Erosion of contacts by arcing

The effect of the current waveshape on the rate of arc erosion is studied for currents of 180-1090 amp, with contacts of molybdenum, steel and a sintered mixture of tungsten and copper. The amount of arc erosion is found to increase with the current amplitude for a constant arc charge. It is not linearly proportional to either the arc charge or its current amplitude. It increases with the current amplitude at an increasing rate over the range of tests. It is found to be sensitively affected by the contact separation in the millimetre range.