GB387384A - Improvements in or relating to multi-phase metal-clad electric switchgear - Google Patents

Abstract

387,384. Switchgear structures. REYROLLE & CO., Ltd., A., Hebburn-on- Tyne, and MIRREY, J., Cairnsmore, Osbaldeston Gardens, Gosforth, Newcastleon-Tyne. Aug. 5, 1931, No. 22190. [Class 38 (v).] Horizontal draw-out pillar-type switchgear is provided with a quick-make switch mounted in the tank of the main circuit-breaker for connecting the fixed contacts on one side thereof together and to earth, so that the apparatus connected to such contacts (for instance, a trailing cable for use in mines) can be earthed without withdrawing the breaker. The contacts D<1> of all the phases carry contacts H which can be engaged simultaneously by the strap G<2> of a U-shaped switch member G<1> pivoted in the cover B2. The member G<1> is rotatable about its pivot by means of a shaft L<2> and links M', M<3>, the shaft being in turn operated from a handle K by means of a link L and lever L<1>. A dead-centre spring toggle N, N<1> ensures the quick action. The member G<1> is connected by means of a flexible conductor G<3> to a terminal J having a plug-and-socket connection with an earthing bar on the fixed part of the gear. Interlocks between the handle K and the handle F of the main breaker comprise cams K<1>, F<1 >so arranged as to prevent both switches being closed at once. A further cam K2 engages a latch O to move it into a recess A<4> on the runway A<3> to prevent withdrawal of the movable part (and consequent severance of the earth connection of the cable) when the earthing switch is closed. The latter may be locked in both the off position (shown in Fig. 4) and in the on position by means of a padlock P, which passes through a fixed arm P<1> and apertures in the cams.