Abstract: A molded case circuit breaker includes a switching mechanism and a current-interrupting section. The current-interrupting section is composed of an insulated case, fixed contact shoes arranged diagonally opposite to each other, a bridging rotary contact shoe, a contact shoe holder, and arc extinguishing devices. The fixed contact shoes are composed of linear contact shoe conductors to reduce a height of the section, and the fixed contact shoes are arranged vertically in parallel and opposite each other so that the fixed contact shoes and the rotary contact shoe form a Z-shaped conducting path.

Abstract: A circuit breaker includes a housing; separable contacts mounted in the housing; and an operating mechanism for opening and closing the separable contacts. An overcurrent assembly is responsive to selected conditions of current flowing through the separable contacts and actuates the operating mechanism to trip open the separable contacts. A bonnet forms a U-shape which surrounds the separable contacts and which cools and splits an arc when the operating mechanism trips open the separable contacts. A first bonnet piece forms a first leg of the bonnet, and a second bonnet piece forms a second leg and a base of the bonnet.

Abstract: A circuit breaker having a safe construction, where no electrically charged portions are exposed in an accessory installation area or anywhere outside a main circuit case even if a cover of the circuit breaker is opened in a live condition. In order to achieve above object, the circuit breaker of this invention includes the main circuit case made of an insulating material, and an opening-closing trip mechanism disposed outside of the main circuit case and electrically insulated from the main circuit. According to this invention, a circuit breaker capable of eliminating the risk of an electric shock, thereby providing the excellent safety can be obtained.

Abstract: A molded case circuit breaker includes a switching mechanism and a current-interrupting section. The current-interrupting section is composed of an insulated case, fixed contact shoes arranged diagonally opposite to each other, a bridging rotary contact shoe, a contact shoe holder, and arc extinguishing devices. The fixed contact shoes are composed of linear contact shoe conductors to reduce a height of the section, and the fixed contact shoes are arranged vertically in parallel and opposite each other so that the fixed contact shoes and the rotary contact shoe form a Z-shaped conducting path.

Abstract: A circuit breaker includes a housing; separable contacts mounted in the housing; and an operating mechanism for opening and closing the separable contacts. An overcurrent assembly is responsive to selected conditions of current flowing through the separable contacts and actuates the operating mechanism to trip open the separable contacts. A bonnet forms a U-shape which surrounds the separable contacts and which cools and splits an arc when the operating mechanism trips open the separable contacts. A first bonnet piece forms a first leg of the bonnet, and a second bonnet piece forms a second leg and a base of the bonnet.

Abstract: In a circuit breaker, bag-like insulating covers 15 are formed integrally with each holder support 14. The holder support 14 is combined with a movable contact holder 13 for holding a movable contact 4, so as to press and retain the movable contact 4 by a contact spring 5. A pair of leg portions of a magnetic drive yoke 6 are inserted into each of the insulating covers 15. Thus, the magnetic drive yokes 6 are covered with the insulating covers 15 so that there is no risk of an interphase short-circuit. In addition, the magnetic drive yokes 6 are unitized with a movable contact mechanism so that the work of assembling the circuit breaker becomes easy.

Abstract: A blocking apparatus for blocking a contact structure from closing in a circuit breaker is provided. The apparatus includes a link extending from the circuit breaker and connected to a movable contact arm. The contact structure, being operated by an operating mechanism, remains in a separated position even when the operating mechanism is in the “ON” position due to the connection with the link of the blocking apparatus. A release assembly releases the link when it is desired to close the movable contact arm.

Abstract: The current-limiting mechanism is provided in particular in order to protect electromechanical contactors from being welded by a short-circuit load. In a first step, the current-limiting mechanism closes a bridging contact of a first bridging current path in order to reduce the current load on the contactor. In a second step, its bridging function is taken over by a switching arc and by a second bridging current path, In the further course of the disconnection process, the switching arc commutates from the bridging contact onto associated running rails or arc runners and runs into an arcing chamber of the current-limiting mechanism. As a result, the short-circuit is interrupted.

