IEC 61439-2:2020
(Main)Low-voltage switchgear and controlgear assemblies - Part 2: Power switchgear and controlgear assemblies
Low-voltage switchgear and controlgear assemblies - Part 2: Power switchgear and controlgear assemblies
IEC 61439-2:2020 defines the specific requirements for the power switchgear and controlgear assembly (abbreviated "PSC-assembly" throughout this document see 3.1.101) as follows:
- assemblies for which the rated voltage does not exceed 1 000 V AC or 1 500 V DC;
- assemblies designed for a nominal frequency of the incoming supply or supplies not exceeding 1 000 Hz;
NOTE 1 Frequencies above 1 kHz are considered as high frequencies, see also IEC 60664-1:2007, 5.3.3.2.5 to take into account additional constraints to insulation coordination.
- assemblies intended for indoor and outdoor applications;
- stationary or movable assemblies with or without enclosures;
- assemblies intended for use in connection with the generation, transmission, distribution and conversion of electrical energy, and for the control of equipment consuming electrical energy and for associated data processing;
- assemblies designed for use under special service conditions, for example in ships and in rail vehicles, provided that the other relevant specific requirements are complied with;
NOTE 2 Supplementary requirements for assemblies in ships are covered by IEC 60092-302-2.
This third edition cancels and replaces the second edition published in 2011. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) addition of Annexes DD, EE and FF for assemblies for use in photovoltaic installation;
b) clarification of the requirements for forms of internal separation and the addition of the requirement, when the form of separation is higher than 1, all parts within the functional unit compartment that remain live when the functional unit is switched off shall be protected to at least IPXXB;
c) alignment with the structure of IEC 61439-1:2020;
d) addition of temperature-rise verification for; (i) temperature-rise verification of assemblies with natural cooling and circuits rated above 1 600 A by a combination of comparison with a reference design and calculation, and; (ii) temperature-rise verification of assemblies with active cooling and rated currents up to 1 600 A;
e) consideration of IP with active cooling.
Ensemble d'appareillage à basse tension - Partie 2 : Ensembles d’appareillage de puissance
L’IEC 61439:2020 définit les exigences spécifiques applicables aux ensembles d’appareillage de puissance (dans l’ensemble du présent document, l’abréviation "ensemble EAP" est utilisée pour désigner un ensemble d’appareillage de puissance; voir 3.1.101) comme suit:
ensembles dont la tension assignée ne dépasse pas 1 000 V en courant alternatif ou 1 500 V en courant continu;
ensembles conçus pour une fréquence nominale de l’alimentation ou des alimentations entrantes ne dépassant pas 1 000 Hz; NOTE 1 Les fréquences supérieures à 1 kHz sont considérées comme des hautes fréquences, voir aussi l’IEC 60664-1:2007, 5.3.3.2.5 pour tenir compte des contraintes supplémentaires relatives à la coordination de l’isolement.
ensembles destinés à des applications d’intérieur et d’extérieur;
ensembles fixes ou mobiles, avec ou sans enveloppe;
ensembles destinés à être utilisés avec des équipements conçus pour la production, le transport, la distribution et la conversion de l’énergie électrique, ainsi que pour la commande des matériels consommant de l’énergie électrique et le traitement des données associées;
ensembles conçus pour être utilisés dans des conditions spéciales d’emploi, par exemple à bord de navires et de véhicules sur rails, à condition que les autres exigences spécifiques correspondantes soient respectées. NOTE 2 Les exigences supplémentaires pour les ensembles à bord des navires sont couvertes par l’IEC 60092-302-2.
Cette troisième édition annule et remplace la deuxième édition parue en 2011 dont elle constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
ajout des Annexes DD, EE et FF pour les ensembles utilisables dans les installations photovoltaïques;
clarification des exigences concernant les formes de séparation interne et ajout de l’exigence selon laquelle, lorsque la forme de séparation de numéro supérieur à 1, toutes les parties à l’intérieur du compartiment de l’unité fonctionnelle qui restent actives lorsque l’unité fonctionnelle est désactivée doivent être protégées au moins selon le degré de protection IPXXB;
alignement sur la structure de l’IEC 61439-1:2020;
ajout de la vérification de l’échauffement pour (i) la vérification de l’échauffement des ensembles à ventilation naturelle et des circuits de courant assigné supérieur à 1 600 A par une combinaison de comparaison entre une conception de référence et le calcul, et (ii) la vérification de l’échauffement des ensembles à ventilation forcée et avec des courants assignés jusqu’à 1 600 A;
prise en compte du degré de protection IP pour la ventilation forcée.
General Information
Relations
Standards Content (Sample)
IEC 61439-2 ®
Edition 3.0 2020-07
INTERNATIONAL
STANDARD
Low-voltage switchgear and controlgear assemblies –
Part 2: Power switchgear and controlgear assemblies
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC 61439-2 ®
Edition 3.0 2020-07
INTERNATIONAL
STANDARD
Low-voltage switchgear and controlgear assemblies –
Part 2: Power switchgear and controlgear assemblies
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.130.20 ISBN 978-2-8322-8587-9
– 2 – IEC 61439-2:2020 © IEC 2020
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 9
5 Interface characteristics . 9
6 Information . 10
7 Service conditions . 11
8 Constructional requirements . 11
9 Performance requirements . 14
10 Design verification . 15
11 Routine verification . 19
Annexes . 22
Annex AA (informative) Items subject to agreement between the PSC-assembly
manufacturer and the user . 23
Annex BB (informative) Forms of internal separation (see 8.101) . 27
Annex CC (informative) Determining power loss by measurement for circuits
exceeding 1600 A in a reference design . 32
Annex DD (informative) Assemblies for use in photovoltaic installations . 34
Annex EE (informative) Items subject to agreement between the photovoltaic
assembly (PVA) manufacturer and the user . 43
Annex FF (informative) Design verification (PVA only) . 47
Annex GG (informative) List of notes concerning certain countries . 49
Bibliography . 50
Figure BB.1 – Symbols used in Figures BB.2, BB.3 and BB.4 . 27
Figure BB.2 – Forms 1 and 2 . 29
Figure BB.3 – Form 3 . 30
Figure BB.4 – Form 4 . 31
Figure CC.1 – Power loss measurement . 33
Figure DD.101 – Indicative arrangement of radiant heat lamps for temperature-rise test
with simulated solar radiation . 41
Table 101 – Values of assumed loading . 19
Table 102 – Test voltages across the open contacts of equipment suitable for isolation . 19
Table 103 – Electrical conditions for the different positions of withdrawable parts . 20
Table 104 – Forms of internal separation . 21
Table AA.1 – Items subject to agreement between the PSC-assembly manufacturer
and the user . 23
Table DD.101 – Solar radiation conditions . 38
Table EE.1 – Items subject to agreement between the PVA manufacturer and the user . 43
Table FF.1 – List of design verifications to be performed on PVA . 47
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES –
Part 2: Power switchgear and controlgear assemblies
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) 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 61439-2 has been prepared by subcommittee 121B: Low-voltage
switchgear and controlgear assemblies, of IEC technical committee 121: Switchgear and
controlgear and their assemblies for low voltage.
This third edition cancels and replaces the second edition published in 2011. It constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of Annexes DD, EE and FF for assemblies for use in photovoltaic installation;
b) clarification of the requirements for forms of internal separation and the addition of the
requirement, when the form of separation is higher than 1, all parts within the functional
unit compartment that remain live when the functional unit is switched off shall be
protected to at least IPXXB;
c) alignment with the structure of IEC 61439-1:2020;
– 4 – IEC 61439-2:2020 © IEC 2020
d) addition of temperature-rise verification for; (i) temperature-rise verification of assemblies
with natural cooling and circuits rated above 1 600 A by a combination of comparison with
a reference design and calculation, and; (ii) temperature-rise verification of assemblies
with active cooling and rated currents up to 1 600 A.
e) consideration of IP with active cooling.
