MD Helicopters MD900 with PW206E, Руководство по эксплуатации самолета

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CSP–900RFM206E–1
ROTORCRAFT FLIGHT MANUAL
MD900 With PW 206E
Systems Description
Original
7–33
7–12.ELECTRICAL SYSTEM
The electric system is designed to maintain separation of the power generating sys
tems. Wiring for each system is physically separated to each side of the helicopter to
the greatest extent possible. Power from the two generators does not pass together
through a single connector at any point on the aircraft to preclude any single point
failure that could result in loss of power to the essential bus.
F92−075B
LEFT
STARTER
GENERATOR
LEFT
START RELAY
LEFT BUS TIE RELAY
LEFT PWR RLY
LEFT GEN BUS
EXTERNAL POWER
LEFT AVNCS BUS
LEFT AVIONICS RELAY
BAT
RIGHT
STARTER
GENERATOR
RIGHT
START RELAY
LEFT BUS TIE RELAY
RIGHT PWR RLY
RIGHT GEN BUS
RIGHT AVNCS BUS
RIGHT GCU
RIGHT AVIONICS
RELAY
SHUNT 2
LEFT GCU
SHUNT 1
ESS PWR
ESS PWR
BATTERY RELAY
RT ESS BUS
RELAY
RIGHT ESS BUS
LEFT ESS BUS
BATTERY BUS
EXTERNAL
POWER
RELAY
RIGHT DC BUS
LEFT DC BUS
RT
LT
LT ESS BUS
RELAY
Figure 7–19. Battery Power and External Power Subsystem Block Diagram
Two engine−mounted starter−generators rated at 200 amperes each provide
29 volts DC to the aircraft. Bus tie relays provide redundancy by allowing either
generator to provide power to all busses.
The left and right essential bus relays allow the left and right essential buses
to be powered by either of the two generators, or by the battery if all power from
the generators is lost.
Starter and generator functions are directed by individual generator control
units (GCU), each of which provides starter control, voltage regulation, and protec
tive functions. Electric power is distributed by two electric busses and a battery
bus. A starter contactor connects the starter generator to the battery bus. After