GB389657A - Improvements in and relating to isolating arrangements for enclosed electrical apparatus - Google Patents

Abstract

389,657. Switchgear structures ; high-tension switches. INTERNATIONAL GENERAL ELECTRIC CO., Inc., 120, Broadway, New York, U.S.A.-(Assignees of Allgemeine Elektricitõts-Ges.; 2, Friedrich Karl-Ufer, Berlin.) April 7, 1932, No. 10022. Convention date, April 8, 1931. [Class 38 (v).] Cases; earthing parts of.-For isolating enclosed switches, transformers, choke coils, or other apparatus, the lead-in insulator or insulators are provided on their upper ends with movable contacts and are rotatably mounted about their axes. In a three-phase power switch having oil, gas, or liquid quenching medium, the insulators 2, 3 are connected by arms 13 and links 19 to an operating member 18 arranged inside (as shown) or outside the tank, and each carries a knife-blade 7 normally engaging a contact on an insulator, as 9, 20. Back-contacts 16 are provided on two phases so that in the isolating position, Fig. 4, all phases are connected together and earthed at 17. Where a common operating means for the main and isolating switches is not provided, a suitable interlock may be arranged by mounting the fixed contacts 4, 5 of the main switch eccentrically, so that in the isolating position they assume the position 4<1> in which no closure of the main contacts can be effected. Similarly, opening of the isolating contacts is prevented when the main switch is closed. The rotational movement of the insulators may be combined with longitudinal movement whereby their lower flanges press against the underside of the tank cover in the closed position and seal the tank. In certain cases only the supply side of the apparatus may be isolated. Specification 329,020, [Class 38 (v), Electric switches &c.], is referred to.