:2020 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies requirements for high-voltage alternating current disconnecting circuit-breakers intended for rated voltages above 52 kV. This second edition replaces the 2005 version and reflects the latest technological and regulatory developments. It applies to systems operating at frequencies of 50 Hz and 60 Hz and aligns with the IEC 62271 series for high-voltage switchgear and controlgear.

The standard covers essential design, construction, testing, and performance criteria to ensure safety, reliability, and performance of these critical components in electric power systems. Key technical updates include restructuring to comply with IEC 62271-1:2017, incorporation of new test procedures, and adaptations reflecting changes in related standards such as IEC 62271-100 and IEC 62271-102.

---

Key Topics

• Scope and Ratings

  • Designed for disconnecting circuit-breakers operating above 52 kV.
  • Covers rated insulation levels and operational parameters for AC high-voltage systems.

• Design and Construction Requirements

  • Comprehensive guidelines for mechanical and electrical design aspects.
  • Inclusion of locking devices, position indication systems, and mechanical load specifications.
  • Removal of static terminal load tests, replaced by static mechanical load design requirements.

• Testing and Verification

  • Type testing procedures including dielectric, radio interference voltage (RIV), tightness, and electromagnetic compatibility (EMC) tests.
  • New tests on auxiliary and control circuits.
  • Introduction of X-radiation testing for vacuum interrupters to ensure operational safety.
  • Tests for interlocking and temporary mechanical locking mechanisms.
  • Specific tests governing mechanical operation sequences and combined mechanical and short-circuit assessments.

• Service Conditions and Safety

  • Outlines normal and special service conditions.
  • Emphasizes safety considerations during transport, storage, installation, operation, and maintenance.
  • Advances in safety protocols related to circuit-breaker operation and environmental impact.

• Classification and Application Guidance

  • Disconnecting circuit-breaker classifications for various system applications.
  • Informative guidelines on selecting disconnecting circuit-breakers to match operational requirements.
  • Detailed normative references and terminology definitions adapted from the latest International Electrotechnical Vocabulary (IEV) editions.

---

Applications

IEC 62271-108:2020 is essential for manufacturers, electrical engineers, and utility professionals involved in the design, testing, procurement, and operation of high-voltage switchgear. Typical applications include:

• Power transmission and distribution networks where reliable isolation and fault interruption above 52 kV are critical.
• Grid substations requiring integrated switching and circuit-breaking solutions.
• Industrial high-voltage installations needing robust disconnecting circuit-breakers to ensure equipment protection and system safety.
• Renewable energy plants where stable operation of high-voltage components is necessary for grid integration.

Adhering to this standard helps ensure equipment meets international safety and performance benchmarks, enhances operational reliability, and facilitates global trade and regulatory compliance.

---

Related Standards

IEC 62271-108:2020 is part of the broader IEC 62271 series, which governs various aspects of high-voltage switchgear and controlgear. Key related standards include:

• IEC 62271-1:2017 – General rules for high-voltage switchgear and controlgear; provides the foundational framework for design and testing.
• IEC 62271-100 – Circuit-breakers for rated voltages above 1 kV, covering more general circuit-breaker requirements.
• IEC 62271-102:2018 – High-voltage alternating current switch-fuse combinations.
• Other IEC standards addressing insulating materials, testing methodologies, and safety regulations applicable to high-voltage equipment.

Together, these standards create a comprehensive regulatory environment that guides manufacturers and users through effective design, testing, and operation of electrical equipment in high-voltage systems.

---

Keywords: IEC 62271-108, high-voltage switchgear, disconnecting circuit-breakers, rated voltages above 52 kV, high-voltage alternating current, IEC standards, high-voltage controlgear, electrical testing, high-voltage safety, power system reliability, vacuum interrupters, circuit-breaker design.

