Wire Harness – A Detailed Component Guide

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Wire Harness A Detailed Component Guide
Everything from Aerospace to electrical and
electronic devices, that need to supply power
and send signals for the application to operate,
require wire harnesses to power the system.
While it may seem to be a very small and simple
construction, its important to note that there
are multiple important components that are
required to make up the harness. They consist of
multiple branches that run in different
directions, with required terminals at the end of
each branch. Such a construction helps connect
multiple points or circuits with multiple
breakouts and terminations. There could be dozens
of wires held within one single wire harness, to
make which are required hundreds of components
and terminations, with each component playing
its role in affecting the performance of the
entire wire harness. This is why every component
must be very carefully chosen, after considering
everything from the environment the wire harness
needs to be used in, the temperature, the
pressure, the space and flexibility constraints,
and any exposure to chemicals, moisture, or
fumes. The chief components of any wire harness
system generally include the wires, the
conductors, the conductive material, the
insulation and sheathing, the plating, the
connectors, and the shielding. Conductive
material Whether your application needs a single
solid strand of material, or many thin strands,
depends upon the conductive requirements of the
application. If the conductor is required to
provide power, the size will be determined by the
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amount of current it needs to carry. Further,
where a signal needs to be transmitted, the
length and speed will determine the conductor
material. Insulation and sheathing The insulation
and sheathing of a wire harness may either
comprise of thermoset or thermoplastic
compositions, depending upon the application.
The operating temperature, harshness of the
environment, exposure to chemicals or fluids,
and the current and voltage requirements, all of
these determine the material for insulating the
harness. Plating Plating is required when
corrosion is a challenge for the application.
Plating will provide improved conductivity,
along with the required corrosion resistance for
the conductors to function in the most
challenging environments. Where the wire harness
will be required to function amidst moisture, tin
can prove to be the best choice, as it has
amazing resistance to corrosion. Similarly, for
the wire harnesses that need to function under
high temperatures, silver or nickel can prove to
be an ideal choice as they enable conductors to
work reliably up to 200C and 260C
respectively. Connectors The type and speed of
the signal to be transmitted is what decides on
the connectors for a wire harness. However, the
most basic ones include crimp- type connector,
or a soldered or welded connection. The type of
connector will also ultimately decide on the
choice of the terminal. Shielding Proper
shielding can control the electromagnetic
interference and any radio frequency
interference if present. There are a variety of
shields to be selected from, such as foil
shields, braided shields, and spiral shields. It
is the frequency requirement and the flex life
that decide on the shield to be used. The most
ideal choice is a combination of foil and braided
shielding, which offers the best protection from
interference at all frequencies. But, it is also
equally expensive. Also to be considered is the
fact that the outer sheath material should meet
the physical challenges of the harnesss
environment, retain its flexibility, and also be
flame retardant. PVC seems to be the ideal choice
here. Making the right choice for each component
is crucial, which is why it is always advisable
to approach a professional and experienced wire
harness
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manufacturer, one like Miracle Electronics, who
has immense experience in manufacturing a
variety of harnesses like EMI shielded harnesses,
multiwire harnesses, flat harnesses, ribbon
harnesses, RF harnesses, airborne looms, and
military looms (). Hence, no matter what your
application, Miracle Electronics always has a
solution!