Structured Cabling for Security Systems
Whether you’re installing surveillance cameras, access control readers and locks, or data servers, you’ll need the structured cabling that goes with your new security systems. Your security hardware will always connect to the structured cabling of your building, generally designed to be forward- and backward-compatible to support all the network devices you’ll ever need. Most, if not all, wiring for security systems is low-voltage, which means a lot of electrical contractors also do security wiring. The best time to run the cables is during construction of the building, of course, but there’s nothing that says you can’t install your security system after the fact. If you and your electrical contractor were thinking ahead, there might be extra cable runs that make installing a security system easier.
A Brief Overview
Most of today’s security systems are IP-based, meaning they use an Internet network to transmit information to the various control panels and computers. These setups are a lot easier to install and manage because they use fewer cables to achieve the same end as the old systems. Legacy systems that haven’t been updated generally require more wires dedicated to individual purposes, which can increase the installation time and complexity.
Whether you’ve got an IP system, an older coax network, or a combination of both, you’ve still got a variety of types of structured cabling running through your building. Many critical lines are shielded, meaning they have an extra metal insulator wrapped around the transmission cords. This is designed to reduce electromagnetic interference both to and from the shielded line, since nearby wires or conductive materials can add noise to a simple insulated wire. Power wires in particular produce a large electromagnetic field, so shielding wires is doubly important near them.
Older DVRs use coaxial cables to transmit analog camera feeds to the encoder. A variation of this is siamese cable, which runs the separate coax and power cables together. Siamese cables reduce installation time and complexity, but perform the same as separately run cables.
Most CCTV systems today use Power over Ethernet, or PoE, instead of a dedicated power cable. Traditional Ethernet cables like Cat 5e and Cat 6 transmit data and power to the cameras. These wires can generally run 100 meters without losing or corrupting data, but some Cat 6 applications are limited to 55 meters.
For access control systems, the structured cabling can get a lot more complex. In most modern cases, a composite cable that carries all the separately insulated wires is run to simplify installation and maintenance. Called banana cables – partly because most of them are yellow, partly because they’re designed to be easily peeled apart – composite cables carry power and data for the reader, door contact sensor, Request to Exit component, and electric lock. The various cables inside a banana cable are rated by gauge and number of conductors – an 18/2 wire, for example, is 18-gauge cable with a pair of wires in a single shielded cable.
Running wire for IP or PoE access control is significantly less complicated, since every component runs on a simple Ethernet cable just like an IP surveillance camera system. These systems are less difficult to expand, as well, since plugging into the Ethernet network is easier than running a new cable directly from the control panel to the new door.
Concealing and Protecting Your Wires
Running cables for security systems is one thing – making sure they’re not exposed is another. In a lot of cases, wires are run through the walls, but sometimes they need extra insulation or weatherproofing. Conduit, either in metal or plastic, provides additional protection against a variety of factors, including electromagnetic interference, water, corrosion, tampering, and even fire. Some conduit can even run through concrete walls, providing outlets in places otherwise unsuitable for hardwired security systems. In places where embedded cabling is simply not viable, wiremolds or raceways can run wires along a wall in a small plastic or metal case to provide similar benefits.
No matter how you run your cabling, you’ll need to think ahead when you have an electrician run the lines. Offices and retail spaces are easily wired with more Ethernet cables or outlets to support future expansion, and homes are often easier. Regardless, you always want to plan ahead. You can’t just start running wires here and there – every cable should have a purpose, whether you decide to use it now or not.