Gas blast interrupter - uses initial contact movement to compress gas charge blasted between arcing contacts to decompressed chamber to extinguish arc

摘要

A gas blast interrupter has a pair of tubular inner arcing contacts (16, 18) and a pair of outer current carrying tubular contacts (38, 42). Each contact pair has a fixed and an overlapping movable contact, with the coaxial movable contacts (18, 38) defining a chamber divided by an immovable piston (28) into a gas compression chamber (32) and depression chamber (34). The interrupter is sealed in a container (10) of Sulphur Hexafluoride with the movable contacts axially movable in unison by a control rod (20) projecting through one container end wall (12). On opening, the movable contacts (18, 38) move an initial distance of 1" before the contacts open causing arcing across the inner contacts (16, 18), compressing the compression chamber gas, both chambers being sealed. Opening of the contacts opens the compression chamber (32) and orifices connecting this through the hollow inner movable contact (18) with the depression chamber (34). The sudden blast of gs extinguishes the arc between the inner contacts.