Evaluation of RTV coating for station insulators subjected to coastal contamination

Measurements and analysis of contaminant samples from a nuclear power station which has suffered flashovers due to wind-swept salt spray are presented. The results of a program of laboratory tests on artificially contaminated porcelain station insulators, with and without a room temperature vulcanized (RTV) silicone rubber coating, are reported. Data from clean fog and salt mist tests are used to determine the improvement in flashover voltage level over a range of high contamination severity on RTV-coated insulators. Visual observations and leakage current measurements made during surface discharge activity are utilized to demonstrate the influence of the RTV coating on discharge behavior. Switching impulse test results are also presented