Electrical Flashcards
How many AC generators?
one for each engine
How many phases are the AC gens? and what Volt/Cycles?
3 phase
115/200V
320-480 cycles per second
What voltage do the AC gens operate at?
115 +- 2
below 108 +-2 = Rectifier failure PFL
What is the gen cut in range?
43-48%
What is the gen shift range?
65-75%
Can the gens be stopped?
No, only disconnected from the buses
What can you do if a gen fails?
Reset it
What do the bus contactors do?
Connect generators to the buses per the protection panels signal
What does the protection panel do?
protects the buses from a bad gen and the gen from a bad bus, also controls crossover
What do TRUs do?
Convert AC to DC power
What V and Amp are TRUs?
28 VDC
50 AMP
What warrants a PFL concerning TRU?
Failure or output below 25.5 Volts
What light comes on for dual TRU fail?
XMFR RECT OUT
Do the TRUs power all 3 DC buses?
Yes, via a diode module
What volts and Amps is the battery?
24 Volt
10 Amp
How long does the battery last on 80% charge?
15 min
What does the battery do?
supplies DC power to essential DC busses without TRU
When does the battery connect and disconnect?
18 Volts
10 Volts
What are the autosyn instruments?
Hydraulics
Oil Px
Fuel Flow
Oxygen
What is the power and cycles of the APU?
115/200 V
400 Cycles per second
How is the static inverter activated?
pressing the start button (30 sec)
selecting MAX
OXY/Fuel check switch held in GAGE TEST
What does the static inverter do?
powers 1st engine on start up
operation of right autosyn
oxygen indicators
How long will the standby ADI last without power?
9 min of life and +/- 6 deg accuracy