Abstract: A magnetic release system for a circuit breaker, the magnetic release system includes a contact structure; a strap configured to conduct a first level of electrical current and a second level of electrical current; a u-shaped collar having a pole face, the u-shaped collar disposed around the strap; a release lever disposed proximate the pole face, the release lever rotatably mounted on the strap; wherein the release lever is releasably engaged with the contact structure; and wherein the release lever prevents movement of the contact structure at the first level of electrical current and releases the contact structure at the second level of electrical current.

Abstract: A contact arrangement for a circuit breaker is disclosed. The movable and the stationary contacts within the breaker are each split and angled such that one contact forms a female V cross sectional shape and the other forms a mating male V cross sectional shape. Together, these contacts split the current in a manner which reduces the popping force.

Abstract: A circuit breaker rotary contact arm is used within a plurality of single pole modules ganged together to form a single multi-pole circuit breaker. To provide for use in quiescent conditions having high ampere ratings, low ampere rated rotary contact arm assemblies are combined in parallel to form a higher rated single pole module, which are then ganged together to form a single multi-pole circuit breaker having a high quiescent ampere rating.

Abstract: The present invention provides a current limiting circuit breaker having a current responsive device for opening a pair of contacts or switch upon short circuit conditions. The current responsive device utilizes an insulating object driven by a magnetic force caused by a short circuit current. Upon opening of the contacts with the use of the insulating object, let-through current flows through a secondary contact, positioned on the insulating object, to a positive temperature coefficient resistivity element which limits the current and arcing in the contacts. The PTC elements could be pure metallic materials such as pure tungsten, pure iron, etc. Conductive polymer and ceramic PTC materials could also be used for some specific applications. The present invention also provides a method of electrically connecting a drive plate and a line terminal on the current limiting circuit breaker.

Abstract: A switch device for switching an electrical connection between two connection parts is disclosed. Conventional switch devices comprise a contact lever having a switch contact, the flow of current taking place by way of the contact lever when the switch device is closed. To achieve a rapid switching process, a low mass inertia of the contact lever is required. However, this generally leads to a lower current capacity. By arranging the lever-side switch contact on a separate electrical connection device, it becomes possible to separate the function of current conduction from the function of contact guidance. Since the contact lever therefore no longer performs any current-conducting function, it may be optimized in mechanical respects exclusively.

Abstract: A circuit breaker assembly includes first and second rotary contact assemblies mountable to a base member, a circuit breaker operating mechanism mounted to the first rotary contact assembly, and a trip bar in mechanical communication with the first rotary contact assembly and the circuit breaker operating mechanism. The rotary contact assemblies each include rotors rotatable about axes therethrough and movable contact arms pivotally mounted within the rotors. The circuit breaker operating mechanism serves to position the rotors to separate movable contacts thereon from fixed contacts. A trip override device includes spring links operably connected via springs to each of the rotors of the rotary contact assemblies and the trip bar. The trip bar comprises trip levers protruding radially therefrom and being in mechanical communication with the rotary contact assemblies.

Abstract: A circuit breaker rotary contact assembly employs a rotor assembly to operate the moveable contact arms. Separate pivots are provided to the rotor assembly and the moveable contact arms to ensure that the contacts close prior to complete rotation of the rotor assembly. The additional rotation force provided by the rotor assembly then translates into lateral displacement of the moveable contacts relative to the fixed contacts, resulting in contact wiping function. An alternate embodiment utilizes a common pivot for both the rotor assembly and the moveable contact arms, while providing post closure motion by means of a fixed contact compression spring.

Abstract: A circuit breaker (10) including a stationary line bus assembly (47). The stationary line bus assembly (47)comprises a bus body (124) supported by support legs (132) with the bus body (124) having a first longitudinal end portion (125) and a second longitudinal end portion (126), with each end portion terminating at a common end portion (127). The second end portion (126) includes a stationary contact bus (46) in a spaced relationship from the first end portion (125). A line terminal (18) is mounted on the first longitudinal end portion (125) and a contact (44) is attached to the second longitudinal end portion (126). In one embodiment, a bus support (130) is attached to the bus body (124) in the space between the first end portion (125) and the second end portion (126) and separated from the support legs (132) of the bus body (124) by an insulating barrier (134). The stationary bus support (130) can have several configuration.

