General Order 128
Definitions of Terms as Used in These Rule
23.5     Supply System means an underground electrical
supply system including all of the subsurface and associated above–ground
structures, conductors, services and appurtenances located on poles, on or
in buildings or in electrical stations and which are used for transmitting
and distributing electrical energy.
alarm, police, traffic control, signal and other circuits that operate in
excess of the voltage, power and cable shield or sheath limitations for
communication systems (Rule 20.4) are included in this definition.