IEC 60947-4-2:2011 specifies the requirements for AC semiconductor motor controllers and starters, which may include a series mechanical switching device, for circuits with a rated voltage up to 1,000 V AC. This standard addresses controllers and starters with and without bypass means. It updates and replaces the previous edition and its amendments, incorporating significant changes such as updated EMC references, new marking requirements for electronic relays, and revised test requirements for overload relays. It also includes new classes for overload current withstand times and testing for environmental conditions like damp heat and salt mist. This standard should be used alongside IEC 60947-1:2007 for comprehensive guidance.