How a GPU works?
Moderators: sky's the limit, sepia, Sulako, North Shore
Ground Power Unit Question
G.P.U.'s can produce direct current or alternating current depending on their type of construction. Normally you will find the 28 volt d.c. units used on general aviation and small commercial equipment. For the "big iron" the ground power is usually 3 phase alternating current for the aircraft. Any d.c. service rquired in the larger aircraft is handled by power rectifiers which change the a.c. to d.c. . An a.c. gpu will have a plug with 8 female sockets to interface with the aircraft ( 6 wires for the 3 phase supply and 2 wires which comprise an interlock circuit for power activation ). On a d.c. gpu there are only 3 female socket inputs to the aircraft ( 2 for the actual dc power and 1 wire to complete an interlock circuit for power actuation ).

