Impact of RTV Silicone Rubber Coating on Outdoor Insulators Performance Under Various Conditions

Coastal regions experience salt fog formation due to wave and tidal motions. This fog adheres to insulators, increasing surface conductivity and accumulating pollutants. Consequently, this leads to increased leakage currents and the potential failure of insulators over a period of time. This study investigates how the application of room temperature-vulcanized (RTV) silicon rubber (SiR) coating affects the hydrophobicity, insulation resistance, and leakage current of outdoor insulators under various environmental conditions. Hydrophobicity tests show that coated insulators have better water repellency, achieving hydrophobicity class 1 (HC 1) in clean conditions and HC 2 in polluted conditions, whereas uncoated insulators only reach HC 3. Insulation resistance measurements demonstrate that insulators coated with RTV SiR have significantly greater resistance than those that are uncoated, especially in polluted conditions. The leakage current tests show that the RTV SiR coating significantly reduces both leakage current intensity and total harmonic distortion (THD) under all test conditions. The coated insulators consistently showed lower cross-product values, even in harsh situations like salt fog, while the uncoated insulators had flashover at 50 kV. The results emphasize the significance of using RTV SiR coatings to improve the reliability and effectiveness of insulators under challenging conditions.