Electrical System - NATOPS CH. 2.6

Question 1

What are the sources of AC power?

Answer 1

Generators, APU, External power

Question 2

How are the main generators driven?

Answer 2

Transmission

Question 3

What battery do we have?

Answer 3

24V Nickel Cadmium battery

Question 4

Two primary uses of the battery

Answer 4

Start the APU

Power the battery utility bus

Question 5

Description of the Main Generators

Answer 5

Oil cooled, 30/45kVa, 115 Vac, 3 phase, 400 Hz power

Question 6

Description of the APU Generator

Answer 6

Air cooled, 35kVA, 115 Vac, 3 phase, 400 Hz

Question 7

Functions of the GCU

Answer 7

Connects generators to AC bus

Regulated generator output

Protects against over voltage, undervoltage, feeder faults, under frequency

Question 8

With weight on wheels, at what percent Nr does the GCU remove the main generators from the ac power system?

Answer 8

94% Nr

Question 9

In flight, under frequency protection is disabled and generators remain online until ______ Nr.

Answer 9

80% Nr

Question 10

A minimum of _____ Nr is required for the GCU to reconnect the generators to the ac power system.

Answer 10

97% Nr

Question 11

What is external power monitored for?

Answer 11

Phase rotation, over voltage, under voltage, over frequency, under frequency.

Question 12

External power system includes a ___ amp circuit breaker that places a ___ amp draw.

Answer 12

4 amp, 2 amp

Question 13

What are the five AC buses?

Answer 13

No. 1 AC Primary
No. 2 AC Primary
AC Secondary
AC Essential
AC Monitor

Question 14

Three Pigs

Answer 14

1. Backup Hyd Pump on No. 1 AC Primary
2. Mission computer and TR De-Ice on AC Secondary
3. Main Rotor De-Ice on AC Monitor

Question 15

What does the RESET switch do on the generators?

Answer 15

Resets the GCU if it was disabled or disconnected

Question 16

External power will automatically be ____________ when either a main or APU generator is brought online.

Answer 16

Disconnected

Question 17

With only one generator and backup pump off, what is the only bus that gets dropped?

Answer 17

AC Monitor

Question 18

With one generator and backup pump on, what are the two buses that get dropped?

Answer 18

AC Secondary, AC Monitor

Question 19

What voltage is DC power?

Answer 19

28 Vdc

Question 20

With an _____ charge, normal battery life is _____ minutes during the day, and _____ minutes at night.

Answer 20

80%, 11 minutes, 9 minutes

Question 21

What are the functions of the battery analyzer/conditioner?

Answer 21

Monitor for fault conditions, battery charge, internal temperature, cell conditions, and provides battery charging capability.

Question 22

Where does the charging circuit of the battery analyzer/conditioner get its power?

Answer 22

No. 2 AC Primary

Question 23

Where does the battery analyzer/conditioner get its dc charging power from?

Answer 23

No. 2 DC Primary

Question 24

What are the five buses in the DC power system?

Answer 24

No. 1 DC Primary
No. 2 DC Primary
DC Essential
Battery Bus
Battery Utility Bus

Question 25

What powers the No. 1 DC Primary Bus, DC Essential, and Battery Bus?

Answer 25

No. 1 Converter

Question 26

What powers the No. 2 DC Primary Bus?

Answer 26

No. 2 Converter

Question 27

What powers the battery utility bus?

Answer 27

Battery

Question 28

If both converters fail, what does the battery power?

Answer 28

Battery Utility Bus, Battery Bus, DC Essential bus

Question 29

With no other source of DC power and the battery below a _____ charge, battery power may not be sufficient to activate the fire extinguished CADs.

Answer 29

30%

Question 30

When do you get BATT CHARGE LOW?

Answer 30

Less than 40%

Question 31

What bus do you lose with battery only, less than 35% charge?

Answer 31

DC Essential

Question 32

______ _______ _________ will be inoperative when the ac essential bus is lost and _______ ______ capability will be lost when the dc essential bus is lost.

Answer 32

Stab auto programming Manual slew

Question 33

Warning: Without electrical power to the dc primary buses, the engine and inlet anti-ice valves are automatically opened. With an improperly operating engine inlet anti-ice system, a loss of up to _____ power available per engine is possible.

Answer 33

49%