Abstract: A switching system for switching an electrical device, comprising: a vacuum interrupter including a fixed electrode, and a mobile electrode, the mobile electrode configured to move between a closed position and an open position. The switching system further comprising an elastic return means configured to apply a driving force to the mobile electrode, and a retaining member for retaining the elastic return means, the retaining member configured to move from a retention configuration, in which the elastic return means is immobilized, into a movement configuration, in which the elastic return means is released. The switching system is configured so that the mobile electrode moves from the closed position to the open position under the action of the elastic return means when the retaining member leaves its retention configuration.

Abstract: The present invention relates to a multi-contact disconnect switch for a lightning arrester configured to maintain contact points of a contact shaft evenly and to improve the operation stability of the contact shaft, and more particularly to, a multi-contact disconnect switch for a lightning arrester including a first body having a passage formed therein and a multi-contact unit positioned on one side of the passage, and a second body having a contact shaft inserted into the passage and coupled to the other side of the first body, wherein, when the second body is coupled to the first body in a contact state, an end of the contact shaft is in contact with the multi-contact unit, and thus the multi-contact unit is in multi-contact with a contact circumferential surface of the contact shaft.

Abstract: A switchgear assembly includes an indicator assembly to indicate whether a movable contact is in an open or a closed position. The indicator assembly includes an indicator body having first and second sections. The indicator body is rotatable to display the first section in the open position and the second section in the closed position. The indicator assembly also includes a drive gear having a first helical spline and coupled to an actuator of the switchgear assembly such that operation of the actuator moves the drive gear, and an elongated driven gear having a second helical spline extending along a length of the driven gear and engaged with the first helical spline of the drive gear such that movement of the drive gear rotates the driven gear. The driven gear is coupled to the indicator body such that rotation of the driven gear causes rotation of the indicator body.

Abstract: A high voltage relay resistant to instantaneous high-current impact is disclosed. The high voltage relay includes an electromagnet system, a control system, a contact system, and a base support. In various embodiments, an electromagnetic force generated by the contact system is used to resolve a problem of contact separation caused by an electric repulsion force generated by an instantaneous high-current.

Abstract: An adjusting device adjusts the stroke of a vacuum switching tube and the bias of a contact compression spring of a switching device mechanism, the spring being paired with the vacuum switching tube, for a medium-voltage switch and/or high-voltage switch. The adjusting device can be driven by a switch shaft, the switch shaft is connected to a transmission element via a connection element, and the transmission element can be connected to a movable switch contact of a medium-voltage switch and/or a high-voltage switch. The transmission element is arranged in a rotatable manner and in a laterally movable manner in the connection element along a recess.

Abstract: An armature core of a linear motor, the armature core including: a core body having a plurality of teeth parts around which a winding is wound, and consisting of laminated steel sheets; a block disposed inside of the core body; a fastening hole provided in the block, and through which a fastener is inserted; and a fastener insertion member having a fastener insertion hole, and arrangeable at the core body in a state in which outside of the core body and inside of the fastening hole are in communication via the fastener insertion hole, in which the core body is fixed to a fixing target via the block, by the fastener inserted in the fastener insertion hole being fastened to the block via the fastening hole, and the armature core has a seal structure which, in a state in which the fastener insertion member surrounds an opening part of the fastening hole, blocks passage of fluid from the opening part to outside of the fastener insertion member.

Abstract: A method for operating a drive of a vacuum interrupter in opening mode includes: dividing an opening movement of at least one movable contact into serial phases, an opening phase, and an isolating phase, driven in at least two different velocities. In the opening phase a velocity of the opening movement is lower than in the isolating phase.

Abstract: Connector tongues that may provide a high signal quality or signal integrity to allow high speed data transfers, may be reliably manufactured, and may be durable and have good wear performance.

Abstract: Provided is a bidirectional electrical connection socket, to which a fitting portion of a bidirectional electrical connection plug can be inserted and connected, the fitting portion having two contact interface substrates, the bidirectional electrical connection socket including: an insulating base having one end formed with a tongue, each of two connection surfaces thereof has a contact interface formed by terminals; and a metal housing covering the tongue to form a connection slot, characterized in that the contact interfaces have connection points with circuit serial numbers arranged reversely, two fitting gaps between the contact interface substrates and the connection surfaces of the tongue are smaller than 0.15 mm, and the heights of the spaces on the connection surfaces are smaller than the large space of the standard electrical connection socket with the minimum height specification specified by USB Association, but greater than the small space of the standard electrical connection socket.