Abstract: Stationary contact structures for an electrical contactor include a base plate portion, a riser portion and a turnback portion. The riser portion extends substantially perpendicularly from the base plate portion and a stationary contact pad is disposed directly above the riser, reducing the occurrence of mutually opposing flux during closure of movable contacts in the device. A current carrying extension may extend beyond the riser for carrying current during steady state operation. In such case, separate current carrying paths are defined in the stationary contact for transient and steady state operation. The portions of the structure are formed by processes, such as extrusion, which permit the desired geometry to be obtained between the base plate and riser. The turnback portion may descend towards the base plate portion to introduce arcs into an elevated position in a splitter plate stack.

Abstract: A circuit breaker (10) including a stationary line bus assembly (47). The stationary line bus assembly (47)comprises a bus body (124) supported by support legs (132) with the bus body (124) having a first longitudinal end portion (125) and a second longitudinal end portion (126), with each end portion terminating at a common end portion (127). The second end portion (126) includes a stationary contact bus (46) in a spaced relationship from the first end portion (125). A line terminal (18) is mounted on the first longitudinal end portion (125) and a contact (44) is attached to the second longitudinal end portion (126). In one embodiment, a bus support (130) is attached to the bus body (124) in the space between the first end portion (125) and the second end portion (126) and separated from the support legs (132) of the bus body (124) by an insulating barrier (134). The stationary bus support (130) can have several configuration.

Abstract: A current limiting device includes first and second contact members, each contact member having, at a first end, contacts defining a contact pair; a contacting pressure is applied to said contact pair; and a cylindrical insulator cylindrically surrounding the contacts when the contacts are closed. The device is arranged such that at least one of the first and second contact members is rotatably supported at a second end. Also, an electrical path is defined through which currents flow in substantial opposition to the first and second contact members and in opposite directions to each other. The first ends of the first and second contact members are positioned within the space defined by the cylindrical insulator in the closed contact state. The contact of at least one of the rotatably supported contact members is positioned outside of the space defined by the cylindrical insulator when the contacts are open.

Abstract: A rotary contact circuit breaker employs a crank to couple a switching mechanism to the rotary contact pole structure. The use of a crank allows for the mechanism and pole structure the individually optimized without effecting the performance of the other. In particular the crank allows for a mechanism that is able to achieve maximum torque delivery to the pole structure.

Abstract: A circuit breaker rotary contact arm is used within a plurality of single pole circuit breakers ganged together to form a single multi-pole circuit breaker. To provide uniform contact wear among the associated circuit breaker contacts, the rotor carrying the rotary contact arm pivot is slotted to automatically position the rotary contact arm to allow for changes in the contact geometry while maintaining constant contact compressive forces. The individual circuit breakers connect with the central operation mechanism by means of a single pin.

Abstract: A rotary contact arrangement for circuit breakers of the type including a pair of movable contacts (30,36), one arranged on each end of the rotary contact arm (32), utilizes a single pair of contact springs (38), one spring on each side of the rotary contact arm (32). The springs (38) are aligned to intersect the axis of rotation of the rotary contact arm (32) for automatic uniform contact force adjustment throughout the operating life of the circuit breaker.

Abstract: A rotor spring insulator assembly comprises a base member having a D-shaped opening therein and a connecting rod of a D-shaped cross section dimensioned to be received in the D-shaped opening of the base member. The flat edge of the D-shaped connecting rod faces a spring of a rotor thereby maximizing the distance and the amount of insulative material between the connecting rod and the spring to minimize the chance that arcing will occur between the connecting rod and the spring.

Abstract: An auxiliary magnetic trip unit for a circuit breaker arranged on the load strap of an industrial-rated circuit breaker to interrupt circuit current upon occurrence of a high-level short circuit fault. The magnetic trip unit employs a magnet yoke, an armature, a trip lever for interacting with a latching mechanism of a circuit breaker operating mechanism, and a lever arranged to restrain the armature from moving toward the magnet yoke and to release the armature in response to a predetermined level of pressurized gas. Thus providing an auxiliary magnetic trip unit for use with circuit breakers for selective short circuit overcurrent protection in an electrical distribution system with circuit breakers connected in series.

