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SELECTIVE ELECTRONIC TRIGGER APPLIED IN A CURRENT SWITCH.
SELECTIVE ELECTRONIC TRIGGER APPLIED IN A CURRENT SWITCH.
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机译:应用于电流开关中的选择性电子触发器。
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摘要
An electric current-limiting circuit breaker comprises a pair of separable contacts and a selective solid state trip unit including an actuator cooperating with a latch mechanism for actuating the contacts to a positive open position upon occurrence of an overcurrent condition. The movable contact may also be moved by electrodynamic repulsion towards the open position when the fault current exceeds a predetermined threshold to effect current limiting. A tripping control device has an electronic counter which counts successive opening and closing cycles of the contacts so as to trip mechanism after a given number of cycles. The trip unit further comprises a first time delay tripping circuit, and a second instantaneous tripping circuit which cooperates with the cycle counter so as to ensure either instantaneous tripping or tripping by counting up to a number of cycles preselected on a setting selector.
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