IEC 62271-212:2016

IEC 62271-212 ®
Edition 1.0 2016-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
High-voltage switchgear and controlgear –
Part 212: Compact Equipment Assembly for Distribution Substation (CEADS)

Appareillage à haute tension –
Partie 212: Ensemble Compact d'Equipement pour Postes de Distribution
(ECEPD)
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IEC 62271-212 ®
Edition 1.0 2016-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
High-voltage switchgear and controlgear –

Part 212: Compact Equipment Assembly for Distribution Substation (CEADS)

Appareillage à haute tension –

Partie 212: Ensemble Compact d'Equipement pour Postes de Distribution

(ECEPD)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.130.10 ISBN 978-2-8322-3633-8

– 2 – IEC 62271-212:2016 © IEC 2016
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 General . 10
1.1 Scope . 10
1.2 Normative references . 10
2 Normal and special service conditions . 12
2.1 Normal service conditions . 12
2.2 Special service conditions . 12
3 Terms and definitions . 12
4 Ratings . 14
4.1 Rated voltage . 14
4.2 Rated insulation level . 15
4.3 Rated frequency (f ) . 15
r
4.4 Rated normal current and temperature rise . 15
4.4.1 Rated normal current (I ,I ) . 15
r nA
4.4.2 Temperature rise . 15
4.5 Rated short-time withstand currents (I , I , I ) . 16
k ke cw
4.5.101 Rated short-time phase to phase and rated short-time phase to earth
withstand currents of high-voltage functional unit and rated short-time
withstand current of high-voltage interconnection (I , I ) . 16
k ke
4.5.102 Rated short-time withstand currents of low-voltage functional unit and
low-voltage interconnection (I ). 16
cw
4.5.103 Short-time withstand currents of high-voltage/low-voltage transformer
functional unit . 16
4.6 Rated peak withstand currents (I , I , I ) . 16
p pe pk
4.6.101 Rated peak phase to phase and rated peak phase to earth withstand
currents of high-voltage functional unit and rated peak withstand current
of high-voltage interconnection (I , I ) . 16
p pe
4.6.102 Rated peak withstand currents of low-voltage and low-voltage
interconnection (I ) . 17
pk
4.6.103 Peak withstand currents of high-voltage/low-voltage transformer

functional unit . 17
4.7 Rated durations of short circuit (t , t , t ) . 17
k ke cw
4.7.101 Rated duration of phase to phase short circuit (t ) and rated duration of
k
phase to earth short circuit (t ) of high-voltage functional unit and
ke
rated duration of short-circuit of high-voltage interconnection . 17
4.7.102 Rated duration of short circuit (t ) for low-voltage functional unit and
cw
low-voltage interconnection . 17
4.7.103 Duration of short circuit for high-voltage/low-voltage transformer
functional unit . 17
4.8 Rated supply voltage of closing and opening devices and of auxiliary and
control circuits . 17
4.9 Rated supply frequency of closing and opening devices and of auxiliary
circuits . 17
4.101 Rated power and total losses of CEADS . 18
4.102 Ratings of the internal arc classification (IAC) . 18
4.102.1 General . 18
4.102.2 Types of accessibility (A, B, AB) . 18
4.102.3 Classified sides . 18