Abstract: A circuit interrupter including a housing, separable main contacts within the housing, and an operating mechanism within the housing and interconnected with the contacts. An arc extinguisher assembly is disposed within the housing. Also provided within the housing is a slot motor assembly having a cavity region within which the contacts are substantially located. The slot motor assembly electro-magnetically interacts with current flowing between the contacts, and includes magnetic plates positioned in a slot motor housing. The slot motor housing has a tendency to move an arc existing between the contacts toward the arc extinguisher assembly. The slot motor assembly also includes an insulation member positioned within the cavity region and between the magnetic plates and the slot motor housing.

Abstract: A rotary contact arrangement for circuit breakers of the type including a pair of contact springs arranged on each side of a rotary contact arm, as the contact springs interconnect between the rotors and the contact arm via a pair of U-shaped levers. The provision of the U-shaped levers provides uniform contact pressure between both pairs of fixed and moveable contacts to prevent contact erosion.

Abstract: A circuit breaker rotary contact assembly employs a common pivot between the rotor assembly and the rotary contact arm. A pair of off-center expansion springs directly engage the rotor at one end and engage the rotary contact arm via a linkage arrangement at an opposite end thereof.

Abstract: The circuit breaker of the present invention is a molded case circuit breaker 10 having a moving contact 42 and crossbar assembly comprising a crossbar 55 having a formation pivotally mounted in the circuit breaker housing 12 with the formation having two spaced apart sidewalls 842, with each sidewall 842 having a first cam surface 830, a cam node 832, a second cam surface 834 and a bearing surface 826. Mounted in the formation, between the sidewalls 842, is a moving contact arm assembly 811 that is mechanically coupled to the circuit breaker operating mechanism 40 and electrically coupled to the load terminal 16 of the circuit breaker 10. The moving contact and crossbar assembly 811 comprises a movable contact arm 45 coupled to a pivot pin 818 positioned between the sidewalls 842 and in rotational contact with a bearing surface 826 of each sidewall 842.

Abstract: A switching device has an openable contact arrangement including at least one movable contact member disposed on a movable contact arm and at least one stationary contact member. At least one movable braking body is provided for limiting the movement of the contact arm in opening the contact arrangement. The inertias of the contact arm with the movable contact member and the braking body are designed so that the contact arm is braked and the braking body is moved upon an impact of the contact arm with the braking body.

Abstract: A cassette assembly for rotary contact circuit breakers utilizing a first electrically insulative cassette half piece and a second electrically insulative cassette half piece which are arranged to mate with each other to form an enclosure. The electrically insulative cassette half pieces include improper installation rejection features for both the rotor and arc chute assemblies. The inner surface of a electrically insulative cassette half piece including a groove and recesses formed therein. A rotor is properly positioned within the electrically insulative cassette half piece by inserting a pin on the face of the rotor into the groove. An arc chute assembly is properly positioned within the electrically insulative cassette half piece by inserting a tab located on a side member of the arc chute assembly into a corresponding recess located in the electrically insulative cassette half piece.

Abstract: A ferromagnetic structure for use in a circuit interruption mechanism, the, ferromagnetic structure has a first ferromagnetic layer having a lower surface and an upper surface, a second ferromagnetic layer having a lower surface and an upper surface, at least one ferromagnetic layer being positioned within the first and second ferromagnetic layers and having a lower surface and an upper surface, at least one recess in the lower surfaces of the ferromagnetic layers; and at least one protrusion in the upper surfaces of the ferromagnetic layers, the protrusions are received into the recesses.

Abstract: A circuit breaker having at least one cassette for receiving a conductive path. The conductive path is partially looped upon itself so that a first portion and a second portion of the conductive path are in a facially spaced relationship and the portions partially define an area for receiving a ferromagnetic material. The ferromagnetic material is insulated from the first portion and a support structure provides support for the first portion at two positions and the area is positioned in between these positions.

Abstract: A movable switch contact arrangement for a low-voltage circuit breaker has a contact lever holder for holding a plurality of contact levers. The contact lever holder includes a base body and additional bodies attachable thereto, as well as external mounting arms for rotatable mounting to open and close the circuit breaker. Contact lever holders of different widths can be produced by combining the base body with additional bodies of different types in order to adapt the circuit breaker to a desired rated current.

