Shielding in Security Alarm Cables

[Greg Anixter]

You may have heard of security alarm cable if you’ve spent an appreciable amount of time researching electrical infrastructure, but have you ever heard of shielding? Just like other specially engineered types of electrical equipment, security cables are no different. Marine cable and welding cable need to be flexible. Solar cable needs to be resistant to UV light. These are just facts of life for certain classes of cable.

While not all cables are shielded, many are, and it’s a term you’re liable to come across if you deal with them on a regular basis. With that in mind, what does shielding mean with respect to cables?

It’s not like a type of physical armor, but it does serve a similar purpose, although not against mechanical stress. For many types of wire, shielding takes the form of a special or reflective foil insulation that protects the cables against a specific type of interference known as EMI or electromagnetic interference.

Electromagnetic interference is basically any electromagnetic radiation that interrupts the signal carried by a wire or cable. All electrical operations emit some or other form of electromagnetic radiation, some of which can be interruptive to the signal carried by a wire. Additionally, cables and wires are more suspect to the ravages of EMI when they are exposed, travel long distances, or are located in close proximity to other electrical infrastructure or conductors.

This is a specific concern for security alarm cables specifically because of the nature of their use. These types of wires and cables transmit signals to the nodes on a security system and are responsible for secure monitoring and data transmission. This is vital to public safety and security. Considering the fact that these types of instrumentation cables are utilized in the wiring of fire alarm, video surveillance and other security systems, EMI can serve a serious hindrance to practical operation.

Electromagnetic interference can scramble or muddle the information sent along a security or alarm system, making it less efficient or even crippling it. Therefore, it’s a good practice for many security and alarm cables to be shielded to protect them from this interference, even if it is not overtly necessary given the circumstances.

Whether or not you will need to utilize shielded cables in the wiring of your security and alarm systems must be evaluated on a case by case basis and you should justifiably rely on the input of an electrical engineer.

Of course, you don’t need to get the insight of an electrical engineer if all you’re looking for is some more information on electromagnetic interference and the different categories and ratings of security and alarm cable. You can find that information right at EWCSWire.com, and what you can’t find their customer service team will be happy to answer. Just get in touch with them anytime you want to learn more about shielding in different types of cable and what it means from a perspective of functionality. You can reach them by email at [e-mail] or by phone at 800-262-1598.