IEC 61439-1:2011 defines the service conditions, construction requirements, technical characteristics, and verification processes for low-voltage switchgear and controlgear assemblies. It serves as the foundational standard but cannot be used alone for specifying or determining the conformity of assemblies. Assemblies must also comply with subsequent parts of the IEC 61439 series. This standard applies to assemblies rated up to 1,000 V AC or 1,500 V DC, including stationary or movable types, with or without enclosures. It covers assemblies used in electrical energy generation, transmission, distribution, and control, as well as those for specialized conditions such as ships, rail vehicles, and machines, provided additional relevant requirements are met.

The second edition of this standard, replacing the 2009 edition, includes significant updates such as revised service conditions in Clause 7; numerous changes to verification methods in Clause 10; modifications to routine verification concerning clearances and creepage distances; updated tables in Annexes C and D; revised EMC requirements in Annex J; new Annexes N, O, and P providing guidance on temperature rise verification, short-circuit withstand strength, and integration with IEC/TR 61117; and general editorial improvements.