The text of this document is based on the following documents:
FDIS Report on voting
121B/104/FDIS 121B/109/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
In this document, general terms and definitions are defined in Clause 3. Further terms and
definitions specific to Annex DD are given in this annex to facilitate easier reading.
The reader's attention is drawn to the fact that Annex GG lists all the “in-some-country”
clauses on differing practices of a less permanent nature relating to the subject of this
document.
This document is to be read in conjunction with IEC 61439-1:2020. The provisions of the
general rules dealt with in IEC 61439-1 are only applicable to this document insofar as they
are specifically cited. When this document states “addition”, “modification” or “replacement”,
the relevant text in IEC 61439-1 is to be adapted accordingly.
Subclauses that are numbered with a 101 (102, 103, etc.) suffix are additional to the same
subclause in IEC 61439-1.
Tables and figures in this document that are new are numbered starting with 101.
New annexes in this document are lettered AA, BB, etc.
In this document, the term PSC-assembly is defined in 3.1.101.
NOTE Throughout the IEC 61439 series of standards, the term assembly (see 3.1.1 of IEC 61439-1:2020) is used
for a low-voltage switchgear and controlgear assembly.
A list of all parts of the IEC 61439 series, under the general title Low-voltage switchgear and
controlgear assemblies can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES –
Part 2: Power switchgear and controlgear assemblies
1 Scope
This part of IEC 61439 defines the specific requirements for the power switchgear and
controlgear assembly (abbreviated ‘PSC-assembly’ throughout this document see 3.1.101) as
follows:
• assemblies for which the rated voltage does not exceed 1 000 V AC or 1 500 V DC;
• assemblies designed for a nominal frequency of the incoming supply or supplies not
exceeding 1 000 Hz;
NOTE 1 Frequencies above 1 kHz are considered as high frequencies, see also IEC 60664-1:2007, 5.3.3.2.5
to take into account additional constraints to insulation coordination.
• assemblies intended for indoor and outdoor applications;
• stationary or movable assemblies with or without enclosures;
• assemblies intended for use in connection with the generation, transmission, distribution
and conversion of electrical energy, and for the control of equipment consuming electrical
energy and for associated data processing;
• assemblies designed for use under special service conditions, for example in ships and in
rail vehicles, provided that the other relevant specific requirements are complied with;
NOTE 2 Supplementary requirements for assemblies in ships are covered by IEC 60092-302-2.
This document also applies to assemblies for use in photovoltaic installations, designated as
photovoltaic assemblies (PVA). The particular characteristics, specific service conditions and
the requirements for PVA’s are included in Annexes DD, EE and FF.
This document provides supplementary requirements for PSC-assemblies intended for use as
part of the electrical equipment of machines and can be applied in addition to the
requirements given in IEC 60204-1.
This document applies to all assemblies whether they are designed, manufactured and
verified on a one-off basis or fully standardised and manufactured in quantity.
The manufacture and/or assembly can be carried out by an entity other than the original
manufacturer (see 3.10.1 of IEC 61439-1:2020).
This document does not apply to individual devices, for example, circuit-breakers, fuse
switches and self-contained components such as, motor starters, power electronic converter
systems and equipment (PECS), switch mode power supplies (SMPS), uninterruptable power
supplies (UPS), basic drive modules (BDM), complete drive modules (CDM), adjustable speed
power drives systems (PDS), stand-alone energy storage systems (battery and capacitor
systems), and other electronic equipment which comply with their relevant product standards.
This document describes their integration into a PSC-assembly or an empty enclosure used
as a part of a PSC-assembly.
For some applications, such as, explosive atmospheres, functional safety, there may be a
need to comply with the requirements of other standards or legislation in addition to those
specified in the IEC 61439 series.
– 6 – IEC 61439-2:2020 © IEC 2020
This document does not apply to the specific types of assemblies covered by other parts of
IEC 61439. For assemblies not covered by other parts, this part applies.
Unless local legislation details additional requirements, equipment within the scope of this
document, which complies with this document, is deemed to meet essential safety
requirements. This includes fully verified specifier options, for example user choice of
protection against accidental contact with hazardous live parts of IPXXB or IP3XD. Where
special requirements are agreed between the user and manufacturer, that are not fully
specified within this document, for example, (i) part of the assembly is outside the scope of
this document, (ii) exceptional vibration is present at the place of installation, (iii) exceptional
voltage variations occur in service, or (iv) possible adverse effects from sonic or ultrasonic
sources, a risk assessment and/or additional or more severe verifications may be required to
demonstrate that the essential safety requirements have been fulfilled.
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.
Clause 2 of IEC 61439-1:2020 is applicable in addition to the following:
Addition:
IEC 60204-1:2016, Safety of machinery – Electrical equipment of machines – Part 1: General
requirements
IEC 60947-3:2008, Low-voltage switchgear and controlgear – Part 3: Switches, disconnectors,
switch-disconnectors and fuse-combination units
IEC 60947-3:2008/AMD1:2012
IEC 60947-3:2008/AMD2:2015
IEC 61140:2016, Protection against electric shock – Common aspects for installation and
equipment
IEC 61439-1:2020, Low-voltage switchgear and controlgear assemblies – Part 1: General
rules
IEC 62262:2002, Degrees of protection provided by enclosures for electrical equipment
against external mechanical impacts (IK code)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61439-1:2020 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
Clause 3 of IEC 61439-1:2020 is applicable, except as follows.
3.1 General terms
Additional terms and definitions:
3.1.101
power switchgear and controlgear assembly
PSC-assembly
assembly used to distribute and control electrical energy for all types of loads, intended for
industrial, commercial and similar applications where operation by ordinary persons is not
intended
Note 1 to entry: It is not excluded for a PSC-assembly to be located in an area accessible to ordinary persons.
3.1.102
test situation
condition of a PSC-assembly or part of it in which the relevant main circuits are open on its
supply side but not necessarily isolated whilst the associated auxiliary circuits are connected,
allowing operational tests of the incorporated device(s)
3.1.103
form of internal separation
classification of physical separation within a PSC-assembly
3.1.104
(electric) actuator
device that produces a specified movement when excited by an electric signal
[SOURCE: IEC 60050-151:2001, 151-13-49]
3.1.105
distribution circuit
electric circuit supplying one or more distribution boards
[SOURCE: IEC 60050-826:2004, 826-14-02]
3.1.106
final circuit
electric circuit intended to supply directly electric current to current using equipment or socket
outlets
[SOURCE: IEC 60050-826:2004, 826-14-03]
3.2 Constructional units of assemblies
Replacement of the title:
3.2 Constructional units of PSC-assemblies
Additional terms and definitions:
3.2.101
withdrawable part
removable part intended to be moved from the connected position to the isolated position and
to a test position, if any, whilst remaining mechanically attached to the PSC-assembly
– 8 – IEC 61439-2:2020 © IEC 2020
3.2.102
test position
position of a withdrawable part in which the relevant main circuits are open on its supply side
but not necessarily isolated and in which the auxiliary circuits are connected allowing
operation tests of the incorporated device(s), the withdrawable part remaining mechanically
attached to the PSC-assembly
Note 1 to entry: The opening can also be achieved without any mechanical movement of the withdrawable part by
operation of a suitable device.