Abstract: A switching device includes a first conventional switching point and a second conventional switching point which are electrically connected in series by a non-conventional switching point. A switch-off method for operating a switching device is also provided.

Abstract: A method for insulating an RC voltage divider includes installing at least one part of an active part of the voltage divider within an inner housing and insulating the at least one part of the active part with an insulating oil within the inner housing, hermetically sealing the inner housing, enclosing the inner housing in an outer housing and filling a space between the inner housing and the outer housing with an insulating gas. A system for insulating an RC voltage divider is also provided.

Abstract: An embedded pole is provided which includes a conductive path and a movable contact. The movable contact is selectively movable between a first position in which the conductive path is closed and a second position in which the conductive path is open. An insulation element is coupled to and selectively movable in conjunction with the movable contact. The embedded pole further includes a sensor coupled to the insulation element and operable to detect a displacement of the insulation element that corresponds to a movement of the movable contact between the first position and the second position.

Abstract: A fault current limiter arrangement for a low, medium and high voltage electricity grid, including a fault current limiter unit which is arranged in line with a circuit breaker unit including a fixed electrical contact which is connected to a lower electrical terminal and a movable electrical contact which is connected to an upper electrical terminal, in order to interrupt the current flow after the fault current limiter unit has limited the current flow in a detected fault event. The fault current limiter unit includes a movable electrical sliding contact part which is electrically arranged between the upper electrical terminal of the circuit breaker unit and the movable electrical contact of the circuit breaker unit, and which is movable between a short circuit position adjacent to the upper electrical terminal and a remote position far from the upper electrical terminal for providing a maximum electrical resistance for the current flow.

Abstract: The invention is intended to provide a circuit breaker or a circuit breaker operating method enabling a current interruption action to be performed efficiently. A circuit breaker is characterized in that includes a fixed contact and a movable contact that comes in and goes out of contact with the fixed contact; a main circuit conductor that is electrically connected to the fixed contact and the movable contact; an operating mechanism including a mover configured by concatenating permanent magnets or magnetic materials alternately having opposite N and S magnetic polarities along the direction of motion axis of the movable contact and magnetic poles disposed to face the N and S magnetic polarities of the mover and wound with windings; a current detector that detects a current flowing through the main circuit conductor; and a control device that varies the amount of a current to be supplied to the windings of the magnetic poles, depending on a current value detected by the current detector.

Abstract: The invention provides a switchgear that is capable of increasing a degree of freedom of a position of a moving arcing contact in a circuit breaker, does not require dimension management of components and a mechanism for adjusting a position of the moving arcing contact, and is capable of simplifying fabrication of components and assembly of devices and reducing cost.

Abstract: The present disclosure relates to a system, for selectively actuating a safety mechanism, to protect against electrical shock, using a transformable material. The system includes the transformable material, being: (1) connectable electrically to an electrical component having an unwanted electrical charge and (2) changeable between a deformed shape and an undeformed shape based on electrical input resulting from the electrical charge at the electrical component. The transformable material is also (3) connected mechanically to the safety mechanism so that change in the transformable material causes movement of the safety mechanism. The transformable material is further (4) configured and arranged in the system to, in response to being exposed to the electrical input, change to its undeformed shape and thereby actuate the safety mechanism.

Abstract: The fast switch includes: a housing; a vacuum interrupter installed in the housing, connected to a main circuit, and configured to open and close the main circuit; a contact spring coupled to a mover of the vacuum interrupter, and configured to provide a contact force; an insulating rod connected to the contact spring; a permanent magnet actuator connected to a lower end of the insulating rod, and configured to provide a switching driving force; a first capacitor configured to provide a discharge current to a coil of the permanent magnet actuator; a driving coil connected to a lower end of the permanent magnet actuator; and a second capacitor configured to provide a discharge current to the driving coil.

Abstract: This switching device comprises at least one pair of fixed contacts and, for each pair of fixed contacts, a movable contact that is movable between a closed position and an open position. A contact holder capable of holding in place each movable contact is also provided. The contact holder is movable along a vertical direction between a first position corresponding to the closed position of each movable contact and a second position corresponding to the open position of the or each movable contact. The device also includes a plate capable of applying a force on the movable contact holder so as to move it between its first and second positions. The plate is movable relative to the movable contact holder. The device includes a sensor capable of measuring the movement of the movable plate relative to the movable contact holder, during the actuation of the movement of the plate in order to drive the movement of the contact holder from its first position to its second position.

