Electrical Flashcards
ACPC
AC Power Center
GCU’s
Generator Control Units
2 IDG’s rated at:
40 KVA, 115 VAC, 400 Hz; up to FL410
APU rated at:
40 KVA, 115 VAC, 400 Hz; up to FL410
ADG rated at:
15 KVA, 115 VAC, 400 Hz
GCU protection removes generator output for:
- over/under voltage
- over/under frequency
- generator or BUS overcurrent
- generator phase sequence
Purpose of IDG’s
Convert variable N2 speed to constant 12,000 rpm gen. speed
IDG FAULT switchlight indicates:
High oil temp. OR low oil press. within IDG
IDG DISC switchlight indicates:
IDG disconnected (automatically or manually)
Once disconnected, can an IDG be reconnected in flight?
No
What is the primary source of AC electrical power?
IDG’s
Where is the AC external power receptacle located?
Forward right side of aircraft
What type of batteries do we have?
Nicad (nickel cadmium)
Where are the batteries located?
Nose compartment (main) Aft equipment bay (APU)
TRU’s
Transformer Rectifier Units
How many TRU’s?
4 (nose compartment)
- TRU 1
- TRU 2
- ESS TRU 2
- ESS TRU 1
What is overvoltage protection rated at?
45 KVA for 5 minutes
60 KVA for 5 seconds
How is the oil cooled?
Fuel/oil heat exchanger
When will the IDG switchlight FAULT lamp illuminate?
Oil overheat/underpressure
How is the IDG separated from the accessory gearbox when the DISC switchlight is pressed?
Electrical solenoid
What are the 2 ways the IDG can disconnect?
Mechanically, or by shearing of the driveshaft
What do the GCU’s & ACPC provide?
Bus priority & protection during normal/non-normal ops
What are the reasons a generator is taken offline?
- over/under voltage
- over/under frequency
- generator & bus over current
- generator phase sequence
What must be present for the green AVAIL portion of the AC - AVAIL/IN USE switchlight to illuminate?
External power must be the correct:
- voltage
- frequency
- phase