Application Considerations for Gapped Silicon-Carbide Arresters Currently Installed on Utility High Voltage Installations

Utilities have expressed concern recently about the electrical integrity and performance capability of the large number of gapped silicon-carbide arresters that they currently have installed on their operating system. These arresters, manufactured from the early 1950s thru the late 1970s, were the state-of-the-art overvoltage protection device at the time they were installed. While these gapped silicon-carbide arresters have a good service history, current state-of-the-art metal oxide arresters provide an opportunity to upgrade arrester performance and improve service reliability. This paper discusses some of the issues that should be addressed in evaluating these arrester installations