Abstract: A molded case circuit breaker having a contact on mechanism which can perform a trip operation and automatically rotates the handle to the on position or a position toward the on position if the handle is manipulated to move to the off (or reset) position in a state that the contacts are melt-adhered to each other, the contact on mechanism, including: a contact on plate which is vertically movable by being guided according to the operation of the switching mechanism, a trip bar that drives the restricting unit to a releasing position, a lever connected to the handle and that provides a pivot point of the handle, a lever pin fixed to the lever, for driving the restricting unit to the releasing position by pressing the trip bar, and thereby operating the switching mechanism to the trip position, and a trip spring providing an elastic driving force for enabling the switching mechanism to operate to the trip position when the restricting unit is moved to the releasing position.

Abstract: Disclosed herein is an abnormal current detection circuit for circuit breaker, comprising a full-wave amplifier, a positive wave-period comparator for comparing a positive wave-period amplification voltage signal with a positive wave-period reference voltage signal to output a pulse signal, a negative wave-period comparator for comparing a negative wave-period amplification voltage signal with a negative wave-period reference voltage signal to output a pulse signal, a combining circuit for combining pulse signals outputted from the positive wave-period comparator and the negative wave-period comparator to output a full-wave combining signal, a reference voltage generator for generating a reference voltage signal, and a comparative driving circuit section for comparing the combining signal with the reference voltage signal to output a signal for controlling a circuit breaker to be driven to a circuit breaking position when the combining signal is greater or equal to the reference voltage signal.

Abstract: A withdrawable device of a vacuum circuit breaker for transferring a vacuum circuit breaker received in a cradle, includes: a carriage on which the vacuum circuit breaker is loaded; a first transfer unit fixed to the carriage; a second transfer unit installed at one side of the cradle such that it can be driven, and transferring a transfer force to the first transfer unit; and a transfer limiting unit for selectively limiting driving of the second transfer unit.

Abstract: A water-cooling type cooler and an inverter employing the same are disclosed. A guide pin for distributing cooling water is formed in the middle of a cooling water flow path having a bent face, to make a flow rate of cooling water at the bent portion of the cooling water flow path uniform to thus improve cooling performance of the water-cooling type cooler. In addition, because the cooling performance of the water-cooling type cooler is improved without extending the cooling pin, an increase in the weight of the water-cooling type cooler can be reduced and a fabrication cost of the water-cooling type cooler can be reduced.

Abstract: Disclosed is an interlock apparatus for a move-out type circuit breaker, capable of automatically discharging elastic energy charged in a closing spring and a trip spring when a main body of the circuit breaker is moved-in or moved-out, the apparatus including, a releasing protrusion member fixed to a predetermined position on a path that the circuit breaker is moved-in or moved-out and protruded upwardly from the predetermined position, an automatic releasing mechanism configured to be moved up by coming in contact with the releasing protrusion member upon moved-in or moved-out the circuit breaker to thereby drive a latching mechanism for latching the closing spring and the trip spring in a charged state to the release position.

Abstract: A method for adjusting a trip sensitivity in a thermal overload protection apparatus, including setting an adjusting reference point; measuring a normal position of bimetals; measuring a moving distance at a time of trip operation of a trip latch mechanism; deciding an assembling position of a shifter mechanism based on the measured moving distance at the time of trip operation of the trip latch mechanism, information on a trip distance between a pre-determined shifter mechanism and the trip latch mechanism and information on a size of the shifter mechanism; conducting a predetermined overcurrent to the thermal overload protection apparatus; measuring a conducting time of the overcurrent until a trip event; calculating a difference between the conducting time measured in the measuring step and a predetermined trip time by converting a rotation angle; and marking a graduation of a set trip operation current by the rotation angle calculated in the calculating step.

Abstract: Disclosed is an electrode for a vacuum interrupter, capable of reducing damage of contacts due to heat concentration to the center of the contacts, by reducing magnetic flux concentration to the center of the electrode, and capable of rapidly extinguishing an arc by diffusing the arc by forming a wide range of magnetic flux.

Abstract: Disclosed is a withdrawable device of main circuit for a circuit breaker. A ring-shaped guide recess is formed at a central part of a transfer nut screw-coupled to a lead screw, and supporting surfaces are formed on side surfaces of the guide recess. And, rotation prevention pins are elastically supported by springs in a moving direction of the transfer nut, and are selectively locked, thereby allowing the transfer nut to perform an idle operation. Accordingly, a structure for an idle operation of the transfer nut is simplified, and the number of components is reduced. An axial load is attenuated to a plane-contact distributed load, not a point-contact concentrated load, thereby preventing damage of the components. Also, a vacuum circuit breaker has enhanced reliability of the idle operation at a run position and a test position.

Abstract: Disclosed is a circuit breaker having a rebound preventor, the circuit breaker including, a main body, a fixed contact fixed to the main body, a movable contact contactable with or separated from the fixed contact and movably installed at the main body, a main shaft connected to one side of the movable contact and rotatably installed on the main body, a trip mechanism coupled to another side of the main shaft and configured to rotate the main shaft, and a rebound preventor having one end rotatably installed on the main body and provided with a stopping unit formed at another end thereof and engaged with the main shaft, wherein the rebound preventor is rotated with being engaged with the main shaft, and the stopping unit restricts a reverse rotation of the main shaft in a state where the rebound preventor has been rotated over a prescribed range.

