SIST EN IEC 62271-211:2024

SLOVENSKI STANDARD
01-december-2024
Visokonapetostne stikalne in krmilne naprave - 211. del: Neposredna povezava
med elektroenergetskimi transformatorji in plinsko izoliranimi stikalnimi
napravami v kovinskih ohišjih za naznačene napetosti nad 52 kV (IEC 62271-
211:2024)
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 62271-211:2024)
Hochspannungs-Schaltgeräte und -Schaltanlagen - Teil 211: Direkte Verbindungen
zwischen Leistungstransformatoren und gasisolierten metallgekapselten Schaltanlagen
für Bemessungsspannungen über 52 kV (IEC 62271-211:2024)
Appareillage à haute tension - Partie 211: Raccordements directs entre transformateurs
de puissance et appareillage sous enveloppe métallique à isolation gazeuse de tension
assignée supérieure à 52 kV (IEC 62271-211:2024)
Ta slovenski standard je istoveten z: EN IEC 62271-211:2024
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 62271-211

NORME EUROPÉENNE
EUROPÄISCHE NORM November 2024
ICS 29.130.10 Supersedes EN 62271-211:2014;
EN 62271-211:2014/AC:2015;
EN 62271-211:2014/AC:2017-09
English Version
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 62271-211:2024)
Appareillage à haute tension - Partie 211: Raccordements Hochspannungs-Schaltgeräte und -Schaltanlagen - Teil
directs entre transformateurs de puissance et appareillage 211: Direkte Verbindungen zwischen
sous enveloppe métallique à isolation gazeuse de tensions Leistungstransformatoren und gasisolierten
assignées supérieures à 52 kV metallgekapselten Schaltanlagen für
(IEC 62271-211:2024) Bemessungsspannungen über 52 kV
(IEC 62271-211:2024)
This European Standard was approved by CENELEC on 2024-10-09. 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
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62271-211:2024 E

European foreword
The text of document 17C/935/FDIS, future edition 2 of IEC 62271-211, 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 62271-211:2024.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2025-11-30
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2027-11-30
document have to be withdrawn
This document supersedes EN 62271-211:2014 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.
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 62271-211:2024 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 62271-209:2019 NOTE Approved as EN IEC 62271-209:2019 (not modified)
Approved as EN IEC 62271-209:2019/A1:2022 (not
IEC 62271-209:2019/AMD1:2022 NOTE
modified)
ISO 17892-2:2014 NOTE Approved as EN ISO 17892-2:2014 (not modified)
IEC 60071-1:2019 NOTE Approved as EN IEC 60071-1:2019 (not modified)
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 60076 series Power transformers EN 60076 series
IEC 60076-1 2011 Power transformers - Part 1: General EN 60076-1 2011
IEC 60137 2017 Insulated bushings for alternating voltages EN 60137 2017
above 1000 V
IEC 61936-1 2021 Power installations exceeding 1 kV AC and EN IEC 61936-1 2021
1,5 kV DC - Part 1: AC
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 62271-203 2022 High-voltage switchgear and controlgear - EN IEC 62271-203 2022
Part 203: AC gas-insulated metal-enclosed
switchgear for rated voltages above 52 kV
IEC 62271-207 2023 High-voltage switchgear and controlgear - EN IEC 62271-207 2023
Part 207: Seismic qualification for gas-
insulated switchgear assemblies, metal
enclosed and solid-insulation enclosed
switchgear for rated voltages above 1 kV

IEC 62271-211 ®
Edition 2.0 2024-09
INTERNATIONAL
STANDARD
High-voltage switchgear and controlgear –

Part 211: Direct connection between power transformers and gas-insulated

metal-enclosed switchgear for rated voltages above 52 kV

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.130.10 ISBN 978-2-8322-9578-6

