1.1 These requirements cover light-sensitive control units of the plug-in, locking type, rated 480 V ac or less, for controlling outdoor electric lighting fixtures used for area lighting.

1.2 These requirements also cover receptacle devices equipped electrically and mechanically to receive the light-sensitive control units described in 1.

1.3 Shorting and open-circuit devices, used as substitutes, where necessary, for the light-sensitive control units described in 1, are also covered by the requirements in this standard, where applicable.

1.4 These requirements do not cover photoelectric switches, intended for residential, industrial or commercial use, of the non-plug-in, nonlocking type.