Electrical (FM: 6.60) Flashcards
757/767: According to the graphic, the R UTILITY BUS OFF light is illuminated. What is the cause for its illumination?
a) The DC bus tie breaker is closed
b) The center number 2 ELEC HYD pump sheds
c) One or both galley busses shed or are unpowered
d) The associated utility bus is unpowered
D) The associated utility bus is unpowered
757/767: According to the graphic, the L GEN DRIVE DISC DRIVE light is illuminated. What is the cause for its illumination?
a) The IDG has automatically disconnected
b) Low oil temperature in the IDG
c) High oil pressure in the IDG
d) High oil temperature or low oil pressure
D) High oil temperature or low oil pressure
757/767: According to the graphic, the STBY POWER OFF light is illuminated. The aircraft is in flight. Which bus may not be powered?
a) HOT BAT bus
b) Left main DC bus
c) STANDBY AC bus
d) Right Transfer bus
C) STANDBY AC bus
757/767: According to the graphic, what is providing power to the standby busses?
a) Left main AC and DC
b) Left main DC bus
c) Right main AC and DC
d) Right Transfer bus
A) Left main AC and DC
757/767: When external power is connected, which bus is automatically powered?
a) Ground handling bus
b) Ground service bus
c) STBY AC bus
d) STBY DC bus
A) Ground handling bus
757/767: When the associated AC bus tie breaker is armed for automatic operation, the AC busses are powered according to the following system priorities:
a) Opposite Engine generator, associated Engine generator then APU generator
b) Associated Engine generator, APU generator then opposite Engine Generator
c) APU generator, associated Engine generator then opposite Engine generator
d) AC priority is not set when the BUS TIE switches are in AUTO
B) Associated Engine generator, APU generator then opposite Engine Generator
757/767: As the first engine is started with APU supplying electrical and pneumatic power, what load shed occurs?
a) Only the respective utility bus load sheds
b) Only the respective utility bus and all galley busses load shed
c) Both utility and all galley busses load shed
d) The utility busses remain powered but all the galley busses load shed
C) Both utility and all galley busses load shed
757 (as installed)/767: During flight, the Hydraulic Motor Generator (HMG) automatically starts and supplies AC power:
a) When the left hydraulic system pressure drops below a preset level
b) When the center and right hydraulic systems fail
c) When the HMG PWR switch is selected to ON
d) When primary AC power is lost on both main AC busses
D) When primary AC power is lost on both main AC busses
9) 757/767: The center busses transfer from the left main busses directly to the static inverter and the hot battery bus when:
a) At least two generators are operating and three autopilots are armed for an autoland approach
b) The right main AC bus fails during a coupled approach
c) Any one generator is operating and any two autopilots armed for an autoland approach
d) There is a failure of the left main AC bus and the airplane is above 200 feet RA
A) At least two generators are operating and three autopilots are armed for an autoland approach
757/763: On a three autopilot approach with a LAND 3 indication, what will the ASA indicate if an engine-driven generator is lost below 200 feet AGL without the APU running?
a) NO AUTOLAND
b) LAND 2 / NO LAND 3
c) LAND 2
d) LAND 3
D) LAND 3
757 (as installed): Once commanded to operate, are there limitations associated with how long the HMG can run?
a) Yes, 60 minutes or when power is restored to both Main AC busses
b) No, The HMG has no time limit
c) Yes, 30 minutes or when power is restored to the HOT BAT bus
d) Yes, 90 minutes is the maximum operating time
B) No, The HMG has no time limit
757/767: According to the graphic, what is providing power to the Ground Handling bus?
a) External power
b) An engine generator if operating on the ground
c) APU
d) The APU generator or an Engine generator if operating in flight
A) External power
The main aircraft battery and the APU battery are connected to their own respective battery chargers. Both battery chargers are powered by the:
a) Right Transfer bus on the ground or airborne
b) Ground service bus on the ground or airborne
c) Ground handling bus while airborne
d) BAT bus on the ground or airborne
B) Ground service bus on the ground or airborne
757/767: The Integrated Drive Generator (IDG) oil is cooled by:
a) A dedicated electric cooler powered by the STBY AC bus
b) A hydraulic / oil heat exchanger located in the right fuel tank (757) and left fuel tank (767)
c) A dedicated electric cooler powered by the main AC TIE bus
d) A fuel/oil heat exchanger
D) A fuel/oil heat exchanger
757/767: The main DC electrical system is powered:
a) Directly from the battery when the battery charger is available and supplying power
b) Directly from the associated engine DC generator
c) Directly from the battery bus
d) From the associated AC system through a transformer rectifier unit
D) From the associated AC system through a transformer rectifier unit