IEC 60947-3:2020 PDF

IEC 60947-3:2020 applies to switches, disconnectors, switch-disconnectors and fuse-combination units and their dedicated accessories to be used in distribution circuits and motor circuits of which the rated voltage does not exceed 1 000 V AC or 1 500 V DC. This fourth edition cancels and replaces the third edition published in 2008, Amendment 1:2012 and Amendment 2:2015. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - addition of critical load current tests for DC switches (see 9.3.9); - addition of requirements for a conditional short-circuit rating for disconnectors, switches, and switch-disconnectors protected by circuit-breakers (see 9.3.7.2); - addition of new categories for high-efficiency motors switching (see Annex A); - addition of new Annex E for connection to aluminium conductors; - addition of new Annex F for power losses measurement. The contents of the corrigendum of October 2021 have been included in this copy.