– 2 – IEC 62271-211:2024 © IEC 2024
CONTENTS
FOREWORD . 4
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Normal and special service conditions . 10
4.1 Normal service conditions . 10
4.2 Special service conditions . 10
5 Ratings . 10
5.1 General . 10
5.2 Rated voltage (U ) . 10
r
5.3 Rated insulation level (U , U , U ) . 10
d p s
5.4 Rated frequency (f ) . 10
r
5.5 Rated continuous current (I ) . 11
r
5.6 Rated short-time withstand current (I ) and rated thermal short-time
k
current (I ) . 11
th
5.7 Rated peak withstand current (I ) and rated dynamic current (I ) . 11
p d
5.8 Rated duration of short-circuit (t ) and of thermal short-time current (t ) . 11
k th
6 Design and construction . 11
6.1 Gas and vacuum tightness . 11
6.2 Gas pressure for insulation of the bushing inside the gas-insulated
switchgear (GIS) enclosure . 12
6.3 Pressure withstands requirements . 12
6.4 Standard dimensions and tolerances. 12
6.4.1 General . 12
6.4.2 Single-phase direct connection between oil-filled transformer and
switchgear . 13
6.4.3 Three-phase direct connection between oil-filled transformer and
switchgear . 13
6.4.4 Connection between gas-insulated transformer and switchgear . 13
6.4.5 Transformer tolerances . 13
6.4.6 Mounting of the transformer on its foundation . 13
6.5 Limits of supply . 13
6.6 Mechanical forces applied on the connection interface . 15
6.7 Mechanical forces applied on the bushing flange . 15
6.8 Horizontal and vertical displacement . 17
6.9 Vibrations . 17
7 Type tests . 17
7.1 General . 17
7.2 Dielectric tests . 17
7.2.1 Dielectric tests of bushing . 17
7.2.2 Dielectric tests of transformer connection in a single-phase enclosure . 18
7.2.3 Dielectric tests of transformer connection in a three-phase enclosure . 18
7.3 Cantilever loads withstand tests . 18
7.4 Gas tightness tests . 18
8 Routine tests . 18

IEC 62271-211:2024 © IEC 2024 – 3 –
8.1 General . 18
8.2 External pressure test of the bushing . 18
8.3 Tightness tests . 19
9 Guide to the selection of switchgear and controlgear (informative) . 19
10 Information to be given with enquiries, tenders and orders (informative) . 19
11 Transport, storage, installation, operating instructions and maintenance. 19
12 Safety . 19
13 Environmental aspects . 20
Bibliography . 25

Figure 1 – Typical direct connection between power transformer and gas-insulated
metal-enclosed switchgear . 21
Figure 2 – Standard dimensions for typical direct connection between power

transformer and gas-insulated metal-enclosed switchgear . 22
Figure 3 – Transformer tolerances for a typical direct connection shown on the
example of a three-phase power transformer connected to a single-phase
gas-insulated metal-enclosed switchgear . 23
Figure 4 – Transformer tolerances for a typical direct connection shown on the
example of a three-phase power transformer connected to a three-phase gas-insulated
metal-enclosed switchgear up to 170 kV . 24

