Evaluation of a Setscrew Connector for Aluminum Wire

A new setscrew connector for residential aluminum wiring repair is evaluated by means of a static zero-current test, a high-current "heat cycle" test, an environmental test, and a wire disturbance test. Additionally, the current partitioning between the two paths between the wire and the connector body is determined. After a short time in service, the resistance of the direct contact between the wire and the connector body increases to the extent that most of the current flows from the wire to the connector body through the setscrew. Further connection resistance increase then occurs at an insignificant rate, resulting in a satisfactory long life projection. The connector resists contact deterioration from the wire disturbances that occur during installation, provided that the setscrews are fully tightened as specified. The connector must be tool-held to reliably achieve the required degree of tightening, however. The connector's corrosion inhibitor is found to be involved in the initial connection resistance increase. This connector is considered to be a satisfactory candidate for residential aluminum wire repair.