4.102.4 Rated arc fault currents (I , I ) . 18
A Ae
4.102.5 Rated arc fault duration (t , t ) . 19
A Ae
5 Design and construction . 19
5.1 Requirements for liquids in switchgear and controlgear . 19
5.2 Requirements for gases in switchgear and controlgear . 20
5.3 Earthing of switchgear and controlgear . 20
5.4 Auxiliary and control equipment . 20
5.5 Dependent power operation . 20
5.6 Stored energy operation . 21
5.7 Independent manual or power operation (independent unlatched operation) . 21
5.8 Operation of releases . 21
5.9 Low- and high-pressure interlocking and monitoring devices . 21
5.10 Nameplates. 21
5.11 Interlocking devices . 21
5.12 Position indication . 21
5.13 Degrees of protection provided by enclosures . 21
5.14 Creepage distances for outdoor insulators . 22
5.15 Gas and vacuum tightness . 22
5.16 Liquid tightness . 22
5.17 Fire hazard (flammability) . 22
5.18 Electromagnetic compatibility (EMC) . 22
5.19 X-ray emission . 22
5.20 Corrosion . 23
5.101 Protection against mechanical stresses . 23
5.102 Protection of the environment due to internal defects . 23
5.103 Internal arc fault . 23
5.104 Enclosures . 24
5.105 Sound emission . 24
5.106 Electromagnetic fields . 24
6 Type tests . 24
6.1 General . 24
6.1.1 Grouping of tests . 25
6.1.2 Information for identification of test objects . 25
6.1.3 Information to be included in type-test reports . 25
6.2 Dielectric tests . 26
6.2.1 General . 26
6.2.2 Dielectric tests on the high-voltage interconnection . 26
6.2.3 Dielectric tests on the low-voltage interconnection . 27
6.2.4 Dielectric tests on high-voltage functional unit . 28
6.2.5 Dielectric tests on high-voltage/low-voltage transformer functional unit . 28
6.2.6 Dielectric tests on low-voltage functional unit . 28
6.2.7 Partial discharge test . 29
6.3 Radio interference voltage (r.i.v) test . 29
6.4 Measurement of the resistance of circuits . 29
6.5 Temperature-rise tests . 29
6.5.1 General . 29
6.5.2 Test conditions . 29
6.5.3 Test methods . 30

– 4 – IEC 62271-212:2016 © IEC 2016
6.5.4 Special case of dry-type high-voltage/low-voltage transformer functional
unit . 33
6.5.5 Measurements . 33
6.6 Short-time withstand current and peak withstand current tests . 35
6.6.1 Short-time and peak withstand current tests on main circuit of high-
voltage and low-voltage functional units . 35
6.6.2 Short-time and peak withstand current tests on high-voltage and low-
voltage interconnections . 35
6.6.3 Short-time and peak withstand current tests on earthing circuits . 35
6.6.4 Short-time and peak withstand current tests on high-voltage/low-voltage
transformer functional unit . 36
6.7 Verification of the protection, . 36
6.7.1 Verification of degree of protection (IP coding) . 36
6.7.2 Verification of resistance to mechanical impacts (IK coding) . 36
6.8 Tightness tests . 36
6.9 Electromagnetic compatibility tests (EMC) . 36
6.10 Additional tests on auxiliary and control circuits . 36
6.10.1 General . 36
6.10.2 Functional tests . 37
6.10.3 Electrical continuity of earthed metallic parts test . 37
6.10.4 Verification of the operational characteristics of auxiliary contacts . 37
6.10.5 Environmental tests . 37
6.10.6 Dielectric test . 37
6.11 X-radiation test procedure for vacuum interrupters . 37
6.101 Internal arc test . 37
6.101.1 General . 37
6.101.2 Test conditions . 38
6.101.3 Arrangement of the equipment . 38
6.101.4 Test procedure . 39
6.101.5 Criteria to pass the test . 39
6.101.6 Test report . 39
6.101.7 Extension of validity of test results . 40
6.102 Verification of making and breaking capacities . 40
6.103 Mechanical operation tests . 40
6.104 Mechanical stability test . 40
6.105 Pressure withstand test for gas-filled compartments. 40
6.106 Measurements of leakage currents of non-metallic enclosures . 41
6.107 Weatherproofing test . 41
6.108 Tightness and mechanical strength for liquid filled compartments . 41
6.109 Measurement or calculation of electromagnetic fields . 41
7 Routine tests . 42
7.1 Dielectric tests on the main circuit . 42
7.1.1 General . 42
7.1.2 Dielectric tests on high-voltage functional unit . 42
7.1.3 Dielectric tests on high-voltage/low-voltage transformer functional unit
and high-voltage interconnection . 43
7.1.4 Dielectric tests on low-voltage functional unit and low-voltage
interconnection . 43
7.2 Tests on auxiliary and control circuits . 43
7.3 Measurement of the resistance of the main circuit . 43

