BS 5550-7.5.2:1981
Cinematography. Production and presentation. Film and television location lighting. Specification for location lighting power distribution units
Specifies power distribution units for outdoor and indoor use for the protection and control of temporary electricity supplies. The units specified are three-phase, four-wire a.c., at declared voltages up to 415 V (240 V to earth) and a capacity up to 600 A per phase.