A320 Lounge Electrics 1 Flashcards
Which part of the engine provides the electrical power?
Spool 2, which is the N2 indication
What does IDG stand for?
Integrated Drive Generator
What does GCU stand for?
Generator Control Unit
Is the IDG the mechanical or electrical part of the generator?
Mechanical
Is the GCU the mechanical or electrical part of the generator?
Electrical
What does the GCU do?
It is the computer which controls how the generator is working and making sure it is outputting the correct frequency, voltage etc., by changing the excitation current.
It also opens and closes the generator line contactor
What does the IDG do?
As the engine speeds up or slows down (idle or TOGA), the IDG takes the varying input and creates a constant output, of approximately 1200rpm. Means the generator can produce the correct voltage and frequency
What is the voltage of the AC system?
115/200v
Consider it as 115V due to the way the 3 phase frequency is measured
How many phase and kVA is the AC electrical system?
3 phase
90kVA
What is the approximate rpm output of the IDG?
1200rpm
What does GLC stand for?
Generator Line Contactor
What does the GLC do?
Connects the generator control unit to the rest of the electrical system
How many GCUs are there?
One per generator, plus one for the EMER GEN
What does the IDG push button do?
Controls the mechanical side of the generator. Mechanically disconnects the IDG from the accessory gearbox via a clutch. If we do this, a clutch opens, and no matter what the accessory gearbox is doing, it’s no longer connected to the IDG, so the IDG stops spinning. If it stops spinning, the coil of wire isn’t moving relative to the second coil of wire, so we don’t induce current, so the generator is effectively shut off
What causes the IDG to auto disconnect?
Temperature above 200 degrees
Can you reengage the IDG once it has been disconnected?
No
What is important when pushing the IDG disconnect push button?
It’s a guarded switch, so needs cross-confirmation. Also it must not be pressed for more than 3 seconds
What is the principal difference between the IDG pushbutton and the generator pushbutton?
The IDG is mechanical, the GEN is electrical, and can be reversed
What does the GEN pb do?
Opens the generator line contactor
GCU becomes depowered, so the excitation current gets turned off
Turns off the GCU computer
What is a bus bar?
Connects the two sides of the electrical system together
What do bus ties do?
They close when there is a failure on one side of the electrical system, to allow that side to receive power from the other side. They also close to allow ground power to supply both sides
What does GAPCU stand for?
Ground and Auxiliary Power Control Unit
What does the GAPCU do?
Exactly the same as the GCU
How many AC busses are there?
- AC1, AC2 and AC ESS
How is AC bus 1 powered normally, and what are the bus ties doing?
Powered by GEN1, as the bus tie is open
How is AC ESS BUS normally powered?
AC BUS1, via a bus bar which connects AC1 and AC2
Is the AC ESS feed normally open or closed?
Normally open
What does the AC ESS feed do?
Can be closed to allow AC BUS 2 to power the AC ESS BUS
