Shielding and Armor are often found side by side in Wire and Cable catalogs, which makes it look like they're practically the same thing. Both are metallic, wrapped around cable components, and protect the integrity of the cable. Although they have a lot in common, shielding and armor are not the same and the terms shouldn't be used interchangeably. So what makes them different?
Shielding is a layer of metal between the part of the cable that passes electricity, also known as the conductor, and the outer layer of a cable is known as the jacket. Shielding is made of copper, aluminum foil, steel, or another conductive material. These materials work as “noise” insulation for the conductor, keeping the cable’s signal in and signals from other nearby cables out. It protects the cable from an invisible signal and current interference also called electrostatic interference. This allows the cable to work with uninterrupted signals, doing its job effectively and efficiently.
The armor gives cable physical protection. This layer of metal, also made of copper or aluminum, is wrapped around the outside of the cable. The armor is strong, sturdy, and defends the cable when it’s used in harsh environments, like those in commercial buildings or underground installations. The armor prevents the wire from being crushed or otherwise physically damaged its environment. Though it may provide some blockage against interference, cable armor is not meant for use where physical protection is not needed.
Shielding vs Armor
While shielding and armor serve different and important purposes for cable, not all cables have both, or either, of these components. Depending on the environment the product will be used in, the type of cable, and the function it is serving, a cable may not need the added strength of the armor. If a cable is isolated or distanced from other sources of electrostatic signals, it may not need shielding either.