Standards Content (Sample)

IEC 62271-108 ®
Edition 2.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –
Part 108: High-voltage alternating current disconnecting circuit-breakers for
rated voltages above 52 kV
Appareillage à haute tension –
Partie 108: Disjoncteurs-sectionneurs à courant alternatif à haute tension
de tensions assignées supérieures à 52 kV

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IEC 62271-108 ®
Edition 2.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
High-voltage switchgear and controlgear –

Part 108: High-voltage alternating current disconnecting circuit-breakers for

rated voltages above 52 kV
Appareillage à haute tension –

Partie 108: Disjoncteurs-sectionneurs à courant alternatif à haute tension

de tensions assignées supérieures à 52 kV

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.130.10 ISBN 978-2-8322-8507-7

– 2 – IEC 62271-108:2020 © IEC 2020
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
3.1 General terms and definitions . 7
3.2 Assemblies of switchgear and controlgear . 7
3.3 Parts of assemblies . 7
3.4 Switching devices . 7
3.5 Parts of switchgear and controlgear . 7
3.6 Operational characteristics of switchgear and controlgear . 7
3.7 Characteristic quantities . 8
3.8 Index of definitions . 8
4 Normal and special service conditions . 9
5 Ratings . 9
5.1 General . 9
5.3 Rated insulation level (U , U , U ) . 9
d p s
6 Design and construction . 9
6.1 General . 9
6.11 Nameplates. 9
6.12 Locking devices . 10
6.13 Position indication . 10
6.101 Requirements for simultaneity of poles during single closing and single
opening operations . 10
6.102 Operation of disconnecting circuit-breakers . 10
6.103 Pressure limits of fluids for operation . 10
6.104 Vent outlets . 10
6.105 Time quantities . 10
6.106 Static mechanical loads . 11
6.107 Disconnecting circuit-breaker classification . 11
6.108 Requirements in respect of the isolating distance of disconnecting circuit-
breakers . 11
7 Type tests . 11
7.1 General . 11
7.2 Dielectric tests . 11
7.3 Radio interference voltage (RIV) test . 11
7.4 Resistance measurement . 11
7.5 Continuous current tests . 11
7.6 Short-time withstand current and peak withstand current tests . 12
7.7 Verification of the protection . 12
7.8 Tightness tests . 12
7.9 Electromagnetic compatibility tests (EMC) . 12
7.10 Additional tests on auxiliary and control circuits . 12
7.11 X-radiation for vacuum interrupters . 12
7.101 Mechanical and environmental tests . 12
7.102 Miscellaneous provisions for making and breaking tests . 13
7.103 General considerations for making and breaking tests . 13

7.104 Demonstration of arcing times . 13
7.105 Short-circuit test quantities . 13
7.106 Short-circuit test procedure . 13
7.107 Terminal fault tests . 13
7.108 Additional short-circuit tests . 13
7.109 Short-line fault tests . 13
7.110 Out-of-phase making and breaking tests . 13
7.111 Capacitive current tests . 14
7.112 Tests to verify the proper function of the position indicating device . 14
7.113 Combined function test . 14
8 Routine tests . 18
8.1 General . 18
9 Guide to the selection of disconnecting circuit-breakers (informative) . 18
10 Information to be given with enquires, tenders and orders (informative) . 18
11 Transport, storage, installation, operation instructions and maintenance. 19
12 Safety . 19
13 Influence of the product on the environment . 19
Annex A (informative) Explanatory notes and examples of disconnecting circuit-
breakers . 20
Bibliography . 21

Figure 1 – Test sequence for mechanical operations and short-circuit combined
function tests when performed as separate tests . 15
Figure 2 – Test sequence for mechanical operations and short-circuit combined
function tests when performed in one sequence . 16
Figure A.1 – A making or breaking unit (or several identical units connected in series)
which satisfies the dielectric requirements of a disconnector . 20
Figure A.2 – Device with a single gap which is divided into a making or breaking
section and an isolating section . 20
Figure A.3 – Circuit-breaker which, together with a series connected disconnector,
commonly satisfies the dielectric requirements of a disconnector in open position . 20

– 4 – IEC 62271-108:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 108: High-voltage alternating current disconnecting
circuit-breakers 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 co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
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Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62271-108 has been prepared by subcommittee 17A, Switching
devices of IEC technical committee 17: High-voltage switchgear and controlgear.
This second edition cancels and replaces the first edition published in 2005. This edition
contains the following significant technical changes with respect to the previous edition:
– The document has been restructured according to IEC 62271-1:2017.
– The document has been adapted to some of the changes introduced in IEC 62271-100:– .
– The document has been adapted to some of the changes introduced in IEC 62271-
102:2018.
– References have been reviewed and updated.
_____________
Under preparation. Stage at the time of publication: IEC CDV 62271-100:2020.

