Electrical Flashcards
Bat Discharge Light amber?
Eccessive battery discharge detected
TR Unit light amber?
on ground any TR failed
in flight TR 1 failed or TR 2 and TR 3 failed
ELEC light amber?
a fault exists in DC power system or Standby power
Note: Operates only with airplane on ground
What does the BAT switch on ( guarded Position )
provides power to switched hot battery bus
energizes relays to provide automatic switching of standby electrical system to battery power with loss of normal power.
Generator Drive ( DRIVE ) lights mean amber IDG low oil pressure caused by one of the following
IDG failure
engine shutdown
auto disconnect due to high oil temperature
IDG disconnect switch
Note: IDG cannot be reconnected in the air.
Standby Power Off ( PWR OFF ) light amber
one or more of the following buses are unpowered
AC standby bus
DC standby bus
battery bus
GRD Power available light blue
ground power is connected and meets airplane quality standards
Transfer bus off lights amber
related transfer bus is not powered
Source off lights amber
no source has been selected to power the bus or has been manually disconnected
Note: source has been selected to power opposite transfer bus, both transfer busses are powered
GEN OFF BUS lights blue
IDG is not supplying power to the related transfer bus
BUS TRANSFER switch
AUTO
OFF
BTB operate automatically power to AC Transfer busses
Note: DC cross tie relay automatically provides normal or isolated operation as required
isolates AC transfer bus 1 from AC bus 2
Ground Service switch
FWD attendant panel
provides manual control to ground service busses without activation AC transfer busses
