Electrical Power System

Question 1

Electrical power sources

Answer 1

2 IDGs, Main Battery, Auxiliary Battery, APU, External Power

Question 2

How much voltage from IDG in flight vs on the ground?

Answer 2

In flight, 180 KVA
On the ground, 90 KVA

Question 3

How much voltage from the APU?

Answer 3

90 KVA

Question 4

What does the APU power on the ground?

Answer 4

All buses

Question 5

What does the APU power in flight?

Answer 5

Both AC transfer buses

Question 6

What does the Drive Disconnect Switch do

Question 7

IDG Load Limit on the Ground?

Answer 7

32% N1 if IDG load is 41%

Question 8

What does the Transform Rectifier do?

Answer 8

Converts 115V AC to 28V DC

Question 9

How many Transform Rectifiers are there?

Answer 9

3

Question 10

How are each Transform Rectifiers Powered?

Answer 10

TR1 - Transfer Bus 1
TR2 - Transfer Bus 2
TR3 - Normally Transfer Bus 2 with a backup on Transfer Bus 1

Question 11

How many Transform Rectifiers required for Total Load?

Answer 11

2

Question 12

What does Transform Rectifier 3 power?

Answer 12

Battery bus and backs up Transfer Bus 1 and 2

Question 13

What does Transform Rectifier 1 and 2 Power?

Answer 13

DC Bus 1, 2 and Standby Bus

Question 14

When is the Cross Bus Tie Closed?

Answer 14

Glideslope Capture for ILS
Bus Tie Circuit Breaker Switched Open

Question 15

How long can the Main and Aux Battery power the aircraft?

Answer 15

30 minutes

Question 16

What DC Buses are powered following a loss of both generators?

Answer 16

Battery Bus, Hot Battery Bus, Switched Hot Battery Bus, DC Standby Bus, AC Standby Bus (Static Inverter)

Question 17

What does BATT DISCHARGE mean?

Answer 17

Excessive Battery Discharge Detected

Question 18

What does the Static Inverter do?

Answer 18

Supplies AC Power to the AC Standby Bus during loss of normal electric power

Question 19

AVAIL Light Meaning?

Answer 19

External Power is connected and meets the quality standards but is not powered on

Question 20

Can you reset the Generator Drive Disconnect?

Answer 20

No, must be done by maintenance

Question 21

When does the generator drive automatically disconnect?

Answer 21

High oil temperature

Question 22

DRIVE Light?

Answer 22

Low oil in IDG or over temperature in IDG

Question 23

What does the test show for electrical?

Answer 23

AC Voltmeter - 115(+/- 5)
Frequency - 400 (+/- 10)

Question 24

Major AC Buses

Answer 24

Left/Right Bus, Transfer Bus 1/2, Sync Bus

Question 25

What buses does IDG 1 Normally power?

Answer 25

Left bus and Transfer Bus 1

Question 26

What buses does IDG 2 Normally power?

Answer 26

Right Bus and Transfer Bus 2

Question 27

What powers the sync bus?

Answer 27

First IDG Online

Question 28

IDG Load shedding on the ground

Answer 28

Phase 1 - Most significant equipment

Question 29

How to restore APU Load Shedding?

Answer 29

XFER Bus 2 open then auto

Question 30

What does the APU Power in Single IDG operations?

Answer 30

Transfer Bus (1 first choice) (1&2 if on aux load)

Question 31

Load Shedding for single IDG

Answer 31

Phase 5 - Not used Phase 4 - Main bus 1, Spare 1 and 2, Galley Bus Phase 3 and 2 - Aux Phase 1 - Control Cabinet for Aux Load

Question 32

ELEC Light Meaning?

Answer 32

Only powered on the ground. Fault in DC or Standby Power System

Question 33

Standby System Componets/Buses

Answer 33

Aux Battery Main Battery Static Inverter AC/DC Standby Bus Battery Bus Switched Hot Battery Bus Hot Battery Bus

Question 34

What does Transform Rectifier Light Mean?

Answer 34

TR1 or TR2 and 3 have failed

Question 35

Battery Powered Equipment?

Answer 35

Can PX Left Pitot Fire Protection Left Nav Equipment VHF/V/UHF 1 Thrust Reverser Left Side Flight Instruments Landing Gear Indicators