Leakage Current on Porcelain and Silicone Insulators Under Sea or Light Industrial Pollution

The leakage current on heavily polluted silicone rubber insulators is usually smaller than on similarly polluted porcelain insulators. In this paper, results are presented that show that under light contamination, the currents on the two types of insulators can have similar values. Results are also presented from two different sites that show that under certain conditions the currents on silicone insulators can be higher than on porcelain. The phenomenon is explained, referring to the superior washability of the porcelain and moisture absorption of the pollution layer on the silicone rubber insulators during times of high humidity.