Development and Application of a New Semiconductive-Glaze Insulator

The development and application of a new bell-shaped porcelain suspension insulator with a semiconductive-glaze is described. The new design developed jointly by Ontario Hydro and the Canadian Porcelain Company, provides a significant improvement in insulation strength over conventional porcelain insulators under wet and contaminated conditions. The higher insulation strength facilitates line compaction, reduces contamination problems on existing lines, and allows novel applications including line conversions to higher voltages and increased current loadings.