35results about How to "Improve short circuit breaking capacity" patented technology

The invention relates to a low-voltage circuit breaker with a pneumatic tripping device. The low-voltage circuit breaker comprises a base and a shell. A plurality of independent monopole contact devices are arranged in parallel on the base. An operating mechanism of the circuit breaker with a tripping traction rod is fixedly arranged on one of the monopole contact devices. The monopole contact device comprises a second shell, wherein both ends of the monopole contact device are provided with a moveable contact bridge with a moveable contact and a stationary contact corresponding to the moveable contact. The moveable contact bridge with the moveable contact can move linearly up and down, so that the two moveable contacts are respectively connected or disconnected with the stationary contact correspondingly. An arc extinguishing region is formed among the moveable contact, the stationary contact and the second shell. The pneumatic tripping device is arranged between two adjacent monopole contact devices. The pneumatic tripping device detects the gas pressure in the arc extinguishing regions installed on both sides of the monopole contact device, and drives the operating mechanism to trip when the gas pressure exceeds the predetermined threshold value. Compared with the prior art, the circuit breaker provided by the invention has the advantages of accelerating the short-circuit breaking speed and improving the short-circuit breaking capacity of the circuit breaker and the like.

The invention provides a circuit breaker used in a distribution system, comprising a circuit breaker loop which comprises an overload release, a magnetic release system, a main contact, an auxiliary contact and an operation mechanism, wherein the operation mechanism is used for controlling the closure or cutting off of the main contact and the auxiliary contact under the conditions of the normal working and the overload fault. The circuit breaker also comprises an electronic release accessory loop comprising a selective resistor and an electronic release which are connected in series, wherein the selective resistor and the electronic release are connected with an input circuit part connected to the first electrode of the circuit breaker in series and at least comprising the main contact and the magnetic release system in parallel. Under the condition of a short-circuit fault, the main contact is cut off under the pushing of the magnetic release system so that short-circuit current passes through the auxiliary contact, the selective resistor and the electronic release, the electronic release selectively controls the operation mechanism according to the elimination of the short-circuit fault in the preset delay time, and furthermore, the operation mechanism controls the main contact and the auxiliary contact to carry out corresponding closing or cutting-off operation.

The invention relates to an electric meter box, in particular to a power purchase type intelligent electric meter box. The electric meter box comprises a power supply device, an electric meter, a breaker and a terminal, wherein the power supply device is arranged in the box body; the power supply device is connected with the electric meter and the breaker through a current inductor. The electric meter box is characterized in that a signal booster is arranged in an electric meter box body; an indicating part and an interacting platform are arranged on the outer side of an inner door of the box body; a high-receiving sensitivity antenna is arranged outside the box body through a universal joint; the breaker and the terminal are connected with the indicating part; the breaker, the electric meter, the interaction platform and the signal booster are connected with a current-using management terminal; the signal booster is connected with the high-receiving sensitivity antenna; the breaker, the current-using management terminal and the indicating part form an alarming-tripping circuit. The electric meter box has the advantages that equipment is advanced, layout is reasonable, the electric meter box can prevent electric shock, on-site switching on / off is realized, signal boosting is realized, and the function of an interaction platform is realized.

The invention relates to a low-voltage circuit breaker with a pneumatic tripping device. The low-voltage circuit breaker comprises a base and a shell. A plurality of independent monopole contact devices are arranged in parallel on the base. An operating mechanism of the circuit breaker with a tripping traction rod is fixedly arranged on one of the monopole contact devices. The monopole contact device comprises a second shell, wherein both ends of the monopole contact device are provided with a moveable contact bridge with a moveable contact and a stationary contact corresponding to the moveable contact. The moveable contact bridge with the moveable contact can move linearly up and down, so that the two moveable contacts are respectively connected or disconnected with the stationary contact correspondingly. An arc extinguishing region is formed among the moveable contact, the stationary contact and the second shell. The pneumatic tripping device is arranged between two adjacent monopole contact devices. The pneumatic tripping device detects the gas pressure in the arc extinguishing regions installed on both sides of the monopole contact device, and drives the operating mechanism to trip when the gas pressure exceeds the predetermined threshold value. Compared with the prior art, the circuit breaker provided by the invention has the advantages of accelerating the short-circuit breaking speed and improving the short-circuit breaking capacity of the circuit breaker and the like.

