About Wire Harness and Cable Assembly: Today, cable assemblies and wiring harnesses are integral parts of any electronic device or system.
Every cable assembly and wiring harness comprises several components, each contributing individually to the product’s overall performance. Because of their different compositions, cable assemblies and wiring harnesses are used in different industries.
This article will discuss whether a cable assembly and a wiring harness are the same or differ.
A cable of matted wires of different colors with connectors in the car’s electrical wiring.
Cable assemblies Vs. Wiring harness assemblies
You often consider both cable assemblies and wiring harnesses as the same but have considerable differences. The basic difference is that a cable has two ends, while a wiring harness has multiple ends. Further, each end of the wiring harness has its termination.
Wire being processed to connect to a machine.
Wire harness and cable assembly: Component differences
A wiring harness and a cable assembly comprise several different components. Each of these components is available in different configurations to suit various applications.
Wire harness components:
Wire: The wire is the main component of any wiring harness, as it helps carry current or signals. These wires are mostly made of copper, and some may also have a special coating. The wire’s capacity should equal or exceed the voltage it needs to carry.
Connectors:
Connectors of different sizes and varieties, made from plastic, metal, and ceramic, can be found to connect these wires.
Grommets:
A grommet is a type of insulator, either attached to the terminal or the connector. Its main purpose is to protect the connector from the moisture.
Fuses:
The fuse’s main purpose is to stop the power surge so that the overloading current does not damage the device receiving power. A harness can use a fuse from different classes. Generally, a fuse has a rating of 32 volts or less.
Outer covering:
Also known as sleeves or tubes, outer coverings protect the wire from the environment, abrasion and electrical shocks. An outer covering can be made from polyolefin or nylon.
Relays:
With relays, you can turn on or off high amperage circuits. Due to this power of relays, you can use wiring harnesses to power multiple devices. Relays also vary based on their amperage requirements.
Terminals:
Terminals are the metal components through which wires are terminated. You attach the terminal at the wire ends and then insert the wire into the connector or any other connecting equipment.
Ties:
Cable ties keep the wires intact in the harness so that they form a bundle together in a definite direction. You can also attach the harness to any structure using ties and clamps to minimize movement.
Locks:
You can insert the lock into the connector so the terminal remains attached to the wires and does not come out. It also ensures that the terminal inserts securely into the connector.
The Cable assembly components:
Conductor or circuits:
The application determines the type and number of conductors used in an assembly. Pure or bare copper is usually the preferred conductor type, but sometimes, to facilitate the termination process and avoid corrosion, bare copper is plated with certain materials. The most common plating material is tin.
A cable assembly designed for high-temperature conditions can have silver or nickel coating on copper to withstand temperatures between 200-260 degrees Celsius.
Some applications might require extra breaking strength, and copper alloys and copper-clad steel are the best choices.
Further, the conductor used in an assembly is either one solid conductor or a stranded one with many tiny conductors. Stranded conductors help overcome the rigidity of solid conductors. They are available in different variations depending on the application requirements. As the strands’ number increases, their diameter decreases for a given size conductor. Such a stranded conductor has high flexibility.
Primary insulation:
Most insulators are made from thermoplastic and thermoset compositions, but the applications determine the insulation’s type, thickness, and material.
The selection of insulation is based on operating temperature, level of voltage the assembly will carry, possible exposure of chemicals and fluids and many other factors.
For high-speed signal transmission, foamed insulation is the best. When more than one conductor is there, the insulation is marked with some identifying feature. It may be a print label, a strip or colored insulation.
Twisting of conductors:
Cables used in telecommunications must undergo electromagnetic interference due to external sources. Crosstalk is another interference source for these cables from adjacent cable pairs. Twisting the conductors combats this effect, as pairs are adjacent for only half a twist.
Shielding:
Shielding is another method of protecting cables from RFI and EMI, apart from cabling the twisted pairs or the conductors. The common shield options are foil, braid, and spiral.
However, a combination of braid and foil shield offers the best protection from electromagnetic and radio frequency interference.
Outer sheath:
After the cable is completely constructed, manufacturers apply an outer sheath or jacket to protect it further. This sheath makes the cable flame retardant physically tough to withstand harsh weather conditions, chemical resistant, and flexible to allow easy installation.
An outer jacket comprises different materials, but PVC is the most common and cost-effective. There are also urethane-based, elastomer-based, fluorocarbons, alloy-based and non-halogens materials. Every material offers different characteristics to the cable depending on the application.
Connectors and strain relief:
The use of connectors in a cable assembly depends on the speed and type of signal to be transmitted. For power signals, a crimp connector is best, while for high-speed signals, a soldered/welded connector will do.
Besides the connectors, manufacturers also determine whether a cable assembly needs strain relief. Strain relief protects the cable assembly from termination failure by preventing the force applied to the cable from transmitting to the terminals. Strain relief can be solid or segmented, depending on the application requirement.