3.2.103
isolated position
position of a withdrawable part in which an isolating distance is established in main and
auxiliary circuits on its supply side, the withdrawable part remaining mechanically attached to
the PSC-assembly
Note 1 to entry: The isolating distance can also be established without any mechanical movement of the
withdrawable part by operation of a suitable device, e.g. a disconnector in accordance with IEC 60947-3.
3.2.104
isolating distance
clearance between open contacts of withdrawable parts meeting the safety requirements
specified for disconnectors
[SOURCE: IEC 60050-441:2000, 441-17-35, modified – The context information has been
moved to after contacts and changed.]
3.4 Structural parts of assemblies
Addition:
3.4.101
active cooling
use of equipment mounted on or within the assembly, installed to reduce or control the
assembly’s internal air temperature during normal operation, which requires energization to
operate
Note 1 to entry: Examples include fans, internal air conditioning, heat exchangers, etc.
3.4.102
pressure relief flap
mechanical component provided to limit the pressure rise in case of internal arc-faults
Additional terms and definitions:
3.101 Electrical connections of functional units
3.101.1
disconnectable connection
connection which is connected or disconnected by manual operation of the connecting means
without a tool
3.101.2
withdrawable connection
connection which is connected or disconnected by bringing the functional unit into the
connected or isolated position
3.102 Gangways within PSC-assemblies
3.102.1
operating gangway within a PSC-assembly
space to be used by the operator for the proper operation and supervision of the PSC-
assembly
3.102.2
maintenance gangway within a PSC-assembly
space which is accessible to authorized personnel only and primarily intended for use when
servicing the installed equipment
3.103 Location
3.103.1
location with restricted access
location accessible for all persons who are permitted to have access to the location (e.g.
private housing, private parking areas or similar places)
3.103.2
location with non-restricted access
location accessible for all persons, e.g. the access is given in a public area
4 Symbols and abbreviations
Clause 4 of IEC 61439-1:2020 is applicable.
5 Interface characteristics
Clause 5 of IEC 61439-1:2020 is applicable, except as follows.
5.1 General
Replacement:
The characteristics of the PSC-assembly shall ensure compatibility with the ratings of the
circuits to which it is connected and the installation conditions. These characteristics shall be
declared by the PSC-assembly manufacturer using the criteria identified in 5.2 to 5.6 of
IEC 61439-1:2020, as amended by this document.
The specification schedule detailed in the informative Annex AA is intended to help the user
and the PSC-assembly manufacturer to meet this objective, whether the user:
– selects catalogue products, the characteristics of which meet their needs, and the
requirements of this document; and/or,
– makes a specific agreement with the manufacturer.
NOTE Annex AA also relates to the topics dealt with in Clauses 6 and 7.
In some cases, information provided by the PSC-assembly manufacturer may take the place
of an agreement.
)
5.3.3 Group rated current of a main circuit (I
ng
Addition:
For further information on the assumed loading of the outgoing circuits, see 5.4.
– 10 – IEC 61439-2:2020 © IEC 2020
5.4 Rated diversity factor (RDF)
Addition:
In the absence of an agreement between the assembly manufacturer and the user concerning
the actual load currents, the assumed loading of the outgoing circuits of the assembly or
group of outgoing circuits may be based on the values in Table 101.
For a motor or electric actuator circuit, the assumed load current is the rated current of the
motor multiplied with the loading factor of Table 101. If only the rated voltage and rated power
of the motor is provided, then the rated current of the motor can be taken from
IEC 60947-4-1:2018, Annex G.
For all other distribution and final circuits, it is assumed load current is the rated current of the
protective device, I , as required by the user, multiplied with the loading factor of Table 101.
n
5.6 Other characteristics
Replacement of item f):
f) degree of protection against contact with hazardous live parts, ingress of solid foreign
bodies and water, IP code (See 8.2.2 of IEC 61439-1:2020), including the degree of
protection for any distinct positions for removable and withdrawable parts;
Replacement of item g):
g) intended for use by electrically skilled, competent or instructed persons (see 3.7.13,
3.7.14 and 3.7.15 of IEC 61439-1:2020);
Replacement of item l):
l) type of construction – fixed, removable or withdrawable parts (see 8.5.1 of
IEC 61439-1:2020 and 8.5.2);
Addition:
aa) form of internal separation and associated degree of protection(s), IP code (see 8.101);
bb) types of electrical connections of functional units (see 8.5.101);
cc) mounting orientation (horizontal, vertical, etc.) if the assembly can be mounted in
different positions from vertical.
6 Information
Clause 6 of IEC 61439-1:2020 is applicable, except as follows.
6.1 Assembly designation marking
Replacement of the title and item g):
6.1 PSC-assembly designation marking
g) IEC 61439-2;
6.2.2 Instructions for handling, installation, operation and maintenance
Addition:
A PSC-assembly that can be energized from more than one source shall carry a warning label
indicating that the assembly is energized from more than one source, and that parts inside the
assembly can still be live unless all supplies are isolated.
7 Service conditions
Clause 7 of IEC 61439-1:2020 is applicable.
8 Constructional requirements
Clause 8 of IEC 61439-1:2020 is applicable, except as follows.
8.1.1 General
Addition:
For assemblies intended to be used for machines, the requirements given in 11.4 of
IEC 60204-1:2016 shall apply.
8.2 Degree of protection provided by an assembly enclosure
Replacement of the title:
8.2 Degree of protection provided by a PSC-assembly enclosure
8.2.1 Protection against mechanical impact (IK code)
Replacement of text:
Where a degree of protection (IK code) provided by a PSC-assembly enclosure against
mechanical impact is declared by the original manufacturer, this shall be verified in
accordance with 10.2.6.
NOTE It is not mandatory for the manufacturer to declare an IK code.
Additional subclause:
8.2.101 PSC-assembly with withdrawable parts
The degree of protection (IP code) indicated for PSC-assemblies normally applies to the
connected position (see 3.2.3 of IEC 61439-1:2020) of withdrawable parts. The assembly
manufacturer shall indicate the degree of protection (IP code) obtained in the other positions.
PSC-assemblies with withdrawable parts may be so designed that the degree of protection (IP
code) applying to the connected position is also maintained in the test and in isolated
positions.
If, after the removal of a withdrawable part, it is not possible to maintain the original degree of
protection (e.g. by closing a door), the assembly manufacturer shall make available covers or
similar to restore the original degree of protection. If these measures are not available, the IP
tests shall be carried out without the removable part in place.
– 12 – IEC 61439-2:2020 © IEC 2020
8.3.2 Clearances
Addition:
The isolating distance between the withdrawable unit's main contacts and their associated
fixed contacts in the isolated position shall be capable of withstanding the test voltage for the
declared impulse withstand voltage as specified in Table 102.
NOTE For altitudes above 2 000 m, refer to IEC 60664-1.
8.4.3.2.2 Requirements for earth continuity providing protection against the
consequences of faults within the class I assembly
Replacement of the title.
8.4.3.2.2 Requirements for earth continuity providing protection against the
consequences of faults within the class I PSC-assembly
Replacement of last paragraph:
When removable or withdrawable parts are equipped with a metal supporting surface that
have suitable conductivity and corrosion resistance, these surfaces shall be considered
sufficient for ensuring earth continuity, provided that the pressure exerted on them is
sufficiently high. The continuity of the exposed conductive parts of a withdrawable part shall
remain effective from the connected position to the isolated position inclusively.
8.4.6.1 Devices to be operated or components to be replaced by ordinary persons
This subclause of IEC 61439-1 is not applicable.
