This topic can get a bit technical and complicated. Lucky for you, I will not force you into either. This post will just show the bare basics and guide you through how to select the correct type of wire.
Types of Wires
There are basically two types of wires used in all systems: Plenum and PVC. Plenum and PVC refers to the smoke rating of the wire jacket. Plenum is a “Low Smoke” jacket and is approved for use in open indoor areas, like the plenum of the ceiling. PVC is a “Higher Smoke” jacket and is only approved for running in conduit or in plenums where a designated return air duct is used. PVC omits a toxic chemical into the air when burned, and the last thing you want is to spread toxins through out the building because either the building has an open ceiling return air system and the toxins are sucked up into the air conditioning and the blown about, or not run PVC in conduit and those who are close to the burning wire are affected. I always use plenum wire for indoor application just to be safe. Wiring that is used outdoors carry an outdoor rating and is filled with gel to prevent corrosion. When faced with running outside wire, I always run plenum wire up to the exterior wall of a building and create a splice to continue with the outdoor wire
AWG
American Wire Gauge is a standard that we use to determine the circular mills of the copper in the wire…how thick the wire is. AWG is an important consideration because voltage and data will only travel so far on smaller wires. You will have to consult the installation guide for the equipment that you have purchased to find their data limitation as for voltage use the table below and you will coast through most of your installations. On a side note, most manufacturers also follow this table for data transmition.
AWG Distance* 24 300 22 500 18 1000 16 1500 Table 1.1 - *Wiring must be home ran and not daisy chained
I have yet to use a thicker gauge wire than 16AWG in an intrusion system, other systems are a different story. Personally, if my device is more than 1,000ft away from my control panel, I will install a secondary power supply.
Final Thoughts
Intrusion systems can be the easiest system to install if you keep sick by the following:
- Always use plenum wiring for indoor applications. It will cost you more money, but save you a lot of liability in the long run.
- Use 22AWG and 18AWG in the distances laid out in table 1.1 and stick with them. Don’t try to “stretch”, as it could lead to hours and days of trouble shooting to fix
- Keep wire color simple. Set a standard and stick with it throughout the job/carreer. For instance, always use the red and black wires for positive and negative power, and the green and white wires for signal. This will avoid confusion with some of your lesser experienced installers.
