Electrical Flashcards
What are the sources of dc power?
4 engine generators 1 APU generator 2 nickel cadmium batteries 1 lead acid backup battery External power cart
What 2 electrical systems does the emb 145 have?
28v dc system
115v 400hz ac system
Which generators are driven by the left and right engines?
Left engine are 1 and 3
Right engine are 2 and 4
How many hours can an aircraft be operated with a generator bearing fail message?
20 hours.
How are the engine generators cooled in the air and on the ground?
NACA air inlets in the air
Fan on the ground.
What are the engine generator output limits?
400 amps
600 amps for 5 minutes
800 amps for 5 seconds
What controls the contactors in the electrical system?
Electrical distribution logic
When are all the dc buses powered on the ground?
3 generators are operating
1 generator and shed bus override
GPU
When do the engine and APU generators come online?
Engines at 56.4% N2
APU 95% +7 seconds
What are the APU generator output limits?
400 amps below 30,000’
300 amps above 30,000’
600 amps for 2 minutes
800 amps for 5 seconds
What happens when you release the APU generator button?
The APU line contactor is commanded open and disconnects APU power.
How is the APU powered when starting?
By the central bus through the APU starting contactor.
What can power the APU for start?
External power
Battery 2
Battery 2 plus main generators
Why isn’t there electrical interruption while starting the APU?
Battery 1 is isolated from the load busses.
Describe the 2 main batteries and how long will they hold power for?
24 volt, 44 amp hour nickel cadmium batteries
40 minutes.