The standards for low-voltage power switchgear and controlgear assemblies, IEC 61439-1 & 2 Ed. 3, have recently been published and will soon be published as BS EN 61439-1 &2 Ed. 3. The new editions include many changes, with one particular change, the introduction of ‘group rated current of a main circuit’ having a major impact on the way assemblies are specified and rated. Without a clear understanding of the change there will be misunderstandings and issues.
This presentation will provide an overview on the significant changes in the standards and then focus on the introduction of the characteristic, group rated current of a main circuit: what it is, why it has been introduced, the effect and obligations on manufacturers and specifiers, the advantages and disadvantage, how to avoid issues and benefit from using the new characteristic.