Electrical Flashcards
Location of the main battery?
Nose compartment
Location of the APU battery?
Aft equipment bay
Max engine generator load?
40 KVA
Max APU generator load?
40 KVA
Max Transformer Rectifier Unit (TRU) load?
120 amps
Max permissible time for ground operations with battery power only?
5 minutes
What is the reason for the previous limitation?
To prevent ED1 and ED2 from overheating (Fans are AC powered)
How many TRUs are installed in the CRJ-900?
4
Where are the TRUs located?
Nose compartment
The main battery is rated to?
17 ampere hour, 24 volts
APU battery is rated to?
43 ampere, 24 volt
How many generators are installed?
4; 2 engine generators, 1 APU generator, 1 ADG
What is the function of the 4 TRUs?
To convert 115 volt AC to 28 volt DC
How are the TRUs cooled?
Individual fans
Which buses are powered when the Battery Master switch is selected on?
Main battery direct bus
APU battery direct bus
DC battery bus
If the main buses are powered, are the essential buses automatically powered?
Yes
Is there an on/off switch for the TRUs?
No, they are automatically powered when the AC buses are powered
What controls the DC tie contacters?
The DC Power Centers (DCPC) automatically control DC tie operation
When will the Air Driven Generator (ADG) automatically deploy?
With complete loss of A/C power
With the ADG deployed, what are the basic items that are powered?
AC ESS Bus
Hydraulic pump 3B (regardless of switch position)
Flaps/slats
STAB trim CH 2
What is the ADG max load?
15 KVA
The Main aircraft generators supply power to __ AC Buses
4
Power for 28 VDC is supplied by…
Transformer Rectifier Units (TRU’s)
Cranking power for starting the APU is provided by:
APU Battery
The Main and APU batteries are kept in 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 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 converting:
Variable engine speed to constant generator speed
The IDG’s may be disconnected from the gearbox by:
Disconnect switches located in the cockpit
Once disconnected, the IDG…
Can only be manually re-connected on the ground with the engine shut-down by Maintenance
The IDGs convert variable engine speed to a constant generator speed of:
12,000 RPM
Fault protection for each generator is incorporated in each:
(GCU) Generator Control Unit
The priority for allowing power to AC Bus 1 would be:
IDG 1, APU, IDG 2, External AC
IDG 2 normally powers
Ac Bus 2 and the Service Bus
Main Tie, Cross Tie, and ESS Tie Contactors
Are controlled automatically by the Direct Control Power Center (DCPC)
An Amber IDG fault light/caution light indicates
Low oil pressure and/or High Oil Temp within the IDG
An AUTO XFER fail light (amber) on the electrical panel indicates
Generator over current or a bus fault
An AC ESS XFER switch light on the Electrical panel indicates
AC Essential Bus is not being powered by AC Bus 1