The invention relates to a circuit breaker structure achieving rapid releasing through electric repulsion force and a circuit breaker. The circuit breaker structure comprises a static contact, a moving contact, an elastic piece and an operating mechanism. An execution unit is arranged between the moving contact and the operating mechanism and comprises a draw bar, the draw bar and the operating mechanism are hinged and matched, the draw bar moves to actuate the operating mechanism, a first connecting bar is arranged at the tail end of the moving contact, a second connecting bar is fixedly connected with the tail end of a rotating shaft, the other end of the second connecting bar actuates the draw bar, one end of the first connecting bar is rotationally connected with the tail end of the moving contact, and the other end of the first connecting bar is fixedly connected with the middle of the second connecting bar. When the rotating shaft and the moving contact are linked, the first connecting bar and the second connecting bar do not move. When the moving contact overcomes elastic force of the elastic piece and moves relative to the rotating shaft, the first connecting bar drives the second connecting bar to move to drive the draw bar to make the operating mechanism released, when the moving contact is repelled by the electric repulsion force, the circuit breaker operating mechanism can be synchronously triggered, the mechanism can be rapidly released, and secondary drop of the moving contact and fusion welding of the contacts can be avoided.

The invention discloses a rapid tripping device which comprises a mechanism support, a connecting rod device, a contact connecting rod, a main shaft, a moving contact, a static contact, a jump pin anda lock catch assembly device. One end of the jump pin is in lap joint with the lock catch assembly device, the other end of the jump pin is connected with the mechanism support through a rotating shaft, and the moving contact and the static contact make contact with each other in a non-overload state. In the over-loaded state, due to existence of electrodynamic repulsion, the acting force of thejump pin on the buckle surface on the lock catch assembly device is suddenly increased, so the lock plate overcomes the pressure of the lock catch pressure spring to deflect upwards; and the push surface pushes a second lock catch to rotate clockwise, the position of a first lock catch assembly is unlocked after the second lock catch rotates clockwise, the first lock catch assembly rotates clockwise, the buckle surface is separated from the jump pin, the jump pin rotates anticlockwise, the tripping process is completed, and the contact is opened.

The invention relates to a double-breakpoint molded case circuit breaker which is a molded case circuit breaker with double breakpoints connected in series in the same direction. A double-breakpoint contact structure of the molded case circuit breaker is of a double-breakpoint structure in which movable contact rods of two single breakpoints are connected in series to form a pole; the breaker of the structure has the advantages of reliable contact, high electric stability and easiness in regulation of contact parameters of a single-breakpoint breaker, also has the advantage of good arc extinguishment effect of the double-breakpoint breaker and is simple, reasonable in structure and capable of effectively improving the short circuit breaking capability of the molded case circuit breaker. According to the double-breakpoint molded case circuit breaker disclosed by the invention, when the breaker is subjected to short circuit breaking, the arc extinguishment capability of the double-breakpoint structure is theoretically double that of the single-breakpoint structure, and the double-breakpoint structure is beneficial for improving the short circuit breaking capability of the breaker.

The invention discloses a surge protection device (100) with a short circuit current protection function. The surge protection device comprises a surge protection module (102) and a short circuit current protection module (101). The surge protection module discharges and inhibits surge current and voltage. The surge protection module is a pluggable module. The short circuit current protection module is integrated in a base. The short circuit current protection module provides short circuit protection and plugging installation for the surge protection module. According to the surge protection device, the problem that an impact current is brought to backup protection by using an external overcurrent protection device is overcome; the current limiting capability is high; the short circuit breaking capacity is high; the minimum instant tripping current value is low; the surge protection device can tolerate a fault mode occurring in transient over voltage TOV; and a protection effect is achieved under a low current.

The invention provides a breaker structure achieving quick tripping through electro-dynamic repulsion force. In the process that moving contacts are repulsed by electro-dynamic repulsion force, a breaker operation mechanism can be triggered synchronously so that the mechanism can be quickly tripped before an electromagnetic system acts, the acting time of the mechanism is shortened, secondary falling of the moving contacts and contact fusion welding are avoided, short circuit breaking capacity of the breaker is improved, and actions are quick and reliable.

