ELECTRICAL Flashcards
If the electrical loads exceed power available (airplane or external), ELMS _____.
A. generates EICAS warnings
B. automatically sheds nonessential systems
C. automatically deploys the RAT
D. automatically starts the APU
B. automatically sheds nonessential systems
When AC power is removed from the airplane with the BATTERY switch ON, the PA system remains powered _____.
A. in flight or on the ground
B. if the IFE/PASS power switch is ON
C. on the ground for 10 minutes only
D. in flight only if the RAT deploys
A. in flight or on the ground
What does the main DC electrical system use to produce DC power?
A. PMA’s
B. TRU’s
C. PMG’s
D. RAT
B. TRU’s
Can you turn the battery off in flight?
A. No, the switch is inhibited.
B. Yes, if the battery charger is working normally.
C. Yes, the switch is not inhibited.
D. Yes, with the backup generator operational.
A. No, the switch is inhibited.
Several events can cause the backup AC electrical system to operate automatically, one of these events is when _____.
A. the APU is inoperative
B. flaps are extended out of the UP position
C. the landing gear is down and locked
D. power to one or both main AC busses is lost
D. power to one or both main AC busses is lost
The main battery charger, when powered, will power the _____.
A. the right flight control bus
B. APU battery charger
C. hot battery bus
D. the C1 and C2 TRU’s
C. hot battery bus
The ground service bus is normally powered by the right main bus. The _____ and _____ are alternate sources of power.
A. left main bus, hot battery bus
B. APU generator, primary external power
C. battery bus, hot battery bus
D. left transfer bus, right transfer bus
B. APU generator, primary external power
During power source transfers (such as switching from the APU generator to an engine generator) operating sources are momentarily paralleled to prevent power interuption _____.
A. on the ground
B. in the air
C. neither on the ground nor in the air
D. both on the ground and in the air
A. on the ground
While on the ground, normally the IDG can be electrically disconnected from the main busses by selecting an external electric power source or _____.
A. by manually deselecting external power
B. by manually deselecting the backup generator system
C. by selecting the DRIVE DISC switch to OFF
D. by selecting the GEN CTRL switch to OFF
D. by selecting the GEN CTRL switch to OFF
What does the illumination of a generator DRIVE light indicate?
A. The respective generator breaker is open.
B. High IDG oil pressure.
C. Low IDG oil pressure
D. Failure of a backup generator.
C. Low IDG oil pressure
If an IDG is manually disconnected in flight with the DRIVE DISC switch, can the pilots reconnect it?
A. No, maintenance action is required on the ground.
B. Yes, by resetting the circuit breaker, then closing the DRIVE DISC switch.
C. Yes, by closing the DRIVE DISC switch.
D. Yes, by selecting ISLN for the respective bus and then closing the DRIVE DISC switch.
A. No, maintenance action is required on the ground.
The _____ powers the AC standby bus if the left transfer bus is not powered.
A. left IDG
B. hot battery bus
C. main battery
D. standby inverter
D. standby inverter
What are the components of the standby electrical system?
A. The AC backup generators, the Standby inverter, the RAT generator, and the Main battery.
B. The APU backup battery, the Main battery, Standby inverter, and the RAT generator.
C. The Main battery, Standby inverter, RAT generator, and the C1 and C2 TRU’s.
D. The Standby inverter, the RAT generator, the AC backup generator, and the C1 and C2 TRU’s
C. The Main battery, Standby inverter, RAT generator, and the C1 and C2 TRU’s.
What causes the IDG drive to automatically disconnect from the engine?
A. High generator drive temperature.
B. A fault detected on the main bus.
C. Low IDG oil pressure.
D. High IDG oil pressure.
A. High generator drive temperature.
The entire airplane AC/DC electrical load is supplied by _____.
A. any one main AC power source and the main battery
B. the RAT if both AC busses lose power
C. any one main AC power source
D. any two main AC power sources
D. any two main AC power sources