Driving of circuit protector with contact bridge magnetically actuated - delaying opening and closing of bridge upon short circuit until contact surfaces have cooled sufficiently to prevent sticking

摘要

A method of driving a circuit protector whose movable contact bridge (8) has a remote controlled magnetic actuator (28). When a short circuit occurs, the short circuit current produces a magnetic force which opens the contacts (4-7). After the contacts have been opened, their movement is inhibited by an electromagnetic inhibitor (20). Thus, opening and closing of the contact bridge (8) is delayed. The contacts (4-7) are closed again when the contact surfaces have cooled sufficiently to stop them fusing together. ADVANTAGE - A simple system which reliably prevents the fuse contacts from fusing together in the case of short circuiting.