Abstract: An electrically conducting strap for use in a rotary circuit breaker cassette provides dual connectors to accommodate either an electronic or mechanical trip unit within the circuit breaker and electrical distribution system. The continuous, integral strap includes a first section including a fixed contact mounted thereon, a U-shaped second section, a third section having two apertures for connection to associated electrical equipment, and a fourth section having two apertures for connection to a line of a distribution system providing electrical power to a load. Thus, the circuit breaker has the advantage of reduced cost and increased ease of manufacturability since a common cassette is used.

Abstract: A movable contact arrangement for a low-voltage circuit breaker which has a contact lever bracket equipped with contact levers and may move around a pivot bearing for opening and closing the circuit breaker. A journal, which engages with a bearing opening close to an inner end of a stationary conductor segment, is molded onto a main arm of the contact lever bracket. The journal is positioned more or less in the center and has a length that does not exceed the width of the contact arrangement. The bearing opening is also positioned within the width of the contact arrangement. This reduces the width of the circuit breaker, especially in multipole designs, while simultaneously improving the load carrying capacity and service life of the pivot bearing.

Abstract: A circuit breaker rotary contact arrangement is disclosed in which the ends of the line and load straps supporting the fixed contacts are hook-shaped to control the angle of the repulsive force exhibited between the fixed contacts and the movable contacts arranged at the opposing ends of the rotary contact arm. The fixed contacts face outwardly away from the central pivot of the contact arm such that a horizontal component of the popping force acts away from the center of rotation keeping the contact arm in tension for avoiding a buckling effect allowing contact arms with smaller cross sectional area to be used to increase contact arm mobility and reduce the cost.

Abstract: A supplemental magnetic trip unit is arranged on the load strap of an industrial-rated circuit breaker to interrupt circuit current upon occurrence of a short circuit fault. The trip unit employs a U-shaped magnet and a hinged armature that articulates the circuit breaker operating mechanism latch to allow the circuit breaker contacts to become separated upon the urgence of the powerful circuit breaker operating mechanism springs.

Abstract: An electrical circuit breaker includes a moveable contact piece connected to an actuating means and provided with a contact face arranged to make contact with a contact face of a second contact piece by movement of the moveable contact piece generally in a first direction. The circuit breaker further includes an electrical connector for conveying current to the moveable contact piece which includes at least two adjacent limbs adapted to convey the current in opposing directions so as to generate an electromagnetic force repelling the adjacent limbs from one another, which force is used to assist in maintaining the contact faces in abutment.

Abstract: A switching contact system of a low-voltage circuit breaker has a bus with cord-like flexible conductors attached thereto. The flexible conductors are accommodated between a connecting surface (30) of the bus (26) and an end piece (27), which is in contact with the connecting surface (30) of the bus (26) with at least two contact surfaces. The parts are connected by heat effect, such as soldering or electron beam welding.

Abstract: A circuit breaker rotary contact assembly employs a common pivot between the rotor assembly and the rotary contact arm. A pair of off-center expansion springs directly engage the rotor at one end and engage the rotary contact arm via a linkage arrangement at an opposite end thereof.

Abstract: A U-shaped magnetic plate is positioned on the side of a movable contact shoe opposite to a fixed contact shoe, and the tips of the respective legs of the magnetic plate face via a gap the movable contact shoe in a closed condition of the movable contact shoe. A magnetic plate is attached to the surface of the movable contact shoe at the side of the fixed contact, so that the magnetic plates form a closed magnetic circuit surrounding the movable contact shoe. If a high current, such as short circuit current, flows, a magnetic flux passing through the closed magnetic circuit induces an attractive force between the upper end surfaces of the U-shaper magnetic plate and the end surface of the magnetic plate. Accordingly, the movable contact shoe is rapidly opened to quickly interrupt the current, before a signal from an overcurrent trip apparatus operates an opening and closing mechanism. The opening speed of the movable contact shoe is increased when high current flows.