– Some definitions have been reviewed and adapted to the latest IEV editions.
– Rated static terminal load and static terminal load test have been removed and a design
requirement for static mechanical loads has been included.
– Additional type tests for auxiliary and control circuits have been included.
– X-radiation test procedure for vacuum interrupters has been included.
– Type test for testing of interlocking device and type test for testing of temporary
mechanical locking devices have been included.
– Special requirements for making and breaking tests on class E2 disconnecting circuit-
breakers have been removed.
The text of this standard is based on the following documents:
FDIS Report on voting
17A/1269/FDIS 17A/1274/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This document is to be read in conjunction with IEC 62271-100:– and IEC 62271-102:2018, to
which it refers and which are applicable, unless otherwise specified. In order to simplify the
indication of corresponding requirements, the same numbering of clauses and subclauses is
used as in IEC 62271-1:2017. Amendments to these clauses and subclauses are given under
the same numbering, whilst additional subclauses are numbered from 101.
A list of all parts of the IEC 62271 series, under the general title High-voltage switchgear and
controlgear, can be found on the IEC website.
In Canada, disconnecting circuit-breakers are accepted only when a visible gap is provided.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 62271-108:2020 © IEC 2020
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 108: High-voltage alternating current disconnecting
circuit-breakers for rated voltages above 52 kV

1 Scope
This part of IEC 62271 applies to high-voltage alternating current disconnecting circuit-
breakers for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above
52 kV.
This document identifies which requirements of IEC 62271-1, IEC 62271-100:– and
IEC 62271-102 are applicable. It also gives the additional requirements specific to these
devices.
This document covers single switching devices which perform the functions of both a circuit-
breaker and a disconnector by means of contacts housed in a single enclosure, and in which
the circuit-breaker contacts in the open position satisfy, or contribute to, the isolating
requirements of the disconnector function. As there is interaction between the requirements of
the separate functions, it is important to consider the standardization of requirements. This
document details the requirements for a disconnecting circuit-breaker, identifying where these
differ from the separate requirements of a discrete circuit-breaker and a disconnector.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60050-441:1984, International electrotechnical vocabulary (IEV) – Part 441: Switchgear,
controlgear and fuses
IEC 60050-441:1984/AMD1:2000 (available at: http://www.electropedia.org)
IEC 60050-614:2016, International electrotechnical vocabulary (IEV) – Part 614: Generation,
transmission and distribution of electricity – Operation (available at:
http://www.electropedia.org)
IEC 62271-1:2017, High-voltage switchgear and controlgear – Part 1: Common specifications
for alternating current switchgear and controlgear
IEC 62271-100:–, High-voltage switchgear and controlgear – Part 100: Alternating current
circuit-breakers
IEC 62271-102:2018, High-voltage switchgear and controlgear – Part 102: Alternating current
disconnectors and earthing switches
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-441,
IEC 60050-614 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
NOTE 1 Certain definitions taken from IEC 60050-441, IEC 60050-614 and IEC 62271-1 are recalled here for
ease of reference.
NOTE 2 Additional definitions given here are classified in a manner that aligns with the classification used in
IEC 60050-441.
3.1 General terms and definitions
No particular definitions.
3.2 Assemblies of switchgear and controlgear
No particular definitions.
3.3 Parts of assemblies
No particular definitions.
3.4 Switching devices
3.4.101
circuit-breaker
mechanical switching device, capable of making, carrying and breaking currents under normal
circuit conditions and also making, carrying for a specified time and breaking currents under
specified abnormal circuit conditions such as those of short circuit
[SOURCE: IEC 60050-441:2000, 441-14-20]
3.4.102
disconnecting circuit-breaker
circuit-breaker satisfying the requirements of a disconnector, when the contacts are in open
position
Note 1 to entry: For design examples of disconnecting circuit-breakers, refer to Annex A.
3.5 Parts of switchgear and controlgear
3.5.101
power kinematic chain
mechanical connecting system between the operating mechanism and the moving contacts,
both included
3.6 Operational characteristics of switchgear and controlgear
3.6.101
closed position
position in which the predetermined continuity of the main
circuit of the device is secured
[SOURCE: IEC 60050-441:2000, 441-16-22]

