Airframe electrical: part II Flashcards
Wire can either be
Solid or stranded
What two wire materials are used?
Copper and aluminum
Why is wire tinned?
To enhance corrosion preventative properties.
What strands wire is most
Commonly used?
19 or 37
What materials are used
To insulate wires?
Nylon, Teflon, braided fiberglass.
What are wires coated with in areas of high abrasion?
An extruded nylon jacket
Why are wires shielded?
When used in areas of electronic/magnetic sensitivity.
What is coaxial?
A special type of shielding, used in com/nav circuits. The shielding also acts as Ground or return path.
What is wire sized according to?
The AWG system, American wire gauge system.
What is the cross sectional area of a wire expressed in?
Circular mils
What is proper wire size based on?
The current carrying capability of a wire
The allowable voltage drop
Physical strength
What is the smallest gauge aluminum wire allowed on an aircraft?
8
What is the primary concern when routing wires?
To avoid heat, liquids and abrasion.
How far should wires be away from something so that they are clear?
3inches
What is the general bend radius of shielded wire and coaxial cables?
Generally 3x the diameter of individual wire and for coaxial it is 6x the diameter
What three purposes are there behind bundling wires?
Neatness,
Efficiency of routing,
Ease of troubleshooting
How should wires in a bundle be laced together?
Zip ties or nylon cord
How frequently are ties in wire bundles made?
Every two to three inches
How are bundles secured to the aircraft?
Adel clamps.
What materials is conduit constructed of?
Aluminum, braided metal, or non metallic materials.
What are terminals used for?
Connecting wires to a post or a terminal strip.
By what two methods are terminals attached?
Crimped on
Soldered on
What are junction boxes used for?
For housing multiple terminal strips
What are junction boxes constructed of?
Aluminum alloy or fiberglass
What is splicing?
Attaching two conductors in a permanent way.
What are methods of circuit protection?
Fuses, circuit breakers, and current limiters.
What is the purpose of circuit protections?
To protect the wiring.
What is nominal rating?
The continuous current flow of a device