8.4.6.2 Requirements related to accessibility in service by authorized persons
8.4.6.2.1 General
Addition:
The most appropriate form of internal separation for a PSC-assembly is determined by the
operations to be undertaken when the assembly is energized and in service, but with
individual circuits de-energized (see 8.101).
Additional subclause:
8.4.6.2.101 Operating and maintenance gangways within a PSC-assembly
Operating and maintenance gangways (see 3.102.1 and 3.102.2) within a PSC-assembly shall
comply with the requirements for basic protection as specified in IEC 61140.
Recesses up to one metre in depth within a PSC-assembly are not considered to be
gangways.
8.5.2 Removable parts
Replacement of the title:
8.5.2 Removable and withdrawable parts
Replacement of text:
The removable and withdrawable parts shall be so constructed that their electrical equipment
can be safely removed and/or isolated from or connected to the main circuit even if the circuit
is live. The removable and withdrawable parts may be provided with an insertion interlock
(see 3.2.5 of IEC 61439-1:2020).
Clearances and creepage distances (see 8.3.2 and 8.3.3 of IEC 61439-1:2020) shall be
complied with in the different positions as well as during transfer from one position to another.
Additional subclauses:
8.5.2.101 Withdrawable parts
Withdrawable parts shall, in addition, have an isolated position (see 3.2.103) and may have a
test position (see 3.2.102), or a test situation (see 3.1.102). They shall be distinctly located in
these positions. These positions shall be clearly discernible.
In PSC-assemblies with withdrawable parts all live parts shall be protected in such a manner
that they cannot unintentionally be touched when the door, if any, is open and the
withdrawable part is withdrawn from the connected position or removed. Where an obstacle or
shutter is used they shall meet the requirements of 8.4.6.2.1 of IEC 61439-1:2020.
For the electrical conditions associated with the different positions of withdrawable parts, see
Table 103.
8.5.2.102 Interlocking and padlocking of removable and withdrawable parts
A removable or withdrawable part shall be fitted with a device that ensures that it can only be
removed and inserted after its main circuit has been switched off from the load.
In order to prevent unauthorized operation, the removable and withdrawable parts or their
associated assembly location may be provided with a lockable means to secure them in one
or more of their positions.
8.5.3 Selection of switching devices and components
Addition:
NOTE 2 The standards with which components can comply, include, for example, IEC 60947 (all parts),
IEC 60269 (all parts), IEC 60898 (all parts), IEC 61008 (all parts), IEC 61009 (all parts), IEC 62423, IEC 61800-5-
1, IEC 61010-2-201.
Additional subclauses:
8.5.101 Description of the types of electrical connections of functional units
A functional unit can have the same or different types of electrical connection for incoming
and outgoing supplies; for example, a withdrawable connection can be used for the incoming
and fixed or disconnectable for the outgoing.
NOTE 1 Particularly when multiple supplies are involved, the specifier carries out an assessment in order to
choose the most appropriate connection.
– 14 – IEC 61439-2:2020 © IEC 2020
The types of electrical connections of functional units within PSC-assemblies or parts of PSC-
assemblies can be denoted by a three-letter code:
– the first letter denotes the type of electrical connection of the main incoming circuit;
– the second letter denotes the type of electrical connection of the main outgoing circuit;
– the third letter denotes the type of electrical connection of the auxiliary circuits.
The following letters shall be used:
– F for fixed connections (see 3.2.6 of IEC 61439-1:2020);
– D for disconnectable connections (see 3.101.1);
– W for withdrawable connections (see 3.101.2).
NOTE 2 This coding system relates to the capability to remove, withdraw and re-insert functional units.
8.101 Internal separation of PSC-assemblies
Typical arrangements of internal separation by barriers or partitions are described in Table
104 and are classified as forms of internal separation (for examples, see Annex BB including
Figure BB.1).
Internal separation may be used to attain one or more of the following conditions between
functional units, separate compartments or enclosed protected spaces:
– protection against contact with hazardous parts, the degree of protection shall be at least
IPXXB (see 8.4.2.3 of IEC 61439-1:2020);
– protection against the passage of solid foreign bodies and contact with hazardous parts,
the degree of protection shall be at least IP2X.
Unless otherwise agreed between the user and the manufacturer, when the form of internal
separation is higher than 1, all parts within the functional unit compartment that remain live
when the functional unit is switched off shall be protected to at least IPXXB. This requirement
only applies when the removable cover or door, as used for normal access to the functional
unit, is removed or opened.
NOTE 1 The degree of protection IP2X covers the degree of protection IPXXB. IP2X covers the prevention of
entry of solid foreign bodies and the prevention of contact with hazardous parts.
NOTE 2 Separation can be achieved by means of partitions or barriers (metallic or non-metallic), insulation of live
parts or the integral housing of a device e.g. a moulded case circuit-breaker.
If the application requires the form of internal separation is of a higher level than provided by
the degree of protection IPXXB (IP code), it shall be specified by the user.
See 8.4.2.3 of IEC 61439-1:2020 with regard to stability and durability of barriers and
partitions.
See 8.4.6.2 of IEC 61439-1:2020 and above with regard to accessibility for maintenance on
isolated functional units.
NOTE 3 The internal separation described is not intended to guarantee the integrity of the assembly in the event
of an internal arc-fault.
9 Performance requirements
Clause 9 of IEC 61439-1:2020 is applicable, except as follows.
9.3.1 General
Addition:
NOTE 3 For guidance on performance of a PSC-assembly under condition of internal arc-faults, see
IEC TR 61439-0. For guidance on testing, see IEC TR 61641. For guidance on the integration of internal arc-fault
mitigation systems into PSC-assemblies, see IEC TS 63107.
10 Design verification
Clause 10 of IEC 61439-1:2020 is applicable, except as follows.
10.2.6 Verification of protection against mechanical impact (IK code)
Replacement:
When a mechanical impact test is performed, it shall be carried out as follows.
Verification of the degree of protection against mechanical impacts (IK code) shall be carried
out in accordance with IEC 62262.
The enclosure shall be fixed as for normal use.
The impact energy shall be applied:
– three times to each surface exposed in normal use whose largest dimension is less than or
equal to 1 m;
– five times to each surface exposed in normal use whose largest dimension is greater than
1 m.
Unless otherwise specified, the degree of protection against mechanical impact indicated by
the assembly manufacturer applies to the complete assembly when installed in accordance
with the assembly manufacturer's instructions.
When the assembly does not have the same IK rating throughout, (e.g. locks, hinges, socket
outlets, displays which may have a lower IK rating), the manufacturer shall declare the
exclusion(s) applicable to the assembly.
The impacts shall be applied with even distribution over the faces of the enclosure. After the
test, some deformation of the enclosure is permissible. Visual inspection shall verify that:
– the degree of protection (IP code) of enclosure is not impaired, where doubt exists the
appropriate IP test according to 10.3;
– dielectric properties have been maintained, where doubt exists the appropriate dielectric
tests according to 10.9 of IEC 61439-1:2020, as modified in this document, should be
carried out;
– removable covers can be removed and reinstalled;
– doors can be opened and closed.
10.2.8 Mechanical operation
Addition:
In the case of withdrawable parts, the operating cycle includes any physical movements from
the connected to the isolated position and back to the connected position.
– 16 – IEC 61439-2:2020 © IEC 2020
10.3 Degree of protection of assemblies (IP Code)
Replacement of the title
10.3 Degree of protection of PSC-assemblies (IP Code)
Addition:
The internal separation of PSC-assemblies shall be in accordance with 8.101 and the
associated degree of protection shall be tested in accordance with IEC 60529.
