Electrical Flashcards
The minimum battery voltage for APU start is____.
- 23 volts
When a source of power is connected to a bus system, _____ occurs.
- it automatically disconnects an existing source
What does a GRD POWER AVAILABLE light do?
- provides flight deck indication that AC ground power is connected to the aircraft and meets aircraft power
quality standards
If the BUS TRANS switch is in the AUTO position and the source powering the transfer bus is disconnected or
fails, what does the source powering the opposite transfer bus through the BTBs do?
- automatically picks up the unpowered transfer bus
What do the three transformer rectifier (TR) units do?
- convert 115-volt AC to 28-volt DC
What do the three transformer rectifier (TR) units do?
- convert 115-volt AC to 28-volt DC
Inflight, when does an amber TR UNIT light illuminate?
- TR1 or TR2 and TR3 has failed
How long does a fully charged battery have sufficient capacity to provide electrical power for? (Single-
Battery configuration)
- A minimum of 30 minutes
When does an amber BAT DISCHARGE light illuminate?
- excessive battery discharge is detected
When does an amber BAT DISCHARGE light illuminate?
- excessive battery discharge is detected
If one or more of the following buses are unpowered, __________, it is indicated by an illuminated STANDBY
Power (PWR) OFF Light
- all answers are correct
In flight or on the ground, with the STANDBY POWER Switch in AUTO (guarded position) in with the loss of all
AC power, the AC standby bus is powered by __________________ and the DC standby bus is powered by
- The battery
The light on the overhead panel that illuminates if the APU is running and not supplying power to a bus, is
the_____.
- APU GEN OFF BUS
On the ground and inflight, the APU generator can supply power to ____________.
- both transfer busses
The electrical system is designed to ___________ during single generator operation.
- shed electrical loads incrementally
