Influence of non-soluble contaminants on flashover performance of artificially contaminated polymer insulators

The results of clean-fog tests on two polymer insulator types indicate that both EPDM/silicone alloy and silicone rubber insulators performed about the same in slurries composed of Kaolin with and without NaCl salt regardless of the NSDD (non-soluble deposit density) levels. Although the surface of silicone rubber insulators was slightly more hydrophobic than the EPDM/silicone alloy insulators (contact angle for silicone rubber was about 10 degrees higher), there was practically no difference in the flashover strength between the two materials.