GB477702A - Improvements in liquid break electric circuit breakers - Google Patents

Abstract

477,702. Liquid - blast switches. BRITISH THOMSON-HOUSTON CO., Ltd., GOODALL, J. M., and COX, H. E. July 22, 1936, No. 20341. [Class 38 (v)] An explosion-chamber type circuit-breaker has the interior of the chamber subdivided by a transverse partition having an aper-. ture through which the movable contact passes to engage the fixed contact, venting apertures being provided in a region remote from the partition and venting orifices being made through the chamber-wall at either side the partition which provide restricted outlets for the products of the arc to flow in a direction transverse to the axis of movement of the movable contact, the venting apertures having an area comparable with that of the orifices. In Fig. 1 (Comp.) a contact structure 3 as described in Specification 477,691 is mounted in a preferably metal cylinder 6 secured to the upper cover of, and carrying the lower part of, the explosion chamber. The lower part comprises an assemblage of insulating rings 7, bottom cover 8, the plate 12 constituting the transverse partition, and plates 16, 17, 20. Plate 12 is centrally apertured to admit the movable contact 11, and the plates 20 are suitably shaped to provide the venting orifices 13, 14. Plates 16, 17 serve to direct the arcproducts across the axis of movement of 11, the former being cut away at 19, and the latter apertured at 18 to allow liquid to be moved across the arc by the pressure in the lower part of the chamber. Venting apertures are shown at 15 for the upper part, whereas for the lower part, aperture 10 for contact 11 is made large enough to provide the necessary clearance. In Fig. 1 (Prov.), 4 is the partition, 5 are the orifices, and 6, 7 are the apertures. The apertures are stated to allow liquid to escape so that a gas bubble at high pressure forms on the side of the arc remote from the orifices. Figures are given for a breaker of 750,000 kVA rating.