IEC 60947-4-2:2020 applies to semiconductor motor controllers, starters and soft-starters which can include a series mechanical switching device, intended to be connected to circuits the rated voltage of which does not exceed 1 000 V AC. This fourth edition cancels and replaces the third edition published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - scope exclusions; - editorial correction of notes and hanging paragraphs; - reference to IEC 62683-1; - safety aspects related to: - general aspects; - limited energy circuits; - electronic circuits; - mention of dedicated wiring accessories; - power consumption measurement; - alignment to IEC 60947-1:2020.