Abstract :
DEVELOPMENTS in theory, calculation, and test results of circuit interruption by means of the oil blast, have placed new tools in the hands of designers, enabling them to construct apparatus of greater efficiency and consistency of performance than heretofore possible. Various applications of these new methods have been made to circuit breakers of all classes and voltages. Circuit breakers equipped with the oil blast device show consistently short arc lengths and unusually short periods of arc duration, even at high rates of recovery voltage rise and over wide ranges of current. The result of this is that contact burning and oil deterioration are minimized and maintenance is greatly reduced. The rapid arc extinction characteristic of the oil blast design makes it admirably suited to breakers requiring high speed of operation.
