Medium to high voltage load circuit interrupters including metal resistors having a positive temperature coefficient of resistivity (PTC elements)

Abstract

A medium to high voltage load circuit interrupter and method for breaking the flow of electric current in a line having a load and a source. A main switch is connected in series with the line. A metal resistor having a positive temperature coefficient of resistivity (PTC element) is connected in series to the arcing switch, wherein the metal resistor and arcing switch are connected in parallel with the main switch. The main switch moves from the closed position to the open position prior to the arcing switch moving from the closed position to the open position. The circuit interrupter further includes an arc chute having a channel and electrically coupled to the arcing switch wherein the arcing switch is positioned within the channel when the arcing switch is in a closed position. In one embodiment, the PTC element is positioned on an insulator positioned between a ground and the main switch and an arcing switch. In another embodiment, the PTC element is positioned within a channel in the arc chute. The PTC element is, for example, in the shape of a serpentine, and is comprised, for example, of a pure metal such as pure tungsten, iron, tantalum or chromium.

Dependencies are inferred from the claim text.