Round robin testing of RTV silicone rubber coatings for outdoor insulation

This paper presents the results of round robin tests performed to evaluate the electrical performance of room temperature vulcanizing (RTV) silicone rubber coatings used for improving the contamination performance of outdoor ceramic insulators. The tests, performed in six different laboratories, included several salt-fog chambers and a tracking wheel. Most test facilities were equipped with an online data acquisition system for measurement of leakage current activity. Four generic formulations of RTV silicone rubber coatings applied on ceramic rods were evaluated. The results indicate a general consensus in the ranking of the coatings' leakage current suppression capability, despite the variation in the experimental conditions employed. This suggests that guidelines for a laboratory test for evaluating the RTV coating material's electrical performance under contaminated conditions could be developed.