Easa Module 6.11 Electrical Cables

Front 1

Metals used for the majority of aircraft electrical wiring

Back 1

Copper & Aluminium

Front 2

What are Lays

Back 2

Wire strands arrangement

Front 3

Why are conductors stranded

Back 3

Provides wire flexibility

Front 4

Why are conductor strands plated

Back 4

Provides corrosion protection

Front 5

The common conductor strand plating materials

Back 5

Nickel, tin & silver

Front 6

Why are conductor strands annealed

Back 6

Provides wire flexibility

Front 7

The purpose of wire/cable Insulation

Back 7

Provides protection against short circuit and environmental conditions

Front 8

Application methods of wire/cable insulation

Back 8

Extruded and Wrapped

Front 9

Main properties of Polyimide

Back 9

Man made insulation tape material, applied to conductor by wrapping

Front 10

What is Carbon arc tracking

Back 10

Phenomenon where polyimide insulation forms conductive path when subjected to heat (typically from short circuit)

Front 11

What is Wet tracking

Back 11

Carbon arc tracking where moisture/fluid acts to unravel polyimide tape and as a low resistance path

Front 12

What is Dry tracking

Back 12

Carbon arc tracking where chaffing acts to breakdown polyimide insulation

Front 13

What does AWG mean

Back 13

American Wire Gauge

Front 14

What does CSA mean

Back 14

Cross Sectional Area (metric)

Front 15

What does CMA mean

Back 15

Circular Mil Area (imperial)

Front 16

Wire propeties if AWG number reduced

Back 16

Increases cross-section of conductor, decreases overall resistance and increases current carrying capability

Front 17

Wire propeties if AWG number increased

Back 17

Decreases cross-section of conductor, increases overall resistance and decreases current carrying capability

Front 18

Main reason for using aluminium as conductor

Back 18

Typically used for large current over long distances

Front 19

Define Airframe wire/cable classification

Back 19

Sufficiently robust wire to satisfy the requirements of ‘Open’ airframe wiring and the general wiring of Powerplants

Front 20

Define Interconnect wire/cable classification

Back 20

Used in protected areas of wiring such as the interconnection of equipment within racks, junction or relay boxes

Front 21

Define Equipment wire/cable classification

Back 21

Used within equipment such as LRU (Line Replaceable Unit)

Front 22

What is the basic construction of Single core wire

Back 22

One insulated conductor

Front 23

What is the basic construction of Multi core cable

Back 23

Multiple insulated conductors twisted together with an outer insulating jacket

Front 24

What is the basic construction of Shielded wire

Back 24

Insulated conductor surrounded by a metallic sheath, then enclosed in an outer insulating jacket

Front 25

What is the basic construction of Multi core shileded cable

Back 25

Multiple insulated conductors twisted together surrounded by a metallic sheath, then enclosed in an outer insulating jacket

Front 26

What is the basic construction of Databus cable

Back 26

Two insulated conductors (one blue insulation, one white insulation) twisted together surrounded by a metallic sheath, then enclosed in an outer insulating jacket

Front 27

What is the basic construction of Coaxial cable

Back 27

Typically used sed for radio signals, it has a centre conductor covered by a inner insualtion (dielectric) surrounded by a metallic braided conductor then enclosed in an outer insulating jacket

Front 28

What is the basic construction of High tension cable

Back 28

Designed for high voltages, it is a stainless steel conductor in one or two layers of rubber/silicone insulation, surrounded by a metal braided shield

Front 29

What is the basic construction of Thermocouple cables

Back 29

Typcially nickel chromel and nickel alumel conductors individually insulated which are then either flat-laided or twisted within an taped outer sheath.

Front 30

Properties of Fire resistant wire/cable

Back 30

Must retain a defined level of electrical insulation in the presence of a fire for 5 minutes.

Front 31

Properties of Fire proof wire/cable

Back 31

Required to operate for fifteen minutes in a designated fire.

Front 32

How is wire/cable stored

Back 32

Typcially on drums/reels, sealed ends

Front 33

Precaustions when handling wire/cable

Back 33

Not dragged over rough surfaces, not kinked

Front 34

What is the minimum bend radius of single wire/cable

Back 34

Minimum bend radius should be 10 times the outside diameter of the wire/cable

Front 35

What is the minimum bend radius of bend radius of a bundle

Back 35

Minimum bend radius of a bundle is six times the diameter of the bundle