IDG

Question 1

What is an IDG?

Answer 1

Integrated drive generator and a CSD (constant speed drive) combined into a single unit to convert a variable N2 speed into a constant 12,000 RPM generator speed to generate 400Hz constant frequency power, regardless of engine speed

Question 2

What’s the IDG switch used for?

Answer 2

To manually disconnect the IDG from the engine

Question 3

Will the IDG disconnect automatically? if so, for what reason?

Answer 3

YES. For over torque, and or over temp condition.

Question 4

What would cause the FAULT light on the IDG to illuminate?

Answer 4

HOT / LOP
High oil temperature / Low oil pressure

Question 5

Once disconnected, can we reconnect the IDG in flight?

Answer 5

No, must be on the ground with engine off, by MX

Question 6

What does the white DISC light indicate?

Answer 6

Selected - Disconnect is successful

Question 7

What is the AC ESS XFER (ALTN) button used for?

Answer 7

Used to manually switch ESS BUS feed from AC BUS-1 to AC BUS-2

Question 8

Will the ESS BUS automatically transfer to AC BUS-2?

Answer 8

Yes, when AC BUS-1 fails

Question 9

If the white ALTN lights comes on, what does that indicate?

Answer 9

It indicates that AC ESS BUS is no longer being powered by AC BUS-1 which is the normal power source, instead it’s being powered by alternate power source - AC BUS-2

Question 10

What is the difference between the MAIN BUS, ESS BUS, and BATT BUS?

Answer 10

MAIN BUS:
Provide you with normal load for galley, and flight entertainment, and main cabin lights. These loads can be load-shed in flight without affecting the safe operations of aircraft.

ESS BUS:
Provides you with essential loads-for equipment and instruments required for the continued safe operation of the aircraft

BATT BUS:
Provide you with emergency loads, equipment that required for safe, landing of the aircraft, such as radios, fuel controls, landing gear, and fire protection