Appliance couplers for household and similar general purposes - Part 2-4: Appliance couplers dependent on appliance weight for engagement (IEC 60320-2-4:2005 + A1:2009) (english version)
Plugs, socket-outlets and couplers for industrial purposes - Part 4: Switched socket-outlets and connectors with or without interlock (IEC 60309-4:2006, modified + A1:2012) (english version)
Safety of machinery - Electrical equipment of machines - Part 31: Particular safety and EMC requirements for sewing machines, units and systems (IEC 60204-31:2013) (english version)