The degree of protection associated with withdrawable parts as specified in accordance with
8.2.101 shall be tested in accordance with IEC 60529.
For the verification of the degrees of protection IP5X and IP6X enclosures with active cooling,
in particular when fans and air filters are used, the original manufacturer shall obtain
confirmation from the cooling equipment manufacturer that the cooling equipment has the
required degree of protection. The IP test on the enclosure with the cooling equipment fitted
shall then be carried out in accordance with IEC 60529 without the cooling equipment
operating.
NOTE It is expected that the user will maintain the cooling equipment in accordance with the assembly
manufacturer’s instructions in order to maintain the cooling equipment in an efficient condition and in turn the
cooling efficiency.
10.9.3.2 Impulse withstand voltage test
Addition:
The impulse withstand voltage capability of the isolating distance between the withdrawable
parts main contacts and their associated fixed contacts shall be verified to confirm compliance
with 8.3.2. This verification test shall not be made on such devices (e.g. withdrawable circuit-
breakers) of the assembly that have already been verified to at least the same requirement
according to their relevant product standard.
10.10 Temperature-rise
Clause 10.10 of IEC 61439-1:2020 is applicable with the following additions.
10.10.4.1 General
Addition to the first paragraph:
3) assembly with natural cooling with a rated current exceeding 1 600 A and where a
reference design is available (10.10.4.101);
4) assembly with active cooling and a rated current not exceeding 1 600 A (10.10.4.102).
Additional subclauses:
10.10.4.101 Assembly with natural cooling and rated current exceeding 1 600 A
10.10.4.101.1 Verification method
This method is used to verify the temperature-rise performance of assemblies with circuits
rated in excess of 1600 A. Circuits including busbars rated in excess of 1 600 A shall have
been verified by test according to 10.10.2 of IEC 61439-1:2020 or by comparison with a
reference design in accordance with 10.10.3 of IEC 61439-1:2020.
Verification of the temperature-rise of a single or multiple compartment assembly with natural
cooling with the total supply current exceeding 1 600 A may be made by a combination of
comparison to a reference design and calculation in accordance with the method of
IEC TR 60890. All the constraints listed in IEC TR 60890 and the general conditions listed in
10.10.4.1 of IEC 61439-1:2020 plus the following conditions shall be fulfilled:
a) the assembly to be verified is from the same assembly system (same manufacturer, same
generic design, same physical construction), same or lower current rating of the
, and the same or lower group rated currents, I , of the corresponding
assembly, I
nA ng
circuits as the reference design(s);
b) circuits with a group rated current I above 1 600 A, including their position and
ng
configuration, shall be verified by test or shall be a variation in accordance with 10.10.3 of
IEC 61439-1:2020. For these circuits the conditions of 10.10.4.1 of IEC 61439-1:2020 do
not apply;
c) the power loss of the circuits rated in excess of 1 600 A in each section tested shall have
been determined from measured values obtained during the temperature-rise verification
test performed on a reference design to take into account eddy currents, skin effects,
current displacement and temperature. The power loss of the main busbars shall be
calculated from measured values obtained during a temperature-rise test according to
10.10.2.3.7 a) of IEC 61439-1:2020. The power loss of distribution busbars shall be
calculat
...
IEC 61439-2 ®
Edition 3.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage switchgear and controlgear assemblies –
Part 2: Power switchgear and controlgear assemblies
Ensembles d’appareillage à basse tension –
Partie 2: Ensembles d’appareillage de puissance
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.
A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.
Recherche de publications IEC - Electropedia - www.electropedia.org
webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au
La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en
en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans
comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire
projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.
IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary
Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais
Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et Définitions des
Disponible en ligne et une fois par mois par email. publications IEC parues depuis 2002. Plus certaines entrées
antérieures extraites des publications des CE 37, 77, 86 et
Service Clients - webstore.iec.ch/csc CISPR de l'IEC.
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC 61439-2 ®
Edition 3.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage switchgear and controlgear assemblies –
Part 2: Power switchgear and controlgear assemblies
Ensembles d’appareillage à basse tension –
Partie 2: Ensembles d’appareillage de puissance
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.130.20 ISBN 978-2-8322-9069-9
– 2 – IEC 61439-2:2020 © IEC 2020
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 9
5 Interface characteristics . 9
6 Information . 10
7 Service conditions . 11
8 Constructional requirements . 11
9 Performance requirements . 14
10 Design verification . 15
11 Routine verification . 19
Annexes . 22
Annex AA (informative) Items subject to agreement between the PSC-assembly
manufacturer and the user . 23
Annex BB (informative) Forms of internal separation (see 8.101) . 27
Annex CC (informative) Determining power loss by measurement for circuits
exceeding 1600 A in a reference design . 32
Annex DD (informative) Assemblies for use in photovoltaic installations . 34
Annex EE (informative) Items subject to agreement between the photovoltaic
assembly (PVA) manufacturer and the user . 43
Annex FF (informative) Design verification (PVA only) . 47
Annex GG (informative) List of notes concerning certain countries . 49
Bibliography . 50
Figure BB.1 – Symbols used in Figures BB.2, BB.3 and BB.4 . 27
Figure BB.2 – Forms 1 and 2 . 29
Figure BB.3 – Form 3 . 30
Figure BB.4 – Form 4 . 31
Figure CC.1 – Power loss measurement . 33
Figure DD.101 – Indicative arrangement of radiant heat lamps for temperature-rise test
with simulated solar radiation . 41
Table 101 – Values of assumed loading . 19
Table 102 – Test voltages across the open contacts of equipment suitable for isolation . 19
Table 103 – Electrical conditions for the different positions of withdrawable parts . 20
Table 104 – Forms of internal separation . 21
Table AA.1 – Items subject to agreement between the PSC-assembly manufacturer
and the user . 23
Table DD.101 – Solar radiation conditions . 38
Table EE.1 – Items subject to agreement between the PVA manufacturer and the user . 43
Table FF.1 – List of design verifications to be performed on PVA . 47
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES –
Part 2: Power switchgear and controlgear assemblies
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) 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 61439-2 has been prepared by subcommittee 121B: Low-voltage
switchgear and controlgear assemblies, of IEC technical committee 121: Switchgear and
controlgear and their assemblies for low voltage.
This third edition cancels and replaces the second edition published in 2011. It constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of Annexes DD, EE and FF for assemblies for use in photovoltaic installation;
b) clarification of the requirements for forms of internal separation and the addition of the
requirement, when the form of separation is higher than 1, all parts within the functional
unit compartment that remain live when the functional unit is switched off shall be
protected to at least IPXXB;
c) alignment with the structure of IEC 61439-1:2020;
– 4 – IEC 61439-2:2020 © IEC 2020
d) addition of temperature-rise verification for; (i) temperature-rise verification of assemblies
with natural cooling and circuits rated above 1 600 A by a combination of comparison with
a reference design and calculation, and; (ii) temperature-rise verification of assemblies
with active cooling and rated currents up to 1 600 A.
e) consideration of IP with active cooling.
The text of this document is based on the following documents:
FDIS Report on voting
121B/104/FDIS 121B/109/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
In this document, general terms and definitions are defined in Clause 3. Further terms and
definitions specific to Annex DD are given in this annex to facilitate easier reading.
The reader's attention is drawn to the fact that Annex GG lists all the “in-some-country”
clauses on differing practices of a less permanent nature relating to the subject of this
document.
