Factors affecting minimum safe leakage distance

There are several important factors which determine the minimum safe leakage distance for insulation. However, two basic factors are (a) the magnitude of surface leakage currents, and (b) the effects of these currents on the insulation. The magnitude of this current depends upon the characteristic of the surface, surface contamination and the voltage gradient. Since the power loss caused by the leakage current is inconsequential in power systems, concern need be given only to the damage these currents may do to the surface of the insulation.