Electrical Flashcards
Bus Tie power priority logic:
Onside engine driven generator
External power
APU generator
Offside engine driven generator
The AC and DC GND/FLT buses supply power to passenger, galley, and cargo compartments even when EXT PWR is switched off.
Can the APU be started in the emergency electrical configuration?
To conserve battery power in the emergency electrical configuration, APU start is inhibited for 45 seconds. If a start is attempted after 45 seconds and it does not start or the APU generator malfunctions, the drain will significantly shorten the life of the batteries.
What occurs during landing in the emergency electrical configuration?
Below 100 knots, the DC BAT Bus automatically connects to the aircraft batteries. As airspeed continues to decrease below 50 knots, the AC ESS Bus sheds and all DUs are lost.
Which battery powers the AC ESS Bus and the DC ESS Bus?
Battery 1 provides DC power to the static inverter which powers the AC ESS Bus. Battery 2 supplies DC power to the DC ESS bus.
What is significant about the circuit breakers on the overhead panel?
All circuit breakers on the overhead panel are associated with systems which are powered while in the emergency electrical configuration.
What is the significance of the different colored circuit breakers?
Green colored circuit breakers are directly monitored by the ECAM, as well as the systems associated with it.
Black colored circuit breakers are not monitored by the ECAM, a failure message appear will appear only if the breaker’s associated system or component is monitored.
To avoid damage to the IDG _____ _____, the IDG pbs should only be used when the respective engine is _____ and not be pressed for more than _____ seconds.
Disconnect Mechanism, Running, 3 Seconds
How can the AC and DC GND/FLT Buses can be powered for ground servicing without energizing the entire system?
The AC and DC GND/FLT Buses can be powered for ground servicing without energizing the entire system when the MAINT BUS switch on the ceiling panel aft of the flight deck is selected to ON.
What is the purpose of the Bus Tie?
To seperate the two sides of the electrical system but provides the ability to connect them if necessary.
How does the IDG work?
The IDG takes variable speed and produces a constant output. There is a disconnect/clutch if needed.
Why is there a limiation of 3 seconds on the IDG pb?
To protect the solenoid.
When reseting a system, how long must you wait for a pb or a circuit breaker?
- 3 seconds for pbs
- 5 seconds for circuit breakers
Which component allows DC electricity from battery 1 to be transformed into AC?
Static Inverter
How is AC power from the emergency generator transformed into DC?
A third (identical) transformer rectifier, the ESS TR, can power the essential DC circuit from the emergency generator, if the engine and APU generators all fail, or if TR 1 or TR 2 fails. Each TR controls its contactor by internal logic.
If all electrical main generators are lost, what would happen if the RAT failed?
If the RAT stalls or if the aircraft is on the ground with speed below 100 knots, the emergency generator has nothing to drive it. The emergency generation network transfers automatically to the batteries and static inverter, and the system automatically sheds the AC SHED ESS and DC SHED ESS buses.