This document is to be read in conjunction with IEC 61439-1:2020. The provisions of the
general rules dealt with in IEC 61439-1 are only applicable to this document insofar as they
are specifically cited. When this document states “addition”, “modification” or “replacement”,
the relevant text in IEC 61439-1 is to be adapted accordingly.
Subclauses that are numbered with a 101 (102, 103, etc.) suffix are additional to the same
subclause in IEC 61439-1.
Tables and figures in this document that are new are numbered starting with 101.
New annexes in this document are lettered AA, BB, etc.
In this document, the term PSC-assembly is defined in 3.1.101.
NOTE Throughout the IEC 61439 series of standards, the term assembly (see 3.1.1 of IEC 61439-1:2020) is used
for a low-voltage switchgear and controlgear assembly.
A list of all parts of the IEC 61439 series, under the general title Low-voltage switchgear and
controlgear assemblies can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES –
Part 2: Power switchgear and controlgear assemblies
1 Scope
This part of IEC 61439 defines the specific requirements for the power switchgear and
controlgear assembly (abbreviated ‘PSC-assembly’ throughout this document see 3.1.101) as
follows:
• assemblies for which the rated voltage does not exceed 1 000 V AC or 1 500 V DC;
• assemblies designed for a nominal frequency of the incoming supply or supplies not
exceeding 1 000 Hz;
NOTE 1 Frequencies above 1 kHz are considered as high frequencies, see also IEC 60664-1:2007, 5.3.3.2.5
to take into account additional constraints to insulation coordination.
• assemblies intended for indoor and outdoor applications;
• stationary or movable assemblies with or without enclosures;
• assemblies intended for use in connection with the generation, transmission, distribution
and conversion of electrical energy, and for the control of equipment consuming electrical
energy and for associated data processing;
• assemblies designed for use under special service conditions, for example in ships and in
rail vehicles, provided that the other relevant specific requirements are complied with;
NOTE 2 Supplementary requirements for assemblies in ships are covered by IEC 60092-302-2.
This document also applies to assemblies for use in photovoltaic installations, designated as
photovoltaic assemblies (PVA). The particular characteristics, specific service conditions and
the requirements for PVA’s are included in Annexes DD, EE and FF.
This document provides supplementary requirements for PSC-assemblies intended for use as
part of the electrical equipment of machines and can be applied in addition to the
requirements given in IEC 60204-1.
This document applies to all assemblies whether they are designed, manufactured and
verified on a one-off basis or fully standardised and manufactured in quantity.
The manufacture and/or assembly can be carried out by an entity other than the original
manufacturer (see 3.10.1 of IEC 61439-1:2020).
This document does not apply to individual devices, for example, circuit-breakers, fuse
switches and self-contained components such as, motor starters, power electronic converter
systems and equipment (PECS), switch mode power supplies (SMPS), uninterruptable power
supplies (UPS), basic drive modules (BDM), complete drive modules (CDM), adjustable speed
power drives systems (PDS), stand-alone energy storage systems (battery and capacitor
systems), and other electronic equipment which comply with their relevant product standards.
This document describes their integration into a PSC-assembly or an empty enclosure used
as a part of a PSC-assembly.
For some applications, such as, explosive atmospheres, functional safety, there may be a
need to comply with the requirements of other standards or legislation in addition to those
specified in the IEC 61439 series.
– 6 – IEC 61439-2:2020 © IEC 2020
This document does not apply to the specific types of assemblies covered by other parts of
IEC 61439. For assemblies not covered by other parts, this part applies.
Unless local legislation details additional requirements, equipment within the scope of this
document, which complies with this document, is deemed to meet essential safety
requirements. This includes fully verified specifier options, for example user choice of
protection against accidental contact with hazardous live parts of IPXXB or IP3XD. Where
special requirements are agreed between the user and manufacturer, that are not fully
specified within this document, for example, (i) part of the assembly is outside the scope of
this document, (ii) exceptional vibration is present at the place of installation, (iii) exceptional
voltage variations occur in service, or (iv) possible adverse effects from sonic or ultrasonic
sources, a risk assessment and/or additional or more severe verifications may be required to
demonstrate that the essential safety requirements have been fulfilled.
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.
Clause 2 of IEC 61439-1:2020 is applicable in addition to the following:
Addition:
IEC 60204-1:2016, Safety of machinery – Electrical equipment of machines – Part 1: General
requirements
IEC 60947-3:2008, Low-voltage switchgear and controlgear – Part 3: Switches, disconnectors,
switch-disconnectors and fuse-combination units
IEC 60947-3:2008/AMD1:2012
IEC 60947-3:2008/AMD2:2015
IEC 61140:2016, Protection against electric shock – Common aspects for installation and
equipment
IEC 61439-1:2020, Low-voltage switchgear and controlgear assemblies – Part 1: General
rules
IEC 62262:2002, Degrees of protection provided by enclosures for electrical equipment
against external mechanical impacts (IK code)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61439-1:2020 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
Clause 3 of IEC 61439-1:2020 is applicable, except as follows.
3.1 General terms
Additional terms and definitions:
3.1.101
power switchgear and controlgear assembly
PSC-assembly
assembly used to distribute and control electrical energy for all types of loads, intended for
industrial, commercial and similar applications where operation by ordinary persons is not
intended
Note 1 to entry: It is not excluded for a PSC-assembly to be located in an area accessible to ordinary persons.
3.1.102
test situation
condition of a PSC-assembly or part of it in which the relevant main circuits are open on its
supply side but not necessarily isolated whilst the associated auxiliary circuits are connected,
allowing operational tests of the incorporated device(s)
3.1.103
form of internal separation
classification of physical separation within a PSC-assembly
3.1.104
(electric) actuator
device that produces a specified movement when excited by an electric signal
[SOURCE: IEC 60050-151:2001, 151-13-49]
3.1.105
distribution circuit
electric circuit supplying one or more distribution boards
[SOURCE: IEC 60050-826:2004, 826-14-02]
3.1.106
final circuit
electric circuit intended to supply directly electric current to current using equipment or socket
outlets
[SOURCE: IEC 60050-826:2004, 826-14-03]
3.2 Constructional units of assemblies
Replacement of the title:
3.2 Constructional units of PSC-assemblies
Additional terms and definitions:
3.2.101
withdrawable part
removable part intended to be moved from the connected position to the isolated position and
to a test position, if any, whilst remaining mechanically attached to the PSC-assembly
– 8 – IEC 61439-2:2020 © IEC 2020
3.2.102
test position
position of a withdrawable part in which the relevant main circuits are open on its supply side
but not necessarily isolated and in which the auxiliary circuits are connected allowing
operation tests of the incorporated device(s), the withdrawable part remaining mechanically
attached to the PSC-assembly
Note 1 to entry: The opening can also be achieved without any mechanical movement of the withdrawable part by
operation of a suitable device.
3.2.103
isolated position
position of a withdrawable part in which an isolating distance is established in main and
auxiliary circuits on its supply side, the withdrawable part remaining mechanically attached to
the PSC-assembly
Note 1 to entry: The isolating distance can also be established without any mechanical movement of the
withdrawable part by operation of a suitable device, e.g. a disconnector in accordance with IEC 60947-3.
3.2.104
isolating distance
clearance between open contacts of withdrawable parts meeting the safety requirements
specified for disconnectors
[SOURCE: IEC 60050-441:2000, 441-17-35, modified – The context information has been
moved to after contacts and changed.]
3.4 Structural parts of assemblies
Addition:
3.4.101
active cooling
use of equipment mounted on or within the assembly, installed to reduce or control the
assembly’s internal air temperature during normal operation, which requires energization to
operate
Note 1 to entry: Examples include fans, internal air conditioning, heat exchangers, etc.
