ROTARY PUFFER SWITCH

摘要

A puffer switch has a cylindrical shell filled with an electrically insulating gas, such as sulphur hexafluoride. A plurality of spaced parallel plates cooperating with the shell for defining a separate compression chamber or volume for each phase of an electrical power circuit that is to be switched. Located in each volume is at least one set of contacts which are subject to arcing as the contacts open or close. A movable contact in each of the sets of contacts has an associated impeller blade which is mounted to rotate with the movable contact and to sweep through the volume for compressing insulating gas in front of the impeller blade. A nozzle associated with the impeller blade directs the compressed insulating gas onto the set of contacts at a point where the arc is possible. The switch is assembled in a low cost manner by supporting spaced parallel plates defining the volumes between them as a slip-in unit which fits into a shell. A thermosetting plastic is used for parts which become hot. A lower cost thermoplastic is used for most parts which do not become as hot.