Electrical

Question 1

During cruise, you notice a BAT DISCHARGE light illuminated. When you check battery voltage, what would you expect to see as normal?

Answer 1

Normal range is 22 to 30V on battery voltage.
The amber BAT DISCHARGE light illuminates when excessive battery discharge is detected.

Question 2

How long can a fully charged battery/batteries provide standby power?

Answer 2

For a single battery, standby power can be provided for 30 minutes minimum.

For dual batteries, standby power can be provided for 60 minutes minimum

Question 3

You receive a MASTER CAUTION/ELEC and notice a DRIVE light illuminated on the overhead panel. What has occurred and what should be your next course of action?

Answer 3

DRIVE light illuminated indicated Integrated Drive Generator low oil pressure caused by on of the following:
1. IDG Failure
2. Engine shutdown
3. IDG automatic shutdown due to high oil temperature
4. IDG disconnected through generator drive DISCONNECT switch.

If you get these, carefully assess any related info. Reference the QRH for corrective action

Question 4

Why would the QRH direct the generator drive DISCONNECT switch to be placed in the Disconnect position?

Answer 4

Disconnection reduces risk by preventing further generator drive damage.

Question 5

what does a SOURCE OFF light indicate?

Answer 5

No source has been manually selected to power the related transfer bus, or the manually selected source has been disconnected.

Question 6

How is the transfer bus powered if the respective IDG is disconnected?

Answer 6

If the BUS TRANSFER switch is in the AUTO position, the source powering the opposition transfer bus will automatically pick up the unpowered transfer bus through the bus tie breaker.

Question 7

While in cruise, you receive a MASTER CAUTION/ELEC and notice a TR UNIT light illuminated on the overhead panel. What could have caused it?

Answer 7

TR 1 Failed OR

TR 2 and TR 3 Failed

Question 8

While in cruise flight, you receive a MASTER CAUTION/ELC and the following lights on the overhead panel: TRANSFER BUS OFF (both), SOURCE OFF (both) and GEN OFF BUS (both). What will provide power to essential systems immediately?

Answer 8

The standby power system will immediately provide power with the loss of both IDGs during cruise.

1. AC standby bus is powered by the batteries via the static inverter
2. The DC standby bus, battery bus, hot battery bus, and switched hot battery bus are powered directly from the battery/batteries.

Question 9

What is the standby power system consisting of?

Answer 9

1. Static Inverter
2. AC standby bus
3. DC standby bus
4. battery bus
5. hot battery bus
6. switched hot battery bus
7. main batteries

Question 10

What does the STANDBY PWR OFF light indicate when illuminated amber?

Answer 10

one or more of the following buses are unpowered:
1. AC Standby bus
2. DC standby bus
3. Battery bus

Question 11

With a loss of both engine driven generators, what other source of electrical power may be available?

Answer 11

As the only source of power, the APU generator can meet electrical requirements for all ground conditions and most flight conditions

Question 12

What considerations should you keep in mind for starting the APU following a loss of both engine driven generators?

Answer 12

APU start attempts are not recommended above 25000 FT

with both busses off, only one start attempt is recommended because multiple start attempts reduce standby power capacity

Question 13

If APU generator is the only remaining source of AC power, can you continue to your destination?

Answer 13

If APU generator is only remaining source of AC power you may only continue to your destination if it is the nearest suitable airport to you.