Electrical

Question 1

Nominal kVA rating of each engine generator

Answer 1

30 kVA to 35,000’ MSL

25 kVA to 41,000’ MSL

Question 2

The engine generator is tripped off and removed from the AC buses for what conditions?

Answer 2

Over/under voltage
Over/under frequency
Generator and bus over current

Question 3

Name the 5 AC buses

Answer 3

AC BUS 1
AC BUS 2
AC ESS BUS
AC UTILITY BUS 1
AC UTILITY BUS 2

Question 4

Bus priority logic for AC BUS 1 and AC BUS 2:

Answer 4

1. On-side engine-driven generator
2. APU generator
3. Cross-side engine-driven generator
4. External AC power

Question 5

Name the 9 DC electrical buses

Answer 5

DC BUS 1
DC BUS 2
DC ESS BUS
DC EMER BUS
DC UTIL BUS 1
DC UTIL BUS 2
BATT BUS
MAIN BATT DIRECT BUS
APU BATT DIRECT BUS

Question 6

Name the 4 Transformer-Rectifier Units (TRU’s)

Answer 6

TRU 1
TRU 2
ESS TRU 1
ESS TRU 2

Question 7

What is the amperage rating for each TRU?

Answer 7

100 amps

Question 8

TRU 1 normally supplies 28V DC to which buses?

Answer 8

DC BUS 1

DC UTIL BUS 1

Question 9

TRU 2 normally supplies 28V DC to which buses?

Answer 9

DC BUS 2

DC UTIL BUS2

Question 10

ESS TRU 1 normally supplies 28V DC to which buses?

Answer 10

DC ESS BUS

DC BATT BUS

Question 11

ESS TRU 2 normally supplies 28V DC to which buses?

Answer 11

DC ESS BUS

DC BATT BUS

Question 12

The DC EMER BUS provides power to:

Answer 12

Engine fire extinguishers 
Engine fuel shutoff valves
Engine hydraulic shutoff valves
APU fire extinguisher 
APU fuel shutoff valve

Question 13

Main Battery volts/amps rating?

Answer 13

24 volt

17 amp/hour

Question 14

APU battery volts/amps rating?

Answer 14

24 volt

43 amp/hour

Question 15

AIR-DRIVEN GENERATOR (ADG) power rating:

Answer 15

115 volt
400 Hz
15 kVA

Question 16

Automatic deployment of the ADG occurs when:

Answer 16

1. Both AC BUS 1 and AC BUS 2 become unpowered
2. 1 of 3 main generators must be online prior to both main AC buses losing power
3. Weight off wheels

Question 17

ADG provides power to:

Answer 17

AC ESS BUS

hydraulic pump 3B

Question 18

Pulling the ADG Manual Deploy Handle accomplishes:

Answer 18

Releases up lock allowing ADG deployment

Emergency AC transfer contactor and emergency DC transfer contactor energized immediately

In case ADG fails, enables the DC ESS BUS to be powered by BATT BUS through the emergency DC transfer contactor.