Tips for running low voltage wiring


This is a wide ranging subject that includes many topics. We’ll try to hit the main highlights in this brief overview using bullet points for efficiency.

  • Always use wire properly rated for the location. Class 2 and 3 wiring (CL2, CL3) are power limited cables for general purpose use. These are the most common cables for use in low voltage installations.
  • CL2R and CL3R are the same as above but for use in vertical riser shafts.
  • CL2P and CL3P are the same as above but for use in ducts and air plenums.
  • The riser and plenum rated cables are designed to reduce the emission of toxic gasses in case of a fire.
  • CM are communication cables for general purpose use.
  • Although there are cables listed as “direct burial” many are really not ruggedized to the point that they will offer long term reliability when literally buried directly in the dirt. This is especially true of speaker wires, including the wire used for our “pigtail” equipped speakers. All these cable should be installed using burial grade conduit or connected inside a weatherproof junction box to ensure long term reliability.
  • When running underground cables it helps to run them in straight lines, if at all possible. Be sure to make a physical map of all runs with landmarks detailed for future reference. Some time spent now will ensure much easier repairs if needed later.
  • Be sure to use adequate gauge cables, especially speaker wires. Here’s a link to a useful gauge versus distance chart from Belden,
  • When running multiple cables, avoid running low level signal cables and speaker wires in the same conduit as AC wiring. Be sure to check and follow the recommended bending radius for the cables you’re installing.
  • Don’t use steel electrical staples or office staples to hold wires to adjacent surfaces. Use fastening devices specifically designed for attaching wires. And don’t bind or crush them under the attaching devices.
  • Keep low voltage and speaker wires at least 12-inches away from any AC wires when running them together. If they must cross each other, cross them at a 90-degree angle.
  • Either use silicone filled waterproof grade terminators or solder and seal all connections.
  • Label every wire at both ends with permanent waterproof marking devices.