Abstract: Disclosed is a breaker for providing successive trip mechanism based on PTC current-limiting device, which includes a first switch having first fixed/movable contact points; a second switch having second fixed/movable contact and connected to the first switch in parallel; PTC current-limiting device connected to the first and second switches in parallel or series and allowing a change of current flow direction from the first switch to the second switch at a fault current; a movable arm to which the movable contact points are installed at an interval therebetween and opening/closing the switches by operating the movable contact points; a fixed arm including first and second fixed arm conductors for guiding current flow toward the first fixed contact point in a normal load current mode and 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 operation of the movable arm in

Abstract: Disclosed is a breaker for providing successive trip mechanism based on PTC current-limiting device, which includes a first switch having first fixed/movable contact points; a second switch having second fixed/movable contact and connected to the first switch in parallel; PTC current-limiting device connected to the first and second switches in parallel or series and allowing a change of current flow direction from the first switch to the second switch at a fault current; a movable arm to which the movable contact points are installed at an interval therebetween and opening/closing the switches by operating the movable contact points; a fixed arm including first and second fixed arm conductors for guiding current flow toward the first fixed contact point in a normal load current mode and 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 operation of the movable arm in

Abstract: Disclosed is a PTC (Positive Temperature Coefficient) current limiting device for limiting a current by use of PTC characteristics, which includes a PTC element having the PTC characteristics; a pair of electrode units arranged on both sides to face each other with the PTC element being interposed therebetween; and a molding part prepared around the PTC element and the electrode units to surround at least an interface region between the PTC element and the electrode units, the molding part being made of elastic insulating material. The molding part is made of an elastic insulating material or any insulating materials selected from vacuum, gas and oil. Thus, this device may effectively restrain an arc generated while limiting overcurrent or short circuit current, and also prevent flashover between electrodes.

Abstract: Disclosed is a PTC (Positive Temperature Coefficient) current limiting device, which limits a current using PTC characteristics. The device includes a PTC element having the PTC characteristics; and upper and lower contact electrodes arranged to face each other with the PTC element being interposed therebetween, wherein, assuming that a distance from an end of the upper contact electrode to an end of the PTC element is a1, a distance from an end of the lower contact electrode to the end of the PTC element is a2, a thickness of the PTC element is b, and L=a1+a2+b, the following equations are satisfied: V/L<10 and V/b<50, where V is a rated voltage of the PTC current limiting device, a unit for a1, a2 and b is mm, and a unit for V is volt. This PTC current limiting device may prevent generation of flashover between electrodes.