Natural and accelerated aging of non ceramic insulators: leakage current and surface characterization

Natural and laboratory aged insulators were characterized in order to evaluate the surface degradation. Emphasis was given to the comparative study between different materials used as weathershed, i.e., silicone, EPDM, epoxy and polyethylene. It was observed that under severe conditions of salinity, epoxy insulators suffered from loss of hydrophobicity besides have failed in the 1000 hours salt fog test. EPDM and polyethylene insulators suffered from loss of hydrophobicity but passed in the 1000 hours salt fog test and showed low leakage currents. Silicone insulators did not show loss of hydrophobicity and showed low leakage currents along the 1000 hours salt fog test.