ATA 24 Electrical

Question 1

What are the 4 main AC power and 1 standby source?

Answer 1

Ground power, both IDG’s, and APU power, and the batteries are the standby DC power.

Question 2

The Electrical Meters, Battery, and Galley Power Module P5-provide front face BITE for ____________.

Answer 2

Standby power and DC generation system.

Question 3

The ELEC light on the Electrical Meters, Battery, and Galley Power Module
illuminates in the air or on ground to indicate a DC or standby power system fault
True or False.

Answer 3

True

Light does not come on in Flight

Question 4

How is IDG oil cooled?

Answer 4

Air/oil cooler located on the engine fan case.

Question 5

What could an illuminated IDG drive light indicate?

Answer 5

Low oil pressure

Question 6

The APU Generator Unit (AGCU) uses __________ ____________ located inside the SCU to control APU starter-generator output.

Answer 6

voltage regulator

Question 7

List the functions of an engine generator GCU.

Answer 7

Monitors the power quality at the IDG and feeder lines in the power distribution panels.

Question 8

Where can you find SCU ?

Answer 8

E2 rack EE bay

Question 9

Which panel can you find SPCU?

Answer 9

P6

Question 10

The GEN OFF BUS light is ____ in colour and indicates that the __________ __________ ___________ is _________.

Answer 10

Blue, Engine Generator Control Breaker (GCB) is open.

Question 11

Where are the DC electrical power parameters displayed?

Answer 11

P5-Overhead panel beside the AC volts/amps indication.

Question 12

What is the purpose of the SPCU?

Answer 12

Controls DC power generation

Question 13

The TR UNIT amber light is on in flight, what does this indicate?

Answer 13

TR unit failure

Question 14

What is the normal power source for the battery bus?

Answer 14

Transformer rectifier units

Question 15

What is the normal power source for the AC standby bus?

Answer 15

AC transfer bus 1 or
the static inverter

Question 16

What is the “standby power” source for the DC standby bus?

Answer 16

DC Bus 1 or
the hot battery bus

Question 17

The static inverter RCCB is normally ______.

Answer 17

Closed

Question 18

What controls the blue GND POWER AVAILABLE light?

Answer 18

External Power Contacter?

Question 19

After the external power contactor is energized closed, how is it kept closed?

Answer 19

BPCU?

Question 20

Can you power only the ground service buses, is so the how?

Answer 20

Yes, via the the AC transfer bus on that side has power or the ground service switch is on and there is external power connected to the aircraft

AC transfer bus on
ground service switch is on
external power connected to the aircraft

Question 21

How is BPCU BITE performed?

Answer 21

You flick the test switch to turn off any faults and do a test of the BPCU, at the end of the test only the BPCU pass or fail light should come on.

Question 22

Where are the power distribution panels located?

Answer 22

E and E Bay

Question 23

What controls load shedding?

Answer 23

The load shed relays

Question 24

Where ca you find standby power Unit?

Answer 24

P6

Question 25

Where can you find bus power unit?

Answer 25

E and E bay

Question 26

The load shed relays control power to which buses?

Answer 26

Main and galley buses

Question 27

What are 3 of the bus power control units many functions?

Answer 27

External Power, Load Shed and cockpit power control.