Practical Application of the Oil Blast Principle of Circuit Interruption

The oil-blast principle of circuit interruption may be applied to oil circuit breakers of many types which cover a wide range of service, voltage and interrupting requirements. Although the mechanical construction and configuration of the interrupting elements varies widely for varying requirements, nevertheless the same principle of operation applies. It is shown that the oil-blast utilized for efficient arc extinction may be produced electrically by decomposition of oil or mechanically by a spring driven piston in an oil cylinder. Whichever of the two methods is employed, comparable performance results. Several types of breakers which operate on the oil-blast principle are described and test data given. In all designs of breakers on which the new principle has been used, marked reductions in arc duration and arc length result, even at the higher rates of recovery voltage rise. The principle is therefore applicable to breakers of the high speed type.