3.4.102
pressure relief flap
mechanical component provided to limit the pressure rise in case of internal arc-faults
Additional terms and definitions:
3.101 Electrical connections of functional units
3.101.1
disconnectable connection
connection which is connected or disconnected by manual operation of the connecting means
without a tool
3.101.2
withdrawable connection
connection which is connected or disconnected by bringing the functional unit into the
connected or isolated position
3.102 Gangways within PSC-assemblies
3.102.1
operating gangway within a PSC-assembly
space to be used by the operator for the proper operation and supervision of the PSC-
assembly
3.102.2
maintenance gangway within a PSC-assembly
space which is accessible to authorized personnel only and primarily intended for use when
servicing the installed equipment
3.103 Location
3.103.1
location with restricted access
location accessible for all persons who are permitted to have access to the location (e.g.
private housing, private parking areas or similar places)
3.103.2
location with non-restricted access
location accessible for all persons, e.g. the access is given in a public area
4 Symbols and abbreviations
Clause 4 of IEC 61439-1:2020 is applicable.
5 Interface characteristics
Clause 5 of IEC 61439-1:2020 is applicable, except as follows.
5.1 General
Replacement:
The characteristics of the PSC-assembly shall ensure compatibility with the ratings of the
circuits to which it is connected and the installation conditions. These characteristics shall be
declared by the PSC-assembly manufacturer using the criteria identified in 5.2 to 5.6 of
IEC 61439-1:2020, as amended by this document.
The specification schedule detailed in the informative Annex AA is intended to help the user
and the PSC-assembly manufacturer to meet this objective, whether the user:
– selects catalogue products, the characteristics of which meet their needs, and the
requirements of this document; and/or,
– makes a specific agreement with the manufacturer.
NOTE Annex AA also relates to the topics dealt with in Clauses 6 and 7.
In some cases, information provided by the PSC-assembly manufacturer may take the place
of an agreement.
)
5.3.3 Group rated current of a main circuit (I
ng
Addition:
For further information on the assumed loading of the outgoing circuits, see 5.4.
– 10 – IEC 61439-2:2020 © IEC 2020
5.4 Rated diversity factor (RDF)
Addition:
In the absence of an agreement between the assembly manufacturer and the user concerning
the actual load currents, the assumed loading of the outgoing circuits of the assembly or
group of outgoing circuits may be based on the values in Table 101.
For a motor or electric actuator circuit, the assumed load current is the rated current of the
motor multiplied with the loading factor of Table 101. If only the rated voltage and rated power
of the motor is provided, then the rated current of the motor can be taken from
IEC 60947-4-1:2018, Annex G.
For all other distribution and final circuits, it is assumed load current is the rated current of the
protective device, I , as required by the user, multiplied with the loading factor of Table 101.
n
5.6 Other characteristics
Replacement of item f):
f) degree of protection against contact with hazardous live parts, ingress of solid foreign
bodies and water, IP code (See 8.2.2 of IEC 61439-1:2020), including the degree of
protection for any distinct positions for removable and withdrawable parts;
Replacement of item g):
g) intended for use by electrically skilled, competent or instructed persons (see 3.7.13,
3.7.14 and 3.7.15 of IEC 61439-1:2020);
Replacement of item l):
l) type of construction – fixed, removable or withdrawable parts (see 8.5.1 of
IEC 61439-1:2020 and 8.5.2);
Addition:
aa) form of internal separation and associated degree of protection(s), IP code (see 8.101);
bb) types of electrical connections of functional units (see 8.5.101);
cc) mounting orientation (horizontal, vertical, etc.) if the assembly can be mounted in
different positions from vertical.
6 Information
Clause 6 of IEC 61439-1:2020 is applicable, except as follows.
6.1 Assembly designation marking
Replacement of the title and item g):
6.1 PSC-assembly designation marking
g) IEC 61439-2;
6.2.2 Instructions for handling, installation, operation and maintenance
Addition:
A PSC-assembly that can be energized from more than one source shall carry a warning label
indicating that the assembly is energized from more than one source, and that parts inside the
assembly can still be live unless all supplies are isolated.
7 Service conditions
Clause 7 of IEC 61439-1:2020 is applicable.
8 Constructional requirements
Clause 8 of IEC 61439-1:2020 is applicable, except as follows.
8.1.1 General
Addition:
For assemblies intended to be used for machines, the requirements given in 11.4 of
IEC 60204-1:2016 shall apply.
8.2 Degree of protection provided by an assembly enclosure
Replacement of the title:
8.2 Degree of protection provided by a PSC-assembly enclosure
8.2.1 Protection against mechanical impact (IK code)
Replacement of text:
Where a degree of protection (IK code) provided by a PSC-assembly enclosure against
mechanical impact is declared by the original manufacturer, this shall be verified in
accordance with 10.2.6.
NOTE It is not mandatory for the manufacturer to declare an IK code.
Additional subclause:
8.2.101 PSC-assembly with withdrawable parts
The degree of protection (IP code) indicated for PSC-assemblies normally applies to the
connected position (see 3.2.3 of IEC 61439-1:2020) of withdrawable parts. The assembly
manufacturer shall indicate the degree of protection (IP code) obtained in the other positions.
PSC-assemblies with withdrawable parts may be so designed that the degree of protection (IP
code) applying to the connected position is also maintained in the test and in isolated
positions.
If, after the removal of a withdrawable part, it is not possible to maintain the original degree of
protection (e.g. by closing a door), the assembly manufacturer shall make available covers or
similar to restore the original degree of protection. If these measures are not available, the IP
tests shall be carried out without the removable part in place.
– 12 – IEC 61439-2:2020 © IEC 2020
8.3.2 Clearances
Addition:
The isolating distance between the withdrawable unit's main contacts and their associated
fixed contacts in the isolated position shall be capable of withstanding the test voltage for the
declared impulse withstand voltage as specified in Table 102.
NOTE For altitudes above 2 000 m, refer to IEC 60664-1.
8.4.3.2.2 Requirements for earth continuity providing protection against the
consequences of faults within the class I assembly
Replacement of the title.
8.4.3.2.2 Requirements for earth continuity providing protection against the
consequences of faults within the class I PSC-assembly
Replacement of last paragraph:
When removable or withdrawable parts are equipped with a metal supporting surface that
have suitable conductivity and corrosion resistance, these surfaces shall be considered
sufficient for ensuring earth continuity, provided that the pressure exerted on them is
sufficiently high. The continuity of the exposed conductive parts of a withdrawable part shall
remain effective from the connected position to the isolated position inclusively.
8.4.6.1 Devices to be operated or components to be replaced by ordinary persons
This subclause of IEC 61439-1 is not applicable.
8.4.6.2 Requirements related to accessibility in service by authorized persons
8.4.6.2.1 General
Addition:
The most appropriate form of internal separation for a PSC-assembly is determined by the
operations to be undertaken when the assembly is energized and in service, but with
individual circuits de-energized (see 8.101).
Additional subclause:
8.4.6.2.101 Operating and maintenance gangways within a PSC-assembly
Operating and maintenance gangways (see 3.102.1 and 3.102.2) within a PSC-assembly shall
comply with the requirements for basic protection as specified in IEC 61140.
Recesses up to one metre in depth within a PSC-assembly are not considered to be
gangways.
8.5.2 Removable parts
Replacement of the title:
8.5.2 Removable and withdrawable parts
Replacement of text:
The removable and withdrawable parts shall be so constructed that their electrical equipment
can be safely removed and/or isolated from or connected to the main circuit even if the circuit
is live. The removable and withdrawable parts may be provided with an insertion interlock
(see 3.2.5 of IEC 61439-1:2020).