– 8 – IEC 62271-108:2020 © IEC 2020
3.6.102
open position
position in which the predetermined clearance between
open contacts in the main circuit of the device is secured
[SOURCE: IEC 60050-441:2000, 441-16-23]
3.6.103
interlocking device
device which makes the operation of a switching device dependent upon the position or
operation of one or more other pieces of equipment
[SOURCE: IEC 60050-441:2000, 441-16-49]
3.7 Characteristic quantities
3.7.101
insulation level
set of withstand voltages specified which characterize the dielectric strength of the insulation
[SOURCE: IEC 60050-614:2016, 614-03-23]
3.7.102
external insulation
distances in atmospheric air, and surfaces of solid insulation of disconnectors and earthing
switches in contact with the air, which are subject to dielectric stresses and to the effect of
atmospheric and other external conditions
Note 1 to entry: External insulation is either weather-protected or non-weather-protected, designed to operate
outside or inside closed shelters, respectively.
Note 2 to entry: Other external conditions include pollution, humidity, vermin, etc.
[SOURCE: IEC 60050-614:2016, 614-03-02, modified – Note 1 to entry has been added.]
3.7.103
internal insulation
internal solid, liquid or gaseous parts of the insulation of equipment which are protected from
the effects of atmospheric and other external conditions
[SOURCE: IEC 60050-614:2016, 614-03-03, modified – In the definition, "distances of the"
has been deleted and "parts of the" has been added.]
3.7.104
isolating distance
clearance between open poles meeting the
safety requirements specified for disconnectors
[SOURCE: IEC 60050-441:2000, 441-17-35, modified – In the definition, "contacts" has been
replaced by "poles".]
3.8 Index of definitions
C
Circuit-breaker 3.4.101
Closed position (of a mechanical switching device) 3.6.101
D – E
Disconnecting circuit-breaker 3.4.102

External insulation 3.7.102
I
Insulation level 3.7.101
Interlocking device 3.6.103
Internal insulation 3.7.103
Isolating distance (of a pole of a mechanical switching device) 3.7.104
O – P
Open position (of a mechanical switching device) 3.6.102
Power kinematic chain 3.5.101
4 Normal and special service conditions
Clause 4 of IEC 62271-100:– is applicable.
5 Ratings
5.1 General
Clause 5 of IEC 62271-100:– is applicable with the following additions and modification.
The rated characteristics of the disconnecting circuit-breaker are referred to the rated
operating sequence.
Disconnecting circuit-breakers need not be assigned ratings with respect to bus-transfer
current switching. The bus-transfer current switching capability is covered by the making and
breaking tests in IEC 62271-100:–.
Rated contact zone is not applicable for disconnecting circuit-breakers.
5.3 Rated insulation level (U , U , U )
d p s
Subclause 5.3 of IEC 62271-100:– is applicable with the following addition:
The standard values of rated withstand voltages across the isolating distance of the
disconnecting circuit-breaker are given in columns 3 and 5 of Table 1 and Table 2, columns 3,
6 and 8 of Table 3 and columns 3, 5 and 7 of Table 4 in IEC 62271-1:2017.
6 Design and construction
6.1 General
Clause 6 of IEC 62271-100:– and IEC 62271-102:2018 are applicable, unless stated
otherwise.
The design of the disconnecting circuit-breaker shall take into account the mechanical,
electrical and other requirements of a circuit-breaker and a disconnector as a single device.
6.11 Nameplates
Subclause 6.11 of IEC 62271-100:– is applicable with the following addition:

