IEC 61439-1:2011

IEC 61439-1:2009 lays down the definitions and states the service conditions, construction requirements, technical characteristics and verification requirements for low-voltage switchgear and controlgear assemblies. This standard applies to low-voltage switchgear and controlgear assemblies (ASSEMBLIES) only when required by the relevant ASSEMBLY standard. This first edition of IEC 61439-1 standard cancels and replaces the fourth edition of IEC 60439-1:1999. Significant technical changes with respect to the last edition of IEC 60439-1. IEC 61439-1 is a pure "general rules" standard to be referred to by subsidiary product parts of the IEC 61439 series; the product standard replacing IEC 60439-1 is IEC 61439-2; the discrimination between type-tested assemblies (TTA) and partially type-tested assemblies (PTTA) is eliminated by the verification approach; three different but equivalent types of verification of requirements are introduced: verification by testing, verification by calculation/measurement, or verification by satisfying design rules; the requirements regarding temperature rise have been clarified; the rated diversity factor (RDF) is covered in more detail; requirements from the standard for empty enclosures for assemblies (IEC 62208) have been incorporated; the whole structure of the standard is aligned with its new function as "general rules" standard. However, when a dated reference to IEC 60439-1 is made in another Part of the IEC 60439 series of assembly standards not yet transferred into the new IEC 61439 series, the superseded IEC 60439-1 still applies.

IEC 61439-1:2020 lays down the general definitions and service conditions, construction requirements, technical characteristics and verification requirements for low-voltage switchgear and controlgear assemblies. NOTE Throughout this document, the term assembly(s) (see 3.1.1) is used for a low-voltage switchgear and controlgear assembly(s). For the purpose of determining assembly conformity, the requirements of the relevant part of the IEC 61439 series, Part 2 onwards, apply together with the cited requirements of this document. For assemblies not covered by Part 3 onward, Part 2 applies. 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) clarification that power electric converter systems, switch mode power supplies, uninterruptable power supplies and adjustable speed power drive systems are tested to their particular products standard, but when they are incorporated in assemblies the incorporation is in accordance with the IEC 61439 series of standards; b) introduction of a group rated current for circuits within a loaded assembly and the refocusing of temperature-rise verification on this new characteristic; c) addition of requirements in respect of DC; d) introduction of the concept of class I and class II assemblies regarding protection against electric shock. The contents of the corrigendum 1 of December 2021 and corrigendum 2 of September 2023 have been included in this copy.