IEC 61439-6:2012 specifies the definitions, service conditions, construction requirements, technical characteristics, and verification methods for low-voltage Busbar Trunking Systems (BTS). It applies to BTS with a rated voltage up to 1,000 V a.c. or 1,500 V d.c., used for the generation, transmission, distribution, and control of electrical energy. This standard also covers BTS designed for use under special conditions, such as in ships, rail vehicles, or domestic applications operated by unskilled persons, and for electrical equipment in machines, with supplementary requirements outlined in the IEC 60204 series. This first edition replaces IEC 60439-2 (2000) and its Amendment 1 (2005), incorporating updates such as alignment with IEC 61439-1 (2011), new verification requirements, corrected measurement inconsistencies, and numerous editorial improvements.