Electrical

Question 1

During engine start, if the BAT DISCH caution illuminates on the CAD, what corrective action is required?

• Connect EPU and continue with a normal start
  -Call for maintenance to get a new battery
  -Turn the battery switch off
  -No action is required - it’s normal during engine start

Answer 1

No action is required – it’s normal during engine start.

Question 2

To prevent the starter from overheating when using the battery to start the engine, limit starter to [a] seconds of activation.

Answer 2

30

Question 3

Which component converts stored chemical energy to electrical energy?

Answer 3

Battery

Question 4

In the event of a dual generator failure both the Non-essential and Shed Buses are disconnected from the electrical system. Which of these buses can be reconnected to electrical power from the battery using an overhead switch?

Answer 4

Shed Bus

Question 5

Which component converts mechanical energy to electrical energy?

Answer 5

Generator

Question 6

Which components supply electrical power to the UH-72?

-Main Generator
-External Power Unit
-Back-up Generator
-Battery
-Starter/Generators

Answer 6

Battery
Starter/Generators
External Power Unit

Question 7

The minimum power required to start the UH-72A is [a] Volts?

Answer 7

23.5

Question 8

Which component recharges the battery when the engines are running?

[a]/[b]

Answer 8

Starter
Generator

Question 9

Momentarily placing the BAT MSTR switch to the ENGAGE position connects the battery to the [a] and [b].

Answer 9

Main Bus 1
Main Bus 2

Question 10

On engine start, the ENG START switch disengages at 40% N1, and the generator is automatically connected to the electrical system when N1 is > ______%?

Answer 10

40

Question 11

What is the primary function of the GCU (Generator Control Unit)?

[a] [b]

Answer 11

Voltage
Regulation

Question 12

When operated by the battery, how many VDC (Volts DC) does the electrical power supply system supply to the airborne electrical system?

Answer 12

24

Question 13

A separate power module (battery) supplies 24 VDC as emergency power for the emergency lighting system and the [a] .

Answer 13

Standby Horizon

Question 14

An External Power Unit (EPU) is used for engine start if battery power is less than __________ VDC.

Answer 14

23.5

Question 15

When operated by the generators, how many VDC (Volts DC) does the electrical power supply system supply to the airborne electrical system?

Answer 15

28.5

Question 16

What are the three main sub-systems of the Electrical System?

Electrical power [a] system.

Electrical power [b] system.

Electrical power [c]

Answer 16

Supply
Distribution
Consumers

Question 17

Electrical power consumers are divided into which 3 busses?

-Shed Bus
-Main Electrical Bus
-Non-Essential Bus
-Backup Bus
-Auxiliary Power Distribution Bus
-Main Power Distribution Bus
-Essential Bus

Answer 17

Shed Bus
Non-Essential Bus
Essential Buss

Question 18

The starter-generator automatically transitions from start mode to generator mode when engine N1 speed exceeds [a]%?

Answer 18

40