IEC 61439-2:2020

IEC 61439-2 ®
Edition 3.0 2020-07
INTERNATIONAL
STANDARD
Low-voltage switchgear and controlgear assemblies –
Part 2: Power switchgear and controlgear assemblies

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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
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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
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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,
•
...