GB788942A - An arrangement for testing electric circuit breakers - Google Patents

Abstract

788,942. Testing circuit breakers. LICENTIA PATENT-VERWALTUNGSGES. Dec 23, 1954 [Jan. 11, 1954; Jan. 11, 1954], No. 37179/54. Class 37. In apparatus for testing circuit breakers by the Weil method wherein a test breaker Sp is supplied with high current from a generator G through a current-limiting reactor Ds and an auxiliary current breaker Sh in series, which opens together with the test breaker, a highvoltage oscillatory current is applied to the test breaker gap shortly before expiry of the last current wave by triggering controlled spark gap F to discharge a capacitance C (charged from a high-voltage unidirectional source) into inductance L and recovery voltage adjusting capacitance Ce in series with Rd; and any flashover of the auxiliary breaker Sh due to the recovery voltage developed by the high natural fre- quency of the high current supply circuit G and Ds is prevented by shunting a capacitance Cp across the output thereof in series with a normally open breaker S, which closes simultaneously with the opening of Sp. The capacitance lowers the natural frequency and the rate of rise of the recovery voltage of the high current supply circuit, and a further capacitance Cs in series with resistor Rs and spark gap Fs adjusted to conduct at a preset voltage, is shunted across the generator to absorb and damp put peaks of voltage greater than a predetermined value, so that protection is provided against voltage impulses derived from failure of breaker S and capacitance Cp to prevent flashover of breaker Sh. Specification 788,548 is referred to.