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Flashcards in Electrical Deck (30)
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1

What is the minimum battery voltage for APU start?

23 volts

2

Primary electrical power is provided by ______ engine driven integrated drive generators (IDGs).

two

3

What occurs when a source of power is connected to a bus system?

it automatically disconnects an existing source

4

The APU generator can supply power to ____________ on the ground and inflight

both transfer busses

5

A GRD POWER AVAILABLE light provides flight deck indication that AC ground power is ____________________.

connected to the aircraft and meets aircraft power quality standards

6

If the BUS TRANS switch is in the AUTO position and the source powering the transfer bus is disconnected or fails, the source powering the opposite transfer bus _________________ through the BTBs.

automatically picks up the unpowered transfer bus

7

For single generator operation, the system is designed to ___________.

shed electrical load incrementally

8

The amber DRIVE caution light is illuminated when ____ oil is sensed in the IDG.

low

9

After the IDG disconnect switch is used to disconnect the IDG from the engine, it _________ possible to reactivate the IDG in flight.

is not

10

IDG low oil pressure can be caused by which of the following:

() all answers are correct
() IDG automatic disconnect due to high oil temperature
() IDG disconnected through the generator drive DISCONNECT switch

11

On the ground, an amber _______ light illuminates to indicate the DC system or standby system equipment has failed. This light is inhibited in flight.

ELEC

12

The three transformer rectifier (TR) units convert 115-volt AC to _______ DC.

28-volt

13

Inflight, an amber TR UNIT light illuminates _________.

TR1 or TR2 and TR3 has failed

14

A fully charged battery has sufficient capacity to provide electrical power for a minimum for ________.

30 minutes

15

An amber BAT DISCHARGE light illuminates when _________.

excessive battery discharge is detected

16

During normal operation the guarded Standby Power Switch will be in _____ and the battery switch will be _____.

AUTO; ON

17

An illuminated STANDBY Power (PWR) OFF Light indicates one or more of the following buses are unpowered

) all answers are correct
() AC standby bus, DC standby bus
() battery bus

18

With the STANDBY POWER Switch in AUTO (guarded position) in flight or on the ground with the loss of all AC power, the AC standby bus is powered by __________________ and the DC standby bus is powered by _____________.

battery through static inverter; battery

19

Maintenance (MAINT) Test Switch on the AC and DC Metering Panel is typically used by ________.

maintenance

20

What is the function of the DC Meters Selector?

selects the DC source for the DC Voltmeter and the DC Ammeter indications

21

What is the function of the AC Meters Selector?

selects the AC source for the AC Voltmeter, AC Ammeter and frequency meter indications

22

On the B737-900ER, which switch can be used to remove power from the left and right recirculation fans, forward and aft door area heaters, lavatory water heaters, ECS fan, all 115V AC galley busses, 115V AC shaver outlets, logo light, and potable compressor?

CAB/UTIL Switch

23

On the B737-900ER, which switch can be used to remove power from 115V AC audio entertainment equipment, 115V AC video entertainment equipment, 115V AC airphone equipment, and passenger seat electronic outlets?

IFE/PASS SEAT Switch

24

With ground power available, moving the Ground (GRD) Power Switch to the ON position

() all answers are correct
() removed previously connected power from AC transfer busses
() connects ground power to AC transfer busses if power quality is correct

25

What light on the overhead panel illuminates if the transfer bus is not being powered?

TRANSFER BUS OFF

26

What light on the overhead panel illuminates if the transfer bus is not powered by the source selected by the related generator switch?

SOURCE OFF

27

What light on the overhead panel illuminates if the IDG is not supplying power to the related transfer bus?

GEN OFF BUS

28

On the B737-800, moving the Generator (GEN) Switch to ON, connects ___________ by disconnecting the previous power source and closing the generator circuit breaker.

IDG to the AC Transfer Bus

29

What light on the overhead panel illuminates if the APU is running and not supplying power to a bus?

APU GEN OFF BUS

30

Which switch provides manual control of ground service busses enabling servicing of the aircraft using external power without activating AC transfer busses?

GROUND SERVICE Switch on the FWD Attendant Panel