Table 1 – Moments and forces applied on the bushing flange and transformer . 16

– 4 – IEC 62271-211:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 211: Direct connection between power transformers and
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
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
misinterpretation by any end user.
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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 62271-211 has been prepared by subcommittee 17C: Assemblies, of IEC technical
committee 17: High-voltage switchgear and controlgear. It is an International Standard.
This second edition cancels and replaces the first edition of IEC 62271-211:2014. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) re-numbering of clauses according to IEC 62271-1:2017,
b) Clause 3: updating definition about bushing (3.1), updating some pressure definitions (3.6,
3.7, 3.8, 3.9), rewording definition about proctor density (3.11), new term very-fast-front
overvoltage (3.12),
IEC 62271-211:2024 © IEC 2024 – 5 –
c) Clause 5 (former clause 4): add a subclause 5.1 General, according to IEC 62271-1:2017
and IEC 62271-203:2022,
1) subclause 5.5: new first paragraph, rewording second paragraph,
2) subclause 5.8: modify the term "Rated duration of thermal short-time current" of the
bushing,
d) Clause 6 (former Clause 5): restructure and rewording of subclauses:
1) 6.1 (former 5.3): requirements about gas and vacuum tightness of the transformer
bushing
2) 6.3 (former 5.2): harmonization with IEC 62271-203:2022 about typical maximum
pressure in service for SF , other gases and gas mixtures,
3) 6.4 (former 5.8), rewording
4) 6.5 (former 5.1), some rewording and modification
5) 6.6 (former 5.4), some rewording, updated references
6) 6.7 (former 5.5), some rewording
7) 6.8 (former 5.6), some rewording
8) 6.9 (former 5.7), slight rewording,
e) Clause 7 (former clause 6) type tests: some rewording and clarifications about references,
f) Clause 8 (former clause 7) routine tests:
-mixtures and other gases than SF ,
1) 8.2 (former 7.2): add a paragraph about SF
6 6
2) 8.3 (former 7.3): update reference to relevant on-site test according to
IEC 62271-203:2022,
g) Clause 9 Guide to the selection of switchgear and controlgear (new): informative, to have a
reference to IEC 62271-203:2022,
h) Clause 11 (former 10): updated headline and updated reference according to
IEC 62271-1:2017,
i) new Clauses 12 Safety and 13 Environmental aspects: Adding of references to safety and
environmental aspects,
j) correction of errors in Corrigendum 2 of IEC 62271-211:2017,
k) modified orientation of Figure 1 to Figure 4 for easier reading of the tables,
The text of this International Standard is based on the following documents:
Draft Report on voting
17C/935/FDIS 17C/945/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/publications.
A list of all parts in the IEC 62271 series, published under the general title High-voltage
switchgear and controlgear, can be found on the IEC website.

– 6 – IEC 62271-211:2024 © IEC 2024
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, or
• revised.
IEC 62271-211:2024 © IEC 2024 – 7 –
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 211: Direct connection between power transformers and
gas-insulated metal-enclosed switchgear for rated voltages above 52 kV

1 Scope
This part of IEC 62271 is applicable to single- and three-phase direct connections between gas-
insulated metal-enclosed switchgear (GIS) for rated voltages above 52 kV and transformer
arrangements to establish electrical and mechanical interchange ability and to determine the
limits of supply for the transformer connection.
Direct connections are immersed on one end in the transformer oil or insulating gas and on the
other end in the insulating gas of the switchgear.
Transformer arrangements are single-phase transformers with single-phase enclosed
arrangement, three-phase transformers with three single-phase enclosed arrangements or
three-phase transformers with a three-phase enclosed arrangement with three transformer
bushings.
The connection satisfies the requirements of IEC 62271-203 for gas-insulated metal-enclosed
switchgear, IEC 60076 for power transformer and IEC 60137 for completely immersed
bushings.
For the purpose of this document the term “switchgear” is used for “gas-insulated metal-
enclosed switchgear and the term “transformer” is used for “power transformer”.
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 60076 (all parts), Power transformers
IEC 60076-1:2011, Power transformers – Part 1: General
IEC 60137:2017, Insulated bushings for alternating voltages above 1 000 V
IEC 61936-1:2021, Power installations exceeding 1 kV AC and 1,5 kV DC – Part 1: AC
IEC 62271-1:2017, High-voltage switchgear and controlgear – Part 1: Common specifications
for alternating current switchgear and controlgear
IEC 62271-1:2017/AMD1:2021
IEC 62271-203:2022, High-voltage switchgear and controlgear – Part 203: Gas-insulated metal-
enclosed switchgear for rated voltages above 52 kV
IEC 62271-207:2023, High-voltage switchgear and controlgear – Part 207: Seismic qualification
for gas-insulated switchgear assemblies, metal enclosed and solid-insulation enclosed
switchgear for rated voltages above 1 kV

