Influence of Arc Current on the Wear of Copper Electrodes in Air

Abstract

Experiments and analysis were carried out on the wear due to arcing on copper electrodes in air over a range of average currents from 100 to 1000 A in AC 60Hz. The experiments showed that the anode wear is larger than the cathode wear, and average arc current influences the cathode wear more strongly than the anode wear. The experiments also showed that the wear of a pair of electrodes is proportional to the power of 1.67th of the average arc current. These results were analyzed by the use of an energy balance equation at the cathode and anode. The analysis revealed the following. The energy loss due to electron emission, and the large heat conduction loss causes little cathode wear. As the average arc current increases, the ratio of the energy loss, except for the vaporization energy, to the input energy at the cathode increases considerably. This leads to the strong influence of the arc current on the cathode wear.