GB236293A - Improvements in or relating to electric circuit breakers - Google Patents

Abstract

236,293. Wedmore, E. B., and British Electrical & Allied Industries Research Association. April 5, 1924. Oil-switches; magnetic blow-outs. - Means are provided in a circuit-breaker so to proportion the effective magnetic field, namely that due to current flowing in the arc and in conductors associated therewith, with or without the association of a tank or other magnetizable body, in relation to the speed at which the contacts are separated that rupture of the circuit is obtained with substantially a minimum liberation of energy in the breaker. In Figs. 1 and 2, the conductor 10 has two breaks 15, 16 and in series therewith is a loop 11 - - 14, of which the conductors 11, 13 are adjacent the breaks, the arrangement being that the force exerted by the iron oil tank on the arc is almost equal to chat exerted by the conductor in the opposite direction, the resultant force being small. In Fig. 1, the parallelism of the conductors 12, 17 tends to prevent undue acceleration of the latter due to magnetic effects. In Figs. 3 and 4, magnetic masses 20, 22, attached to insulators 21, 23, are used, and the plate 24 in Fig. 3 serves to prevent the undue acceleration of the conductor 17. According to the Provisional Specification a multiple-break circuit-breaker having consecutive breaks located near together at which parallel arcs are drawn has its contacts staggered for the same purpose.