Electrical System Flashcards
What happens if a power generating source fails?
Bus ties automatically connect to provide no system degradation.
What components power the AC system?
2 IDG APU Inverter RAT AC GPU receptacle
What components power the DC system?
2 NiCad batteries
3 Transformer Rectifier Units (TRU)
DC GPU receptacle
How does the IDG maintain a stable power output?
A CSD (constant speed drive) attaches the IDG to the AGB (accessory gear box)
What monitors and controls the IDGs?
Generator Control Unit
Can one IDG supply the entire electrical system?
Yes
What will cause the Amber IDG light on the overhead panel to illuminate?
High oil temperature
Low oil pressure
HILOP
If an IDG is manually disconnected can it be reconnected by the flight crew?
No.
Maintenance
What is the primary purpose of the AC generators?
To power the AC buses and AC ESS Bus which…
Power three transformer rectifier units (TRU) 1, 2, and ESS
What is the purpose of the Transformer Rectifier Units?
To convert 115 VAC to 28 VDC
Can the APU replace a failed IDG
Yes
What is the AC electrical system’s priority
Onside IDG
INSIDE APU
OUTSIDE GPU
CROSS-side IDG
How is it known that an AC GPU is hooked up to the airplane and ready to provide electricity?
GPU button displays AVAIL and the GPU icon is presented on the electrical synoptic page.
Once the GPU button is pushed in, the button will display IN USE provided another AC power source is not available
What does it mean if the AC GPU is plugged in and the outside GPU panel button displays IN USE?
Ground service bus is in use
Cockpit service button will display AVAIL even though the ground service bus is in use
If the airplane is using the AC GPU and the APU is started what should the pilot be sure to do?
Deselect the GPU button before the next GPU selection