Electrical

Question 1

Location APU battery

Answer 1

Aft equipment bay

Question 2

Max engine generator load

Answer 2

40 KVA

Question 3

Max APU generator load

Answer 3

40 KVA

Question 4

Max transformer rectifier unit (TRU) load

Answer 4

120 amps

Question 5

Max permissible time for ground operations with battery power only

Answer 5

5 min

Question 6

What is the reason for the previous limitation

Answer 6

To prevent ED1 and ED2 from overheating (fan are AC powered)

Question 7

How many TRUs are installed in the CRJ 900

Answer 7

4

Question 8

Where are the TRUs located

Answer 8

Nose compartment

Question 9

The main battery is rated to

Answer 9

17 ampere hour / 24 volts

Question 10

APU battery is rated to

Answer 10

43 ampere hour / 24 volts

Question 11

How many generators are installed

Answer 11

4, 2 engine generators, 1 APU generator, 1 ADG

Question 12

What is the function of the 4 TRUs

Answer 12

To covert 115v AC to 28 v DC power

Question 13

How are the TRUs cooled

Answer 13

Individual fans

Question 14

Which buses are powered when the battery master switch is selected on

Answer 14

Main battery direct bus, APU battery direct bus, DC battery bus

Question 15

If the main buses are powered, are the essential buses automatically powered

Answer 15

Yes

Question 16

What controls the DC tie contractors

Answer 16

The DC power centers (DCPC) automatically control DC tie operation

Question 17

Is there an on/off switch for the TRUs

Answer 17

No, they are automatically powered when the AC busses are powered

Question 18

When will the air driven generator (ADG) automatically deploy

Answer 18

With complete loss of AC power

Question 19

With the ADG deployed, what are the basic items that are powered

Answer 19

AC ESS Bus, Hydraulic pump 3B, flaps/slats, STAB trim CH2

Question 20

What is the ADG max load

Answer 20

15 KVA

Question 21

Location of main battery

Answer 21

Nose compartment

Question 22

Main electrical power for the CRJ

Answer 22

115 Volt AC power (primary)

Question 23

Secondary electrical power for the CRJ

Answer 23

28 Volt DC power (secondary)

Question 24

How many circuit breaker panels are there in the CRJ

Answer 24

4 total

2 circuit breaker panels in the flight deck
1 aft equipment bay
1 forward nose compartment

Question 25

GCU (generator control unit) controls what

Answer 25

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

Question 26

IDG does what with N2 variable speed

Answer 26

It coverts the variable N2 engine speed to a constant 12,000 RPM generator speed

Question 27

IDG FAULT switch/light indicates

Answer 27

High oil temperature or low oil pressure within the IDG

Question 28

DISC of The IDG switch/light indicates

Answer 28

IDG has automatically disconnect by Shearing without disconnecting it manually

Question 29

How many AC generators must you have to support the plane

Answer 29

1 AC generator can support the whole plane

Question 30

Battery chargers get power from where

Answer 30

Main battery charger gets its power from AC BUS 1

APU battery charger gets its power from AC Service BUS

Question 31

DC Emergency BUS powered by

Answer 31

APU battery direct BUS (considered hot BUS)