Electrical Flashcards
The tow basic principles of operations for the 737 electrical system are (Select ALL correct answers)
2) 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.
Sources of AC power include ______. (Select ALL correct answers)
1) Battery through Static Inverters.
2) APU Generator
3) Engine-Driven Generators
Illumination of the Generator DRIVE light (amber) indicates the respective IDG experienced low oil pressure due to ________.
all of the above
Placing the GND 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 BUS (bright blue)
If neither AC Transfer Bus is powered by and IDG momentarily positioning either APU GEN switch to ON ______.
all of the above
When the APU generator is powering Transfer Bus 1, Transfer Bus 2 can be powered with ______. (Select ALL of the correct answers.)
1) the APU Generator
2) IDG 2
The APU generator operating in flight as a single electrical source _______.
automatically sheds the Galley and Main Busses
Moving a GEN1 or GEN2 (Generator) switch to ON ______.
all of the above
If the aircraft take off with the APU generator powering both Transfer Busses and the APU fails or is shut down, the ______ automatically connects IDG’s 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 automation 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
When the standby electrical power is required, the A/C standby bus is powered by _______.
the Main and Auxiliary Battery via the static inverter
Two fully-charged batteries have sufficient capacity to provide standby power for a minimum of _______ minutes.
60
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 ______ convert(s). batter power for use by the AC Standby Bus.
Static Inverter
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
Hint: its all of them
