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Repairing Damaged Electrical Wiring
Always inspect the electrical wiring for damaged or loose connections
When repairing and maintaining refrigeration equipment, it is a good practice to inspect the electrical wiring for any obvious issues such as damaged wiring or any loose connections. This is especially important for older systems that have not been repaired or maintained for years.
One common issue on older systems is the wiring insulation becomes so brittle that it cracks or crumbles when you move it. When this happens, you will need to replace the damaged wiring with the same gauge and type of wire. Normally, this is not an issue, as most technicians usually keep various gauge and style wiring on their truck. However, sometimes you might find that you do not have the right wire on your truck, and you may be forced to get the right wire to complete the repair. This might present a dilemma — you might not have the time to go get the right wire. For these scenarios, I keep shrink tubes of various sizes on my truck. As a temporary solution, I can slip a piece of heat shrink tubing around the damaged sections and use a heat gun to shrink it onto the wiring. This will allow you to get the system up and running until you can return to properly replace the defective wiring.
While inspecting the wiring, also look for any darkened electrical terminals or connections. This is normally a sign of a loose connection causing excessive heat to be generated at that location. Either tighten the connection or replace as needed. Inspect any electrical connectors used, such as wire nuts, and replace any damaged or darkened wire nuts. Be sure to use the right wire nuts for the wires to be connected.
There are various sizes and styles of wire nuts, and each has a minimum and maximum number of wires that it can safely connect based on the gauge and style of wiring to be connected. Always follow the manufacturer’s recommendation when selecting the wire nut for wires to be connected. For example, Ideal’s yellow 74B is recommended for a minimum of two #18 and a maximum of four #14 with one #18.
When connecting wiring with a wire nut, if all the wires are of the same style, the wires should be stripped equally to the manufacturer's specifications. Then line up the wires evenly and tighten the wire nut until the wires start to twist and there is no exposed copper. Slightly pull the wire to ensure you have a good connection. If solid and stranded wires are being connected, it is good practice to strip the end of the stranded wire slightly longer than the solid. Some technicians prefer to pre-twist the wires before connecting with a wire nut, as they believe this makes a better connection and will prevent an individual wire from being dislodged from the connection.
When replacing wiring, you may find that you have to replace a section of stranded wire but only have solid wire, or the opposite — you have to replace a section of solid wiring and only have stranded. Generally, this should not be an issue as long as the wire can handle the same ampacity as the original wire. However, there are differences between the two wire types that may prevent you from switching over. Stranded wire is more flexible than solid wire and is less likely to break from bending and twisting, while solid wire is less flexible. Stranded wiring allows for solderless crimp connectors to be used where solid wire does not.
Ensuring the electrical wiring is in good condition on the equipment you repair and maintain is definitely a plus for both you and your customers.
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