Electrical

Question 1

How many NiCad batteries are there on the aircraft?

Answer 1

Three.

Question 2

How many engine-driven DC starter-generators are there on the aircraft?

Answer 2

Two.

Question 3

How many transformer rectified units (TRUs) are there on the aircraft?

Answer 3

Two.

Question 4

How many APU generators are there on the aircraft?

Answer 4

One.

Question 5

T or F: the electrical system comprises both a direct current (DC) system and an alternating current (AC) system.

Answer 5

True.

Question 6

T or F: DC power to the electrical system is supplied by two-engine driven DC generators only.

Answer 6

False, it is also supplied by three NiCad batteries, two TRUs, and an APU generator.

Question 7

T or F: circuit breaker panels can be found in the left and right main landing gear wheel wells.

Answer 7

True.

Question 8

How many circuit breaker panels are there in the flight compartment?

Answer 8

Four.

Question 9

Which of the following are NOT electrical buses?

Answer 9

There is no emergency bus.

These are buses: battery bus, left and right essential buses, left and right main buses, left and right secondary buses.

Question 10

The aircraft is equipped with which of the following battteries?

Answer 10

Three 24V batteries: main, auxiliary, standby.

Question 11

Which batteries are used for engine starting when ground power is not available?

Answer 11

Main and auxiliary.

Question 12

How long will the batteries power the aircraft if normal electrical power fails?

Answer 12

60 minutes.

Question 13

How many battery switches are there?

Answer 13

Four (one for each battery and a master).

Question 14

T or F: if the battery master is in the OFF position, the other batteries can still be used to power the aircraft.

Answer 14

False.

Question 15

T or F: when the battery master is in the OFF position, all battery power is turned off no matter what position the other switches are in.

Answer 15

True.

Question 16

If the battery is being charged at a 100% rate of charge, how will it be depicted on the MFD battery page?

Answer 16

1.00

Question 17

How is a battery that is discharging displayed on the MFD electrical page?

Answer 17

A negative number.

Question 18

When the battery temperature is within limits, what color does it display on the MFD electrical page?

Answer 18

White.

Question 19

When the battery temperature exceeds normal limits, what colors would display on the MFD electrical page?

Answer 19

Yellow then red.

Question 20

If any battery temperature is 50 - 65ºC, what color does the battery temperature display as on the MFD battery page?

Answer 20

Yellow.

Question 21

Where can the GPU be connected to the aircraft for DC power?

Answer 21

Left forward fuselage.

Question 22

When connected to external power on the ground, DC EXT PWR ON is displayed in what color?

Answer 22

Green.

Question 23

T or F: the EPCU protects the system from too high and too low DC power voltage from the DC external power source?

Answer 23

True.

Question 24

After engine start, how many volts does the DC generator provide?

Answer 24

28V DC.

Question 25

Where are the transformer rectifier units (TRUs) located?

Answer 25

In the nose.

Question 26

TRUs change 3-phase 115v AC to what?

Answer 26

28V DC.

Question 27

During normal operation, which busses do the TRUs power?

Answer 27

Left or right secondary bus.

Question 28

A L TRU caution light will illuminate when what happens?

Answer 28

The left TRU is offline or has failed.

Question 29

On the ground, what busses does the APU generator provide power for?

Answer 29

Left and right main, essential, and secondary buses.

Question 30

What does it mean when a plus sign (+) is displayed in front of a value on the MFD electrical page?

Answer 30

An overload of the power source.

Question 31

The entire DC electrical system can still be powered when up to how many power sources have failed?

Answer 31

Two.

Question 32

When does the EPCU send a signal to the generator to trip it offline during a main DC bus fault?

Answer 32

After 5 seconds.

Question 33

If the right main bus has a bus fault, which battery is disconnected from the system?

Answer 33

Main battery.

Question 34

T or F: if a secondary bus fault occurs, the increased current will trip the circuit breaker for the respective TRU.

Answer 34

True.

Question 35

In addition to an inoperative TRU, what is required for the EPCU to enter emergency mode?

Answer 35

Airplane is in the air, both DC generators are not available.

Question 36

In addition to a dual DC generator failure, what is required for the EPCU to enter emergency mode?

Answer 36

Airplane is in the air, at least one TRU is not available.

Question 37

T or F: in EPCU emergency mode, the batteries are the main source of power.

Answer 37

True.

Question 38

When in EPCU emergency mode, which busses automatically disconnect from the batteries?

Answer 38

Main buses.

Question 39

What is the voltage output of the AC generators?

Answer 39

Three-phase 115V AC.

Question 40

Where are the AC generators mounted on the aircraft?

Answer 40

Propeller reduction gearbox.

Question 41

How many external AC power ports are there on the aircraft?

Answer 41

One.

Question 42

When the aircraft is powered by external DC power, which busses are powered?

Answer 42

Left and right main, essential, and secondary buses.

Question 43

T or F: when a DC generator fails, the main bus tie switch must be manually selected to keep the associated main DC bus powered.

Answer 43

False, the EPCU can override switch position.

Question 44

Which switch should pilots use to connect the main battery to its associated main feeder bus?

Answer 44

MAIN BATT.

Question 45

T or F: the electrical system has a single hot battery bus to keep certain items powered at all times.

Answer 45

True.

Question 46

T or F: the hot battery bus can be powered by any of the three batteries.

Answer 46

False.

Question 47

At what point will DC electrical bus load shedding begin?

Answer 47

Three DC sources fail.

Question 48

In EPCU emergency mode, the ____ are the main power source for the available DC busses.

Answer 48

Batteries.

Question 49

The AC generators connect to the system when the engines are running, Gen 1 and 2 switches are selected on, and ____.

Answer 49

Condition levers are in the MIN to MAX range.

Question 50

Which of the following statements regarding the AC cross tie function is most accurate?

Answer 50

It works automatically to ensure both AC buses are powered in the even of an AC generator failure.