Application of Insulators in a Contaminated Environment

The application and maintenance of outdoor ceramic insulation on overhead transmission systems has been an art learned by experience. This document combines the experiences of electric utilities, manufacturers, and research laboratories into a single comprehensive report on the design and maintenance of transmission insulation in a contaminated environment. It is intended as a practical reference and guideline to be used by all electric utility engineers and operating personnel. The reader will find a short description of contamination flashover, followed by detailed sections on site severity measurement, test procedures, design practices and maintenance practices. The emphasis in this report is on power frequency voltages, but some occasional references to overvoltages and dc are also made.