The Influence of Corrosion Inhibitor and Surface Abrasion on the Failure of Aluminum-Wired Twist-on Connections

Aluminum wire splices made using constrained spring twist-on connectors, without corrosion inhibitor, have been found to be failure-prone. Corrosion and poor initial conductor-to-conductor contact were determined to be major factors in the failure process. In this investigation installation involving the use of inhibitor and aluminum surface abrasion are tested as possible ways of preventing the failures. The tests show that installation using inhibitor and aluminum surface abrasion results in low initial connection resistance and stable operation during two years of testing within rated conditions, a substantial improvement in performance. The initial resistance and long-term performance are compared for several combinations of the installation variables involving inhibitor and abrasion. Limitations of the inhibitor, potential problems from its use, and the need for standards for inhibitors for this application are discussed.