Abstract: The present invention relates to a safety shutter of a vacuum circuit breaker, and more particularly, to a safety shutter of a vacuum circuit breaker which is mounted on a cradle of a drawable type vacuum circuit breaker and opened or closed when a main body is retracted or pulled out to protect the safety of users from a charging part.

Abstract: A pushrod assembly for a medium voltage vacuum circuit breaker and vacuum circuit breaker are disclosed. The pushrod assembly can include a pushrod with an insulating body, whereby an electrical conducting terminal is arranged on a first abutting face of the insulating body and a guiding means is arranged on an opposing side of the electrical conducting terminal on a second abutting face of the insulating body for mechanically connecting the pushrod with an electromagnetic actuator. The pushrod can be integrated in the electromagnetic actuator and thus can be part of the electromagnetic actuator.

Abstract: A flexible shunt for a vacuum circuit breaker can have a reduced straight length and improved flexibility even with an increased thickness within a predetermined accommodation space of a main circuit part. The flexible shunt comprises a pair of conductive plates, each including a clamp connecting portion configured as a flat conductive member, the clamp connecting portion being connected the clamp, a terminal side connecting portion configured as a flat conductive member, the terminal side connecting portion being connected to the terminal side, and a flexible curved portion configured to connect the clamp connecting portion to the terminal side connecting portion, the flexible curved portion being formed to be projected outwardly.

Abstract: An electrode assembly for a circuit breaker is provided. The electrode assembly includes a conductive assembly and a heat transfer assembly. The conductive assembly includes a stem portion and a contact portion. The heat transfer assembly includes a number of elongated bodies, a first heat transfer surface, and a second heat transfer surface. The first heat transfer surface is disposed on the conductive assembly. Each heat transfer assembly body includes a second heat transfer surface. Each heat transfer assembly body is coupled to the conductive assembly with the first heat transfer surface coupled to a number of second heat transfer surfaces.

Abstract: In a vacuum circuit breaker corresponding to three-phase, which is configured by linearly arranging three pressure tanks respectively corresponding to one-phase, in which insulation gas is encapsulated, and a vacuum valve is installed, each pressure tank has a nearly longitudinal shape or a nearly square shape, viewed from a plane surface, and the vacuum valve is arranged in each of the pressure tanks in a state where a drive direction of the movable conductor is aligned with an upper lower direction, and the movable conductor is positioned lower than the vacuum valve, and keeps a sufficient insulation distance with respect to the movable-side connection conductor, and is neared to a position in one of diagonal directions or longitudinal directions of the pressure tank having a nearly square shape or nearly ellipsoidal shape, and moreover, the operation mechanism is arranged and configured at a position, which is lower than the vacuum valve.

Abstract: The present invention relates to a vacuum circuit breaker, and more particularly, to a structure for preventing the eccentricity of a movable contact in a vacuum circuit breaker, wherein the concentricity of a fixed contact and the movable contact is maintained by preventing the eccentricity of and maintaining the straightness of the movable contact when the vacuum circuit breaker opens/closes so as to improve sealing performance and to prevent the increase in temperature.

Abstract: The invention relates to an on-load tap changer for switching among different winding taps of a step transformer without interruption according to the preamble of the first patent claim. The general inventive concept lies in actuating both the selector contact unit and the switching means for uninterrupted load switching by means of a common motor drive without an energy store being connected therebetween.

Abstract: A switching apparatus includes: a vacuum valve which houses a fixed side electrode fixed to a fixed current-carrying shaft and a movable side electrode fixed to a movable current-carrying shaft coaxially arranged with the fixed current-carrying shaft in face-to-face relation to the fixed side electrode; and a buffering mechanism which is coaxially disposed with the fixed current-carrying shaft on the fixed side of the vacuum valve and reduces a collision load at the time when the movable side electrode is close contact with the fixed side electrode.

Abstract: Switchgear comprising: an air-insulated earthing disconnecting switch switchable among the closing position, disconnecting position, and earthing position; a vacuum interrupter electrically connected to the air-insulated earthing disconnecting switch; an operating device of the air-insulated earthing disconnecting switch having a motor; and an operating-force transmission unit transmitting driving force from the motor to a movable electrode of the air-insulated earthing disconnecting switch, wherein the operating-force transmission unit includes an operation rod fixedly coupled to the movable electrode, a shaft rotatably driven by the motor, a lever fixed to the shaft and making an arc motion with the shaft rotatably driven, a coupling pin coupling the lever and the operation rod, and limit switches detecting that the air-insulated earthing disconnecting switch is in the closing position, disconnecting position, or earthing position by means of the coupling pin driven by the operation of the rod operating wit

Abstract: Disclosed are a power transmission device for a vacuum interrupter, and a vacuum breaker having the same. The device includes: a driving link coupled to an adjuster; a driven link coupled to a movable electrode of a vacuum interrupter; connection links configured to connect the driving link and the driven link with each other, and coupled to the driving link and the driven link such that an interval between the driving link and the driven link is varied; cams coupled to the connection links in a perpendicular direction; and cam guides having guide recesses for slidably coupling the cams, and configured to guide the interval between the driving link and the driven link to be changed.

