A320 Lounge Electrics 1

Question 1

Which part of the engine provides the electrical power?

Answer 1

Spool 2, which is the N2 indication

Question 2

What does IDG stand for?

Answer 2

Integrated Drive Generator

Question 3

What does GCU stand for?

Answer 3

Generator Control Unit

Question 4

Is the IDG the mechanical or electrical part of the generator?

Answer 4

Mechanical

Question 5

Is the GCU the mechanical or electrical part of the generator?

Answer 5

Electrical

Question 6

What does the GCU do?

Answer 6

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

Question 7

What does the IDG do?

Answer 7

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

Question 8

What is the voltage of the AC system?

Answer 8

115/200v

Consider it as 115V due to the way the 3 phase frequency is measured

Question 9

How many phase and kVA is the AC electrical system?

Answer 9

3 phase
90kVA

Question 10

What is the approximate rpm output of the IDG?

Answer 10

1200rpm

Question 11

What does GLC stand for?

Answer 11

Generator Line Contactor

Question 12

What does the GLC do?

Answer 12

Connects the generator control unit to the rest of the electrical system

Question 13

How many GCUs are there?

Answer 13

One per generator, plus one for the EMER GEN

Question 14

What does the IDG push button do?

Answer 14

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

Question 15

What causes the IDG to auto disconnect?

Answer 15

Temperature above 200 degrees

Question 16

Can you reengage the IDG once it has been disconnected?

Answer 16

No

Question 17

What is important when pushing the IDG disconnect push button?

Answer 17

It’s a guarded switch, so needs cross-confirmation. Also it must not be pressed for more than 3 seconds

Question 18

What is the principal difference between the IDG pushbutton and the generator pushbutton?

Answer 18

The IDG is mechanical, the GEN is electrical, and can be reversed

Question 19

What does the GEN pb do?

Answer 19

Opens the generator line contactor

GCU becomes depowered, so the excitation current gets turned off

Turns off the GCU computer

Question 20

What is a bus bar?

Answer 20

Connects the two sides of the electrical system together

Question 21

What do bus ties do?

Answer 21

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

Question 22

What does GAPCU stand for?

Answer 22

Ground and Auxiliary Power Control Unit

Question 23

What does the GAPCU do?

Answer 23

Exactly the same as the GCU

Question 24

How many AC busses are there?

Answer 24

3. AC1, AC2 and AC ESS

Question 25

How is AC bus 1 powered normally, and what are the bus ties doing?

Answer 25

Powered by GEN1, as the bus tie is open

Question 26

How is AC ESS BUS normally powered?

Answer 26

AC BUS1, via a bus bar which connects AC1 and AC2

Question 27

Is the AC ESS feed normally open or closed?

Answer 27

Normally open

Question 28

What does the AC ESS feed do?

Answer 28

Can be closed to allow AC BUS 2 to power the AC ESS BUS