How To Permanently And Neatly Repair Low-Voltage Wiring That Has Been Damaged By Animal Chewing

Posted on: 1 October 2015

Low voltage electrical wiring is common in many homes; it is often seen in use with electric garage door opener sensors, fire and burglar alarms, and interior and exterior accent lighting. Unfortunately, low voltage wiring is vulnerable to damage caused by pets or other animals that like to chew on exposed wires. Since low voltage wiring contains current levels that are imperceptible to animals, there is no pain deterrent to stop the chewing, and the result is a damaged or severed section of wire. The good news is the damage is not difficult to repair; all it requires are a few basic tools and inexpensive supplies. Here is what you need to know:

Tools and materials needed

  • 40-watt or greater soldering iron

  • Rosin core solder with 60% tin and 40% lead composition

  • Wire strippers

  • Electrical tape

  • Heat-shrink tubing size assortment

  • Utility knife

  • Candle or cigarette lighter

  • Heat-resistant work surface

  • Alligator clips

Step-by-step procedure

1. Remove the damaged section of wiring - With a pair of wire cutters/strippers, make clean, perpendicular cuts across the wiring on both sides of the damaged section. Be careful to remove all damaged wire, but also take into consideration how much length you will have remaining for use, and don't cut out more than is necessary.

2. Strip away the outer insulation - Many low voltage wires are encased in two layers of insulation: an outer covering over two separately-insulated wires. If your wire does not contain outer insulation, then skip to step 3; otherwise, continue reading below.

To remove the outer insulation, measure approximately 2 inches from the ends of each wire and make shallow cuts with a utility knife around the circumference of the wires. Work slowly and carefully to prevent cutting too deeply and keep your cutting depth uniform as you work your way around the wires. Once the insulation has been cut completely through, pull it off the ends of the wires to expose the two individual strands of wiring.

3. Strip the insulation from the individual strands - When the individual strands are exposed to view, measure one-half of an inch from each end and use your wire strippers to remove the insulation from all four strands. Be sure to adjust your wire strippers to the appropriate size setting so that you don't accidentally sever the wires entirely.

4. Tin the exposed wire ends - Heat your soldering iron to approximately 400 degrees, if your iron can be adjusted to a specific temperature. Otherwise, turn it on and allow it to heat for at least 5 minutes before proceeding.

Place an alligator clip flush with the edge of the insulation on each wire so only the bare copper wires are visible; the clips will serve as heat sinks to help prevent you from accidentally melting the insulation. Once the clips are in place, touch the soldering iron to the copper wires for a few seconds, then touch the rosin core solder to the wires. If you have heated the wiring sufficiently, the solder will instantly melt and flow into the spaces between the individual fine strands of wire. If it doesn't flow, touch the iron to the wires for a few seconds longer to heat them to the melting point of the solder.

5. Slip on the correct size piece of heat-shrink tubing - After tinning all four wire ends, identify a piece of heat-shrink tubing that will just fit over the bundle of wires. Slide the piece of tubing chosen over one end of the wires and push it out of the way until the final step in the process.

6. Join the wire ends - Once the heat-shrink tubing has been slipped over the wire, match the wires from each end with one another so proper polarity is maintained and you don't risk causing damage to the powered device or light. Hold the matching pair of wires together, then heat the pair of wires with the soldering iron until the encased solder in each wire melts and mixes together. This will join the pairs of wires and create strong electrical joints. After soldering the wires together, wrap a few turns of electrical tape around the bare metal wires so they are covered and protected.

7. Finish by shrinking the tubing - When the wires are joined and wrapped with electrical tape, slide the heat-shrink tubing back down the wire until it covers the site of the repair and the individual wires. Next, apply an open flame from a lighter by moving it along the length of the tubing until it shrinks; be careful not to melt the tubing or wiring, as it only takes a few seconds of heating to form a strong, watertight joint.

If you'd like to leave this work to the professionals, contact local electrical services like Beckstoffer-Welsh Inc