Electrical Flashcards
Nominal kVA rating of each engine generator
30 kVA to 35,000’ MSL
25 kVA to 41,000’ MSL
The engine generator is tripped off and removed from the AC buses for what conditions?
Over/under voltage
Over/under frequency
Generator and bus over current
Name the 5 AC buses
AC BUS 1 AC BUS 2 AC ESS BUS AC UTILITY BUS 1 AC UTILITY BUS 2
Bus priority logic for AC BUS 1 and AC BUS 2:
- On-side engine-driven generator
- APU generator
- Cross-side engine-driven generator
- External AC power
Name the 9 DC electrical buses
DC BUS 1 DC BUS 2 DC ESS BUS DC EMER BUS DC UTIL BUS 1 DC UTIL BUS 2 BATT BUS MAIN BATT DIRECT BUS APU BATT DIRECT BUS
Name the 4 Transformer-Rectifier Units (TRU’s)
TRU 1
TRU 2
ESS TRU 1
ESS TRU 2
What is the amperage rating for each TRU?
100 amps
TRU 1 normally supplies 28V DC to which buses?
DC BUS 1
DC UTIL BUS 1
TRU 2 normally supplies 28V DC to which buses?
DC BUS 2
DC UTIL BUS2
ESS TRU 1 normally supplies 28V DC to which buses?
DC ESS BUS
DC BATT BUS
ESS TRU 2 normally supplies 28V DC to which buses?
DC ESS BUS
DC BATT BUS
The DC EMER BUS provides power to:
Engine fire extinguishers Engine fuel shutoff valves Engine hydraulic shutoff valves APU fire extinguisher APU fuel shutoff valve
Main Battery volts/amps rating?
24 volt
17 amp/hour
APU battery volts/amps rating?
24 volt
43 amp/hour
AIR-DRIVEN GENERATOR (ADG) power rating:
115 volt
400 Hz
15 kVA
Automatic deployment of the ADG occurs when:
- Both AC BUS 1 and AC BUS 2 become unpowered
- 1 of 3 main generators must be online prior to both main AC buses losing power
- Weight off wheels
ADG provides power to:
AC ESS BUS
hydraulic pump 3B
Pulling the ADG Manual Deploy Handle accomplishes:
Releases up lock allowing ADG deployment
Emergency AC transfer contactor and emergency DC transfer contactor energized immediately
In case ADG fails, enables the DC ESS BUS to be powered by BATT BUS through the emergency DC transfer contactor.
