Wiring and Installation

Question 1

A wiring diagram of a complete circuit for a system is also known as a?

Answer 1

Schematic

Question 2

What does a block diagram do?

Answer 2

Gives an overview of a system, but not enough detail for troubleshooting.

Question 3

What is a pictorial diagram?

Answer 3

A block diagram with pictures. Might help to recognize components to an orientation on the aircraft.

Question 4

What is a schematic diagram?

Answer 4

Provides enough information to understand the entire system. This would aid in trouble shooting.

Question 5

What is the first step in trouble shooting?

Answer 5

Is to know how the system operates.

Question 6

Can diagrams be used like schematics?

Answer 6

Yes wiring diagrams describe an entire circuit for a system.

Question 7

Can detailed level wiring diagrams be used as schematics?

Answer 7

No

Question 8

Can block diagrams by used as a schematics.

Answer 8

No they can help understand a system but are generally too symbolic to use for troubleshooting.

Question 9

What are pictorial diagrams used for?

Answer 9

Generally for educational purposes.

Question 10

Why are wires normally stranded?

Answer 10

So they can withstand vibration. It also makes it more flexible so that it can be installed more easily

Question 11

Why is wire plated or coated?

Answer 11

It is plated or coated with a different metal to avoid the corrosion that would be a problem with pure copper wire.

Question 12

Why are different metals used?

Answer 12

It determines the temperature that the wire can withstand.

Question 13

What is a shielded wire?

Answer 13

It is enclosed in a braided metal jacket. EMR is trapped by the braid and is carried to ground.

Question 14

What is a coaxial cable?

Answer 14

It consists of a central conductor, inner insulator, braided metal outer conductor, and an outer insulation.

Question 15

What is coaxial cable used for?

Answer 15

To connect a radio with its antenna. There is also triaxial and quadraxial cable.

Question 16

Why are wires put into bundles?

Answer 16

To facilitate installation.

Question 17

What are the restrictions on aluminum wires?

Answer 17

-Must be 8-gauge or larger.
-Not installed in areas of sever vibration.
-Not installed where frequent connections required.
-Not to be used where the length is less than 3ft.
-Not to be used in areas where corrosive fumes exist.
-Not recommended for use in communications or navigation systems.

Question 18

Do you get to pick the wire?

Answer 18

No you find out what you are supposed to use.

Question 19

SWAMP

Answer 19

Severe Wind and Moisture Problems.

Question 20

Will you be soldering wires?

Answer 20

No wires are always spliced using crimped connectors.

Question 21

What can affect the wire size?

Answer 21

Strands, insulation, and shielding

Question 22

How are wires identified?

Answer 22

The number on the wire may indicate the system it is part of, the wire number in that system, the segment of the wire, the size and whether it is a ground wire.

Question 23

What are the circumstances for installing twisted wire?

Answer 23

-In the vicinity of magnetic compass or flux valve.
-Three-phase distribution wiring.
-Certain other wires (usually radio wiring) as specified on engineering drawings.

Question 24

Why don’t you solder joints?

Answer 24

They are usually stiff, and vibration can harden the wire and cause it to break.

Question 25

What do you solder?

Answer 25

Splices, they keep the joint flexible so vibration cannot cause the wire to break.

Question 26

When is a grommet needed?

Answer 26

A hole were the bundle ends up less than 3/8” from the edge

Question 27

What happens when two wires are in free air next to each other?

Answer 27

-They may couple capacitively, resulting in crosstalk.
-A charge on the 1st wire induces an opposite charge on the 2nd wire.

Question 28

What is the difference between grounding and bonding?

Answer 28

Grounding is the purposed of completing a circuit and bonding is to ensure there is no voltage difference.

Question 29

Why do you lace bundles?

Answer 29

Less damaging and survives vibration better.

Question 30

How do you describe a switch? Such as SPST

Answer 30

-Pole refers to the number of circuits controlled
-Throw refers to the number of choices.

Question 31

Why is wire plated?

Answer 31

So it won’t corrode.

Question 32

What materials are wire plated with?

Answer 32

Tin, copper, or silver.

Question 33

How do you change the inductance in a wire?

Answer 33

By twisting the wire.