1. Field of the Invention
This invention relates to circuit breakers having thermally adjustable trip means.
2. Description of the Prior Art
The conventional thermal tripping mechanism of a circuit breaker is well known in the art and consists mainly of a movable trip bar which carries a releasable latch. As shown in U.S. Pat. No. 3,211,860, the trip bar is actuated by adjacent bimetal strips which respond to temperature generated by an overload current flowing to the circuit breaker. The circuit breaker of the type shown in that patent is a fixed calibrated circuit breaker which is set for a given amperage rating which has been conventional for the circuit breaker used in some countries such as the United States. In other countries there is a preference for manually adjustable thermal tripping devices to change thermal rating of the circuit breaker to suit load requirements.