Electrical Flashcards
What provides normal AC power?
IDGs
What connects the Main AC buses ?
2 Synchronous buses
What are the auxiliry sources of AC power?
2 APU generators
2 EXT power connections
How is AC converted to DC?
Transformer Recifiers
When on the ground, auxiliary AC power can be provided by ________.
2 APU generators or
2 EXT power connections
T/F: Both AC and DC Power Flow are displayed on the Electrical Synoptic Display.
False
What is the normal position of the Split System Breaker?
Closed and the AC buses are interconnected
How is IDG oil cooled?
By Engine fuel flow and fan bypass air
What do the IDG DRICE DISC switch fo?
Disconnect the IDG from the engine, must be reset on the ground
When will the split system breaker be open?
When two aux sources on the ground are powering the system
A fault is detected
When is uninterrupted power transfer availible?
On the ground only
What does turning a IDG GEN CONT switch to OFF do?
Opens the associated Generator Control Breaker.
When can IDG disconnect be preformed?
With the engine running above idle speed
What does a IDG DRIVE light indicate?
IDG Oil Pressure
IDG Oil Temperature
When will an automatic IDG disconnect occur?
With engine running and excessive oil temperature detected.
What connects the auxiliary power to the main AC busses?
The synchronous bus
What power Main Deck Cargo Handling Bus?
Number 2 Auxiliary Power Source
There are ______ IDGs, _____ APU generator(s), and _____ external power source(s) that supply AC power to the B747-400.
4,2,2
T/F: Disconnecting an IDG is an irrevocable action that can only be reset on the ground.
True
External Power and an APU generator cannot both be connected to the same side of the synchronous bus simultaneously. What divides the synchronous bus and allows each side to be powered by two different auxiliary sources?
Split System Breaker (SSB)
How many IDGs are required to power the electrical system?
1
What is the purpose of the ground handling bus?
Power items without the need of flight deck activation.
How is the ground handling bus powered?
When any auxiliary power is available