Clearances and creepage distances (see 8.3.2 and 8.3.3 of IEC 61439-1:2020) shall be
complied with in the different positions as well as during transfer from one position to another.
Additional subclauses:
8.5.2.101 Withdrawable parts
Withdrawable parts shall, in addition, have an isolated position (see 3.2.103) and may have a
test position (see 3.2.102), or a test situation (see 3.1.102). They shall be distinctly located in
these positions. These positions shall be clearly discernible.
In PSC-assemblies with withdrawable parts all live parts shall be protected in such a manner
that they cannot unintentionally be touched when the door, if any, is open and the
withdrawable part is withdrawn from the connected position or removed. Where an obstacle or
shutter is used they shall meet the requirements of 8.4.6.2.1 of IEC 61439-1:2020.
For the electrical conditions associated with the different positions of withdrawable parts, see
Table 103.
8.5.2.102 Interlocking and padlocking of removable and withdrawable parts
A removable or withdrawable part shall be fitted with a device that ensures that it can only be
removed and inserted after its main circuit has been switched off from the load.
In order to prevent unauthorized operation, the removable and withdrawable parts or their
associated assembly location may be provided with a lockable means to secure them in one
or more of their positions.
8.5.3 Selection of switching devices and components
Addition:
NOTE 2 The standards with which components can comply, include, for example, IEC 60947 (all parts),
IEC 60269 (all parts), IEC 60898 (all parts), IEC 61008 (all parts), IEC 61009 (all parts), IEC 62423, IEC 61800-5-
1, IEC 61010-2-201.
Additional subclauses:
8.5.101 Description of the types of electrical connections of functional units
A functional unit can have the same or different types of electrical connection for incoming
and outgoing supplies; for example, a withdrawable connection can be used for the incoming
and fixed or disconnectable for the outgoing.
NOTE 1 Particularly when multiple supplies are involved, the specifier carries out an assessment in order to
choose the most appropriate connection.
– 14 – IEC 61439-2:2020 © IEC 2020
The types of electrical connections of functional units within PSC-assemblies or parts of PSC-
assemblies can be denoted by a three-letter code:
– the first letter denotes the type of electrical connection of the main incoming circuit;
– the second letter denotes the type of electrical connection of the main outgoing circuit;
– the third letter denotes the type of electrical connection of the auxiliary circuits.
The following letters shall be used:
– F for fixed connections (see 3.2.6 of IEC 61439-1:2020);
– D for disconnectable connections (see 3.101.1);
– W for withdrawable connections (see 3.101.2).
NOTE 2 This coding system relates to the capability to remove, withdraw and re-insert functional units.
8.101 Internal separation of PSC-assemblies
Typical arrangements of internal separation by barriers or partitions are described in
Table 104 and are classified as forms of internal separation (for examples, see Annex BB
including Figure BB.1).
Internal separation may be used to attain one or more of the following conditions between
functional units, separate compartments or enclosed protected spaces:
– protection against contact with hazardous parts, the degree of protection shall be at least
IPXXB (see 8.4.2.3 of IEC 61439-1:2020);
– protection against the passage of solid foreign bodies and contact with hazardous parts,
the degree of protection shall be at least IP2X.
Unless otherwise agreed between the user and the manufacturer, when the form of internal
separation is higher than 1, all parts within the functional unit compartment that remain live
when the functional unit is switched off shall be protected to at least IPXXB. This requirement
only applies when the removable cover or door, as used for normal access to the functional
unit, is removed or opened.
NOTE 1 The degree of protection IP2X covers the degree of protection IPXXB. IP2X covers the prevention of
entry of solid foreign bodies and the prevention of contact with hazardous parts.
NOTE 2 Separation can be achieved by means of partitions or barriers (metallic or non-metallic), insulation of live
parts or the integral housing of a device e.g. a moulded case circuit-breaker.
If the application requires the form of internal separation is of a higher level than provided by
the degree of protection IPXXB (IP code), it shall be specified by the user.
See 8.4.2.3 of IEC 61439-1:2020 with regard to stability and durability of barriers and
partitions.
See 8.4.6.2 of IEC 61439-1:2020 and above with regard to accessibility for maintenance on
isolated functional units.
NOTE 3 The internal separation described is not intended to guarantee the integrity of the assembly in the event
of an internal arc-fault.
9 Performance requirements
Clause 9 of IEC 61439-1:2020 is applicable, except as follows.
9.3.1 General
Addition:
NOTE 3 For guidance on performance of a PSC-assembly under condition of internal arc-faults, see
IEC TR 61439-0. For guidance on testing, see IEC TR 61641. For guidance on the integration of internal arc-fault
mitigation systems into PSC-assemblies, see IEC TS 63107.
10 Design verification
Clause 10 of IEC 61439-1:2020 is applicable, except as follows.
10.2.6 Verification of protection against mechanical impact (IK code)
Replacement:
When a mechanical impact test is performed, it shall be carried out as follows.
Verification of the degree of protection against mechanical impacts (IK code) shall be carried
out in accordance with IEC 62262.
The enclosure shall be fixed as for normal use.
The impact energy shall be applied:
– three times to each surface exposed in normal use whose largest dimension is less than or
equal to 1 m;
– five times to each surface exposed in normal use whose largest dimension is greater than
1 m.
Unless otherwise specified, the degree of protection against mechanical impact indicated by
the assembly manufacturer applies to the complete assembly when installed in accordance
with the assembly manufacturer's instructions.
When the assembly does not have the same IK rating throughout, (e.g. locks, hinges, socket
outlets, displays which may have a lower IK rating), the manufacturer shall declare the
exclusion(s) applicable to the assembly.
The impacts shall be applied with even distribution over the faces of the enclosure. After the
test, some deformation of the enclosure is permissible. Visual inspection shall verify that:
– the degree of protection (IP code) of enclosure is not impaired, where doubt exists the
appropriate IP test according to 10.3;
– dielectric properties have been maintained, where doubt exists the appropriate dielectric
tests according to 10.9 of IEC 61439-1:2020, as modified in this document, should be
carried out;
– removable covers can be removed and reinstalled;
– doors can be opened and closed.
10.2.8 Mechanical operation
Addition:
In the case of withdrawable parts, the operating cycle includes any physical movements from
the connected to the isolated position and back to the connected position.
– 16 – IEC 61439-2:2020 © IEC 2020
10.3 Degree of protection of assemblies (IP Code)
Replacement of the title
10.3 Degree of protection of PSC-assemblies (IP Code)
Addition:
The internal separation of PSC-assemblies shall be in accordance with 8.101 and the
associated degree of protection shall be tested in accordance with IEC 60529.
The degree of protection associated with withdrawable parts as specified in accordance with
8.2.101 shall be tested in accordance with IEC 60529.
For the verification of the degrees of protection IP5X and IP6X enclosures with active cooling,
in particular when fans and air filters are used, the original manufacturer shall obtain
confirmation from the cooling equipment manufacturer that the cooling equipment has the
required degree of protection. The IP test on the enclosure with the cooling equipment fitted
shall then be carried out in accordance with IEC 60529 without the cooling equipment
operating.
NOTE It is expected that the user will maintain the cooling equipment in accordance with the assembly
manufacturer’s instructions in order to maintain the cooling equipment in an efficient condition and in turn the
cooling efficiency.
10.9.3.2 Impulse withstand voltage test
Addition:
The impulse withstand voltage capability of the isolating distance between the withdrawable
parts main contacts and their associated fixed co
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...