Electrical

Question 1

The sources of AC power include:

Answer 1

GPU; APU; IDG1; IDG2; RAT; Inverters

Question 2

Once mechanically disconnected, an IDG cannot be re-connected in flight. T/F

Answer 2

“True”

Question 3

The APU generator:

Answer 3

Can power the entire electrical system

Question 4

Before an engine is started, based on these indications, you know that:

Answer 4

N/A WITHOUT IMAGE

Question 5

Before engine start, according to this ELECTRIC control panel:

Answer 5

N/A WITHOUT IMAGE

Question 6

In the event of a loss of AC power, the Ram Air Turbine (RAT) MUST be manually deployed using the RAT MANUAL DEPLOY handle. T/F

Answer 6

“False”

Question 7

Under normal operating conditions, ____ Transformer Rectifier Units and ____ batteries provide DC power.

Answer 7

3, 2

Question 8

On battery power only, batteries will supply essential loads for how long?

Answer 8

10 minutes

Question 9

Under what circumstances would we use a DC GPU?

Answer 9

For starting APU with BATT2 unavailable

Question 10

System logic provides electrical power for the aircraft according to the following source priority:

Answer 10

RAGO - Respective IDG; APU; GPU; Opposite IDG

Question 11

How many networks make up the electrical system, and why?

Answer 11

2 - segregation and fault isolation

Question 12

Which AC source has priority, the APU or GPU?

Answer 12

APU

Question 13

You receive the aircraft at the gate, and the AC GPU powers it. You start the APU; once it is up and running, how can you tell that the APU generator has automatically taken over the electrical load?

Answer 13

AVAIL light shows on GPU button; APU shows on MFD electrical page

Question 14

During “normal operation,” will a failed IDG de-power the respective AC BUS?

Answer 14

No

Question 15

How many Display Units (DUs) come to life when you bring the batteries on line and which ones are they?

Answer 15

2: DU2 and DU3

Question 16

Can one IDG supply the entire electrical system?

Answer 16

Yes

Question 17

What are the two lights next to the IDGs?

Answer 17

Tells you which IDG relates to EICAS message received

Question 18

When would the amber IDG oil indicator light illuminate?

Answer 18

HOTLOP: High oil temperature; Low oil pressure

Question 19

When the IDG 1 (2) OIL EICAS message displays, what should the pilot do?

Answer 19

Run the QRH - disconnect affected IDG

Question 20

If an IDG is mechanically disconnected, can the flight crew reconnect it on the ground or in flight?

Answer 20

No

Question 21

What is the primary purpose of the IDGs?

Answer 21

Provide AC electrical power

Question 22

What is a TRU?

Answer 22

Transformer Rectifier Unit

Question 23

What is the purpose of the Transformer Rectifier Units?

Answer 23

Converts AC to DC

Question 24

TRU transforms AC to DC, is there a way to change DC to AC?

Answer 24

Yes

Question 25

What is the purpose of the inverter?

Answer 25

Converts DC to AC

Question 26

Can the APU fully replace a failed IDG?

Answer 26

Yes

Question 27

Does the APU generator have the same rating as the IDGs?

Answer 27

Yes

Question 28

At the gate, ground power is connected. What does it mean when the GPU button says AVAIL?

Answer 28

AC ground power connected and voltage, amperage and frequency are good

Question 29

How is it known that an AC GPU is hooked up to the aircraft and ready to provide electricity?

Answer 29

AVAIL light shows on GPU button; GPU shows on MFD electrical page

Question 30

With AVAIL displayed on the GPU button, what happens when the GPU button is pushed in?

Answer 30

IN USE shows on GPU button and AC GPU is connected to the AC BUS TIE according to system priority

Question 31

If the aircraft is using the AC GPU and the APU is started, what should the pilot be sure to do?

Answer 31

Deselect trhe AC GPU button so that it can be selected next time

Question 32

What happens with the BATT 1 selector OFF?

Answer 32

BATT1 supplies power to HOT BATT BUS 1

Question 33

What will charge BATT 1 and BATT 2?

Answer 33

Any AC power source

Question 34

When is the HOT BATTERY BUS powered?

Answer 34

It is always powered

Question 35

What are some items on the HOT BATTERY BUSES?

Answer 35

Engine fire extinguishers; fuel SOV; hydraulic SOV; Engine oil level indication; courtesy/service lights; refueling panel; water and waste system; CMC

Question 36

What happens when the battery 2 switch is OFF?

Answer 36

BATT2 powers HOT BATT BUS 2

Question 37

How many batteries are required for a normal APU start?

Answer 37

2

Question 38

How is Battery 1 used for APU start?

Answer 38

Powers FADEC and EICAS

Question 39

How is Battery 2 used for APU start?

Answer 39

Powers APU start bus

Question 40

Is battery 1 necessary to start the APU?

Answer 40

Yes

Question 41

Why does battery 1 have ON but no AUTO setting?

Answer 41

BATT1 does not require automation for APU start

Question 42

Why does battery 2 have an AUTO setting?

Answer 42

To allow it to power the APU start bus

Question 43

What is the purpose of the DC Ground power?

Answer 43

Provides DC power to start the APU if BATT2 is unavailable

Question 44

Can the DC GPU charge the batteries? T/F

Answer 44

No

Question 45

When will the RAT deploy?

Answer 45

Automatically if AC buses are not powered (electrical emergency); manually if pilot pulls handle

Question 46

Is there an altitude restriction for operation of the RAT?

Answer 46

No

Question 47

Will the RAT supply power immediately after automatic deployment?

Answer 47

No

Question 48

Is there a total power loss during the 8 seconds while the RAT deploys?

Answer 48

No, the batteries supply power

Question 49

Are the power ratings the same for the APU, IDG and RAT?

Answer 49

No - RAT provides lower power

Question 50

The RAT icon is only displayed on the electrical synoptic page when it is deployed. T/F

Answer 50

"TrUE"

Question 51

Can the remote electronic CBs in the forward electronics bay be monitored?

Answer 51

Yes, via the MCDU

Question 52

If an engine is started at the gate with the GPU IN USE, is the electrical system split?

Answer 52

Yes

Question 53

What is available during an electrical emergency?

Answer 53

DU2/DU3; guidance panel; CCD1; MCDU2; Compass backlight; IESS; both audio panels; clock

Question 54

Whenever the electrical load increases beyond the system limit, what happens?

Answer 54

Load sheds galleys and right windshield heating