| abstract |
A varistor 50 comprising: a feed-through conductor 52 and a varistor disc 72 interposed between, and electrically connected to, conductor layers disposed on opposite surfaces of the varistor disc 72, the conductor layers being electrically isolated from one another; wherein the varistor disc 72 comprises a through aperture 60 through which the feed-through conductor extends; a first one of the conductor layers is electrically connected to the feed-through conductor; a second one of the conductor layers is, in normal use, permanently electrically connected to ground the varistor 50. This configuration enables one side of the disc 72 to be connected to the feed-through terminal, and the other side of the disc 72 to be connected to a ground plane, such as an earthed bulkhead of a wall or cabinet, via a metal plate forming part of the varistor 50 housing. |