Pigtailing aluminum wiring is a process that involves connecting a short length of copper wire to the end of an aluminum
wire using a twist-on connector, also known as a wire connector or wire nut. The copper wire is then connected to a device or fixture, such as a switch or outlet. This technique is commonly used as a solution to mitigate the potential fire hazards associated with aluminum wiring.
Aluminum wiring was commonly used in residential construction during the 1960s and 1970s, but it was found to be more susceptible to overheating and failure than copper wiring due to its higher thermal expansion and conductivity. Over time, as the wiring expands and contracts with changes in temperature, it can become loose at the connections, leading to arcing, overheating, and the risk of fire.
By pigtailing the aluminum wiring with copper, the copper provides a more stable and reliable connection that can better withstand the thermal cycling of the wiring. However, it's important that the proper connectors and techniques are used to ensure that the connection is secure and that there is no risk of the wires coming loose or separating.
It's important to note that pigtailing aluminum wiring is not a permanent solution and is not recommended as a long-term fix. The best solution is to replace the aluminum wiring with copper wiring, which can be done by a licensed electrician.