| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a current-limiting circuit breaker that allows one operational handle to perform closing operation of a main contact and an auxiliary contact by placing the main contact and auxiliary contact comprised of a mechanical switch in the same housing. <P>SOLUTION: A current-limiting circuit breaker includes main contacts 11 for cutting off a three-phase cable way and a set of pairs of auxiliary contacts 12 arranged in series with each of the main contacts 11. The auxiliary contacts 12 each are connected with a diode and a snubber circuit in parallel and comprise an electromagnetic coil for an auxiliary contact 14 on each cable way for getting the auxiliary contact 12 on each cable way to perform open operation. If an abnormal current such as a short circuit current flows through a cable way L, operation of a plunger 28 provided in the electromagnetic coil for an auxiliary contact 14 will get the auxiliary contact to perform open operation to perform current-limiting operation, and also the main contact 11 will perform open operation to perform cutting-off operation. The auxiliary contact 12 is held in an open state by an engagement piece 29, and includes an engagement step part 31 for releasing a latch of the engagement piece 29 in response to the rotation in the closing direction of a main shaft 10 opening and closing the main contact 11. <P>COPYRIGHT: (C)2013,JPO&INPIT |
