Gec-alsthom Limited

John Stanley Stewart

Carl Christopher Ennis

Roy Clarke

A vacuum recloser in which an isolator switch is incorporated in series with the vacuum interrupter and is driven by the same actuator. The isolator must only be operated when the vacuum switch is open and no arc current remains. This is ensured in one of two ways (a) by providing a significant lost motion in the isolator drive, giving, say, 20 milliseconds between opening of the vacuum contacts and opening of the isolator contacts, and (b) by latching the isolator drive against opening, compressing a spring against the latch by the actuator attempting to open the isolator, and tripping the latch by a solenoid responsive to lock-out conditions.

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Wilmslow, United Kingdom

John Stanley Stewart