Electrical Flashcards

1
Q

How many networks make up the electrical system on the airplane? Why?

A

2 independent networks.
Redundancy and fault isolation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens if a power generating source fails?

A

Bus-ties automatically connect to provide no system degradation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What components power the AC system?

A

2 Integrated Drive Generators (IDG).
Auxiliary Power Unit (APU).
Inverter.
Ram Air Turbine (RAT).
AC GPU receptacle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What components power the DC system?

A

2 NiCad batteries.
3 Transformer Rectifier Units (TRU).
DC GPU receptacle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does the IDG maintain a stable power output?

A

A Constant Speed Drive (CSD) attaches the IDG to the Accessory Gearbox (AGB).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What monitors and controls the IDG?

A

Each has a Generator Control Unit (GCU).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Can only one IDG supply power to the entire electrical system?

A

Yes (No galley power or FO windshield heating on a single AC power source).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What will cause the amber IDG light on the overhead panel to illuminate?

A

High oil temperature.
Low oil pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

If an IDG is manually disconnected, can it be reconnect by the flight crew?

A

No. This is a maintenance function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the primary purpose of the AC generators?

A

To power the AC BUSES and the AC ESS BUS which provide power to the 3 Transformer Rectifier Units (TRU) 1, 2, and ESS.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the purpose of the Transformer Rectifier Units?

A

To convert 115 VAC to 28 VDC.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Can the APU replace a failed IDG?

A

Yes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the AC electrical systems’s priority?

A

Onside (IDG).
Inside (APU).
Outside (GPU).
Cross-Side (Other IDG).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

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

A

GPU button displays AVAIL and the GPU icon is presented on the electrical synoptic page.
Once the GPU button is pushed in, the button will display IN USE provided another AC power source is not available.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does it mean if the AC GPU is plugged in and the outside GPU panel button displays a IN USE?

A

Ground service bus is use.
Cockpit GPU button will display AVAIL, even though the ground service bus is in use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

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

A

Deselect the GPU button before the next GPU connection.

17
Q

What will charge the batteries?

A

Any AC power source.

18
Q

How long will the aircraft’s battery last with no recharging?

A

10 minutes.

19
Q

What is the purpose of the DC GPU receptacle?

A

For APU start when batteries < 22.0 VDC, or
If battery temp is less than -20°C

20
Q

What is the minimum battery temp for APU start?

21
Q

What is the minimum battery voltage to close the battery bus-ties?

22
Q

What battery is used for the APU start?

A

BATT 2 powers the APU Start Bus
Batt 1 powers, the FADEC & EICAS for monitoring, fire protection, and fire detection.

23
Q

What is the purpose of the inverter?

A

Converts 28 VDC from the batteries to 115 VAC to power the AC STANDBY BUS when an AC source is not available.

24
Q

What is on the AC STANDBY BUS?

A

Engine exciters 1A and 2A

25
Q

What powers the ram air turbine (RAT)?

A

Airflow turns the RAT propeller which spins the turbine inside.

26
Q

When will the RAT deploy?

A

Whenever AC power sources are not powering the AC buses in flight.
Manually by the pilot.

27
Q

How long after deployment before the RAT will supply power?

A

8 seconds.

28
Q

Is there a total loss of power during the 8 second RAT deployment?

A

No. Batteries supply power to the DC ESS BUSES and AC STANDBY BUS.

29
Q

What does the RAT power?

A

AC ESS Bus
AC Standby Bus
TRU ESS
DC ESS 1
DC ESS 2
DC ESS 3
#1 Hot Battery Bus
#2 Hot Battery Bus

30
Q

What is minimum air speed for the RAT?

A

130 KIAS.
Load shedding occurs below the speed.

31
Q

How can you ensure the RAT has deployed successfully?

A

BATT DISCHARGING EICAS message will go away.

32
Q

When is the RAT icon displayed on the electrical synoptic page?

A

When the RAT is deployed.

33
Q

What manages the electrical system?

A

4 Integrated Control Centers (ICC)
2 Secondary Power Distribution Assemblies (SPDA)

34
Q

What is an ICC?

A

An electrical control device, which provides power distribution and protection for electrical loads.

35
Q

What is an SPDA?

A

An electrical load-management unit (powered by the ICC’s) that distribute electrical loads to aircraft systems according to distribution logic and performs BIT”s on many components.

36
Q

Can the flight crew reset the ICC and SPDA remote electronic CB’s?

A

ICC CB’s can only be reset by maintenance.
SPDA CB’s can be reset via the MCDU.