Wire Harnesses
Wire harnesses are a necessary part of electronics manufacturing. They are multi-wire assemblies crafted and formed to serve different purposes, such as environmental conditions and various applications. Beyond their function of organizing wires, the covering or sheath of a wire harness protects connectors and conductor bundles. The wires included in a wire harness may already have insulation and protection or may need a wire harness for optimal performance.
The simplicity of wire harnesses understates their importance in electrical circuits. Although wire harnesses consist of a group of wires held together by an insulating material, their ability to protect conductive wires and organize them for easy configuration makes them an ideal electrician’s tool. In addition, the many varieties of wire harnesses gives engineers the flexibility to design a wide assortment of electronic devices.
Quick links to Wire Harnesses Information
Wire Harness Applications
Any industry that uses cable arrangements for their designs relies on wire harnesses. This aspect of wire harnesses is due to their ability to resolve issues associated with electrical systems. Combining wires into a set bundle makes it easier to connect and assemble complex electrical components. In addition, manufacturers find that organizing wires into a harness is a cost-effective way to improve the performance of a product and makes installations easier.
A few examples of the importance of wire harness use:
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Aerospace – The aerospace industry depends on wire harnesses due to the strict safety and weight requirements of their aircraft, which contain huge dense bundles of wiring and communication cables. The key to power transmission in aircraft, satellites, and other applications is the use of wire harnesses.
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Auto Industry – Since the introduction of the first automobile over 100 years ago, manufacturers have been constantly searching for ways to lighten the load of cars and streamlining designs. An important part of their search has been the use of wire harnesses that are indispensable for saving space, organizing complex electronics, and ensuring the proper fit of wires. Aside from lowering the weight of vehicles, wire harnesses make it possible to separate distinct systems for efficient operation and maintenance.
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Medicine – In the medical field, instant and reliable connections are essential to the preservation of life and patient care. Wire harnesses make it possible to have rapid links of equipment in critical situations. In addition, they are used for various types of equipment, such as X-ray machines and MRI equipment.
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Robotics – An aspect of industry that is rapidly growing is robotics, which are used for a wide range of applications from moving products to assisting with assemblies. The compact nature of robotic devices requires conducting wires that are well organized and correctly positioned for the robotic performance and the safety of workers. Wire harnesses have become a vital and essential part of robot design and construction.
The four examples above are a short list of the many industries that depend on wire harnesses. Construction, information technology, manufacturing, automation, and telecommunications, to name a few, all depend on the efficiency and flexibility of wire harnesses to ensure the quality and performance of their products.
How Wire Harnesses are Made
Regardless of the simplicity of wire harnesses, their manufacture involves a complex set of steps. In most cases, wire harnesses are custom designed and configured to fit a specific application or process. This aspect of their manufacture adds additional complexity to their assembly.
Designing
As with many forms of industrial equipment, the design phase of wire harness manufacturing is the most important part of their construction. The design of a wire harness serves as the guide to every step of the manufacturing process to ensure the windings and sheaths are properly assembled and combined.
The initial step in the design phase is the submission of the technical guidelines from the wire harness customer, which stipulates the use of a wire harness, the necessary materials, and dimensional provisos. The many elements of the guidelines include wire size, types of connectors, component connections, and if there are any aesthetic requirements.
There are several versions of wire harness software used to create wire harness designs. Each wire harness manufacturer has their preference of software, which provides a visual representation of the final product. Due to the critical nature of the design, clients and customers work closely with wire harness engineers to develop and perfect the wire harness rendering.
Bill of Materials
A unique part of wire harness manufacturing is the bill of materials (BOM). It contains the list of components and materials that will be used in the manufacture of a wire harness and is part of wire harness software. The BOM list includes the quantities to be produced, material suppliers, and a technical drawing of the final wire harness with indications of where critical components will be attached to the assembly.
The type of BOM depends on the manufacturing software used to produce the wire harness design. As with the visual representation of a wire harness, the BOM serves as a reference during the manufacturing process. Assemblers and technicians depend on it to ensure they are including the agreed components that the customer originally stipulated.
Cutting and Stripping
The cutting and stripping phase of wire harness construction is the beginning of the physical assembly of a wire harness. The parameters of the design outline the exact dimensional requirements and lengths of the wire. The specifications are adhered to in order to achieve a wire harness’s design.
To ensure accuracy, the cutting process is completed using an automated cutting and stripping machine that is programmed with the dimensional requirements. The machines cut, strip, and measure every piece of wire. The use of automated equipment ensures accuracy and the quality of the final product. When there are large numbers of conductors or difficult materials, the cutting process is divided into two steps, which are the removal of insulation and manual stripping.
Labeling and Marking
The word critical is repeated several times during the assembly of a wire harness and readily applies to the use of labels and markings. Anyone who has worked with wiring or wire harnesses knows the most common form of labeling is the use of the colors black, blue, green, yellow, and red. In the electrical industry, each of the colors represents the function of a particular wire.
Although the color method is used for many products, the wire harness manufacturing industry has taken the labeling and marking of wire harness wires to the next level using an assortment of methods to identify the function of various wires. In many cases, the labels placed on wires are a form of code that may include letters, letters and numbers, numbers, symbols, and other proprietary methods.
To ensure some form of standardization, the Society of Automotive Engineers (SAE) has published standards regarding the placement, types, and positioning of wire harness labels and markings. As a highly respected organization, many manufacturers follow the SAE’s guidelines and publish their compliance with their literature.
Crimping or Soldering
The crimping or soldering of connectors, terminals, and contacts, referred to as pins, is the next critical step in the assembly process. The two basic types are open barrel and closed barrel. In most cases, the attaching of connectors is an automated process due to the increasing demand for wire harnesses.
Secure and reliable connections are a necessity for wire harnesses, as one would imagine. Any failures can be catastrophic. Crimping is an ancient method and has been used for many years to attach connectors to wire harness wiring. It is regarded as the most reliable and dependable method. The choice of crimping over soldering is due to solders tendency to suffer fatigue and stiffen. Crimping is faster, simpler, and has repeatable accuracy.
Taping
Taping is used to organize the types of wires of a wire harness and protect them. It shapes, forms, groups, and fixes the wires and helps with the installation of wire harnesses. It is an important part of keeping wires from becoming tangled. The types of tapes used depend on the type of wire harness and its application. Included in the taping process is the attachment of sheaths that act as protective armor and assist in wire organization.
Assembly
The final step in wire harness manufacturing is the hand assembly of wire harness using a specially designed board. The technicians that assemble wire harnesses are highly trained professionals that use the computer design rendering as their guide. The assembly process can involve a single cork board or several boards placed side by side across the expanse of a room. The process is labor intensive, stressful, time consuming, and complex. It requires close attention to detail and strict adherence to design parameters.
As can be determined by the different steps of wire harness manufacturing, the final step in the process is a close inspection of every part of a wire harness. Regardless of the many inspections completed during the physical aspects of wire harness manufacturing, a final inspection and certification is made to ensure the quality, conformity, and performance of a wire harness.
