Electrical Flashcards
What is the minimum acceptable battery voltage when performing a battery
integrity check?
22 volts DC
What is the voltage and ampere rating of the batteries?
24 volts DC
40 ampere-hours
With the battery switches selected ON and no other power on the aircraft,
which electrical buses are shown as powered on the EPMP?
Essential DC bus (powered by the batteries)
Essential AC bus (powered by the “E” inverter)
With the battery power selected “ON” and no other power sources available,
what are the acceptable readings for the Essential AC and DC bus volts?
Essential AC bus – 115 volts AC, 400 Hz
Essential DC bus – 22-27 volts
What buses are powered with either external battery switch selected ON?
Only the essential buses
ESS- DC = batteries, ESS AC bus (Phase A only) through the “E” inverter
Where can information be found concerning items powered by the emergency
batteries?
QRH, Electrical System Abnormal Procedures tab (EA)
How are the emergency batteries normally tested?
Arm the emergency battery switch with no other power on the aircraft
Where are the feeder bus circuit breakers located?
On the power distribution box (PDB), in the right radio rack
How is AC external power connected to the aircraft?
Select the AUX PWR switch ON with at least 1 battery switch ON
- What is the function of the battery override switch on the AC external power
receptacle?
To connect AC power to the aircraft if the batteries are discharged or removed
- What buses are powered with external DC power connected?
All DC buses are powered ( ESS – DC, LEFT & RIGHT MAIN DC), and the ESS AC bus (Phase A only) through the “E” inverter
- What buses are powered with external AC power connected?
All buses are powered AND the batteries will be charged
Is it possible to charge the batteries using DC external power?
No, the respective MAIN AC buses must be powered in order to charge the
batteries
- What is the output rating of the “E” inverter?
800 volt-amps
- What is a valid indication of “E” inverter operation?
Essential voltmeter switch-light selection on the EPMP and indications of
115 volts, 400 Hz
- What buses are powered by the “E” inverter?
Essential AC bus, phase “A” only
- What are the possible sources of power for the “E” inverter?
Whatever is powering the Essential DC bus
The standby electrical power system (HMG)
- What are the 2 main functions of the battery chargers?
To charge their respective battery
To provide a transformer-rectifier mode of operation for supplemental power if
necessary
- What buses supply power to the battery chargers?
Battery charger #1 (left) – LEFT MAIN AC BUS
Battery charger #2 (right) – RIGHT MAIN AC BUS
- Can one battery charger charge both batteries?
No, only its respective battery