Abstract: A low-voltage circuit breaker has an enclosure with a rear wall and a front part, in which there is a switching contact system with connecting bars. Each of the connecting bars has a web arranged transversally to the longitudinal direction of the connecting bars; the webs are used for contacting the mating surfaces of the rear wall of the enclosure. Fastening means act in the longitudinal direction of the connecting bars.

Abstract: A rotary contact circuit breaker employs a crank to couple a switching mechanism to the rotary contact pole structure. The use of a crank allows for the mechanism and pole structure the individually optimized without effecting the performance of the other. In particular the crank allows for a mechanism that is able to achieve maximum torque delivery to the pole structure.

Abstract: The circuit breaker is characterized by separable contacts operable between a closed and an open position a contact arm having a latching surface and a latch arranged to engage the latching surface when the contacts are blown-open under short-circuit conditions. The arrangement of the latch allows for a positive lock under high magnitude short circuit levels while minimizing the force required by a mechanism to unlock the arm.

Abstract: A contact assembly (22) is adapted for use with a circuit breaker (12) that is set to open a circuit above a predetermined current load. The contact assembly (22) is adapted to reciprocate between a closed position to permit the flow of current through the circuit and an open position to prevent the flow of current. The contact assembly (22) is further adapted to resist unintended reciprocation from the closed position to the open position at current loads up to or exceeding the predetermined current load. The contact assembly includes a line side conductor (38) and a load side conductor (54).

Abstract: The circuit breaker pole or poles comprise a movable contact means with a support carrier movable with respect to the frame between an open position and a closed position and one or more contact fingers movable with respect to the support carrier between a contact position and a retracted position. Electromagnetic compensation means are designed to apply electromagnetic forces on the contact finger or fingers tending to keep the contact finger or fingers in contact with the stationary contact means. Electromagnetic limiting means are designed to apply electromagnetic forces on the contact finger or fingers tending to drive the finger or fingers to their retracted position.

Abstract: An air circuit breaker movable contact arm assembly is presented. The movable contact arm assembly comprises an electrically-conductive support having at least one slot formed therein to receive a first end of the movable contact arm. The movable contact arm comprises first and second sides which face side walls of the electrically-conductive support within the slot. A spring washer is disposed at the first end of the movable contact arm and loads the second side of the movable contact arm against one side wall of the electrically-conductive support to form a variably conducting joint therebetween. By using a spring washer, the movable contact arm pivotally engages the other facing side wall of the electrically-conductive support to provide a variable pivot point. The variable pivot point of the contact arm assembly permits an additional degree of freedom allowing the movable contact arm to rotate about a separate, variable pivot point.

Abstract: A method for retaining a movable contact in a circuit interrupter is applicable to interrupters including first and second contacts, at least one of the contacts being movable. A movable element supporting the movable contact is displaceable between a conducting position wherein the movable contact abuts a cooperating contact to complete a current carrying path through the device, and a non-conducting position wherein the movable contact is electrically separated from the cooperating contact. In accordance with the method, the movable contact is displaced by an interrupt initiation device, and a carrier or retainer is displaced by gas pressure resulting from arcs generated by movement of the contact. The carrier is guided in its displacement within the device housing from a normal operating position to a retaining position. The carrier includes an abutment element that physically contacts the movable element to prevent it from rebounding into contact with the cooperating contact.

Abstract: An electrical switching device prevents moving contacts from welding to stationary contacts in a switching device. This is achieved using an auxiliary magnet system in the main current path, which system produces a contact pressure force corresponding to the excitation current so that no arcs are produce between the contacts when overcurrents and short-circuit currents occur. The moving iron core of the auxiliary magnet system is for this purpose connected to the contact link mounting via which the contacts are switched on and off.

Abstract: A method an apparatus is disclosed for preventing contact welding during fault conditions. This fault current tolerable contactor includes two magnetic components, one in operable association with the movable contacts, and the other fixable attached above the movable contacts such that when a fault condition occurs, a high magnetic force is created to draw the two magnetic components together thereby opening the contacts. The magnetic force keeps the contacts open at least until current zero, and preferably a defined time thereafter to provide enough time for the contacts to cool and prevent welding upon the closure of the contacts.