TH-57C ELECTRICAL SYSTEM
Identify five sources of dc electrical power for the TH-57C.
External Power Unit
State the power rating of the standby battery.
22.5 volt. 1.8 ampere hour
State the purpose of the standby battery.
To supply to 22.5 v power to the pilot’s attitude gyro in the event of a complete loss of power to essential BUS #1.
State the power rating of the main battery.
24 v, 17 amp hour
State the purpose of the RCB.
Provides over current protection to the battery (250 amp for 10-20 sec, but will trip with a constant current of 125 amps.)
State the purpose of the RCB override circuit.
The RCB override is incorporated into the battery and starter switch circuit to prevent the RCB from taking power away from the starter before a complete engine start is accomplished.
State that main generator output.
28 v, 105 amps
Described the functions of the voltage regulator used in the main generator system.
Maintains constant generator voltage under varying loads.
State the purpose of the standby generator.
Provides a backup power source for essential BUS #1 in case the main generator fails.
State the standby generator output.
28 v 7.5 amps
State the power requirements for engine start utilizing external power.
28 volt 400 amps
Describe each function of the voltmeter panel selector switch.