The invention discloses a double-breakpoint current-limiting miniature circuit breaker which solves the problem of poor breaking capacity of an existing miniature circuit breaker. The double-breakpoint current-limiting miniature circuit breaker comprises a shell, an operating mechanism, a contact system and an arc-extinguishing system, wherein the contact system comprises a movable contact and a fixed contact; the shell comprises a front cover and a back cover; the movable contact comprises a first movable contact pin and a second movable contact pin; the fixed contact is provided with a first fixed contact sheet and a second fixed contact sheet; the arc-extinguishing system comprises a first arc-extinguishing chamber and a second arc-extinguishing chamber, both of which are arranged side by side; the shell is internally provided with a clapboard; the clapboard and the front cover form a first containing cavity; the clapboard and the back cover form a second containing cavity; the first movable contact pin, the first fixed contact sheet and the first arc-extinguishing chamber are arranged in the first containing cavity; the second movable contact pin, the second fixed contact sheet and the second arc-extinguishing chamber are arranged in the second containing cavity. The double-breakpoint current-limiting miniature circuit breaker has the advantages of being convenient to assemble, reliable in breaking and arc-extinguishing, strong in current-limiting capability, wide in application range and the like.

The invention discloses a framework circuit breaker arc extinguishing chamber, which belongs to low-voltage electric appliance equipment and comprises an arch isolation cover, a grid plate, an arc striking plate, a first arc isolation wall and a second arc isolation wall, wherein the arc isolation cover is fixedly arranged on the top of the first arc isolation wall and the second arc isolation wall, and in order to increase the exhaust area and to simultaneously control the exhaust directions of the arc isolation cover, more than one inclined exhaust hole is processed along the transverse axial line of the arc isolation cover on the premise of ensuring the intensity requirements. Two ends of the grid plate are respectively connected with the inner walls of the first arc isolation wall and the second arc isolation wall and are in staggered placement in the arc extinguishing chamber in a way that one end is positive and the other end is reverse. In order to lengthen the electric arc through pulling, asymmetric grooves are processed in the middle position of the lower end of the grid plate, simultaneously, in order to increase the length of the grid plate, the top of the grid plate uses the condition that the top is not in contact with the inner wall of the arc isolation cover as the limit, the bottom of the grid plate uses the condition that the bottom is not in contact with the inner wall of the arc striking plate as the limit, and the grid plate is in step-type arrangement along the inclined surface of the arc striking plate. In the practical application, after the arc extinguishing chamber in the structure is adopted, the short circuit breaking capability of a circuit breaker is improved from the original 80kA to 120kA.

The invention discloses an ultrahigh-voltage and extra-high-voltage multi-break quick vacuum circuit breaker topological structure, which is characterized in that the multi-break quick vacuum circuit breaker adopts a series-parallel topological connection structure and is formed by connecting a plurality of same branches in parallel, and the number of the parallel branches and the number of series fractures of each branch are determined according to design parameters; the number of the parallel branches is determined according to the rated through-current capability of the circuit breaker, each parallel branch is formed by connecting a plurality of same circuit breaker units in series, the number of series fractures refers to the requirements of power frequency withstand voltage and lightning impulse withstand voltage of the circuit breaker, one redundancy is added on the basis that the number of fractures meets the insulation requirement, and a vacuum circuit breaker operating mechanism adopts a rapid repulsion mechanism. The topological structure is applied to development and design of ultrahigh-voltage and extra-high-voltage rapid vacuum circuit breakers, the problem that balance and current sharing of all parallel units are difficult to achieve in a traditional topological structure of the circuit breaker is solved, it is only needed to guarantee that the total contact resistance of all parallel branches is equal, and the requirement for model selection of the vacuum arc-extinguishing chamber is lowered.

The invention provides a current-limiting type plastic shell circuit breaker mechanism. The current-limiting type plastic shell circuit breaker mechanism comprises a mechanism support, an upper connecting rod, a lower connecting rod, an upper movable contact, a lower movable contact and a lock catch, and is characterized by further comprising a jump pin assembly, and the jump pin assembly consists of a first jump pin, a second jump pin, a jump pin spring and two jump pin clamp plates; a first jump pin connecting column connected to the mechanism support is arranged at one end of the first jump pin, and a jump pin spring retaining device for retaining the jump pin spring is arranged at the other end of the first jump pin; a part of the first jump pin, a part of the second jump pin, the jump pin spring and the jump pin retaining device are clamped between the two jump pin clamp plates, and the second jump pin is pivotally connected to the jump pin clamp plates; and under non-overload, overload and small-current short circuit states, the second jump pin is connected with the first jump pin to form a rigid body under the action of the jump pin spring and is under a locking state by the lock catch, and under a large-current short circuit state, the second jump pin overcomes the action of the jump pin spring to rotate clockwise relative to the jump pin clamp plates so as to enable the mechanism to trip.

