Protective coatings for improving contamination performance of outdoor high voltage ceramic insulators

This paper presents an overview of the practices employed by utilities and industries to combat the contamination problem with ceramic insulators. It emphasizes two popular methods, namely, coating insulators with greases and RTV (room temperature vulcanizing) silicone rubber coatings. The experience to date, application methods, user concerns, current theories on how and why the coatings perform, life expectancy, and future direction of the technology, are outlined. The paper also describes research activity in the committee on RTV coatings, which is the state of the art in protective coatings. >