Progress report on failures of high voltage bushings with draw leads

Abstract

Over the past several years, several bushings equipped with draw leads have failed in service. These bushings are not isolated to a single manufacturer and all of them have passed standard routine and type tests. A common characteristic of each failure is the arcing marks found between the draw lead cable and the tube in the center of the bushing. Most of the bushings also failed violently, in that the bushing exploded and caused a fire.