– 10 – IEC 62271-108:2020 © IEC 2020
The nameplate shall state that the device is a disconnecting circuit-breaker and the data shall
be applicable to both a circuit-breaker and a disconnector of the declared ratings.
6.12 Locking devices
Subclause 6.12 of IEC 62271-100:– is applicable with the following addition.
Disconnecting circuit-breakers to be mechanically interlocked and/or temporarily mechanically
locked by blocking the shaft or power kinematic chain of the disconnecting circuit–breaker,
and not integrated in switchgear and controlgear assemblies covered by IEC 62271-200,
IEC 62271-201 or IEC 62271-203, shall be designed to withstand the tests specified in
7.101.6 and 7.101.7.
6.13 Position indication
Subclauses 6.13 and 6.104.3.2 of IEC 62271-102:2018 are applicable.
6.101 Requirements for simultaneity of poles during single closing and single opening
operations
Subclause 6.101 of IEC 62271-100:– is applicable.
6.102 Operation of disconnecting circuit-breakers
Subclauses 6.102 of IEC 62271-100:– and 6.104 of IEC 62271-102:2018 are applicable with
the following additions.
6.102.1 Securing of position
Disconnecting circuit-breakers shall be designed in such a way that they cannot come out of
their open or closed position by gravity, wind pressure, vibrations, reasonable shocks or
accidental touching of the operating system.
Disconnecting circuit-breakers shall have provisions for temporary mechanical locking in the
open position. Provisions for temporary mechanical locking in the closed position are required
only if specified by the user.
NOTE 1 Temporary mechanical securing of the disconnecting circuit-breaker in the closed position prevents the
short circuit protection function and is used only when alternative protection is provided.
NOTE 2 Temporary mechanical locking in the closed position is typically required when the disconnecting circuit-
breaker is intended to be used for earthing purposes.
6.102.2 Additional requirements for power operated mechanisms
Subclause 6.104.2 of IEC 62271-102:2018 is not applicable because manual operating
facilities for such a device when in service are not required.
6.103 Pressure limits of fluids for operation
Subclause 6.103 of IEC 62271-100:– is applicable.
6.104 Vent outlets
Subclause 6.104 of IEC 62271-100:– is applicable.
6.105 Time quantities
Subclause 6.105 of IEC 62271-100:– is applicable.

6.106 Static mechanical loads
Subclause 6.106 of IEC 62271-100:– is applicable.
6.107 Disconnecting circuit-breaker classification
Subclause 6.107 of IEC 62271-100:– is applicable.
6.108 Requirements in respect of the isolating distance of disconnecting circuit-
breakers
Subclause 6.102 of IEC 62271-102:2018 is applicable with the following replacement of
second paragraph:
The design shall take into account the long-term effects of contamination caused by wear and
arcing by-products. The effectiveness of the design to withstand these effects in service shall
be verified by testing according to 7.113.
7 Type tests
7.1 General
Clause 7 of IEC 62271-100:– is applicable as appropriate to the rating of the device.
Additional tests are required to demonstrate that the device complies with the relevant
requirements of a disconnector.
In particular, the combined function tests are required to demonstrate that the dielectric
withstand across the isolating distance remains without undue deterioration after the type-
tests specified in IEC 62271-100:–.
If a circuit-breaker already has been type-tested according to IEC 62271-100:–, only the
additional tests indicated below need to be performed.
For convenience of testing, the additional combined function tests may be combined with
those for the circuit-breaker.
7.2 Dielectric tests
Subclause 7.2 of IEC 62271-100:– is applicable with the following addition:
The test values across the isolating distance of the disconnecting circuit-breaker are given in
columns 3 and 5 of Table 1 and Table 2, columns 3, 6 and 8 of Table 3 and columns 3, 5 and
7 of Table 4 in IEC 62271-1:2017.
7.3 Radio interference voltage (RIV) test
Subclause 7.3 of IEC 62271-100:– is applicable.
7.4 Resistance measurement
Subclause 7.4 of IEC 62271-100:– is applicable.
7.5 Continuous current tests
Subclause 7.5 of IEC 62271-100:– is applicable.

