Historical
IEC 60947-4-2 Ed. 2.2 b:2007
Low-voltage switchgear and controlgear - Part 4-2: Contactors and motor-starters - AC semiconductor motor controllers and starters
"Applies to controllers and starters, which may include a series mechanical switching device, intended to be connected to circuits, the rated voltage of which does not exceed 1 000 V a.c. "
International Electrotechnical Commission [iec]