Electrics Flashcards
How can the AC and DC standby bus bars be powered on ground if all AC power is lost?
They will automatically operate if the Standby Power swith is in AUTO
If the generator Drive Disconnect switch is operated, how can it be reconnected in flight?
It can’t!
What causes the TR UNIT caption to illuminate in flight
Failure of TR 1 or TR2+3
Under what circumstances will the TR Cross Bus Tie open and isolate TR1 from TR2?
At GS capture during autopilot or flight director approach or if the Bus Transfer Switch is selected OFF
What are the power sources for the standby AC bus?
Normally powered by the AC transfer bus 1, backed up by the battery via the static inverter.
When will the blue OFF GEN BUS light for the APU illuminate?
When the APU generator is available but not powering a bus.
If ELEC caption illuminates on the electrical panel what would this indicate?
A fault exists in the DC power or Standby power system. Only illuminates on the ground
What is the backup power supply source for TR1 & 2 ?
TR3
What sources of electrical power are available?
Two IDGs, Two batteries, External AC Ground connection, AC APU
During normal flight in cruise phase, what condition will the Cross Bus Tie Relay be in
Closed, providing the BUS TRANSFER SWITCH is in AUTO
What is indicated by STANDBY POWER OFF amber light?
No power to AC Standby Bus, DC Standby Bus, Battery Bus
When will the switched hot battery bus be powered
When the BAT switch is ON and battery is charged
