Electrical

Question 1

What does the “AVAIL” light indicate on the external and APU power switches?

Answer 1

The related power source (APU or EXT) is plugged in and Available, and the power quality is Acceptable.

Question 2

When is the Main Deck Cargo Handling Bus powered?

Answer 2

When “AVAIL” light is displayed on APU 2 or EXT 2 switches
(The FO has to go walk the main deck)

Question 3

What electrical power source provides power for the lower lobe cargo handling, fuel panel, and AUX 4 hydraulic pump?

Answer 3

Ext Power 1 or APU Gen 1 AVAIL or selected ON (powering the Ground Handling Bus).
(The Captain has to walk down to talk to maintenance on the ground).

Question 4

What are some equipment items powered by the Utility buses?

Answer 4

5 fuel pumps,
Galley Equipment

Question 5

What condition would automatically disconnect the IDG if not manually disconnected by the crew?

Answer 5

Excessively high drive oil temperature

Question 6

What does a bus ISLN light illuminated indicate?

Answer 6

The Bus Tie Breaker (BTB) is open. AC Bus is isolated from the synchronous bus

Question 7

How do you reconnect an IDG that has been disconnected?

Answer 7

Maintenance action on the ground only

Question 8

How is the electrical system configured during an automatic ILS Approach (Autoland)?

Answer 8

AC and DC Buses 1,2,3 are isolated from the synchronous bus
AC bus 4 continues to power the synchronous bus