A Multiorifice Interrupter for High-Voltage Oil Circuit Breakers

High-voltage oil circuit breakers for high-speed operation generally use some form of multibreak contact arrangement. These breakers perform satisfactorily but lack the simplicity of the conventional slower-speed two-break construction. The development of an unusually effective multi-orifice oil-flow interrupting unit now makes it possible to reduce the required number of breaks to the point where even three-cycle 230-kv breakers appear practical with only two interrupting units per pole. High-power laboratory tests on low magnetizing and charging currents, as well as. short-circuit currents corresponding to interrupting ratings of 2,500,000 kva and above, have demonstrated the exceptional arc-extinguishing effectiveness and low arc-energy dissipation of this multiorifice interrupter for high-speed oil circuit breakers.