What is a cable assembly?
A cable assembly is the group of wires or cables arranged into a single unit, such as woven braid or an insulated tubing, for organization, easier installation, and protection from mechanical and other types of harmful impact. Cable assemblies are designed for medical environments, military, and high-speed data connection, and the spectrum of their indoor and outdoor applications is quite diverse. You may find yourself using a cable assembly at some point if you need your wiring to be extra protected or you are aiming for smarter use of space.
This blog focuses on features of cable assemblies, the differences between a cable assembly and wire harness, types of cable assemblies, and the factors that should be taken into consideration when choosing an assembly.
Cable assembly vs. wire harness: what is the difference?
Cable assembly and wire harnesses are customized cables consisting of several elements, often confused. However, they are two very different things.
A cable assembly is the collection of wires arranged into a single construction under an exterior sleeve. Cable assemblies are used when there is a need to use the capacities and power of several different cables united into a single construction. An assembly makes sense because it makes them easier to set up and operate together. An assembly helps protect individual cables and decrease the potential mechanical impact. All wires and cables within an assembly are identified for clarity as each has individual characteristics and carries a particular purpose.
In a wire harness, individual wires are cut to fit into the construction. The ends of individual wires are attached to form a wire harness. Each of the wires in a harness still has individual insulation. The insulated wires are simply united together under one wrapping. The goal of the wire harness is to group different wires to ensure more accessible connections. Unlike a cable assembly, a wire harness does not offer significant protection to each wire.
Because of its construction, a cable assembly is more robust than a wire harness and is suitable for outdoor use and withstanding difficult physical conditions. The structure of the cable assembly makes it possible to maneuver it and make it fit inside the tight spaces within the building. The wire harness is primarily used indoors as its construction makes it vulnerable to physical impact. It is also commonly used in motors and garages.
All in all, one might argue that a wire harness is a subtype of a cable assembly if we consider an assembly to be a broad category. However, cable assemblies and wire harnesses are different in their actual function.
What are the variations of a cable assembly?
There are thousands of cable assemblies readily available on the market and countless customizable assembly solutions. However, it is possible to outline some of the most popular types of cable assembly:
- Flat & Ribbon Cable Assemblies. This is an umbrella term for a wide selection of multi-purpose cable assemblies that offer flexibility. These assemblies can be split, multi-branch, non-PVC, and many other types. An actual flat ribbon cable assembly has the wires laid parallel, perfect for application within tight spaces.
- High-speed data assemblies. These assemblies consist of multiple micro coax and twinax cables to optimize the high-speed data performance and conveniently fit a data cable into tight spaces.
- Shielded Cables Assemblies. Often a variation of data assemblies, these are used specifically to protect the assembly from electromagnetic interference with the help of shielding. Aside from data applications, these assemblies can also be used in an industrial setting. The individual wires within such an assembly are usually placed inside an EMI braided sleeve and an additional sleeve that protects from abrasion.
- Sealed cable assemblies offer superior protection from moisture, humidity, and dust.
- Jacketed cable assemblies. While not quite common, cable assemblies can be done with each cable jacketed individually as long as specifically required. For example, jacketed assemblies may be needed in medical establishments because wires must follow specific sterilization rules.
- Custom cable assemblies are available with any specific goal in mind. Cable assemblies can also be grouped according to voltage and power.
Things To Mind When Choosing A Cable Assembly
When choosing a cable assembly, you should consider the goal it will serve and the type of assembly you'll need for the particular application. The best decision is to consult the manufacturer of the assembly. However, there are also several other factors to consider.
- Copper or copper alloy conductors. While copper wires are used for cable assemblies more often than anything else, copper alloys may offer some benefits, especially for small assembly sizes, because of additional strength and flexibility.
- Solid vs. Stranded Wire. This is, once again, a flexibility concern, with stranded wire offering more.
- Plating. For the environments where humidity is high, most likely with tin, which is the most readily-available option. For a higher-cost assembly, silver is a good option for high-frequency applications, while nickel is great for high-temperature environments with its temperature rating of 250 C.
- Insulation. Common options for cable assemblies are PVC, PE, PP, and different variations of Teflon. The key factors to consider when choosing the insulation for a cable assembly are cost, dielectric constant, flexibility, temperature rating, and flame-retardancy. For high temperatures and flammability, teflon is the best option, whereas PVC, PE, and PP are the best options if flexibility is your primary consideration. These three are also the cheaper options.
- Shielding. Shielding options to prevent electromagnetic interference include foil, braid, and foil braid. The latter is the overall best option for EMI protection.
- Jacket. Common materials for an outer jacket are PVC, polyurethane, and Teflon. The factors that should be considered are flame retardancy, whether the jacket is low-smoke zero-halogen, how durable it is, and the maximum operating temperature. Other less common considerations may stem from the environment where the assembly is used.
- Connectors. The cable assembly manufacturer is the best source to consult when choosing the type of connector, as there are plenty of options for each assembly.
