Elec

Question 1

Difference between APU and IDG load shedding?

Answer 1

IDG: first main and galley buses TRX bus 2 than Main an galley buses TRX bus 1 than IFE buses

APU: all main and galley buses, than IFE buses

Question 2

By which TRX bus is AC standby BUS powered?

Answer 2

AC TRX bus 1

Question 3

When is DRIVE light illuminated

Answer 3

When low oil press is sensed in IDG:

IDG fail
Eng shutdown
IDG auto disconnect due high oil temp
Drive disconnect switch

Question 4

What does the ELEC light indicate?

Answer 4

Only in GND working and indicates that a fault exists in DC PWR system or standby PWR system

Question 5

From which bus is TR3 normally powered?

Answer 5

AC TRX BUS 2

Question 6

What does TR1 and TR2 normally power

Answer 6

They power in parallel DC BUS 1 DC BUS 2 and DC STBY BUS

Question 7

What does TR light indicate?

Answer 7

On GND: Any TR unit failed
In FLT: TR1 or TR2 and TR3 failed

Question 8

What is normal battery voltage?

Answer 8

24 volt
Range 22-30 Volt

Question 9

How are batteries Charged?

Answer 9

MAIN BAT by AC GND SVC BUS 2
AUX BAT by AC GND SVC BUS 1

Question 10

What does happen to BAT bus if TR3 fails?

Answer 10

It is powered by MAIN BAT Charger

Question 11

When are the main and aux batt used to pwr DC and AC STBY buses?

Answer 11

When pwr is lost to AC TRX bus 1 or DC BUS 1

Question 12

What does stby PWR OFF light indicate?

Answer 12

AC stby bus and/or DC STBY bus and/or BAT bus unpowered

Question 13

What powers ISFD?

Answer 13

BAT BUS

Question 14

What activates ISFD

Answer 14

Bat switch on, after 10 sec’s init wil start that requires 90 secs