– 8 – IEC 62271-211:2024 © IEC 2024
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62271-1, as well as
the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
bushing
device that enables one or several conductors to pass through an enclosure and insulate the
conductors from it
[SOURCE: IEC 60050-471:2007 [1] , 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.]
3.2
completely immersed bushing
bushing, both ends of which are intended to be immersed in an insulating medium other than
ambient air (e.g. oil or gas)
[SOURCE: IEC 60050-471:2007 [1], 471-02-04]
3.3
gas-insulated switchgear (GIS) 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.
[SOURCE: IEC 62271-203:2022, 3.103, modified – the acronym GIS has been added]
3.4
main circuit end terminal
part of the main circuit of a gas-insulated metal-enclosed switchgear forming part of the
connection interface
[SOURCE: IEC 62271-209:2019 [2], 3.2]
3.5
transformer connection enclosure
part of the gas-insulated metal-enclosed switchgear which houses one end of a completely
immersed bushing fitted on a power transformer and a main circuit end terminal
___________
Numbers in square brackets refer to the Bibliography.

IEC 62271-211:2024 © IEC 2024 – 9 –
3.6
maximum external operating gas pressure
maximum pressure of the gaseous insulating medium in which the bushing is partially or
completely immersed when in operation
Note 1 to entry: It is at least equal to the maximum pressure in the transformer connection enclosure of the GIS at
the highest temperature that the gas used for insulation can reach under specified maximum service conditions.
Note 2 to entry: In case of gas-insulated transformers it is also the maximum insulating pressure of the gaseous
insulating medium in which the end of the bushing is immersed into the power transformer, when in operation, the
bushing-power transformer connection assembly carrying its rating continuous current at the maximum ambient
temperature.
[SOURCE: IEC 60137:2017, 3.32 – modified: Note 1 to entry and Note 2 to entry were added]
3.7
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.
[SOURCE: IEC 62271-203:2022, 3.114]
3.8
filling pressure p for insulation
re
filling density ρ for insulation
re
pressure (in Pa), for insulation, referred to the standard atmospheric air conditions of +20 °C
and 101,3 kPa (or density), which may be expressed in relative or absolute terms, to which the
assembly is filled before being put into service
[SOURCE: IEC 62271-1:2017, 3.6.5.1, modified – deleted the terms "and/or switching", deleted
"or automatically replenished"]
3.9
minimum functional pressure p for insulation
me
minimum functional density ρ for insulation
me
pressure (in Pa), for insulation, referred to the standard atmospheric air conditions of +20 °C
and 101,3 kPa (or density), which may be expressed in relative or absolute terms, at which and
above which the characteristics of the switchgear-power-transformer connection are maintained
[SOURCE: IEC 62271-1:2017, 3.6.5.5, modified – deleted the terms "and/or switching", added
"the characteristics of the switchgear-power-transformer connection" deleted "rated
characteristics of switchgear and controlgear"]
3.10
insulated junction
all parts which are needed to insulate between the transformer and the switchgear, including
but not limited to the insulating flange
3.11
proctor density
highest dry density of a soil for a given compaction effort depending on the amount of water the
soil contains during soil compaction of controlled magnitude according Proctor Standard test
Note 1 to entry: Proctor Standard test is defined in ASTM D-698 [3]. However, other tests methods exist providing
similar information, but not always equivalent, like for example ISO 17892-2 [4], BS 1377-1 [5], UNE 103500 [6], NF
P 94-093 [7] and DIN 18127 [8].

– 10 – IEC 62271-211:2024 © IEC 2024
3.12
very-fast-front overvoltage
VFFO
transient overvoltage, usually unidirectional with time to peak T ≤ 0,1 µs, and with or without
f
superimposed oscillations at frequency 30 kHz < f < 100 MHz
Note 1 to entry: Transient overvoltage generated by switching operations in GIS have a time to peak in a range of
nanoseconds. They are usually named VFTO (very fast transients overvoltage) or related to the grounded
encapsulation named as very-fast-front transient ground potential rises.
[SOURCE: IEC 60071-1:2019 [9], 3.17.2.3, modified – Note 1 to entry added]
4 Normal and special service conditions
4.1 Normal service conditions
Subclause 4.1 of IEC 62271-203:2022 is applicable.
4.2 Special service conditions
Subclause
...