IEC 60309-1 Ed. 4.1 b:2005, Plugs, socket-outlets and couplers for industrial purposes - Part 1: General requirements

This standard applies to plugs and socket-outlets, cable couplers and appliance couplers, with a rated operating voltage not exceeding 690 V d.c. or a.c. and 500 Hz a.c., and a rated current not exceeding 250 A, primarily intended for industrial use, either indoors or outdoors.