Elctrical Flashcards
Placing the GRD PWR switch ON ____
connects external electrical power to both Transfer
Busse
Two fully-charged batteries have sufficient capacity to
provide standby power for a minimum of _____ minutes.
60
The _____ convert(s) battery power for use by the AC
Standby Bus.
Static Inverter
When standby electrical power is required”,” the A/C
standby bus is powered by _______.
the Main and Auxiliary Battery via the static inverter
Illumination of the ELEC light (amber) _____ indicates a fault
in the _____ Power System
on the ground / DC or Standby
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
2) IDG 2
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
Sources of AC power include _____. (Select ALL correct
answers)
1) Battery through Static Inverters.
2) APU Generator
3) Engine-Driven Generators
With the STANDBY POWER switch in _____”,” the batteries
power the standby loads after losing all engine or APU
electrical power _____
AUTO / in the air and on the ground
The BUS TRANSFER switch”,” in the AUTO (guarded)
position”,” allows _______.
Bus Tie Breakers (BTB) to operate automatically
Moving a GEN1 or GEN 2 (Generator) switch to ON _____.
) extinguishes the related GEN OFF BUS light
2) connects related IDG to Transfer Bus
3) disconnects previous source from the related Transfer
Bus
4) all of the above
BAT DISCHARGE light (amber) illuminates when _____
battery discharge is detected in the Main Battery and/or
Auxiliary Battery.
excessive
The _____ Bus is always connected to the battery
Hot Battery
The STANDBY POWER switch is in AUTO. With the loss of all
engine and APU electrical power”,” the batteries will be
powering the: (Select ALL correct answers.
1) Battery Bus
2) AC Standby Bus via the static inverter
3) DC Standby Bus
4) Hot Battery Bus
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.
4) The source of power being connected to a Transfer Bus
automatically disconnects an existing source
Illumination of the Generator DRIVE light (amber) indicates
the respective IDG experienced low oil pressure due to
_______
1) IDG failure
2) engine shutdown
3) IDG auto-decouple due to high oil temperature
4) all of the above
The APU generator”,” operating in flight as a single electrical
source _____
automatically sheds the Galley and Main Busses
Which light(s) indicate(s) the APU generator is ready-toload”,” 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
2) illuminates the opposite SOURCE OFF (amber) light
3) disconnects external power”,” if connected, from both
Transfer Busses
4) all of the above
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
