The effects of electrical discharges between electrodes across insulation surfaces II. Discharges occurring in static air

This paper describes the continuation of the basic investigation, first reported at this conference in 1959¹ of behavior of insulating materials exposed to surface discharges of the type which lead to carbonization and tracking in service and in various wet and dry tracking tests. Attention has been focussed on the variations of the surface layer resistance during and after such discharges. These effects were studied over a range of surface power densities, the power of the discharge with respect to the area of the insulator surface affected by the discharge, of 4 to 360 watts/ cm² in air.