Electric Flashcards
(37 cards)
Location of the APU battery?
Aft equipment bay
Max Engine generator load?
40kVA
Max APU Generator load?
40 kVA
Max transformer rectifier unit (TRU) load ?
120 amps
Location of the MAIN battery
Nose compartment
Max permissible time for ground operations with battery power only?
5 minutes
What is the reason for the 5 minute limitation for ground operations while on battery power only?
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 amps / 24 volts
The APU battery is rated to
43 amps / 24 volts
How many generators are installed?
4
2 Engine Generators
1 APU Generator (Auxiliary Power Unit)
1 ADG (Air Driven Generator)
What is the function of the 4 TRUs?
To convert 115 V AC to 28 V DC
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 busses are powered
What controls the DC tie contactors?
The DC Power Centers (DCPC) automatically control the 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
Flaps / Slats
STAB trim Ch 2
What is the ADG max load?
15 kVA
How are the TRUs cooled?
Individual fans
What is the overload protection for IDG?
45 KVA for 5 minutes
60 KVA for 5 seconds
What is a GCU?
Generator control unit-each generator has one. The GCU provides protection and voltage regulation for its engine generator. The GCUs in conjunction with the AC power center provide bus priority and protection during normal and non-normal operations. The generator output would be tripped off and removed for:
- Over/under voltage
- over/under frequency
- generator and bus over current
- generator phase sequence
- AC power center (ACPC)
What is ACPC?
AC power center - distributes AC power to the aircraft sub-systems. ACPC contains system power contractors, current transformer seem lies and circuit breakers for the purpose of switching AC power to the appropriate electrical bus.
Provides secondary power distribution to hydraulic pumps, slats and flaps and pitch trim circuits via circuit breakers and relays / contractors that are controlled by their specific system control units.