Electrical power is distributed to the aircraft systems via the Main electrical buses.
Each main bus supplies power to systems on the respective side of the aircraft, i.e. the left main bus provides power to the start circuits, controls and instrumentation on the left side of the aircraft and vice versa.
When the starter-generator operates above 60% RPM and the generator switches are ON, the generators will be the primary power source for the each main bus and will supply up to 200 amperes of direct current at normal bus voltage of 28.5VDC.
A hot battery bus will provide power to essential circuits such as:
- Left and right engine stop buttons and control circuitry,
- Avionics frequency memory,
- Clock, and
- Cabin light and cockpit lighting.
The Hot battery bus is energised any time the batteries are connected to the aircraft.
The hot battery bus circuits are protected by fuses located just aft of the batteries in the nose compartment.