Abstract: A three-phase disconnect switch for a power distribution system that supplies three-phase power from a source through a main circuit breaker to multiple three-phase feeder circuits, includes three pairs of contacts adapted for connection to the three phase lines of a selected one of the feeder circuits for opening and closing each of the phase lines, and a movable actuator associated with the three pairs of contacts and responsive to a signal indicating the occurrence of an arcing fault in the selected feeder circuit for initially creating a short circuit across the three phase lines of the feeder circuit and then opening the contacts.

Abstract: An electromagnetic actuator comprising a core moving between a latched position and an open position, a permanent magnet, a coil designed to generate a first magnetic control flux to move the core from an open position to a latched position, and a second magnetic control flux designed to facilitate movement of the moving core from the latched position to the open position. The permanent magnet is positioned on the moving core so as to be at least partly outside the fixed magnetic circuit in which the first magnetic control flux flows in the open position, and to be at least partly inside the fixed magnetic circuit used for flow of a magnetic polarization flux of the magnet in the latched position.

Abstract: The invention relates to a stepping switch with vacuum switching tubes (22) according to the preamble of the first claim. According to the invention, the general inventive concept consists in providing a second cam disc (3) which is rotationally fixed to the driveshaft (1) in addition to the first cam disc (2) which is rotationally fixed to the driveshaft (1) and which is known from the prior art for applying the force of the opening stroke of the contact system of the vacuum switching tubes (22). The second cam disc exerts a sufficiently high closing force onto the movable follower of the vacuum switching tubes (22) via a spring-lever system provided on the rocker arm arrangement (6) even in the event of a short-circuit stress and additionally allows a tolerance compensation of the contact system.

Abstract: A circuit breaker is provided which can be filled with a quenching gas and which has two contact arrangements, which can be moved relative to one another and along a longitudinal axis of the circuit breaker. The contact arrangements form a arcing contact system and a rated current contact system connected electrically in parallel with it. One of the contact arrangements includes inner rated current contacts and outer rated current contacts of the rated current contact system, where the inner rated current contacts overhang the outer rated current contacts in the direction of the longitudinal axis, and the outer rated current contacts coaxially surround the inner rated current contacts. The circuit breaker has a high current carrying capability as well as a reliable switching-on and -off behavior, such as during and after the occurrence of a short-circuit current in the circuit breaker.

Abstract: A tank type vacuum circuit breaker uses a columnar or cylindrical insulation rod at a connection portion between an operating mechanism unit and a vacuum valve. The insulation rod is connected to the operating mechanism unit and the vacuum valve by rod-shaped pins. To prevent the insulation rod itself from falling, connection is made by shifting phases of the pins 90 degrees, respectively, each pin being connected to the operating mechanism unit and the vacuum valve. Accordingly, the falling of the insulation rod, the use of an insulation support tube and an insulation support for ensuring mechanical strength, are avoided. Further fastening of those supports by bolts or the like is not needed. Increases in the number of components, the size of the shape of assembly members around the insulation rod, and weight due to such increases, are prevented.

Abstract: A system having electrical equipment integrated on a structure is provided. The system includes at least one electrical equipment located at a spaced apart relationship and mounted on at least one structure. A method is provided for isolation of electrical equipment. The method includes opening and closing a contact by engaging or disengaging one or more terminals of the electrical equipment correspondingly with a supply line or a distribution line by a mechanism for isolation. The mechanism can be a handle or a moving mechanism which is associated with a movement in a vertical direction or horizontal direction or with a movement that provides isolation.

Abstract: The vacuum switch is compact, requires little effort, and provides a reliable current path having a high current-carrying capacity between the terminals of the vacuum switch, particularly at high switch-on speeds. The vacuum switch has a vacuum chamber, in which a vacuum is present and in which a switching contact is arranged. The switching contact includes a fixed contact piece firmly connected to the vacuum chamber and in electrical contact with a fixed contact terminal, and a moving contact piece movably guided relative to the fixed contact piece. The moving contact piece is at a distance to the fixed contact piece in a disconnect position and contacts the latter in a contact position. A drive unit produces a drive movement. A switching mechanism is connected to the drive unit and the moving contact piece and includes a conductor section that is electrically conducting up to the moving contact piece.

