Sequential isolating circuit breaker and actuator

A sequential isolating circuit breaker comprising a vacuum interrupter and an isolator in series combination between two terminal connections, a single actuator drive link coupled to the vacuum interrupter and to the isolator via an end mechanism, wherein said actuator drive link and said end mechanism are arranged so that:

• upon operation of the actuator drive link to close the circuit breaker, the end mechanism first closes a contactor of the isolator and subsequently closes a contactor of the vacuum interrupter;
• and
• upon operation of the actuator drive link to open the circuit breaker, the end mechanism first opens the contactor of the vacuum interrupter and subsequently opens the contactor of the isolator;
• and wherein:
• the isolator contactor comprises an arm which is pivotable about a first end thereof to subtend a first arc of first magnitude to open or close the isolator, and pivotable about an opposite, second end thereof to subtend an arc of second magnitude, the magnitude of the first arc being greater than the magnitude of the second arc and the pivoting action through each of the first and second arcs being generally sequential;
• the actuator drive link being directly coupled to the arm such that movement of the arm through said arc of second magnitude causes said opening or closing of the vacuum interrupter, the positioning of the coupling of the actuator drive link to the arm determining the relative speed with which the isolator contact and the vacuum interrupter contact close.