Abstract: A high voltage open-air switch has a movable disconnect switch blade which contains a circuit interrupter therein having interrupter contacts in series with the open air disconnect switch contacts. The circuit interrupter has a lower BIL rating than the switch. An operating mechanism causes the independent operation of the interrupter and disconnect switch such that there is a high speed opening of the interrupter contacts, followed by the low speed opening of the disconnect switch contacts, and a slow speed closing of the disconnect switch contacts followed by the high speed closing of the interrupter contacts. The switch can be adapted to numerous switch configurations and permits substantial savings in space by the reduced mounting space requirements for the interrupter assembly.

Abstract: A vaporizable material, for example, a silicone, that is buried beneath the surface of a Teflon nozzle for a sulfur hexafluoride power circuit breaker in an area of the nozzle which is exposed to abrasion and wear due to arc products. In a similar manner, aluminum or titanium or some other vaporizable material is buried beneath the surface of the contact of the circuit interrupter which is exposed to abrasion and wear. When the buried layers are exposed due to abrasion of their covering surfaces, these materials will be vaporized and their presence will be sensed by sensors within the circuit interrupter, thus revealing some predetermined degree of wear of the surfaces of the nozzle and contact and other surfaces within the circuit interrupter which may also be subject to abrasion by arcing or arc products. When aluminum is used as the vaporizable material for the contact, it also senses the presence of flashover to aluminum exterior housings.

Abstract: A fuse assembly for an electrical cutout is provided with capability for rapid arc extinction by a capsule of pressurized insulating gas being located within a fuse tube above the fusible element so that when the fusible element melts and an arc is produced, gas is released from the gas cylinder that quenches and cools the arc and also assists a spring loaded flipper mechanism in expelling a lower conductor from the fuse tube.