Electrical System Flashcards
The aircraft electrical system comprises :
1. AC ?
2. DC ?
- 115 V/400 Hz three-phase AC power
- 28 V DC power
Under normal conditions Generator 1 supplies ?
AC bus 1 and the Essential (ESS) bus
Under normal conditions Generator 2 supplies ?
AC bus 2
The emergency (EMER)
AC bus is energized by which bus ?
The ESS AC bus
DC power is supplied by Transformer Rectifier Units (TRU) to which buses ?
The output of the TRU’s is distributed by DC buses 1, 2, ESS, EMER, Ground Service, and Ground Handling.
In the event of loss of generated AC power, the batteries supply emergency
power to the EMER DC bus and, via the emergency inverter to the …?
EMER AC bus
Total loss of emergency power may occur after ?
30 minutes
The actual available duration is determined by the battery configuration
When AC external power is not available, the ground handling bus will be energized by ?
The batteries
When DC external power is connected to the aircraft what becomes available ?
- The DC ground service bus is energized
- Power is available for the APU starter
AC power is distributed to which buses ?
- AC buses 1 and 2
- ESS AC bus
- EMER AC bus
- Galley buses 1 and 2
- AC Ground Service bus
The Essential AC bus is normally supplied by which generator /
Generator 1
The EMER AC bus is normally supplied by the ESS AC bus. If AC supplies fail and the AC buses 1 and 2 and the ESS AC bus become de-energized, what powers the the EMER AC bus ?
The EMER AC bus is supplied by the batteries via an EMER inverter
During flight where only a single generator is operational what happens to the galley buses ?
They are automatically de-energized
The AC ground service bus is normally supplied by which AC bus ?
AC bus 2
If AC bus 2 is not energized the AC ground service bus will be automati
What are the meanings of the displays on the overhead Electrical panel signify ?
How many TRU’s are there to receive AC power and convert it to DC power ?
4
TRU’s are automatically disconnected in
case of ?
Overheating or detection of a reverse current
DC power is distributed to which buses ?
- DC buses 1 and 2
- Dual DC bus
- ESS DC bus
- EMER DC bus
- DC ground service bus
- DC ground handling bus
The purpose of the dual DC bus is to provide an uninterrupted power source to what systems in th event of a DC bus 1 or 2 failure during landing
Lift dumpers
Anti-skid
Speed brake
When there is no AC power is available, the EMER DC bus is automatically supplied by ?
The batteries
What power source supplies the DC ground service
bus via a TRU ?
The AC ground service bus
The ground handling bus supplies power to ?
The fuelling panel
The towing panel
The hydraulic service panel
The engine starter valve
When no AC power is available, the DC ground handling bus is supplied
directly by ?
The batteries
What controls or indicators in the flight deck directly related to the ground handling bus ?
None
