Electrical Flashcards
The main aircraft generators supply power to ____ AC buses
4
The aircraft engine driven generators and APU generators are rated at
40 KVA
Power for 28 VDC is supplied by
Transformer rectifier units
The APU battery is
24 volts rated at 43 ampere hours
The main battery is
24 volts 17 ampere hours
____ transformer rectifier units TRU supply power to DC buses
4
Cranking power for starting the APU is provided by
APU battery
The ADG supplies AC power to
3B hydraulic pump, ESS AC bus, slats/flaps and pitch trim
The main and APU batteries are kept in a charged condition by battery chargers powered by
AC Bus no.1 and AC service bus
The external AC power receptacle is located
Forward right side of the airplane
Electrical systems warning and caution messages are normally displayed on
EICAS primary page
Electrical system status and advisory messages are normally displayed on
EICAS status page
The integrated drive generator (IDG) provides a means of converging
Variable engine speed to constant generator speed
The IDGs may be disconnected from the accessory gearbox by
Disconnect switches located in the cockpit, otherwise the crankshaft will break when it overheats
Once disconnected, the IDG:
Can only be manually re-connected on the ground with engine shutdown by maintenance
The IDGs convert variable engine speed to
12,000 RPM
Fault protection for each generator is incorporated in each
Generator control unit
The priority for allowing power to AC Bus 1 would be
Gen 1, APU, Gen 2, external AC power
IDG 2 normally powers
AC bus 2, and service bus
The ADG can only supply power to
3B hydraulic pump, AC ESSENTIAL, ADG bus, EICAS, slats, flaps, and pitch trim
115 VAC is supplied to TRUs for DC static conversion, and each TRU is rated at
120 amps
An ESS TRU failure message will be displayed on EICAS when
Output is less than 18 VDC
Which DC Bus tie has automatic operation
All of the above: main tie, cross tie, ESS tie
In flight, the ADG auto deploy monitors the three main AC generators and main AC generators and the main AC buses for
Complete AC power failure
The main battery charger and APU battery charger are in a charging configuration when
Both a and c: battery master switch is “on”, both AC utility buses powered and AC bus 2 powered
Main battery “off” or APU battery “off” caution messages are displayed on EICAS when voltage is
18 VDC
An amber IDG fault light/ caution light indicates
Low IDG oil pressure and/or high IDG oil temperature
A gen 1 overload caution message on EICAS would indicate a load of greater than _______ KVA
40.0
An AUTO XFER fail light (amber) on the electrical panel indicates
Generator over current or a bus fault
An AC ESS XFER light (white) on the electrical panel indicates
AC essential bus is not being powered by AC bus 1
What are the generators rated at
40 kVA up to FL410
Batteries supply DC electrical power to which buses
A, B, and C only: main battery bus, APU battery bus, DC Emer Bus
