October 30, 2019

Selecting The Right Components For Your Wire Harness

The primary attribute of any power-driven system is a wire harness. However, it is one of the last elements that receive consideration. Addressing the electrical system design in the early stage is preferable as possible. This is to match the best design specified for the application at hand.

Many features, associated with a wire harness design, influence the performance of the end product. If wiring is either under-designed or over-designed, a negative outcome might result in the performance of the completed system.

Generally, seeking guidance from wire harness manufacturers can put you on the right track in selecting the right components of the wire harness. The technicians can further assist you in providing an overview of wirings that are suitable for indoor or outdoor usage. Consequently, this article will discuss a variety of selections to consider in designing a wire harness.

Circuits or Conductors

Determining the type and number of circuits or conductors needed is set up to the wiring’s application. Several options are available for the type of conductive material utilized:

  • The stranding used to make the conductor
  • The putting on of plating to the conductive elements

wire, spool, coil

Copper is considered the most versatile and widely used conductor. It is adaptable with numerous coating to delay corrosion and to help in the process of termination. Bare copper is apt to corrosion due to exposure to the atmosphere. This foreseeable effect results in plating most conductors with various coatings: to both delay corrosion and allows copper used in arduous installations.

Tin is one of the most popular materials for coating. The reason why is because aside from it retards corrosion of the bare copper, it is also cost-friendly. However, if the wirings application is for higher temperature environment utilization, coatings such as nickel or silver take place.

Each designed conductor of wire harnesses has been made for a specific use. For example, if the conductor is to give power, then the amount of current it will transmit needs consideration before determining the size of the conductor to use. Furthermore, if a conductor expects to allow for the carrying of a signal, the speed of the indicator and the length of the wirings need attention to determine the right structure of the conductor.

Main Insulations or Sheaths

The insulators are available in either Thermoplastic compositions or Thermoset. As aforementioned about the conductor construction, the thickness, material, and type used for the insulation of primary conductors will depend again on the use of wiring applications.

The materials available should meet the extensive range of applications and environments. The important areas to address are:

  • The operating temperature that the assembly will get exposed to
  • The wirings’ kind and level of voltage transmission
  • And the harsh environment or chemicals it may experience

Twisting or Cabling of Conductors

In 1881, Alexander Graham Bell invented the twisting of wires to cancel out the electromagnetic interference (EMI) from external sources. The noise problem is evident in wirings used for telecommunications where pairs in the same wire are after each other for long distances.

hose coupling, power cable, strange

Due to the proximity, one pair can tempt to crosstalk onto an adjacent pair. This noise is an accompaniment along the length of the wire. The twisted pairs of the wire counters this effect since the pairs are only near each other on the half twist.

The twisted pairs are also cabled together. Cabling is a production operation where the pairs, or conductors, are togetherly wrapped. This procedure provides flexible wiring. Also, it produces a circular configuration that will allow for a visually end-wiring.


Applying overall shields once the conductors are cabled together is crucial to control EMI further. There are many options for overall shields, with each having pros and cons.

Among the popular shields is the metalized foil adhered to a polyester backing, also known as foil shield. A foil shield is less-expensive, reasonably flexible, but not for the long term. It is good at high frequencies but less effective at low frequencies.

Another type is a braided shield. This kind of shield is a composition of several small diameter wires that are braided onto the cable core by using a piece of specialized equipment known as braiders. This type of shield is more expensive than a foil shield since it offers better shielding at low frequencies and gives a better flex life.

One more type of shield is a spiral shield, where small-sized diameter wires are around the cable core, wrapped. It provides excellent flexibility with long flex but is weak at protecting higher frequencies; aside from it is difficult to terminate.


The best-suggested protection against EMI comes from a combination of braid and foil shields. This combination gives excellent stability at all frequencies and is easy to terminate. However, it is the most expensive option.

Outer Sheath or Jacket

An application of outer sheath or jacket will take place once the cable core is constructed. The jacket is the protective covering and is called upon decelerating flame to meet the standard requirements. The jacket can be from a variety of materials such as:

  • PVC
  • Urethane-based products
  • Elastomer-based products
  • Fluorocarbons
  • or Non-halogen materials

Strain Relief Connectors

The strain relief gives a transition point from the wire to the termination area. It also prevents a load applied to the wire from transferring to the terminations causing a termination failure. There are selections for strain relief, like a solid or a segmented design. The segmented design gives the most significant amount of bend relief, but it is more challenging to keep clean if used in sterile environments.

Certification for Safety

Location is one of the significant concerns in designing a wire harness. The critical factors are the following:

  • The region of the world where the harness will finally be used
  • The safety certifications that the specified area regards as law
  • and The environmental standards that should be met by the wire harness


To sum it up, many factors are to be considered when designing a wire harness for your application. Each specification of the structure and design needs concentration and devotion before production can begin.

Paying no attention to these fundamental features may hurt the performance of the end-product. It is always best to seek guidance to your manufacturer with regards to the full application to determine the proper wire harness that will best suit your products’ necessities.

About the author 

Imran Uddin

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