Electrical Flashcards
If the permanent magnet generators are not available, the flight control electronics receive power from the:
• FO’s flight instrument bus.
• 28v DC system and main battery.
• Captain’s flight instrument bus.
• directly from the EEC electronics units.
• 28v DC system and main battery.
What is the minimum number of external power sources required for an external power ONLY engine start?
• Two (Either forward and the aft external)
• Three
• Engine start is not available on external power only
• Two (L&R Fwd)
• Two (L&R Fwd)
The ground handling mode is powered when ___ if no other power source is available.
• both forward external power sources are in use (ON)
• either FWD external power is connected (AVAIL)
• only AFT external power is connected (AVAIL)
• the battery switch is ON
• either FWD external power is connected (AVAIL)
The generator drive may disconnect automatically ____
• only on the ground
• due to excessive frequency variations
• due to bearing failure
• depending on the fault condition detected
• depending on the fault condition detected
How can the flight crew determine circuit breaker status?
• Check the CBIC display.
• Check the Status page display.
• Check the Electrical synoptic.
• Open CBs automatically display on EICAS.
• Check the CBIC display.
What is the purpose of the permanent magnet generators (PMGs)?
A. Powers the Captain’s 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 Captain’s 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:
• External power is plugged in and voltage and frequency are within limits.
• External power is plugged in and is being used.
• AC busses have lost all power and are looking for an external power source.
• The system is available for external power to be plugged in.
• 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 (SGs) in flight?
A. APU will Auto Start.
B. RAT will deploy.
C. First Officer’s flight instruments will be unpowered.
D. Some load shedding will occur.
D. Some load shedding will occur.
Electronic Circuit Breakers can be opened or closed using CBIC on the ground or in flight.
A. True
B. False
A. True
Which circuit breaker types may be reset via CBIC?
A. Thermal
B. Electronic
C. Both A and B are correct
D. Circuit breakers cannot be reset via CBIC
B. Electronic
Which of the following conditions will cause the RAT to deploy automatically in flight?
• Loss of the R 1 bus.
• Loss of the L2 bus with BAT LOW EICAS message.
• Loss of two starter generators
• Loss of all electrical power to the Capt’s and FO’s flight instruments
• Loss of all electrical power to the Capt’s and FO’s flight instruments
To remain within the capacity of the available power sources, __ will occur.
• Load Inhibit
• Non-essential circuit breakers will open as needed
• APU autostart
• Load Shedding
• 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.
• Main battery
• APU battery
• PMGs
• Dedicated standby power bus batteries
• 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.
lnflight, with only one starter generator available ?
• engine anti-ice is no longer available
• power remains available to critical and essential equipment.
• the standby inverter is powered.
• all CACs go to high flow to maintain pressurization
• power remains available to critical and essential equipment.
With the airplane unpowered on the ground, pushing the battery switch to ON:
• begins the left and right CCR start-up process
• Powers the left inboard and outboard displays.
• Powers the left TCP.
• begins the left CCR start-up process.
• 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:
• The APU generator power is automatically applied when all external power is removed.
• APU generator power replaces FWD external power.
• The APU generator powers the R1 and R2 AC busses & FWD external powers the L1 and L2 busses.
• APU generator power must be manually selected ON
• APU generator power replaces FWD external power.
The APU and FWD external can power the aircraft at the same time.
A True
B. False
A True
The bus power control units provide electrical load management when the aircraft is operating on:
• engine starter generators only.
• aft external power only.
• fwd external power only
• any available electrical power source.
• any available electrical power source.
Power source transfers are made without interruption when the aircraft is on the ground.
A True
B. False
B. False
How can crew members differentiate between an open Electronic circuit breaker (ECB) and an open Thermal circuit breaker (TCB)?
• Open TCBs are shown using a crosshatched display while ECBs are solid white.
• Open TCBs are displayed in red, while ECBs are displayed in amber
• TCBs display a capitol “T” immediately to the right of the symbology.
• Open TCBs are shown using a solid white display while ECBs are crosshatched.
• Open TCBs are shown using a crosshatched display while ECBs are solid white.
lnflight, when will the APU auto start?
• With an in-flight engine failure.
• With a loss of three or more starter/generators.
• Anytime the RAT is deployed.
• When power is lost to two main AC Busses.
• With a loss of three or more starter/generators.
