101 Aircraft Power Distribution Flashcards
Discuss Power Distro Components (26 cards)
Where is Aircraft Power Provided From?
IDG’s (8), APU-Driven generator, external power receptacles, and an emergency inverter.
Where is External Power Provided From?
Through two receptacles (1A and 1B) on the port side of aircraft, forward of the wing.
What Receptacle is the Master Receptacle?
External power receptacle 1A.
When the Split System Breaker is Open, What Receptacles Provide Power to what Bus?
1A provides power to AVE sync bus and 1B provides power to the ME sync bus.
Exaplain how Power is Provided to the Aircraft from Engine Power
IDG’s (or APU/Ground Power) provide 115 VAC 400 Hz 3 phase to the GCU’s, which is sent through the BPCU to associated sync bus (ME/AVE).
How is the Freq/Load to Engine Power Controlled?
The FRAPU provides the reference frequency to all eight FLCU’s. The FLCU sends signals to BPCU to monitor load, then it is sent to the CSD’s and then finally to the IDG’s.
What Generator Buses are Powered on the ME Bus?
2, 4, 6, 7, and 8 power the ME sync bus.
What Generator Buses are Powered on the AVE Bus?
1, 3, and 5 power the AVE sync bus.
What Generator Bus can be Transfered Between ME and AVE?
Generator 5 can swap from AVE to ME.
Explain the Function of the Split System Breaker
Splits the sync buses for high power transmission (VLF).
What is the Function of the Bus Power Control Unit?
Incorporates logic to control all Bus Tie Breakers, APU, and external power contactors. It also automatically trips external power contractors when volts, frequency, and current are not within limits.
Where is Control Power for the BPCU Supplied From?
Three independent sources; APU GCU, external power TRU, and Aircraft DC power.
What Does it Mean for the BPCU to “Provide Logic”?
The BPCU can process signals and make decisions based on rules, rather than responding passively to electrical inputs.
What is an IDG and What is its Function?
Integrated Drive Generator, provides 115 vac 400 Hz 3 Phase power by converting the engines mechanical energy into electrical energy.
What Does an IDG Consist of?
A CSD and an AC generator.
How is an IDG cooled?
The generator and CSD are cooled by circulating fuel through the IDG oil cooler.
Explain the Funtion of a Constant Speed Drive (CSD)?
Provide a constant rotational speed to the generator whenever engine speed is above minimal value (12000 RPM).
What is the CSD Speed Controlled by?
Output speed is controlled by an internal governor (CSD governor) and responds to electrical signals from the FLCU.
What is a TRU and What is its Function?
A Transformer Rectifier Unit or “TRU”, it converts 115 vac/400 Hz 3 phase power into 28 VDC. (AC -> DC power).
How Many TRU’s are on the E-6B?
Four AVE TRU’s and Two MA TRU’s with one external power TRU making sevel total TRU’s.
What is the Function of a FRAPU?
Provides reference frequency to all eight FLCU’s.
If the FRAPU Fails, What Device Maintains Generator Frequency?
The CSD Governors maintain frequency at 400 +/-8 Hz.
Explain how the FRAPU Shifts Power for the Aircraft
FRAPU provides momentary paralleling of APU/Ext Power with aircraft generators to perform seamless up-shift in power. Can not shift down.
What is the Purpose of the FLCU’s?
Precise control of CSD speed and Generator Real Load (watts) to divide equally among paralleled generators.