7.4 Tightness test . 43
7.5 Design and visual checks . 43
7.101 Mechanical operation tests on high-voltage functional unit . 43
7.102 Pressure tests of gas-filled compartments . 43
7.103 Tests of auxiliary electrical, pneumatic and hydraulic devices . 44
7.104 Measurement of the resistance of the windings . 44
7.105 Measurement of the voltage ratio . 44
7.106 Measurement of the short circuit impedance and load losses . 44
7.107 Measurement of no-load losses and current . 44
7.108 Inspection of the low-voltage functional unit, including inspection of wiring
and, if necessary, electrical operation test . 44
7.109 Checking of protective measures and of the electrical continuity of the
protective circuits of the low-voltage functional unit . 44
7.110 Tests after assembly on site . 44
8 Guide to the selection of CEADS . 44
8.1 Selection of rated values . 45
8.2 Continuous or temporary overload due to changed service conditions . 45
8.101 Selection of internal arc classification . 45
8.102 Information . 47
9 Information to be given with enquiries, tenders and orders . 51
9.1 Information with enquiries and orders . 51
9.2 Information with tenders . 52
10 Rules for transport, installation, operation and maintenance . 52
10.1 Conditions during transport, storage and installation . 53
10.2 Installation . 53
10.2.1 Unpacking and lifting . 53
10.2.2 Assembly . 53
10.2.3 Mounting . 53
10.2.4 Final installation inspection . 53
10.3 Operation . 53
10.4 Maintenance . 54
10.5 Dismantling, recycling and disposal at the end of service life . 54
11 Safety . 54
11.101 Electrical aspects . 54
11.102 Mechanical aspects . 54
11.103 Thermal aspects . 54
11.104 Internal arc aspects . 54
12 Influence of the product on the environment . 54
Annex AA (normative) Method for testing CEADS under conditions of arcing due to an
internal arc fault . 56
AA.1 General . 56
AA.2 Room simulation . 56
AA.3 Indicators (for assessing the thermal effects of the gases) . 56
AA.3.1 General . 56
AA.3.2 Arrangement of indicators . 57
AA.4 Tolerances for geometrical dimensions of test arrangements . 58
AA.5 Test parameters . 58
AA.6 Test procedure . 58
AA.7 Designation of the internal arc classification . 59

– 6 – IEC 62271-212:2016 © IEC 2016
Annex BB (normative) Test to verify the sound level of a CEADS . 68
BB.1 Purpose . 68
BB.2 Test object . 68
BB.3 Test method . 68
BB.4 Measurements . 68
BB.5 Presentation and calculation of the results . 68
Annex CC (informative) Types and application of CEADS . 69
CC.1 Type of CEADS . 69
CC.1.1 General . 69
CC.1.2 CEADS-G . 69
CC.1.3 CEADS-A . 69
CC.1.4 CEADS-I . 69
CC.2 Application of CEADS . 69
Bibliography . 73

Figure 1 – Test diagram in case of type tested high-voltage functional unit . 31
Figure 2 – Test diagram in case of non-type tested high-voltage functional unit . 31
Figure 3 – Alternative diagram in case of type tested high-voltage functional unit . 32
Figure 4 – Diagram for the open-circuit test . 33
Figure AA.1 – Mounting frame for vertical indicators . 60
Figure AA.2 – Horizontal indicators . 60
Figure AA.3 – Protection of operators in front of classified side(s) of CEADS . 61
Figure AA.4 – Protection of general public around the CEADS . 61
Figure AA.5 – Protection of operators in front of classified side(s) of CEADS having a
pressure relief volume below the floor . 62
Figure AA.6 – Protection of general public around the CEADS having a pressure relief
volume below the floor . 63
Figure AA.7 – Selection of tests on high-voltage switchgear for class IAC-A . 64
Figure AA.8 – Selection of tests on high-voltage switchgear for class IAC-B . 65
Figure AA.9 – Selection of tests on high-voltage interconnection for class IAC-A . 66
Figure AA.10 – Selection of tests on high-voltage interconnection for class IAC-B . 67
Figure CC.1 – Application of CEADS . 70
Figure CC.2 – CEADS Type G . 71
Figure CC.3 – CEADS Type A . 71
Figure CC.4 – CEADS Type I . 72

Table 1 – Locations, causes and examples of measures decreasing the probability of
internal arc faults . 45
Table 2 – Examples of measures limiting the consequences of internal arc faults . 46
Table 3 – Summary of technical requirements, ratings for CEADS – Service conditions . 47
Table 4 – Summary of technical requirements, ratings for CEADS – Ratings of the
CEADS . 48
Table 5 – Summary of technical requirements, ratings for CEADS – Design and
construction of the CEADS . 50

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 212: Compact Equipment Assembly
for Distribution Substation (CEADS)

FOREWORD
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62271-212 has been prepared by subcommittee 17C: Assemblies,
of IEC technical committee 17: High-voltage switchgear and controlgear.
The text of this standard is based on the following documents:
FDIS Report on voting
17C/645/FDIS 17C/650/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.

