Leakage current and charge in rtv coated insulators under pollution conditions

Room temperature valcanizing (RTV) silicone rubber caoting has excellent leakage current suppression characteristics. It is used extensively on porcelain and glass insulators in pollution prone areas as an anti-pollution measure. A pollution aging chamber has been fabricated and an on line 4 channel personal computer (PC) based data acquistion system has been developed to conduct tests on RTV coated porcelain samples. A study of the floe rate, conductivity and pressure of the solution forming the fog is reported. It was observed that a higher charge and a highre average leakage current were obtained at a higher flow rate and a higher conductivity. The results with coated HV insulators are consistent with those published in the literature with RTV caoted fiber glass reinforced plastic (FRP) rods.