GB366966A - Improvements in and relating to electric circuit breakers - Google Patents

Abstract

366,966. Arc - rupturing switches. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Soc. Generale de Constructions Electriques et Mechaniques Alsthom ; 146, Avenue des Champs Elysees, Paris.) Sept. 12, 1930, No. 27320. Convention date, Sept. 12, 1929. [Class 38 (v).] To enable a high-tension air-break switch 3 to open under load, it is shunted by an arrangement of spark-gaps 4, which, just prior to the opening of the switch 3, are supplied with high - frequency currents from a source 5 and thereby caused to break down. A part of the load is thus shunted through the gaps 4, leaving the balance to be dealt with by the switch 3. The diversion of load is assisted by a reactance 2, which also serves to prevent shorting the source 5 through the closed switch 3. In a modification, Fig. 2, a condenser 9 is adapted to be charged, for instance, by the secondary 7 of a transformer having its primary 6 in the line, and to discharge through a spark-gap 8 in series with the gaps 4, which spark-gap 8 serves to open-circuit the line when the switch 3 opens. With this arrangement, excess current on the line may be arranged to initiate the opening of the switch 3. In a further form, Fig. 3 (not shown), the reactance 2 is dispensed with, and the device 4 is arranged in two parts, the discharges through which are in opposition directions but have a common return. An arrangement similar to lightning arresters may be employed as the device 4, and the latter may also be arranged to be discharged across when the switch 3 is being closed.