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7.6 Short-time withstand current and peak withstand current tests
Subclause 7.6 of IEC 62271-100:– is applicable.
7.7 Verification of the protection
Subclause 7.7 of IEC 62271-100:– is applicable.
7.8 Tightness tests
Subclause 7.8 of IEC 62271-100:– is applicable.
7.9 Electromagnetic compatibility tests (EMC)
Subclause 7.9 of IEC 62271-100:– is applicable.
7.10 Additional tests on auxiliary and control circuits
Subclause 7.10 of IEC 62271-100:– is applicable.
7.11 X-radiation for vacuum interrupters
Subclause 7.11 of IEC 62271-100:– is applicable.
7.101 Mechanical and environmental tests
Subclause 7.101 of IEC 62271-100:– is applicable unless stated otherwise, with the following
additions.
7.101.101 Testing of interlocking devices
Subclause 7.102.6 of IEC 62271-102:2018 is applicable only in the case of a disconnecting
circuit-breaker provided with a mechanical interlocking device.
7.101.102 Testing of temporary mechanical locking devices
All mechanical locking devices shall be subjected to five attempts to perform closing operation
and, if applicable, opening operation, in order to demonstrate compliance with requirements in
6.102.1.
For multipole disconnecting circuit-breakers actuated by a single operating device and with at
least one locking device, this shall be tested as a complete unit. In case of single-pole
operated disconnecting circuit-breakers with a locking device applied in each pole, testing of
one complete pole is permitted to represent the additional poles.
Before each attempt, the disconnecting circuit-breaker shall be locked in the intended position
by means of mechanical locking device(s).
The test results are considered to be satisfactory if the locking device(s) can be removed and
re-applied as intended. In order to check the operation of the disconnecting circuit-breaker
after the test, one close no-load operation and one open no-load operation shall be made and
the mechanical characteristics recorded. These mechanical characteristics shall be within the
tolerances specified by the manufacturer. The disconnecting circuit-breaker shall close and
latch satisfactorily.
After the test, a visual inspection of the power kinematic chain of the disconnecting circuit-
breaker shall be done. Any distortion of mechanical parts such that it adversely affects the
operation of the disconnecting circuit-breaker is not allowed.

7.102 Miscellaneous provisions for making and breaking tests
Subclause 7.102 of IEC 62271-100:– is applicable unless stated otherwise.
7.102.9.2 Insulation properties
Subclause 7.102.9.2 of IEC 62271-100:– is applicable with the following addition:
If, during the capacitive current switching tests, restrike(s) occurred, the dielectric
requirements confined to the isolating distance of IEC 62271-102:2018 shall be demonstrated.
The test values across the isolating distance of the disconnecting circuit-breaker are given in
columns 3 and 5 of Table 1 and Table 2, columns 3, 6 and 8 of Table 3 and columns 3, 5 and
7 of Table 4 in IEC 62271-1:2017.
The test arrangement should be such that no interference with the disconnecting circuit-
breaker between the tests is necessary.
However, if this is not possible due to limitation of test facilities, transportation of the test
object between different test plants is allowed. If local safety rules require depressurizing to
enter the test cell or to transport the test object between different test plants, the pressure in
the disconnecting circuit-breaker may be decreased, provided that the gas is reused when
refilling the disconnecting circuit-breaker.
All the used gas may not be available for refilling of the test object. In this case, it is permitted
to top up the test object with new gas to the specified pressure. Proper gas handling should
be used to avoid unnecessary refilling with new gas.
7.103 General considerations for making and breaking tests
Subclause 7.103 of IEC 62271-100:– is applicable.
7.104 Demonstration of arcing times
Subclause 7.104 of IEC 62271-100:– is applicable.
7.105 Short-circuit test quantities
Subclause 7.105 of IEC 62271-100:– is applicable.
7.106 Short-circuit test procedure
Subclause 7.106 of IEC 62271-100:– is applicable.
7.107 Terminal fault tests
Subclause 7.107 of IEC 62271-100:– is applicable.
7.108 Additional short-circuit tests
Subclause 7.108 of IEC 62271-100:– is applicable.
7.109 Short-line fault tests
Subclause 7.109 of IEC 62271-100:– is applicable.
7.110 Out-of-phase making and breaking tests
Subclause 7.110 of IEC 62271-100:– is applicable.

