Electrical System Flashcards
How many electrical power sources are there?
Five
2 engine generator
APU
External power (when AVAIL)
HDG
What is the priority of the AC sources?
1) Engine generators
2) APU
3) Opposite engine generator
What does the “AVAIL” light indicate?
Acceptable external power is plugged into the receptacle
What does the “DRIVE” light indicate?
Generator drive oil pressure is too low or oil temperature is too high
Why do the utility busses turn “OFF” during engine start?
Load shedding, power priority during start
What does the “AUTO” position on the STBY POWER switch do?
Provides power for standby and battery busses
from the main AC and DC busses.
Makes the battery a backup source of power as long as the BAT switch is on.
What happens if the STANDBY POWER switch is in the OFF position?
Standby AC or Standby DC busses are un-powered
What bus charges the battery?
Ground service bus
What happens if you place the standby power switch to BAT position?
The battery powers the standby busses and the battery charger is disconnected
Which bus provides power to the center AC bus?
Left AC bus
How is the ground handling bus powered?
on the ground from APU or external power
Does the ground handling buss needs to be switch “ON’?
No, automatically powered as long as there is a power source (APU/ Ext power)
What are the main sources of DC power
TRUs (2)
In the event of a complete electrical failure with only the battery available what busses are powered?
BAT & Hot BAT buss
Standby AC & Standby DC
Name all the busses
1)Capt inst xfer bus
2) L and 3) R AC xfer bus
4) standby AC and 5) standby DC