Abstract: A pushrod assembly for a circuit breaker having a pushrod with an insulating body, an insulating housing surrounding the push rod, a first insulating shield connected to the pushrod and a second insulating shield connected to the housing. The first insulating shield and the second insulating shield are arranged inside the housing such that an electrical path through a fluid inside the housing is longer than the distance of a first end and a second end of the push rod.

Abstract: The present invention provides a vacuum interrupter for interrupting a voltage. The vacuum interrupter includes a vacuum bottle housing having an interior and an exterior, and at least one vacuum bottle positioned within the interior of the vacuum bottle housing. The at least one vacuum bottle includes axially separable contacts within it, including at least one moveable contact. The vacuum interrupter further includes an operating mechanism coupled to the moveable contact including an actuator, a toggle pivotable by the actuator, and a bi-stable link assembly operable with the toggle to reciprocate the moveable contact. The operating mechanism also includes a spring biasing the contacts apart and a stop to hold the contacts closed in a closed position of the interrupter. The vacuum interrupter further includes a seal between the vacuum bottle housing and the operating mechanism sealing the operating mechanism from the interior of the vacuum bottle housing.

Abstract: It is an object to provide a switchgear capable of alleviating burden to a manager. In order to solve the aforementioned problem, the switchgear according to the present invention includes a plurality of compatible switch units each provided in a housing and closing/interrupting/ground functions so that the plurality of switch units are connected to supply power to the load side.

Abstract: The contact assembly for a vacuum interrupter, comprises: a fixed contact; a fixed electrode coupled to the fixed contact; a movable contact movable to a first position at which the movable contact comes into contact with the fixed contact and a second position at which the movable contact is separated from the fixed contact; a movable electrode coupled to the movable contact and movable with the movable contact; and a contact support member installed to be in contact with the movable contact on the circumference of the movable electrode and increase a contact area contacting the movable contact together with the movable electrode in order to reduce stress applied to the movable contact and the movable electrode when the movable contact moves to the first position.

Abstract: Terminals for a vacuum circuit breaker include: a first terminal having a plurality of supporting rings, a plurality of finger contactors, and ring-shaped springs installed to contact an outer circumferential surface of the finger contactors so as to provide an elastic force to the finger contactors toward the center; a second terminal having an outer diameter larger than an inner diameter of the first terminal formed by an inner circumferential surface of the finger contactors of the first terminal, and configured by a bushing-type electric conductor; and an insulation guide member detachably fixed to a leading end of the second terminal such that an electric insulating property of the second terminal increases when the first and second terminals are disconnected from each other, having an electric insulating property, and tapered so as to have a decreased outer diameter as a distance from the second terminal becomes long.

Abstract: An interlock system for a circuit-interrupting device. The circuit-interrupting device includes a gearbox, a load-breaker in series with a visible disconnect, and an assembly driving the visible disconnect between an open state and a closed state. The interlock system includes a cam and a bias-driven follower. The cam is coupled to a shaft and is driven by the shaft between a first cam state when the load-breaker is in an open state and a second cam state when the load-breaker is in a closed state. The bias-driven follower has a first follower state when the cam is in the first cam state and has a second follower state when the cam is in the second cam state. In the second follower state, the bias-driven follower blocks movement of at least one component of the assembly. The cam and the bias-driver follower are positioned inside the gearbox.

Abstract: A high-voltage switch includes a contact arrangement having two arcing contacts, one of which is supported displaceably against the action of a pretensioned spring. When the contact arrangement is closed, the free ends of the two arcing contacts are supported on one another. When the contact arrangement is opened, the two arcing contacts separate and during this process an arcing zone, accommodating compressed arc gas, is produced which is limited axially by free ends of the two arcing contacts and radially by an insulating nozzle toward the outside. To prevent the displaceably supported arcing contact from returning against the action of the pretensioned spring when a large short-circuit current is interrupted, the switch includes a piston/cylinder system functioning as a restoring device, which communicates with the arcing zone and which, with increasing pressure of the compressed arc gas produced in the arcing zone, generates a restoring force supporting the repelling force of the pretensioned spring.

