Electrical

Question 1

Electrical faults are automatically detected and ____ isolated.

Answer 1

Automatically ()

Question 2

The main electrical power sources are:

Answer 2

4 IDGs, 2 APU Gen, 2 Ext Power

Question 3

The ground service bus is powered whenever the ____bus is powered.

Answer 3

AC Bus 1 ()

Question 4

The First Officer transfer bus is powered by_____.

Answer 4

AC Bus 2 or AC bus 1 () FCOM 6.20.4

Question 5

During automatic ILS approaches AC and DC busses #1, #2, #3 remain connected to the synchronous bus for redundancy electrical backup to autopilots. True or False.

Answer 5

FALSE ()

Question 6

Standby selector power selector switch in BAT will provide approximately ____minutes of emergency power

Answer 6

30 min ()

Question 7

If AC bus 1 is unpowered (all engines operating) which of the following will be observed?

Answer 7

ELEC AC BUS 1 ()

Question 8

When is the EICAS advisory message DRIVE DISC displayed?

Answer 8

IDG disconnect ()

Question 9

AC bus 1, 2 and 3 isolation lights and EICAS advisory message ELEC BUS ISLN may be displayed during autoland. True or False.

Answer 9

False. ( AC BUS ISOL light1,2,3 remain extinguished. The EICAS msg ELEC BUS ISOL is not displayed. The msg “ELECTRICAL SYNOPTIC INHIBITED FOR AUTOLAND” is displayed on the electrical synoptic)

Question 10

The ground handling bus supplies power to:

Answer 10

1. cargo handling equipment and compartment light 2. fueling system 3.Aux hyd. pump #4

Question 11

When the EICAS advisory message ELEC BUS ISLN is displayed:

Answer 11

BUS tie breaker open (BTB), effective bus is disconnected from synchronous bus,ISLN displayed on synoptic

Question 12

The EICAS advisory message BATTERY OFF is displayed when the main battery is discharging.True or False.

Answer 12

False. It is displayed when battery switch is OFF ()

Question 13

When is the EICAS advisory message BAT DISCH APU displayed?

Answer 13

APU battery discharging or during Standby power test ()

Question 14

With both APU generators connected; after the #4 engine has been started, the respective IDG automatically powers its side of the synchronous bus.True or False.

Answer 14

TRUE ()

Question 15

What occurs if available generator power is less than electrical system demand?

Answer 15

Load shedding. No EICAS msg or lights ()

Question 16

When autoland is engaged, system logic provides independent power sources for each of the three autopilots. which statement is true?

Answer 16

AC & DC isolated,AC bus 4 continues to power the synchronous bus ()

Question 17

What does placing the bus tie switch in the auto position do?

Answer 17

pushing the Bus tie switch to AUTO, closes the related BTB and DCIR and elables automatic AC BTB (bus tie breaker) operation

Question 18

What does the EICAS message ELEC GEN OFF 3 mean?

Answer 18

Generator control breaker open and AC bus 3 will be unpowered

Question 19

During preflight, selecting AUTO on the standby power selector, with the battery switch on, activates the primary EICAS display and enables required caution & warning? True or False.

Answer 19

TRUE (FCOM 6.20.7)

Question 20

THE FOUR MAIN DC BUSSES REMAIN INTERCONNECTED THROUGH THE DC ISOLATION RELAYS AND DC TIE BUS IF THERE IS AN AC BUS OR TRASFORMER/RECTIFIER (T/R) FAILURE. True or False.

Answer 20

TRUE ()

Question 21

THE CAPTAIN’S TRANSFER BUS IS NORMALLY POWERED BY

Answer 21

AC BUS 3

Question 22

PUSHING A BUS TIE SW. OFF OPENS THE RESPECTIVE DC ISOLATION RELAY. THE ASSOCIATED DC BUS REMAINS POWERED BY ITS RESPECTIVE AC BUS AND TR. True or False.

Answer 22

TRUE ()

Question 23

IF AC BUS 1 IS UNPOWERED (ALL ENGINES OPERATING) WHICH OF THE FOLLOWING WILL BE OBSERVED?

Answer 23

ELEC AC BUS 1

Question 24

WHICH AC BUS SERVES AS THE PRIMARY BACKUP POWER SOURCE FOR THE CAPTAIN’S AND FIRST OFFICER’S TRANSFER BUSSES?

Answer 24

AC BUS 1 (FCOM 6.20.5)

Question 25

THE GROUND HANDLING BUS SUPPLIES POWER TO

Answer 25

cargo handling equipment and compartment light, fueling system, aux hyd. pump 4 ()

Question 26

WITH THE STANDBY POWER SELECTOR IN THE BAT POSITION AND THE BATTERY SWITCH ON, WHAT IS THE ELECTRICAL SYSTEM CONFIGURATION?

Answer 26

Main bat supplies Stby bat via the main hot bat. bus, main stby inverter and apu charges are disabled