Wire harness and cable assembly: Application differences
In some industries, wiring harnesses serve the purpose while in others, cable assemblies do the job.
Wiring harness applications:
Manufacturing: In modern manufacturing plants, automatic production and assembly lines require complex cabling, wiring systems, and networks.
Wiring harnesses connect different systems to transmit power and signals along these production lines, and properly sealed wires and cabling systems ensure fully optimized production systems.
Automotive applications: When starting an automobile, an electrical component or device transmits power or signals to turn the engine and achieve ignition.
The complex network of wires and wiring harnesses allows these electrical power and signals to be transmitted. All the electrical functionalities of the vehicle, including power brakes, power windows, lighting, audio and entertainment, and engine management systems, connect through wire harness applications to form a fully functional and operating vehicle.
As modern vehicles have innumerable electric units, millions of wires and cables connect these devices to transmit electricity and signals in the entire vehicle.
Agricultural industries: Most vehicles and equipment used in the agricultural industry use wire harness assemblies, which keep the wires organized and have protective features. With such efficient wiring systems, heavy machinery can operate longer.
Cable assembly applications:
Communication systems: Global communication systems need a complicated infrastructure that can smoothly and instantaneously send and receive data. In these communication systems, cable assemblies are integral to routers, hubs, repeaters, peripheral equipment, broadband networks, optical networks and many more.
Cable assemblies also use wireless communication systems such as satellite receivers, DSL routers and RF.
Medical applications: The medical industry uses a variety of devices, instruments, and equipment with varying degrees of intensity. Thus, cable assemblies used in medical equipment are biocompatible, durable, and adaptable. Cable assemblies used in drills, pacemakers, defibrillators, or radiological equipment must function uninterrupted.
As the medical field has different applications, cable assemblies for the medical industry come in various shapes and sizes. Also, the cable assemblies used in medical applications must comply with FDA regulations and guidelines.
Military applications: Cable assemblies are an integral part of military equipment, but each component of the assembly and the harness must meet strict Department of Defense specifications. Also, wiring and cabling systems used in military applications should be strong enough to withstand harsh environmental conditions.
Construction: You need safe, functional, and efficient cable assemblies for wiring residential and commercial buildings. However, all harnesses and assemblies must comply with the relevant industry codes.
Wire harness and cable assembly: manufacturing differences
The manufacturing process involves the following steps:
Wiring harness manufacturing process:
Wire harness manufacturing majorly requires manual efforts rather than automation. A number of processes in wire harness assembly manufacturing need to be done by hand. Some of those processes are:
- Routing of cables and wires through conduits/ sleeves
- Tapping wire ends
- Conducting multiple crimps
- Securing wire components with ties, clamps or tapes
- Installing wires in various lengths
The reasons behind involving manual production in these processes include the complexity of the automation process and the cost-effectiveness of manual labor.
As manual labor is involved, wire harness assembly takes longer than other cable assemblies, a few days to several weeks. The production time also depends on the complexity of the harness.
However, some pre-production processes in wire harness manufacturing need automation, such as:
- Twisting wires
- Soldering ends of wires
- Crimping one or both ends of the wires
- Cutting and stripping wires using automated machines
- Plugging terminal-fitted wires into connectors
Cable assembly manufacturing process:
Design and prototyping:
Designers create the cable’s 3D model using the appropriate connectors, material and assembly components based on the special requirements.
This design must match all the relevant parameters. Once you have a final design, you can make a cable prototype to check its performance and functionality.
Selection of Materials:
Once everything is final, you will need components for the cable production. For this, you need to select materials such as insulation, jacketing, and shielding to ensure that the cable withstands all the factors associated with applications.
Further, the material selection is also based on the regulatory requirement of the application, if there is any.
Selection of connectors:
Once you have suitable materials, you need to choose cable connectors. Choosing suitable connectors ensures reliable and high-performing cable assemblies.
It is also essential that the connectors are compatible with the cable and the equipment. Ensure that the connectors you choose meet industry certifications and special requirements.
Manufacturing:
It’s time for mass production after finalizing the design, material, connectors, and everything else. Cable assembly manufacturers have large facilities to produce cable assemblies in bulk.
The manufacturing process includes cutting wires to desired lengths, stripping them, connecting them to connectors, and applying outer jackets to ensure complete protection.
Testing:
After manufacturing, the cables are passed through various tests to verify if they pass cable standards and meet all functionalities. These tests included environmental testing, functional and electrical testing and many more.
Conclusion:
Now that you know how cable assembly differs from a wiring harness, you must also know that several factors determine whether your application needs a cable assembly or a wiring harness. Based on the applications, you need to be specific while designing your cabling systems.
If you are unsure which product suits your requirements, Cloom’s professional designers will guide you. We are a leading manufacturer of custom cable assemblies and wiring harnesses for various applications.
