What is the Difference Between Cable Shielding and Insulation?


  When you’re working with coaxial cable, it can be very easy to confuse two important components of it: shielding and insulation. While both provide protection for the cable, their respective jobs – as well as the materials used for them – are quite different.

  Cable shielding functions as an electromagnetic energy interceptor: it prevents electrical interference from traveling to the cable’s center conductor and disrupting the data signal. In addition to blocking renegade electrical waves, shielding also ensures that any potentially disruptive energy is disposed of through efficient and proper grounding. In order for shielding to effectively perform its duties, it needs to be highly conductive, and typically comes in two forms: wire braid and foil.

  While insulation offers no protection against electromagnetic interference, it helps shielding to work effectively – and the cable as a whole to function properly – by keeping the center conductor and shield material from coming into contact with each other.

  A standard coaxial cable has two layers of insulation: the first, inner layer is referred to as the dielectric, and is located between a cable’s center conductor and shield. The second, outer layer of insulation is the actual cable jacket, which seals out moisture, protects inner working cable components from abrasion, and provides a buffer between the cable’s shielding material and outside conductors. Polyethylene, polypropylene and polyvinyl chloride (PVC) are among the most commonly used insulation materials.

  Shielding and insulation combined offer a great deal of protection and are both integral parts of coaxial cable functioning, but it is important to be aware that they play independent roles and are by no means interchangeable.

  When you’re deciding on which type of cable to use for a particular application, be sure to keep in mind both shielding and insulation factors, and visit CableOrganizer.com for the wide selection of cables, product specifications and know-how that will help you successfully complete your project!


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