Development of New Semiconductive Glaze Insulators

Development of a new porcelain suspension insulator with a semiconductive glaze and improved shape is described. The development was carried out jointly by Ontario Hydro and Canadian Porcelain Company. These new insulators provide considerably improved performance under wet and contaminated conditions and thus allow the reduction of insulator string lengths, facilitating conversion of existing 115 kV lines to 230 kV operation, and development of compact high-voltage transmission line designs.