GB636276A - Improvements in and relating to tar-changing switches for regulating electrical apparatus - Google Patents

Abstract

636,276. Regulating switches ; oil-break switches. SMIT & CO.'S TRANSFORMATORENFABRIEK N.V., W. Oct. 20, 1947, No. 27997. Convention date, Oct. 23. 1946. [Class 38 (v)] The tap-selector of a tap-changing switch is structurally combined with a circuit-breaker, such that as the selector moves over the tap contacts, the circuit is opened and closed by the breaker and not by the selector. Fig. 1 diagrammatically shows a selector 1 movable over bevel-ended contacts 3a ... 3c so as to close and open the breaker 2, respectively, after and before it engages and disengages the contacts 3a ... 3c. Figs. 10, 11 illustrate one phase of a transformer tap-changing switch comprising an oil-filled cylinder 8 carrying two rows of six contacts 3, the contacts 3 of the same potential being situated above each other and connected by strips 17. A further oilfilled cylinder 5 rotatably mounted by a bearing 11 in the cylinder 8 carries angularly-displaced circuit-breakers 1, 2, each having tap selector rollers 6 co-operating with a row of contacts 3. The contacts of the breakers 1, 2 are joined through connections 16 and a spiral resistor 4 on the cylinder 5, and the breaker 1 is connected to the outgoing line through further connections 16, collector 21, and contact ring 7. In a multi-phase switch, the breakers of each phase are mounted above each other, The arcing products of the circuit-breakers 1, 2 escape through vents 20 of the extinguishing chambers into the cylinder 5 and since the oil of this cylinder is separate from the oil of the cylinder 8, only the former oil requires periodic replacing. Further, the cylinder 5 together with the breakers 1, 2 and current collector 21 can be removed as a whole for inspection purposes. The Specification also describes the application of the invention to other arrangements of tapchanging switches and to selectors for duplicate bus-bars (Figs. 2-9, not shown). The Specification as open to inspection under Sect. 91 also included the subject-matter of Specification 636,312. This subject-matter does not appear in the Specification as accepted.