The invention provides a circuit breaker used in a power distribution system, which includes a circuit breaker circuit. The circuit breaker circuit includes an overload release, a magnetic release system, a main contact, an auxiliary contact and an operating mechanism. The operating mechanism operates normally Controls the closing or cutting of the main contacts and auxiliary contacts under working and overload fault conditions. The circuit breaker also includes an electronic tripping accessory circuit, which includes a selective resistor and an electronic tripper connected in series. The selective resistor and electronic tripper are connected in series with at least the main contact in the first pole of the circuit breaker. The input circuit part of the magnetic tripping system is connected in parallel. In the event of a short-circuit fault, the main contacts are disconnected under the push of the magnetic tripping system, allowing the short-circuit current to flow through the auxiliary contacts, selective resistors and electronic releases. , the electronic tripper selectively controls the operating mechanism according to whether the short-circuit fault is eliminated within a predetermined delay time, and then the operating mechanism controls the main contact and the auxiliary contact to perform corresponding closing or cutting operations.

The invention discloses a small breaker. The breaker comprises a plastic shell, a movable contact, a static contact, an operation mechanism, an electromagnetic tripping mechanism, an arc extinguish chamber and a run-on tab, wherein the electromagnetic tripping mechanism comprises a magnetic yoke; one end of the run-on tab is electrically connected with the static contact, while the other end of the run-on tab extends into the arc extinguish chamber; and the arc extinguish chamber is positioned under the magnetic yoke. The small breaker is characterized by comprising an iron arc guide plate; one end of the arc guide plate, namely a fixed end, is fixed on the bottom of the magnetic yoke, while the other end of the arc guide plate, namely an arc guide end, is bent downwards and close to the movable contact. The small breaker has the advantages of effectively improving the capability of short circuit disjunction of the breaker, easily achieving the level of 6,000A energy level 3, and has short arcing time less than 6 milliseconds.

The invention discloses an insulated shell with an integrated function, which comprises a tubular shell. The inner wall of the tubular shell is provided with a raised or sunken uneven line for increasing the creepage distance between two axial ends of the tubular shell; the creepage distance path formed by the raised or sunken uneven line is provided with more than two climbing or detouring-type sub paths, and thus, the creepage distance is increased, and the voltage-resistance performance is enhanced; due to the construction of creepage extending rings is adopted, the creepage distance is greatly improved, pollution of the whole inner wall of the tubular shell by metal vapor evapotranspiration is avoided, due to double effects of the large creepage distance and the large pollution-free area ratio, the voltage-resistance performance and the back-arc insulation level of the insulated shell with the integrated function are greatly improved, the back-arc electrical insulation index of a vacuum interrupter does not fall, and the insulated shell with the integrated function and the vacuum interrupter is developed towards a high voltage and ultra high voltage direction.

A circuit breaker device disclosed by the present invention comprises a contact structure, an operation structure and an electromagnetic tripping mechanism which are arranged in a shell, the electromagnetic tripping mechanism and the contact structure are arranged in the shell along a first direction, and the electromagnetic tripping mechanism is provided with a driving structure which drives the operation structure to be in a tripping motion state when being triggered and a push rod which is movably arranged between the driving structure and a moving contact component; when the electromagnetic tripping mechanism with the structural design drives the moving contact component to be separated from a static contact, the operation structure is subjected to opening and tripping movement, so that the operation structure drives the moving contact component to move to an opening position in a tripping state, the opening and tripping speed of the circuit breaker is improved under the combined action of the moving contact component and the static contact, the tripping time is shortened, the instant breaking of the moving contact and the static contact is beneficial to the rapid extinguishing of the arc, the contact structure is protected, the short circuit breaking capacity of the circuit breaker is improved, and the electrical life of the circuit breaker is prolonged.

A miniature circuit breaker with double breakpoint current limiting. The problem of poor breaking capacity of the existing miniature circuit breaker is solved. It includes a housing, an operating mechanism, a contact system and an arc extinguishing system. The contact system includes moving contacts and static contacts. The housing includes a front cover and a rear cover. The moving contacts are It includes a first movable contact pin and a second movable contact pin, the static contact is provided with a first static contact piece and a second static contact piece, and the arc extinguishing system includes a first arc extinguishing chamber and a In the second arc extinguishing chamber, a baffle is provided in the housing, and the baffle and the front cover form a first accommodating chamber, and the baffle and the rear cover form a second accommodating chamber. A moving contact foot, the first static contact piece, and the first arc extinguishing chamber are all arranged in the first accommodating cavity, and the second moving contact foot, the second static contact piece, and the second arc extinguishing chamber are all arranged in the second accommodating chamber. Two accommodation chambers. The invention has the advantages of convenient assembly, reliable breaking and arc extinguishing, strong current limiting capability, wide application range and the like.

