Disconnector for surge arrester

Abstract

A disconnector for a surge arrester explosively separates an electrical lead wire, normally a ground lead wire, from the arrester to prevent a permanent fault and to provide an indication of a failed arrester. The disconnector includes an elongated, frangible insulating housing having an elongated opening disposed along and parallel to the longitudinal axis of the insulating housing; a first electrically conductive terminal disposed at a first end of the opening; a second electrically conductive terminal disposed at a second end of the opening; means for forming an arc gap disposed between the first and second terminals, including an arc gap spacer and an arc electrode being either generally flat or including a raised portion; and an explosive cartridge disposed between the first and second terminals and in contact with the arc electrode. The metallic casing of the explosive cartridge holds an explosive charge and may include a generally flat surface parallel to the longitudinal axis of the explosive cartridge for contacting a generally flat surface of the arc electrode, thereby providing means for controlling the transfer of arc generated heat to the explosive charge to assure that the explosive charge will forcefully explode to separate a ground lead wire from a damaged surge arrester.