Electrical

Question 1

The AC electrical system is primarily supplied by:

Answer 1

AC generators(alternators) producing 3-phase 115v at 400Hz up to 30kVA

Question 2

Each generator is controlled by:

Answer 2

A generator control unit (GCU) in conjunction with the related GEN switch

Question 3

AC Bus 1 and AC Bus 2 power supply priority is:

Answer 3

Onside Generator, APU generator, Offside Generator, AC External power

Question 4

Illumination of the AC ESS XFER switchlight indicates:

Answer 4

Alternate power supply to the AC Essential Bus

Question 5

The AVAIL caption illuminates in the EXT. POWER AC switchlight if:

Answer 5

The external AC power applied to the aircraft is within limits and available for use

Question 6

Selecting the OFF/RESET position on a GEN switch:

Answer 6

Turns the generator off and resets the related generator control unit (GCU) after a protective generator shutdown

Question 7

The EMER PWR ONLY warning EICAS message means:

Answer 7

The ADG is deployed and producing power and AC bus 1 and AC bus 2 are not powered

Question 8

The ADG is deployed:

Answer 8

Automatically if both AC Bus 1 and AC Bus 2 become unpowered while airborne

Question 9

Pulling back the ADG handle:

Answer 9

Opens the ADG uplock via a cable

Question 10

Pushing the PWR TXFR OVERRIDE button on the ADG panel transfers:

Answer 10

The AC essential bus and hydraulic pump 3B to the operating APU or IDG generator(s)

Question 11

Illumination of the amber FAIL caption in the left AUTOXFER switchlight indicates:

Answer 11

Due to AC BUS 1 overload, power from the left generator is shut down and supply from the right generator is inhibited (AC bus 1 is isolated/unpowered)

Question 12

The AC utility buses are automatically loadshed when:

Answer 12

Both A and C are correct

i.e. Operating on one generator and the flaps are extended on the ground, One IDG generator is offline while airborne

Question 13

The generator symbol on the AC ELECTRICAL synoptic page is:

Answer 13

White when the related engine is not running

Question 14

After ADG deployment:

Answer 14

The ADG cannot be retracted

Question 15

CBP 2 contains circuit breakers that protect components supplied from:

Answer 15

AC Bus 2, DC Bus 2, DC Utility Bus 2, AC utility Bus 2, and Battery Bus

Question 16

The aircraft batteries are:

Answer 16

24V NICAD-type(only) and are rated at 17amp/hr(main) and 43amp/hr(APU)

Question 17

DC External power

Answer 17

Essentially substitutes for the APU battery

Question 18

In normal electrical system operation, the batteries:

Answer 18

Are isolated except for charging

Question 19

What buses are powered with only the BATT MASTER switch selected to ON while on the ground (no generators or external power in use?)

Answer 19

Battery Bus and the Emergency Bus

Question 20

What buses are supplied by the batteries if power from all the generators fails while airborne(including the ADG)?

Answer 20

Battery Bus, DC Essential Bus, and the Emergency Bus

Question 21

Pushing the MAIN BUS TIE switchlight:

Answer 21

Allows DC Bus 1 and DC Bus 2 to receive power from TRU 1 and/or TRU 2

Question 22

Failure of essential TRU 1 is indicated by:

Answer 22

The ESS TRU FAIL status EICAS message

Question 23

Power to the EICAS displays and the engine and APU start control circuits is supplied from:

Answer 23

The Battery Bus

Question 24

The DC utility buses are loadshed

Answer 24

When the DC BUS TIE switchlight is pushed in

Question 25

A hot APU battery is indicated by:

Answer 25

The APU BATT CHGR FAIL status EICAS message and the CHGR OFF annunciation on the DC ELECTRICAL synoptic page