– 8 – IEC 62271-212:2016 © IEC 2016
This International Standard should be read in conjunction with IEC 62271-1:2007, to which it
refers and which is applicable unless otherwise specified. In order to simplify the indication of
corresponding requirements, the same numbering of clauses and subclauses is used as in
IEC 62271-1. 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 can be found, under the general title High-voltage
switchgear and controlgear, on the IEC website.
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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
Traditionally a high-voltage/low-voltage distribution substation has been constructed by
installing the main electrical components –high-voltage switchgear, distribution transformer(s)
and the corresponding low-voltage distribution panel(s)- within a closed electrical operating
area. It can be a room within a building intended for other (non electrical uses) or a separated
housing (prefabricated or not) designed specifically to contain the electrical equipment of the
substation or an open area limited by fences.
Some years ago in the search for a more standardized and compact substation, the concept
of prefabricated substation was developed. IEC 62271-202 covers this type of substation.
According to this document, the main electrical components (high-voltage switchgear,
transformer and low-voltage switchgear) are fully in compliance with their respective product
standard, and the whole substation, including interconnections and enclosure is designed and
type tested and later manufactured and routine tested in the factory. Correspondingly the
quality of the substation is assured by the manufacturer.
Moreover, also other types of assemblies have been introduced in the market. These are
assemblies comprising the main electrical active components of the substation and their
interconnections, delivered as a single product. The product can therefore be type tested,
manufactured, routine tested in the factory, transported and then installed in a closed
electrical operating area.
This type of factory assembled and type-tested product is covered by this document receiving
the generic name CEADS from Compact Equipment Assembly for Distribution Substation.
Numerous arrangements are possible and this document provides guidance on basic types of
assemblies, which might be envisaged.
A CEADS is not covered by IEC 61936-1. However CEADS is intended to become part of a
distribution substation.
Taking into account the closer proximity of the components that even can share some parts
(enclosure, solid or fluid insulation…) it is very relevant to pay attention to the potential
interaction between them. Therefore to cover CEADS is neither sufficient nor always
applicable to refer to the relevant product standards. This document covers any additional
design and construction requirements and test methods applicable to the different types of
CEADS. In addition to the specified characteristics, particular attention has been paid to the
specification concerning the protection of persons, both operators and general public.
The CEADS is also for the interest of committee TC 14: Power transformers, and committee
TC 121: Switchgear and controlgear and their assemblies for low voltage.

– 10 – IEC 62271-212:2016 © IEC 2016
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 212: Compact Equipment Assembly
for Distribution Substation (CEADS)

1 General
1.1 Scope
This part of IEC 62271 specifies the service conditions, rated characteristics, general
structural requirements and test methods of the assemblies of the main electrical functional
units of a high-voltage/low-voltage distribution substation, duly interconnected, for alternating
current of rated operating voltages above 1 kV and up to and including 52 kV on the high-
voltage side, service frequency 50 Hz or 60 Hz. This assembly is to be cable-connected to the
network, and intended for installation within an indoor or outdoor closed electrical operating
area.
A Compact Equipment Assembly for Distribution Substation (CEADS) as defined in this
document is designed and tested to be a single product with a single serial number and one
set of documentation.
The functions of a CEADS are:
• switching and control for the operation of the high-voltage circuit(s);
• protection of the high-voltage/low-voltage transformer functional unit;
• high-voltage/low-voltage transformation;
• switching and control for the operation and protection of the low-voltage feeders.
However relevant provisions of this document are also applicable to designs where not all of
these functions exist (e.g. equipment comprising only high-voltage/low-voltage transformation
and switching and control for the operation and protection of the low-voltage feeder functions
or equipment without switching and control for the operation of the high-voltage circuit(s)).
NOTE For the purpose of this document a self-protected transformer is considered not as a CEADS, but as a
functional unit, designed and type tested to its own product standard IEC 60076-13:2006.
1.2 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 – Switchgear, controlgear and
fuses
IEC 60050-461:2008, International Electrotechnical Vocabulary – Part 461: Electric cables
IEC 60076 (all parts), Power transformers
IEC 60076-1:2011, Power transformers – Part 1: General
IEC 60076-2:2011, Power transformers – Part 2: Temperature rise for liquid-immersed
transformers
...