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7.111 Capacitive current tests
Subclause 7.111 of IEC 62271-100:– is applicable.
7.112 Tests to verify the proper function of the position indicating device
7.112.1 General
Subclause 7.105 of IEC 62271-102:2018 is applicable with the following additions.
In the case of a disconnecting circuit-breaker with several making (or breaking) units
connected in series, only the moving contacts in the unit located furthest from the opening
operating device of the pole shall be locked.
For convenience of testing, the test may be performed without insulating gas in the blocked
unit or pole.
For disconnecting circuit-breakers with independent power operation actuated by the release
of latching devices, nominal supply voltage for operation of the latch may be used for the test.
7.112.2 Test procedure
Subclause 7.105.2 of IEC 62271-102:2018 is applicable with the following addition:
No adjustment or replacement shall be made along the position indicating chain between the
attempts. No break on the mechanical kinematic chain shall be produced during the test. The
test is considered passed if after each attempt the moving contact(s) remain in the same
position and the position indicating device indicates correctly the position of the moving
contacts.
7.113 Combined function test
7.113.1 General
The disconnecting circuit-breaker shall fulfil the dielectric requirements for the isolating
distance not only in new condition but also in service. Therefore the dielectric withstand
across the isolating distance shall be demonstrated after a mechanical operation test as well
as after the specified short-circuit test-duty.
These additional combined function tests are specific type test requirements for the device;
they are not the condition check tests detailed in 7.2.12 of IEC 62271-100:– and IEC 62271-
102:2018.
These tests verify that the apparatus fully maintains its insulating characteristics between
open contacts after the given mechanical and short-circuit breaking tests. The disconnecting
circuit-breakers that pass successfully these combined function tests are considered to
withstand internal contamination that can occur in service due to contact wear and any
decomposition by-product generated by the arc interruption, thus complying with the design
criterion given in 6.108.
These separate test requirements shall be as detailed in 7.113.2 and 7.113.3. For
convenience the mechanical operations and short-circuit combined function tests may be
performed in one sequence. For the choice of test sequence, see the flow chart diagrams in
Figures 1 and 2.
For disconnecting circuit-breakers assigned to Class E2, test-duty T100s is replaced by the wear phase as
described in IEC TR 62271-310:2008 [1] .
Figure 1 – Test sequence for mechanical operations and short-circuit combined
function tests when performed as separate tests
_____________
Numbers in square brackets refer to the Bibliography.

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For disconnecting circuit-breakers assigned to Class E2, test-duty T100s is replaced by the wear phase as
described in IEC TR 62271-310:2008 [1].
Figure 2 – Test sequence for mechanical operations and short-circuit combined
function tests when performed in one sequence
7.113.2 Mechanical operations combined function test
Following a mechanical operation test as detailed in 7.101, the rated insulating level across
the isolating distance of IEC 62271-102 shall be demonstrated. The test values across the
isolating distance of the disconnecting circuit-breaker are given in columns 3 and 5 of Table 1
and Table 2, columns 3, 6 and 8 of Table 3 and columns 3, 5 and 7 of Table 4 in
IEC 62271-1:2017.
As an alternative, a mechanical operation test confined to the mechanical wear of the contacts
only before the above mentioned dielectric tests may be performed with recording of the
operating characteristics (reference mechanical travel curve) at the beginning and at the end
of the tests only.
The test arrangement should be such that no interference with the disconnecting
circuit-breaker between the tests is necessary.
However, if this is not possible due to limitation of test facilities, transportation of the test
object between different test plants is allowed. If local safety rules require depressurizing to
enter the test cell or to transport the test object between different test plants, the pressure in
the disconnecting circuit-breaker may be decreased. In this case, it is permitted to refill the
disconnecting circuit-breaker either with the gas used at the previous mechanical operation
test or with new gas.
All the used gas may not be available for refilling of the test object. In this case, it is permitted
to top up the test object with new gas to the specified pressure.
7.113.3 Short-circuit combined function test
7.113.3.1 Disconnecting circuit-breakers of class E1
Following a circuit-breaker short-circuit test sequence T100s as detailed in 7.107, the rated
insulating level across the isolating distance of IEC 62271-102 shall be demonstrated. This
requirement may be demonstrated after the short-circuit type testing of IEC 62271-100:–.
The test values across the isolating distance of the disconnecting circuit-breaker are given in
columns 3 and 5 of Table 1 and Table 2, columns 3, 6 and 8 of Table 3 and columns 3, 5 and
7 of Table 4 in IEC 62271-1:2017.
NOTE 1 As there are
...