AIRCRAFT SYSTEMS ELECTRICAL SA227‐ SERIES/FCOM/VTM 6.24.1 ELECTRICAL SYSTEMS The aircraft is equipped with a DC and an AC power system. The DC power distribution system is a segmented three bus system consisting of two essential buses and one nonessential bus. Each bus may be selectively disabled and is over voltage and overload protected. Redundant circuitry is provided to ensure the operation of all essential and emergency electrical and electronic systems. The 115 VAC and 26 VAC buses provide power for AC equipment. Either of two AC inverters powers those buses. DC POWER DISTRIBUTION As shown in Figure 6.24‐1, the battery bus forms the central distribution point for power. Each battery is connected, through a battery relay, to the battery bus relay and then to the battery bus itself. A 150 amp circuit breaker supplies power to the nonessential bus. Power to each bus is controlled by a bus tie switch. Each generator supplies power to the battery bus through a 325 amp circuit limiter. Power supplied to each bus is distributed to the various circuit breakers by smaller bus bars. SIMPLIFIED DC DISTRIBUTION SCHEMATIC
Figure 6.24‐1
Revision: Original Aug 1,2013
GO/FCOM/SA227‐SERIES/VTM