Electrical Flashcards
Location 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 min
What is the reason for the previous limitation
To prevent ED1 and ED2 from overheating (fan 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 hour / 24 volts
How many generators are installed
4, 2 engine generators, 1 APU generator, 1 ADG
What is the function of the 4 TRUs
To covert 115v AC to 28 v DC power
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
What controls the DC tie contractors
The DC power centers (DCPC) automatically control DC tie operation
Is there an on/off switch for the TRUs
No, they are automatically powered when the AC busses are powered
When will the air driven generator (ADG) automatically deploy
With complete loss of AC power
With the ADG deployed, what are the basic items that are powered
AC ESS Bus, Hydraulic pump 3B, flaps/slats, STAB trim CH2
What is the ADG max load
15 KVA
Location of main battery
Nose compartment
Main electrical power for the CRJ
115 Volt AC power (primary)
Secondary electrical power for the CRJ
28 Volt DC power (secondary)
How many circuit breaker panels are there in the CRJ
4 total
2 circuit breaker panels in the flight deck
1 aft equipment bay
1 forward nose compartment
GCU (generator control unit) controls what
Controls and monitors the generators and provides protection and voltage regulation for each generator
- over/under voltage
- over/under frequency
- generator or BUS over current
- generator phase sequence
IDG does what with N2 variable speed
It coverts the variable N2 engine speed to a constant 12,000 RPM generator speed
IDG FAULT switch/light indicates
High oil temperature or low oil pressure within the IDG
DISC of The IDG switch/light indicates
IDG has automatically disconnect by Shearing without disconnecting it manually
How many AC generators must you have to support the plane
1 AC generator can support the whole plane
Battery chargers get power from where
Main battery charger gets its power from AC BUS 1
APU battery charger gets its power from AC Service BUS
DC Emergency BUS powered by
APU battery direct BUS (considered hot BUS)
