Electrode erosion from high current moving arcs

The results of experiments designed to investigate various aspects of the electrode erosion produced by high-current moving arc discharges are described. A simple model for electrode erosion based upon fundamental heat transfer principles is examined and extended to the moving arc regime. This model is used to explain some of the features observed experimentally. Erosion measurements using several state-of-the-art materials (composite materials and materials with admixtures to improve their performance) are reported for both moving arc and stationary arc conditions. The jet plasma effect is shown to influence moving arc electrode erosion in a manner similar to that observed under stationary arc conditions over the range of electrode separations for which it is the dominant influence. In high-current, high-energy switching applications, arc motion results in a substantial decrease in electrode erosion as compared to a conventional spark gap.>