Abstract: An on-load tap changer is provided having a vacuum interrupter that is actuated by a shaft of an actuation assembly. A damper dampens the movement of the shaft. The damper provides more dampening when the shaft is closing the vacuum interrupter than when the shaft is opening the vacuum interrupter. The damper includes a housing at least partially defining an interior chamber into which the shaft extends. A piston with openings extending therethrough is disposed in the interior chamber and is secured to the shaft so as to be movable therewith. A blocking structure is operable to block the openings in the piston when the shaft is closing the vacuum interrupter and to un-block the openings in the piston when the shaft is opening the vacuum interrupter.

Abstract: An electromagnetically operated switching device according to the present invention includes a pair of electromagnetically operated mechanisms for driving a main circuit contact of a switch via a link mechanism symmetrically arranged with respect to an operational center axis, and a length of a spring retaining plate can be regulated in accordance with a change of a link ratio, which is caused by a design change of the main circuit contact.

Abstract: A switchgear includes an earthing and disconnecting switch which linearly moves and is switchable to a disconnecting and an earthing positions, a vacuum valve which performs closing and breaking of a current in a vacuum container producing vacuum inside, and a solid insulator with which the earthing and disconnecting switch and the vacuum valve are covered, therein the earthing and disconnecting switch and the vacuum valve are electrically connected, and closing and breaking of a current is performed in the vacuum valve.

Abstract: An interlock apparatus for a vacuum circuit breaker includes a pair of hindering units configured to allow or prevent a motion of a breaker body to an connection position or a disconnection position; a pair of first interlock bars configured to change a width of the breaker body to be greater than the predetermined spacing distance of the hindering units in a first position where the first interlock bars are spaced from each other, or to change the width of the breaker body to be smaller than the predetermined spacing distance; and a second interlock bar vertically movable to an up position and a down position, the up position for moving the first interlock bars to the first position, and the down position for returning the first interlock bars to the second position by being separated from the interposed position between the first interlock bars.

Abstract: An electromagnet mechanism is coaxially disposed with a vacuum interrupter that is disposed in a circuit breaker, and has a movable core and a fixed core facing each other and an electromagnetic coil that makes the movable core and the fixed core separate or come into contact in response to electromagnetic force. A driving rod which is movably disposed in the axial direction of the electromagnet mechanism is coupled to the movable core, and in which one side is coupled to the circuit breaker and the other side passes through an opening side end plate of the electromagnet mechanism to be extended outward from the opening side end plate of the electromagnet mechanism. An indication unit is disposed on the opening side end plate of the electromagnet mechanism, and indicates a state of the circuit breaker in conjunction with the movement of the driving rod.

Abstract: Disclosed is a vacuum circuit breaker. As a plurality of components of main circuit units are integrally formed as one module by molding using epoxy, the main circuit units are easily fabricated, and assembly errors are prevented. Since the main circuit units are arranged to be symmetrical to each other based on a driving unit, an insulation distance between a switchgear and the main circuit units can be obtained without increasing a size of the switchgear. This may allow the main circuit units to be easily arranged at the right side or at the left side according to an installation state of the switchgear.

Abstract: Sealed chamber for monitoring pressure 23 is provided on sealed tank 37. Sealed tank 37 is filled with insulating gas. And, a connection using insulated pipe 19 is provided between medium-pressure space 18 that makes a medium pressure and sealed chamber for monitoring pressure 23. In sealed chamber for monitoring pressure 23, a pressure monitoring and controlling means is provided for monitoring the internal pressure thereof to activate the pressure-release control in response to the situation where the monitored internal pressure has reached the predetermined setting value. The pressure monitoring and controlling means includes solenoid valve 28 that is capable of opening sealed chamber for monitoring pressure 23 to the atmosphere, pressure detector 26 that detects the internal pressure, and pressure monitor 27, which activates solenoid valve 28 for pressure-release when pressure detector 26 detects that the internal pressure has reached the predetermined abnormal pressure value.

Abstract: Disclosed is a change-over selector with a vacuum arc extinguishing circuit, including a central shaft, a moving contact driven by the central shaft to rotate, and a first static contact and a second static contact circularly arranged on insulation laths of a cage body of the change-over selector, where the moving contact is driven by the central shaft to rotate to switch between the first static contact and the second static contact, the moving contact and the first and second static contacts form a change-over selection main-circuit, a vacuum arc extinguishing sub-circuit including a vacuum tube is connected in parallel to the change-over selection main-circuit, the vacuum tube is opened after the moving contact is separated from the first static contact, and the vacuum tube is closed before the moving contact is electrically connected to the second static contact.