Electrical Flashcards
The two basic principles of operation for the 737 Electrical System are (Select ALL correct answers):
There is no paralleling of the AC sources of power.
Main Busses shed Transfer Busses inflight.
Sources of AC power include _____. (Select ALL correct answers)
Battery through Static Inverters.
APU Generator
Engine-Driven Generators
Illumination of the Generator DRIVE light (amber) indicates the respective IDG experienced low oil pressure due to ________.
IDG failure
engine shutdown
IDG auto-decouple due to high oil temperature
Placing the GRD PWR switch ON _____.
connects external electrical power to both Transfer Busses
The BUS TRANSFER switch”,” in the AUTO (guarded) position”,” allows _______.
Bus Tie Breakers (BTB) to operate automatically
Which light(s) indicate(s) the APU generator is ready-to- load”,” but not powering a bus?
APU GEN OFF BUS (bright blue)
If neither AC Transfer Bus is powered by an IDG”,” momentarily positioning either APU GEN switch to ON ______.
connects APU generator power to both Transfer Busses
illuminates the opposite SOURCE OFF (amber) light
disconnects external power”,” if connected, from both Transfer Busses
When the APU generator is powering Transfer Bus 1”,” Transfer Bus 2 can be powered with _____. (Select ALL of the correct answers.)
the APU Generator
IDG2
The APU generator”,” operating in flight as a single electrical source ______.
automatically sheds the Galley and Main Busses
Moving a GEN1 or GEN 2 (Generator) switch to ON _____.
extinguishes the related GEN OFF BUS light
connects related IDG to Transfer Bus
disconnects previous source from the related Transfer Bus
If the aircraft takes off with the APU generator powering both Transfer Busses”,” and the APU fails or is shut down”,” the _____ automatically connects IDGs to their respective Transfer Bus.
Automatic Generator On-line Feature
Illumination of the ELEC light (amber) _____ indicates a fault in the _____ Power System.
on the ground / DC or Standby
The Cross Bus Tie Relay automatically opens and isolates DC Bus 1 from DC Bus 2 ______.
at Glide Slope capture during a Flight Director or Autopilot ILS approach
The _____ Bus is always connected to the battery.
Hot Battery
BAT DISCHARGE light (amber) illuminates when _____ battery discharge is detected in the Main Battery and/or Auxiliary Battery.
excessive