One question we at CableWholesale get asked all the time is: “do I need to buy a shielded cable?” So today we will go over some instances where buying a shielded cable is appropriate, which types of installations require them, and what different types of shields are available.
The main reason you would want to buy a shielded cable is if you will be running the cable through a busy electrical environment. This usually means there will be many electrical signals mixing together in one space, which may cause electrostatic interference. This is also known as “crosstalk,” which is defined as what happens when “a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel.” Shielding your cable also cuts down on EMI, otherwise known as electromagnetic interference, which occurs when there are electromagnetic signals that run into each other in a close environment.
There are a few different types of cable shields available. Any cable can come with a shield, but the most popular types are Ethernet, VGA, USB and other network cables. You may run into a “quad-shield,” and this is typically used with coax-cables only.
Braid Shield: This type of shield is the most productive when trying to cut through interference. These types of shields are typically constructed out of pure copper or foil. Keep in mind that this type of shield can make a cable more difficult to terminate.
Spiral Shield: This is similar to the braided shield; the difference is just that it is constructed with single strands of aluminum wire wrapping around the cable’s core.
Tape Shield: This type of shield can consist of a few different materials, usually consisting of some sort of polyester and aluminum. This type of shield is typically sensitive to pressure, and can be fragile.
For environments that are exceptionally heavy with electrical interference, you might think about a double shield. This will add another layer of protection against crosstalk, EMI and other types of interference.