Abstract: A run/test position indicator device of a vacuum circuit breaker includes: a position indication cam installed between a girder, a fixed body, and a main body of a carriage, a moving body, and rotating at a certain angle according to a change in the space between the girder and the main body of the carriage; and an indication member, to which the position indication cam is rotatably coupled, having a mark symbol to allow the position indication cam to indicate a run and test position of a main body of circuit breaker.

Abstract: An apparatus for preventing withdrawing and insertion of a carriage of a circuit breaker is disclosed. When a circuit breaker main body is inserted, an interlocking unit operates by interworking with the carriage withdrawing and inserting preventing apparatus, and while the circuit breaker is being closed, a withdrawal and insertion handle prevents a lead screw from being rotated by the interlocking unit. Thus, when the circuit breaker performs a closing operation, unnecessary withdrawing and inserting operation of the carriage is basically prevented to thus prevent various safety accidents, a contact resistance, a temperature increase, and damage to a device resulting from a breakdown.

Abstract: A modular terminal for a molded case circuit breaker by which various types of terminals can be joined together and configuration and assembly are simplified, the modular terminal comprising a plurality of terminal bases each of which is provided for each phase, a terminal which is detachably supported at each terminal base, and a joint piece which connects a pair of the terminal bases adjacent to each other to form a terminal module.

Abstract: Disclosed is a cylinder type bistable permanent magnetic actuator, the bistable actuator including, a cylinder formed by rolling a thin plate so as to form an inner space, a mover reciprocatingly installed within the cylinder in a lengthwise direction of the cylinder, first and second coils installed near both end portions of the cylinder, respectively, by interposing the mover therebetween, and a permanent magnet installed between the first and second coils.

Abstract: Disclosed is a circuit breaker having a cam rotation delaying function employed to block current, the circuit breaker performing a charging operation and a charting operation, the circuit breaker including a closing spring having one end portion rotatably coupled to each of plates, a driving lever rotatably installed at each of the plates and connected to another end portion of the closing spring so as to be rotated responsive to compression and extension of the closing spring, a cam rotatably installed at each of the plates and configured to press the driving lever for rotation, a link mechanism having a plurality of links rotatably installed at each of the plates and connected to the driving lever for operation, a movable contact rotatably installed at a side of each of the plates and contactable with a terminal by an operation of the link mechanism, and a cam delaying mechanism installed at each of the plates and configured to attenuate a rotational force of the cam due to a restoring force of the closing

Abstract: Disclosed is a trip mechanism for a circuit breaker, capable of maintaining a constant characteristic of a normal trip operation in spite of changes in installation angles of the circuit breaker including a horizontal installation, a perpendicular installation and an inclination installation, the trip mechanism including, a coil configured to generate a magnetic absorption force due to a fault current on a circuit, a stationary core fixed to a lower portion of the coil within the coil, a movable core movable down to the stationary core within the coil by the magnetic absorption force generated from the coil, and a trip lever rotatably to connected to the movable core so as to be pulled by the movable core when the movable core is downwardly moved and configured to trigger the switching mechanism such that the movable contactor is moved to an open circuit position.

Abstract: The present invention relates to a high-voltage gas circuit breaker, and there is provided a gas circuit breaker including a movable arc contact and a fixed arc contact engaged with the movable arc contact; a cylinder rod coupled with the movable arc contact; an insulating rod connected to the cylinder rod through a link mechanism in which an end thereof is connected to an operating mechanism; and an ejection nozzle for ejecting an arc-extinguishing gas between the movable arc contact and the fixed arc contact, wherein the link mechanism is reduced in a length direction of the insulating rod to pull the cylinder rod to a side of the insulating rod when the insulating rod is moved apart from the cylinder rod.

Abstract: Disclosed is a bushing terminal of a vacuum circuit breaker used for interrupting current, which includes: a terminal body having a cylinder that can be inserted into the interior of a contactor and annular protrusions formed to be protrude from an outer circumferential surface of the cylinder; and a flange having an insertion hole through which the cylinder is inserted, wherein the annular protrusions are plastic-deformed so as to be fixed to the insertion hole of the flange.

Abstract: Disclosed are a position indicating apparatus for a circuit breaker and a circuit breaker having the same. The circuit breaker having a position indicating apparatus comprises a cradle having a bus bar terminal and a load terminal; a main body having a bus bar connection unit and a load connection unit respectively connected to the bus bar terminal and the load terminal, and configured to be movable to a run position that the terminals and the connection units are connected to each other, and to a test position that the terminals and the connection units are separated from each other; and a position indicating apparatus configured to outwardly display a position of the main body by interworking with motion of the main body, wherein the position indicating apparatus comprises: a movable pin interworking with motion of the main body; and a display unit configured to display a position of the main body corresponding to a position of the movable pin by interworking with motion of the movable pin.

Abstract: Disclosed is a position indicating device for a pull-out type circuit breaker used to cut off a current, the position indicating device including a position indicating plate installed at a lower surface of the circuit breaker to be rotatable up and down and having an arrow marked thereon, an indication supporter installed at a cradle and having stepped pressing surfaces for pressing up the position indicating plate, and a frame portion of a movable carriage, the frame portion having windows for externally showing a rotated state of the position indicating plate, whereby when the circuit breaker is docked with the cradle, the position to indicating plate is rotated by the indication supporter so as to indicate the position of the circuit breaker through the windows, thereby allowing a fast and precise recognition of the position of the circuit breaker.

Abstract: Disclosed is a switching mechanism for a mold cased circuit breaker, capable of indicating a contacts status by a position of a handle.