Patent ID: 7141751

Claim:
A breaker for providing successive trip mechanism based on a PTC (Positive Temperature Coefficient) current-limiting device, the breaker comprising: a first switch having a first fixed contact point and a first movable contact point; a second switch having a second fixed contact point and a second movable contact point and connected to the first switch in parallel; a PTC current-limiting device connected to the second switch in series and to the first switch in parallel, the PTC current-limiting device allowing a change of current flow direction from the first switch to the second switch when a fault current occurs; a movable arm to which the first and second movable contact points are installed at a predetermined interval therebetween, the movable arm opening/closing the first and second switches by operating the first and second movable contact points; a fixed arm including a first fixed arm conductor for guiding current flow toward the first fixed contact point in a normal load current mode, and a second fixed arm conductor for guiding current flow toward the second fixed contact point via the PTC current-limiting device in a fault current mode; and a successive trip means for elastically biasing the second switch by means of an operation of the movable arm in a closing direction when the first and second switches are closed, the successive trip means successively tripping the first and second switches using a time taken for releasing the elastic bias of the second switch when the movable arm is operated in a tripping direction.