Low-voltage switchgear and controlgear assemblies - Part 1: General rules

Overview

IEC 61439-1 lays down the general rules for low-voltage switchgear and controlgear assemblies. It covers definitions, service conditions, construction requirements, technical characteristics and verification requirements. Prepared by IEC TC 121, its third edition was published on 5 May 2020, with corrigenda in 2021 and 2023. In Turkey it is applied as TS EN 61439-1.

Conformity of an assembly is judged not with this general part but with the relevant product part (Part 2 onwards); Part 2 applies to assemblies not covered by Part 3 onward. The 2020 edition introduced group rated current for circuits within a loaded assembly and refocused temperature-rise verification on it. It also added DC requirements and the concept of class I and class II assemblies.

The standard clarifies that UPS, converters, SMPS and drives built into an assembly are tested to their own product standards, while their incorporation follows IEC 61439.

Key points

1. Lays down definitions, service conditions, construction requirements, technical characteristics and verification requirements for LV assemblies.
2. Conformity is determined with the relevant part 2 onward; Part 2 applies to assemblies not covered by Part 3 onward.
3. Group rated current is introduced for circuits within a loaded assembly; temperature-rise verification is refocused on it.
4. DC requirements are added.
5. The concept of class I and class II assemblies is added.
6. UPS, converters, SMPS and drives are tested to their own product standards; their incorporation follows IEC 61439.
7. Edition 3 was published 2020-05-05 (504 pages incl. redline); corrigenda 2021 and 2023.
8. Related documents: IEC 61439-2, IEC 61439-6, EN 61439-1, TS EN 61439-1.

Using it in design

• In the switchboard catalogue, store the assembly's rated current (InA), the group rated current or rated diversity factor per circuit, Icw/Ipk and the form of separation.
• Check that the summed loading of outgoing circuits respects the group rating rather than the sum of nameplate values.
• Mark UPS cabinets as separate products, not as assemblies.

Who should read it

Electrical engineers designing boards and distribution systems, panel builders and specification writers.

Related standards

• IEC 61439-2
• IEC 61439-6
• EN 61439-1
• TS EN 61439-1

Publication details

Authors

IEC TC 121

Publisher

IEC

Year

2020

Document number

IEC 61439-1:2020

Document language

English

Source type

Standard

Access

Citation only

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation