Electrical Flashcards
(33 cards)
The bus power control units provide electrical load management when the aircraft is operating on:
A. Engine starter generators only.
B. Aft external power only.
C. Fwd external power only.
D. Any available electrical power source.”
D. Any available electrical power source.
If the permanent magnet generators are not available, the flight control electronics receive power from the:
A. F/O’s flight instrument bus.
B. 28v DC system and main battery.
C. Captains flight instrument bus.
D. Directly from the EEC electronics units.”
B. 28v DC system and main battery.
What is the minimum number of external power sources required for an external power ONLY engine start?
A. Two (Either forward and the aft external).
B. Three.
C. Engine start is not available on external power only.
D. Two (L&R FWD).
D. Two (L&R FWD).
The ground handling mode is powered when ______ if no other power source is available.
A. Both forward external power sources are in use (ON).
B. Either FWD external power is connected (AVAIL).
C. Only AFT external power is connected (AVAIL).
D. The battery switch is ON.
B. Either FWD external power is connected (AVAIL).
The generator drive may disconnect automatically _________ .
A. Only on the ground.
B. Due to excessive frequency variations.
C. Due to bearing failure.
D. Depending on the fault condition detected.
How can the flight crew determine circuit breaker status?
A. Check the CBIC display.
B. Check the Status page display.
C. Check the Electrical synoptic.
D. Open CB’s automatically display on EICAS.”
A. Check the CBIC display.
What is the purpose of the permanent magnet generators (PMGs)?
A. Powers the Captains standby electrical system.
B. Powers the hot battery buss and main battery charger.
C. Powers the flight control electronics.
D. All the above.
C. Powers the flight control electronics.
The main battery provides power to the following:
A. Electric braking (as backup source).
B. The Captains Flight instrument bus until RAT deployment.
C. Towing and refueling operations.
D. All the above.
D. All the above.
The illuminated “AVAIL” light on the FWD or AFT external power switches indicate:
A. External power is plugged in and voltage and frequency are within limits.
B. External power is plugged in and is being used.
C. AC busses have lost all power and are looking for an external power source.
D. The system is available for external power to be plugged in.
A. External power is plugged in and voltage and frequency are within limits.
Which of the following is true with regard to loss of two Starter Generators (SG’s) in flight?
A. APU will Auto Start.
B. RAT will deploy.
C. First Officers flight instruments will be unpowered.
D. Some load shedding will occur.
D. Some load shedding will occur.
Which type of circuit breaker can be reset using the CBIC, either on the ground or in flight?
A. Electronic circuit breakers.
B. Thermal circuit breakers.
C. Only cabin related circuit breakers.
D. All breakers can be reset using the CBIC, but only with the concurrance of TOMC.
A. Electronic circuit breakers.
Which of the following conditions will cause the RAT to deploy automatically in flight?
A. Loss of the R1 bus.
B. Loss of the L2 bus with BAT.
C. Loss of two starter generators.
D. Loss of all electrical power to the Capt and FO’s flight instruments.
D. Loss of all electrical power to the Capt and FO’s flight instruments.
To remain within the capacity of the available power sources, ____ will occur.
A. Load Inhibit.
B. Non-essential circuit breakers will open as needed.
C. APU autostart.
D. Load Shedding.
D. Load Shedding.
If a loss of all electrical power to Capt’s and FO’s flight instruments occurs in flight, the _____ provides Standby Power until RAT deployment.
A. Main battery.
B. APU battery.
C. PMG’s.
D. Dedicated standby power bus batteries.
A. Main battery.
Which of the following indications will display during automatic load shedding?
A. LOAD SHED is displayed next the affected equipment symbol on the appropriate system synoptic.
B. “LOAD SHED” EICAS message displays.
C. A list of affected aircraft systems on the electrical synoptic.
D. Both A and C are correct.
D. Both A and C are correct.
Inflight, with only one starter generator available ______?
A. Engine anti-ice is no longer available.
B. Power remains available to critical and essential equipment.
C. The standby inverter is powered.
D. All CAC’s go to high flow to maintain pressurization.”
B. Power remains available to critical and essential equipment.
With the airplane unpowered on the ground, pushing the battery switch to ON:
A. Begins the left and right CCR start-up process.
B. Powers the left inboard and outboard displays.
C. Powers the left TCP.
D. Begins the left CCR start-up process.”
D. Begins the left CCR start-up process.
If a drive disconnect switch is pushed, with engines operating:
A. The starter/generator is disengaged from the engine.
B. The “ELEC GEN DRIVE” EICAS message displays.
C. Maintenance action will be required to reconnect the starter/generator.
D. All of the above.
D. All of the above.
If both FWD external power are powering the main AC busses, when the APU starter/generators become available:
A. The APU generator power is automatically applied when all external power is selected OFF.
B. The APU generators automatically replace all external power sources.
C. The APU generator powers the R1 and R2 AC busses & FWD external powers the L1 and L2 busses.”
D. APU generator power must be manually selected ON.
B. The APU generators automatically replace all external power sources.
After the APU is up to speed and has replaced the external power, what happens if external is reselected to ON?
A. the APU reverts to AVAIL and the FWD external powers the electrical system.
B. The APU powers the high load busses and the FWD external powers the 115v busses.
C. The APU generators and FWD external power parallel and share the load.
D. Nothing, the APU generators have priority and won’t allow selection of any external power until the APU is selected OFF.
B. The APU powers the high load busses and the FWD external powers the 115v busses.
With the APU running, and both engines running with all four starter/generators operating, when will the APU begin to power all or part of the aircraft?
A. Immediately, it will parallel with the other generators and share the load.
B. With the loss of one or more of the starter/generators.
C. At engine shut down at the gate.
D. Both B. and C. are correct.
D. Both B. and C. are correct.
The Towing Power panel provides power for ___.
A. Capt’s audio control panel, Capt’s flight interphone.
B. Brakes, Navigation lights.
C. Radio communications.
D. Both A and B are correct.
D. Both A and B are correct.
If any engine generator fails, how is power provided to it’s associated main AC bus?
A. The lost main AC bus is now powered by another main AC bus.
B. The RAT deploys & powers the AC bus.
C. The main battery will energize the AC inverter to power the bus.
D. The PMG’s will provide backup power to the associated bus.”
A. The lost main AC bus is now powered by another main AC bus.
The Large Motor Power Distribution System (LMPS) powers ______ .
A. CAC’s.
B. Hydraulic pumps.
C. Power for APU and Engine starting.
D. All the above.
D. All the above.