A surge protector (100) with short-circuit protection function includes a surge protection module (102) and a short-circuit current protection module (101). The surge protection module discharges and suppresses surge current and voltage. The surge protection module is a plug-in module. The short-circuit current protection module is integrated in the base. The short-circuit current protection module provides short-circuit protection and plug-in installation for the surge protection module. This surge protector overcomes the problem of inrush current caused by using an external overcurrent protection device for backup protection. At the same time, it has strong current limiting capability, good short-circuit breaking capability, small minimum instantaneous tripping current value, and can be used under temporary overvoltage (TOV). It can tolerate failure modes and can also play a protective role under low current.

The invention relates to the technical field of circuit breakers, and especially discloses circuit breaker moving contact with an arc contact. The circuit breaker moving contact comprises a contact system, a contact support, contact springs, a connecting shaft and a flexible connector, wherein the contact system comprises a plurality of contact pieces, the contact pieces are all sleeved on the connecting shaft, the end parts, which are located at two sides of the connecting shaft, of each contact piece are respectively a butt joint end abutted against the contact spring and a connecting end connected with the flexible connector, the side edge of each connecting end is provided with a limiting rod for the butt joint of the connecting end, the middle part of the limiting rod is provided witha concave cavity, the bottom surface of the concave cavity is lower than the surface of the other positions of the limiting rod, the connecting end of at least one contact piece is in butt joint withthe bottom surface of the concave cavity to form an arc contact, the other contact pieces form a main contact, and the butt joint end of the arc contact protrudes out of the butt joint end of the main contact. By adopting the structure, the circuit breaker moving contact with the arc contact which can effectively protect the main contact and can provide reliable high breaking capacity and long electric service life under high voltage.

A circuit breaker for motor protection includes a contact support installed in a housing, a static contact assembly and a movable contact assembly mounted on the contact support, and also includes a rotary handle and a linkage mechanism connected with the rotary handle. The linkage mechanism comprises a gear swing rod and a push rod. The rotary handle rotatably drives the linkage mechanism to drive the push rod to make the movable contact group on the contact support come into contact with and separate from the static contact group. One end of the rotary handle is provided with an upper gear intermeshed with the gear swing rod. The upper gear comprises teeth. A tooth groove is formed between every two adjacent teeth. The gear swing rod is provided with swing rod teeth corresponding to the tooth grooves. Swing rod tooth grooves corresponding to the teeth are formed between the swing rod teeth. The teeth gradually narrow from the inside to the outside. First inclined surfaces are formed on both sides, and second inclined surfaces corresponding to the first inclined surfaces are disposed on both sides of the swing rod tooth grooves.

The invention provides an arc extinguishing chamber and an arc extinguishing device, and belongs to the technical field of low-voltage electrical appliances. The arc extinguishing chamber comprises aplurality of arc extinguishing grid sheets and an arc isolating plate; the plurality of arc extinguishing grid sheets are divided into an upper grid sheet group located at the upper part and a lower grid sheet group located at the lower part from top to bottom, and the thickness of the arc extinguishing grid sheets in the upper grid sheet group is smaller than that in the lower grid sheet group; and the gaps among the arc extinguishing grid sheets in the upper grid sheet group are smaller than the gaps among the arc extinguishing grid sheets in the lower grid sheet group. According to the invention, the number, the thickness, the gaps and the like of the arc extinguishing grid sheets in the arc extinguishing chamber are re-planned, so that the short-circuit breaking capacity of the circuitbreaker is greatly improved through a reasonable and hierarchical new layout.

The invention discloses a small breaker. The breaker comprises a plastic shell, a movable contact, a static contact, an operation mechanism, an electromagnetic tripping mechanism, an arc extinguish chamber and a run-on tab, wherein the electromagnetic tripping mechanism comprises a magnetic yoke; one end of the run-on tab is electrically connected with the static contact, while the other end of the run-on tab extends into the arc extinguish chamber; and the arc extinguish chamber is positioned under the magnetic yoke. The small breaker is characterized by comprising an iron arc guide plate; one end of the arc guide plate, namely a fixed end, is fixed on the bottom of the magnetic yoke, while the other end of the arc guide plate, namely an arc guide end, is bent downwards and close to the movable contact. The small breaker has the advantages of effectively improving the capability of short circuit disjunction of the breaker, easily achieving the level of 6,000A energy level 3, and has short arcing time less than 6 milliseconds.

