ELECTRICAL Flashcards
In normal operation, the left variable frequency (VFG) supplies:
A. AC BUS 1 only.
B. AC ESS BUS only.
C. AC BUS 1 and AC ESS BUS.
D. AC BUS 2.
C
To connect and disconnect external AC power to the airplane:
A. press the EXT AC pushbutton annunciator (PBA) on the ELECTRICAL panel.
B. select the LAMP TEST switch on the external ground power panel.
C. first select the MAIN BATT and APU BATT switches to OFF, then press the EXT AC PBA on the ELECTRICAL panel.
D. first select the BUS ISOL rotary switch to ESS, then press the EXT AC PBA on the ELECTRICAL panel.
A
Prior to pressing the EXT AC push button annunciator (PBA), what advisory
message is shown on the EICAS when a 115-VAC, 400-Hz, 60-kVA external power source is connected to the airplane?
A. EXT AC PWR ONLY
B. EXT AC PWR AVAIL t.’f P.
C. EXT AC PWR IN USE
D. EXT AC PWR ON STBY
B
During bus isolation, when is power removed from AC BUS 1?
A. When the BUS ISOL rotary switch is selected to R
B. When the BUS ISOL switch is selected to L and the L GEN pushbutton annunciator (PBA) is selected to OFF
C. When the APU GEN PBA is selected to OFF
D. When the MAIN BATT and APU BATT switches are selected OFF
B
How much power is produced by the electrical system?
A. 115VAC/28VDC
B. 110V/60Hz
C. 115VAC/12VDC
D. 110VDC/28VAC
A
The purpose of load shedding is to:
A. reduce the occurrence of circuit breaker tripping.
B. reduce overheating of solid-state power controllers (SSPCs) and thermal circuit
breakers (TCBs).
C. allow the activation of more than one hydraulic AC motor pump (ACMP).
D. protect against circuit overloads during periods of high electrical power demand.
D
When is electrical distribution automatically reconfigured to maintain power to all of the DC buses?
A. During a bus isolation procedure
B. During a complete loss of AC power
C. During a single TRU failure
D. During a battery discharge
C
What is the primary source of AC power?
A. Permanent magnet generators (PMGs)
B. Variable frequency generators (VFGs)
C. Fly-by-wire power converters (FBWPCs)
D. Ram air turbine (RAT)
B
