Voltages induced by arcing grounds

THE subject of arcing grounds in transmission systems is one of the greatest interest to operators of power systems of any extent. The almost universal grounding of the neutral in this country is done primarily to alleviate the destructive effects produced by arcing grounds. However, in spite of its great importance, a clear understanding of what happens in an arcing ground in not general. There is no agreement as to the magnitudes of voltages and surges produced, and the various theories proposed call for different properties of the arc. The authors therefore considered it well worth while to attempt in the laboratory to duplicate the conditions of an arcing ground on a transmission system and by spark gap determinations of voltages and by oscillograms to determine the maximum voltages developed and to discriminate between the various theories proposed.