11.6 Electrical Power

Question 1

Why is an integral grey collar fitted to certain CBS?

Answer 1

To indicate theta they must be pulled by maintenance personnel during maintenance work

Question 2

A hot battery bus is always what?

Answer 2

Directly connected to the battery

Question 3

Why is an integral orange collar fitted to certain CBS?

Answer 3

To indicate they must be pulled by flight crew in certain abnormal situations

Question 4

Why must you never attempt to carry out too many APU starts immediately after one another ?

Answer 4

It will overheat the battery and damage it

Question 5

What should you do if the electrolyte used in NI-Ce battery comes into contact with human skin?

Answer 5

Rinse it immediately making sure you only use clean water

Question 6

What does OVERDRIVE mean in relation to CSD operation?

Answer 6

The output speed of CSD is faster than the input speed

Question 7

What’s does UNDERDRIVE mean in relation to CSD operation?

Answer 7

The input speed of the CSD is faster than the output speed

Question 8

What is the main source of electrical power while the AC is on the ground?

Answer 8

External power

Question 9

What is the main advantage of parallel operation of main AC bars?

Answer 9

There is no power loss at failure as another takes over

Question 10

What is CSD?

Answer 10

Constant speed drive

Question 11

How is CSD cooled?

Answer 11

With oil

Question 12

What is the rotational speed of CSD?

Answer 12

12000rpm

Question 13

How are engine driven generators connected

Answer 13

Parallel

Question 14

Frequency and voltage of AC?

Answer 14

400Hz
115V

Question 15

Voltage of DC?

Answer 15

28V

Question 16

How many batteries are there in an aircraft?

Answer 16

2

Question 17

What usually powers AC consumers in flight?

Answer 17

Engine driven generators

Question 18

What usually powers AC consumers in ground?

Answer 18

GPU or APU

Question 19

When are emergency generators released?

Answer 19

At total loss of all other AC power sources

Question 20

What does a red tag do?

Answer 20

Prevent someone from putting circuit breakers back in

Question 21

What is the phase difference of AC?

Answer 21

120 degrees

Question 22

What’s do TRU’s do?

Answer 22

Transform 115v AC to 28V DC

Question 23

What are batteries used for?

Answer 23

APU start emergency power

Question 24

What electrolyte is used in ni - cad battery?

Answer 24

Strong alkaline

Question 25

What is the lowest voltage a battery should get to?

Answer 25

22V

Question 26

What are the 2 short pins of the ground receptacle used for?

Answer 26

Will disconnect power if it comes out
Also guide pin

Question 27

Does an AC circuit use CBs or fuses?

Answer 27

Circuit breakers

Question 28

What is the main task of a fuse/ CB?

Answer 28

.Prevent overheat and fire due to a short circuit

.prevent currents higher than the max allowance for that cross sectional wire

Question 29

What does the essential power distribution consist of?

Answer 29

Supplies all systems that are necessary to operate the aircraft safely

Question 30

How much energy does a 2 and 4 engine aircraft need?

Answer 30

2 = 100kw
4 = 400kw

Question 31

What are two ways for DC power generation?

Answer 31

. Transformer rectifier units (TRU)
. Batteries - nickel cadmium