Electrical

Question 1

List the AC sources for Electrical power?

Answer 1

-2 IDGS
-APU Generator
-RAT
-AC ground power Cart
-Inverter

Question 2

What are DC power sources?

Answer 2

2 lead acid sealed DC Batteries
3 TRUS

Question 3

Which power source has priority, APU or GPU?

Answer 3

APU

Question 4

System Logic provides Electrical power for the aircraft following source priority:

Answer 4

RAGO

Respective IDG
APU
GPU
Opposite IDG

Question 5

In What circumstances would we use a DC GPU?

Answer 5

For APU starts if battery 2 is unavailable
Or in cold temperatures when temp is below -20C it is recommended

Question 6

What does the amber light next to IDG mean?

Answer 6

That IDG must be shutdown

Question 7

What would cause the amber light next to IDG to come on?

Answer 7

HOTLOP
High temps or low pressure
annunciator test

Question 8

If an IDG is disconnected, can it be maually connected by the pilots on the ground or in flight?

Answer 8

no, maintenence must do it

Question 9

Can One IDG power the whole electrical system?

Answer 9

Yes

Question 10

Can the APU fully replace Failed IDG?

Answer 10

Yes

Question 11

What will charge Batteries?

Answer 11

Any AC source

Question 12

What Items are on the Hot Battery Bus1?

Answer 12

battery 1
Engine fire extinguishers1A
Engine fire extinguisher 2A
Engine 1 Fuel shutoff Valve
Engine 1 HYD SOV
Fwd Courtesy service lights
DC ceiling lights

Question 13

Why does Battery 1 have on, but not AUTO?

Answer 13

Battery 1 does not require automation for APU start.

Question 14

Why does Battery 2 have an AUTO selection?

Answer 14

To power the APU start bus

Question 15

regarding the APU Battery 1 supplies _______ with power and Battery 2 supplies_____________.

Answer 15

Battery 1- Fadec
Battery 2- APU Start bus

Question 16

What is the Voltage of battery?

Answer 16

22.8V

Question 17

Below what voltage would batteries need to be charged?

Answer 17

22V

Question 18

Below what voltage would Mx be required to service the batteries?

Answer 18

21V

Question 19

When would the RAT Deploy Automatically?

Answer 19

When AC Buses are not powered

Question 20

During an Electrical Emergency, how long will battery supply power if the RAT does not deploy?

Answer 20

10 mins

Question 21

What is available during an electrical emergency?

Answer 21

DU 2&3, CCD1, MCDU 2, audio panels, clock, IESS and compass backlight.

Question 22

When electrical load increases beyond the system what happens?

Answer 22

Load shedding

Question 23

what are the speeds to remember for RAT?

Answer 23

150KT MIN. DEPLOY
130KT MIN FOR POWER

Question 24

What electrical systems would be found in the FWD electronics bay

Answer 24

SPDA1
ICC
Other avionics/electrical

Question 25

Where is SPDA 2 located?

Answer 25

CENTER EBAy

Question 26

Are all CBS push pull?

Answer 26

No there are electronic CB too, SPDA

Question 27

What items are on Hott Battery Bus 2?

Answer 27

Battery 2 Engine 1B/2B fire extinguishers Engine 2 oil level indicators Engine 2 fuel shutoff Valve off valve Engine 2 HYD shutoff valve Refueling panel Water service panel Central maintenance controller

Question 28

Battery voltage 21.5 volts what must we do?

Answer 28

Charge battery

Question 29

Where is IDG Located?

Answer 29

On engine accessory gearbox

Question 30

What is difference between turning IDG off vs disconnect?

Answer 30

When IDG is disconnected, a selenioid physically disconnects the IDG from the gearbox. Turning the IDG off opens a contractor which isolates it from the AC BUS

Question 31

What are IDGs?

Answer 31

Integrated drive generators

Question 32

What is power rating of IDG?

Answer 32

115V, 40kVA, 400 hz

Question 33

Is power rating if the APU same as the IDG?

Answer 33

Yes 115VAC, 40kVA, 400hz

Question 34

Is the RAT rated the same as the APU and IDG?

Answer 34

No, it is 115 VAv but its only 15 Kva therefore has less power than the Apu or IDG

Question 35

If you get to the plane and battery is below 21V can we charge battery?

Answer 35

No maintenance must be called

Question 36

In an emergency with the RAT deployed what Electricsl buses are powered?

Answer 36

ACC ESS Bus powers AC STBY BUS AND DEC ESS BUS

Question 37

What items are on stby AC buss?

Answer 37

Engine 1 exciter Engine 2 exciter

Question 38

What items are on AC ESS Bus?

Answer 38

ACMP 3A AC fuel pump 2A (think APU start) ACE - slat/flap channels

Question 39

What type of batteries on our aircraft?

Answer 39

2 Lead acid sealed batteries 22.8 V 27amp Hour

Question 40

If battery switch left on with GPU off/ disconnected what will happen?

Answer 40

A bell will sound outside the ground service plug

Question 41

What is a TRU? What is its purpose?

Answer 41

Transformer rectifier unit, converts AC to DC

Question 43

When would you get a battery overheat?

Answer 43

Battery temp above 70 degrees C

Question 44

Normal flow of Electrical power?

Answer 44

Power source (IDG, APU GEN, GPU) supplies AC BUS Secondary Power distribution assemblies (SPDA) directs power to individual systems from there power goes to MAU- modular avionics units