6.11 Electrical Cables and Connectors Flashcards
Explain what is meant by the expression “the aircraft electrical installation is of the single wire type”?
This means only one wire is used to support the supply of electric current to the user.
The return path is established via the metallic structure of the aircraft
Explain what is meant by the term “standard”?
A standard is an accepted or approved example of something against which others are judged or measured.
What are the characteristics of aircraft cables?
Minimum Weight and dimensions
Resistant to fluids
Non-flammable
Resistance to abrasion
Deterioration
What temperature are aircraft cables fire resistant up to?
400 ^C for fire resistant cables
Up to 1100 ^C for 5 minutes
What standards are aircraft wiring manufactured to?
MIL-W
Military spec cables
What material is tinned for general service wire?
Copper
What material is silver or nickel plated for use in high temperature areas?
Copper
Done to prevent oxidation and to facilitate soldering
Define current handling capacity?
In some instances, the wire may be capable of carrying more current than is recommended for the contacts of the related connector.
In this instance, it is the contact rating that dictates the maximum current to be handled by the wire
Give a list of high vibration areas on an aircraft?
Engine
Pylon or Apron
APU compartment
Wheel Well
Wing
How would you provide flexibility to a cable?
Both copper and aluminium wires are stranded for protection against breakage from vibration and to offer more flexibility
What determines the type of insulation in a cable?
Operating environment e.g Abrasive, arc, corrosion resistance
Cut-through strength
dielectric strength
Flame resistance
mechanical strength
smoke emission
fluid resistance and heat distortion
What type of wires would you use in high temperature areas?
Some form of glass braid or fluorocarbon insulation
What type of wires would you use in general aircraft wiring?
Kapton WIring
Describe the type of tools that would be used to remove and install the contacts on a rear release system?
Crimp tool and a rear accessory backshell
What type of wire would you use in cold areas and give a reason why?
normal temperature type wire
What type of wire would you use in circuits that would be required to function after a fire?
Fire Resistant Wire
(Contains Silicon)
What are the two basic methods of applying insulation material to conductors?
Extrusion
Wrapping
What is the registered trade name for “Kapton” wiring?
‘Kapton’ is Aromatic polyamide produced by Dupoint
Give a brief explanation of the problem(s) associated with “Kapton” wiring?
Short Circuit arc tracking (flashover)
How is the problem associated with “Kapton” wiring overcome?
Hybrid wire
Give a brief explanation of how flashover occurs in “Kapton” wiring?
Repeated exposure to moisture and tiny pinholes also occur due to excessive flexing and chafing
What does TKT stand for?
PTFE / Kapton /PTFE
List the characteristics of TKT?
Lightweight
Arc-track resistant
abrasion resistant
superb insulation protection
high heat tolerance (260^C)
Resists smoking when burning