Electrical

Question 1

The two basic principles of operation for the 737 Electrical System are (Select ALL correct answers):

Answer 1

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.

Question 2

Sources of AC power include _____. (Select ALL correct answers)

Answer 2

1) Battery through Static Inverters.
2) APU Generator
3) Engine-Driven Generators

Question 3

Illumination of the Generator DRIVE light (amber) indicates the respective IDG experienced low oil pressure due to ________.

Answer 3

1) IDG failure
2) engine shutdown
3) IDG auto-decouple due to high oil temperature 4) all of the above

Question 4

Placing the GRD PWR switch ON _____.

Answer 4

connects external electrical power to both Transfer Busses

Question 5

The BUS TRANSFER switch”,” in the AUTO (guarded) position”,” allows _______.

Answer 5

Bus Tie Breakers (BTB) to operate automatically

Question 6

Which light(s) indicate(s) the APU generator is ready-to- load”,” but not powering a bus?

Answer 6

APU GEN OFF BUS (bright blue)

Question 7

If neither AC Transfer Bus is powered by an IDG”,” momentarily positioning either APU GEN switch to ON ______

Answer 7

1) 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

Question 8

When the APU generator is powering Transfer Bus 1”,” Transfer Bus 2 can be powered with _____. (Select ALL of the correct answers.)

Answer 8

1) the APU Generator

2) IDG 2

Question 9

The APU generator”,” operating in flight as a single electrical source ______.

Answer 9

automatically sheds the Galley and Main Busses

Question 10

Moving a GEN1 or GEN 2 (Generator) switch to ON _____.

Answer 10

1) 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

Question 11

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.

Answer 11

Automatic Generator On-line Feature

Question 12

Illumination of the ELEC light (amber) _____ indicates a fault in the _____ Power System.

Answer 12

on the ground / DC or Standby

Question 13

The Cross Bus Tie Relay automatically opens and isolates DC Bus 1 from DC Bus 2 ______.

Answer 13

at Glide Slope capture during a Flight Director or Autopilot ILS approach

Question 14

The _____ Bus is always connected to the battery.

Answer 14

Hot Battery

Question 15

BAT DISCHARGE light (amber) illuminates when _____ battery discharge is detected in the Main Battery and/or Auxiliary Battery

Answer 15

excessive

Question 16

When standby electrical power is required”,” the A/C standby bus is powered by _______.

Answer 16

the Main and Auxiliary Battery via the static inverter

Question 17

Two fully-charged batteries have sufficient capacity to provide standby power for a minimum of _____ minutes.

Answer 17

60

Question 18

With the STANDBY POWER switch in _____”,” the batteries power the standby loads after losing all engine or APU electrical power _____.

Answer 18

AUTO / in the air and on the ground

Question 19

The _____ convert(s) battery power for use by the AC Standby Bus.

Answer 19

Static Inverter

Question 20

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.)

Answer 20

1) Battery Bus
2) AC Standby Bus via the static inverter
3) DC Standby Bus
4) Hot Battery Bus