A multi-loop circuit breaker comprises an incoming terminal, an outgoing terminal, an electromagnetic mechanism, a static contact, a movable contact and a thermal stripping mechanism. The electromagnetic mechanism is provided with a coil and a movable iron core, one end of the coil is electrically connected with an incoming terminal, and the movable iron core is located in the coil and movable along the axis thereof; The static contact is electrically connected with the coil, and the movable contact is electrically connected with the thermal stripping mechanism. the multi-loop circuit breakerfurther comprises a linkage rod and at least a first auxiliary current circuit, the first auxiliary current circuit being coupled in parallel with the electromagnetic mechanism; The linkage rod is rotatably arranged, one end of the linkage rod is linked with one end of the movable iron core, and the other end of the linkage rod is in contact with the first auxiliary current circuit. When the shortcircuit occurs, the movable iron core moves to drive the linkage rod to rotate so that the first auxiliary current circuit is first disconnected, and then the static contact is separated from the movable contact. The invention can improve the rated current of the circuit breaker and the short-circuit breaking ability of the circuit breaker.

The invention relates to an arc extinguishing chamber for a breaker. The arc extinguishing chamber comprises an arc extinguishing cover, side walls, a group of arc extinguishing grid pieces and a flame extinguishing piece, wherein the arc extinguishing cover is placed at the top of the arc extinguishing chamber; the side walls are arranged at the left aide and the right side of the arc extinguishing chamber, the group of arc extinguishing grid pieces is arranged between the left side wall and the right side wall of the arc extinguishing chamber; and the flame extinguishing piece is arranged between the arc extinguishing cover and the arc extinguishing grid piece. The arc extinguishing chamber for the breaker is characterized in that the group of the arc extinguishing grid pieces is in staggered arrangement between the side walls of the arc extinguishing chamber, the front end of the arc extinguishing grid piece at one lateral side is provided with an arc initiating piece, the included angle formed by intersecting the upper part seamed-borders of the arc extinguishing grid piece is an obtuse angle; and the intersecting position extends to an arc initiating port. Compared with prior art, the arc extinguishing chamber for the breaker can obviously improve the short circuit breaking capacity of the breaker, quickly initiate arc and effectively protect a main contact.

The invention discloses a contact system with an automatic arc blowing function. The system comprises a contact supporter and a movable contact which rotates along with the contact supporter in an integrated manner, wherein the movable contact has a maximum distance of separating brake rotating, a baffle is arranged at the front end, which is suitable for being contact with a fixed contact, of the movable contact in a rotating manner, and the baffle is provided with two side plates and an arc blowing plate which is connected between the two side plates and faces an arc extinguishing chamber; the system further comprises an elastic bias device for applying acting force on the baffle in the direction, opposite to the direction of the separating brake rotating of the movable contact; when the movable contact is rotated to a maximum distance position and stops rotating, under the inertia effect, the baffle overcomes the acting force on the elastic bias device to continuously rotate in the original direction, and arcs are blown by the arc blowing plate to move towards the arc extinguishing chamber. Through the use of the system, the air blowing effect is improved, the short circuit breaking capacity of the contact system is improved, and the baffle is reset under the driving of the elastic bias device. The contact system disclosed by the invention has the advantages that the structure is simple and the operation is reliable.

The invention provides a breaker with a contact structure capable of being quickly opened. Before short circuit current reaches an expected maximum value, moving contacts can be repulsed by electro-dynamic repulsion force, fixed contacts also can be repulsed synchronously to generate electric arcs, voltage of the electric arcs ascends quickly, ascendance of the short circuit current is effectively restrained, after a mechanism is tripped, under the effect of a connection rod, the fixed contacts still stay at a repulsion position, a large open distance between the contacts is guaranteed, let-through energy of the breaker is effectively reduced, and short circuit breaking capacity of the breaker is improved.

The invention relates to a small circuit breaker, which comprises a shell (1), an operating mechanism (2), a contact system (3), an arc extinguishing chamber (4), a heat tripping system (5), a sealingsystem (6) and an electromagnetic tripping system (7), wherein the contact system (3) comprises a moving contact (301) and a static contact (302). The small circuit breaker removes an arc running channel region, so that the voltage rising speed of electric arcs is greatly improved, and the short circuit breaking capacity is enhanced. The whole mechanism is great separation distance, the blastingmagnetic field is strong, the structure is simple, and the assembly is convenient.