All About Wire Installation In Aircrafts - Miracle Electronics

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Electrical wires are installed in aircrafts in
two ways open wiring and cable harnessing. Open
wiring is when wires are installed without any
special enclosing and cable harnessing is when
wires are installed in bundles to create an
organized installation. However, cable harnesses
for an aircraft should not incorporate more than
75 wires. Also, it should be taken care that the
wires are not more than 2 inches in diameter.
Miracle Electronics are those cable harness
manufacturers in India who know all that it takes
to create the perfect cable harnesses for
application in aircrafts. So, you can approach
them for all your cable harness requirements. If
not, you need to consider the following very
important elements while choosing your cables
and cable harnesses for usage in aircrafts.

• Slack
• Sufficient slack in the wiring of an aircraft
  provides ease of maintenance and terminal
  replacement and free movement and shifting of
  movable equipment to perform servicing,
  maintenance, repairing, and alignment. It also
  prevents any kind of mechanical strain on wires,
  cables, supports, and junctions. This is why
• Wires should be installed with enough slack so
  that they are not under tension when installed.

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• Wires connected to movable equipment should have
  enough length so as to allow travel without
  tension on the bundle.
• Wires at terminals or connectors should have
  enough slack to allow two re-terminations
  without the need for replacing the wires.
• Bend Radius
• The minimum radius of bends in the wire bundles
  must not be less than 10 times the outside
  diameter of the largest wire. However, where the
  wire is well-supported, the radius may be 3
  times the diameter of the wire. There are certain
  situations when it is not practical to install
  the wires within these radius requirements. In
  such cases, the bend should be enclosed in
  insulating tubing. Another important point to
  remember is that RF cables should be bent at a
  radius not less than 6 times the outside diameter
  of the wire.
• Splicing
• Splicing can be done as long as it doesnt affect
  the reliability and electromechanical
  characteristics of the wiring. But, even if this
  condition is take care of splicing can only be
  done if there is engineering approval for the
  same. However, there are certain limitations that
  need to be kept in mind
• Splicing should be kept to the minimum.
• There shouldnt be more than one splice in an
  individual wire segment between two
• connectors or disconnect points.
• Splice should not be used within 12 inches of a
  termination device.
• Splicing should be completely avoided where there
  is extreme vibration.
• Twisting

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• Clamps
• Wires and harnesses within an aircraft are
  supported by clamps, making them a very important
  constituent in aircraft wire installation, which
  is why we include this section in this blog.
• Clamps should be constructed of materials that
  are compatible with the environment in which
  they will be installed. The considerations here
  include temperature, mechanical loads, fluid
  resistance, and exposure to UV rays.
• Clamps should be spaced at intervals of not more
  than 24 inches and sufficient slack should be
  left between the last clamp and electrical
  equipment to prevent strain at the terminal and
  other adverse effects.
• Clamps should be installed with their attachment
  hardware positioned above them so that they are
  prevented from rotating. They must be installed
  with the back rested
• against a structural member. Also, it must be
  taken care that the wires do not come in contact
  with other parts of the aircraft due to
  inappropriate clamping, when subjected to
  vibration.
• Clamps should snugly fit around the wires so as
  not to pinch them, while also taking care that
  the wires do not move through the clamp even with
  the slightest axial pull. However, clamps on RF
  cables must be such that they dont permit free
  movement of the cable through the clamp, but
  allow the cable to slide through the clamp with
  the application of a light axial pull.
• Clamps shouldnt be used where they interfere
  with movable controls, or where wire bundles
  come in contact with movable equipment. Also,
  they must not be used on vertical runs where
  involuntary slack movement could result in
  chafing or other damage.
• These are only some of the very important
  considerations of installing wires and harnesses
  within an aircraft. There is much more to be
  considered, which is why you need experts for the
  job, who can take care of not only the
  installation, but also the protection of wires
  and harnesses against elements like high
  temperatures, fluids, solvents, chafing, and
  movement.
• For more details, please visit Miracle
  Electronics