Prefect Aircraft Information Flashcards
(30 cards)
Where in the Prefect is the battery located?
Compartment at the right, rear of the engine compartment.
What voltage is the Prefect battery?
24v with a capacity of 25Ah
What capacity is the Prefect battery?
25Ah
How is the Prefect battery accessed?
The top cowling gives access to the battery. A standard quick release connector, connects the power cables to the battery.
Can the Prefect battery be used to start the engine?
Yes, the aircraft battery can be used for starting the engine when external power is not available.
It can also be used to supply power to the essential aircraft loads when the generator is not online.
How long can the Prefect battery provide power to essential systems in an emergency?
30 minutes.
What is the full name of the Prefect?
Grob G 120TP-A Prefect.
Describe the external power connector for the Prefect.
The G 120TP-A has an external power socket.
Is is in the rear fuselage on the right side just aft of the wing. The 28v DC connector has 3 pins.
What are the 3 pins in the Prefect external power connector?
A large negative pin
A large positive pin
A small positive pin.
What voltage is the external power connector of the Prefect?
28 Volt DC connector
What is the purpose of the external power connector?
The external power connector can be used to start the engine and supply the complete aircraft system when on the ground.
What is the GPU?
Ground Power Unit (GPU) allows the connection to the ground power card (bus) in order to support engine starting, supplying aircraft systems with power and to charge the aircraft battery.
How is the aircraft battery charged?
Via the Ground Power Unit (GPU).
Where is the Prefect Starter/Generator located?
Located on the aft face of the engine accessory gearbox, above the turbine heat shield.
The Starter/Generator of the Prefect is dual function, what does this mean?
The Starter/Generator can operate either as a DC starter motor or as a DC generator.
What is the power rating of the Prefect generator mode?
6 KW at 28v DC which corresponds to a 200A continuous load through the speed range.
What is the Generator Control Unit?
The GCU regulates voltage and system protection.
What is a torque limiting system?
The GCU (Generator Control Unit) in the Prefect has a torque limiting system that automatically controls the starter/generator to prevent excessive torque being applied to the engine gearbox during the engine start.
What are the Prefect ‘busbars’?
Electrical power is supplied to the various electrically energised components in the aircraft via common points called busbars or buses.
How many busbars are present in the Prefect?
5
Hot battery bus Battery (batt) bus Main battery bus Avionic bus 1 Avionic bus 2
What is the purpose of the Hot battery bus (essential battery bus)
The Hot Battery Bus connects to the battery bus at all times.
It supplied the essential system circuit breakers.
What is the function of the Battery (Batt) Bus?
The Batt bus connects to the aircraft battery through the battery connector.
It supplies power for the critical systems, circuit breakers.
What is the function of the Main Bus?
The Main Bus connects to the starter/generator.
It supplies power to the non-critical systems.
What is the function of the Avionics Bus 1?
The Avionics Bus 1 connects to the Batt Bus. One half of the avionic master switch connects the battery bus to the avionics bus 1.
The avionics bus 1 supplies power to the critical avionic systems. A 25 amp circuit breaker on the battery bus protects the avionics bus 1.
