Abstract: The present disclosure relates to a contact point monitoring module for a vacuum circuit breaker and a vacuum circuit breaker comprising the same. The present disclosure provides a vacuum circuit breaker comprising a push rod assembly which is coupled to a movable electrode of a vacuum interrupter and moves the movable electrode up or down to make a movable contact in a contact closed state or a contact open state, wherein the vacuum circuit breaker comprises a linear sensor which is coupled to a lower side of the push rod assembly and senses displacement according to a moving direction of the push rod; and a sensor holder which is installed adjacent to the lower side of the push rod assembly and is coupled to the linear sensor to process a signal transferred from the linear sensor.

Abstract: The present disclosure relates to a distributing board having a position lock device and, more specifically, having a position lock device which can hold or release, at a specific position, an electric power device unit. The distributing board having a position lock device, according to one embodiment of the present disclosure, comprises an external case and an electric power device unit drawn into and out of the external case, and further comprises: a position setting bracket which is fixed to the external case and has convex-concave parts for setting the position of the electric power device unit; and a lock device which moves with the electric power device unit by being coupled to a portion of the electric power device unit, and which restricts or allows movement of the electric power device unit by being hooked into or released from the positions of the position setting bracket.

Abstract: Cradle-assist assemblies attached to the breaker cradle housing and/or base or residing at least partially in the breaker cradle housing and/or base include at least one actuator configured to laterally translate the at least one right and the at least one left lock members from the extended lock position to the retracted unlocked position in response to input from a user. The at least one actuator and/or transverse member(s) can be held in a defined position so that the lock members of the cradle can be locked in the respective retracted or extended positions until the cradle assist (internal) lock is manually or automatically released.

Abstract: A removable mechanism for a hard drive is revealed. The removable mechanism includes an upper substrate and a base plate hanged and sliding below the upper substrate, and a control handle and a sliding board are set between the upper substrate and the base plate to carry each other. The control handle controls a pivot element sliding on an opening of the base plate. By carrying each other to carry a stop element of the base plate, the stop element slides on a concave opening for dismounting a storage device inserted to the removable drawing mechanism. Thereby, the present application is convenient for dismounting the storage device.

Abstract: Aspects and techniques of the present disclosure relate to enclosures, such as, electrical enclosures, for example, explosion-proof enclosures, and including advantageous features and methods usable with such enclosures. Disclosed features and techniques relate to: an enclosure fastening device; a visual indicator; an enclosure handling assist arrangement; a control handle; and a reset controller.

Abstract: A heat exhaust and dustproof system of a multi-stage distributing board according to an embodiment of the present disclosure includes: multiple compartments provided at a cabinet of a distributing board; and multiple flaps provided at each of the multiple compartments, wherein the flaps are provided with multiple outlets for heat emission.

Abstract: A switchboard is for a power distribution system having a number of electrical lines. The switchboard includes: an enclosure assembly having a chassis; a switching assembly including a plurality of circuit breakers each coupled to the chassis, each of the circuit breakers having a number of terminal lugs structured to be electrically connected to a corresponding one of the electrical lines; and an isolating assembly including a plurality of isolating apparatus, at least one isolating apparatus being coupled to one of the plurality of circuit breakers. The isolating apparatus separates the number of terminal lugs of the one circuit breaker from the number of terminal lugs of each of the other circuit breakers.

Abstract: Dual starters and/or feeders are positioned in a unit housing to be offset from one another in a front to back direction to provide a compact configuration for a MCC cabinet. The dual starters or feeders can communicate with a respective external handle attached to an inwardly oriented shaft. The handles can be rotary handles that connect to a respective gear assembly that transforms rotational input to linear input.

Abstract: An enclosed switchboard includes: a device containing board which contains main circuit devices such as circuit breakers; and a cable connection board which is arranged side by side adjacently to the device containing board, and contains cables that input and output electric power to/from the main circuit devices. In the enclosed switchboard, the cable connection board is configured by one housing; and the inside of the housing is divided into two by a partition plate to be comparted to a cable lead-in compartment which contains lead-in side cables and a cable lead-out compartment which contains lead-out side cables.

Abstract: A switchboard is for a power distribution system having a number of electrical lines. The switchboard includes: an enclosure assembly having a chassis; a switching assembly including a plurality of circuit breakers each coupled to the chassis, each of the circuit breakers having a number of terminal lugs structured to be electrically connected to a corresponding one of the electrical lines; and an isolating assembly including a plurality of isolating apparatus, at least one isolating apparatus being coupled to one of the plurality of circuit breakers. The isolating apparatus separates the number of terminal lugs of the one circuit breaker from the number of terminal lugs of each of the other circuit breakers.

Abstract: An enclosed switchboard includes: a device containing board which contains main circuit devices such as circuit breakers; and a cable connection board which is arranged side by side adjacently to the device containing board, and contains cables that input and output electric power to/from the main circuit devices. In the enclosed switchboard, the cable connection board is configured by one housing; and the inside of the housing is divided into two by a partition plate to be comparted to a cable lead-in compartment which contains lead-in side cables and a cable lead-out compartment which contains lead-out side cables.

Abstract: An enclosed switchboard includes: a device containing board which contains main circuit devices such as circuit breakers; and a cable connection board which is arranged side by side adjacently to the device containing board, and contains cables that input and output electric power to/from the main circuit devices. In the enclosed switchboard, the cable connection board is configured by one housing; and the inside of the housing is divided into two by a partition plate to be comparted to a cable lead-in compartment which contains lead-in side cables and a cable lead-out compartment which contains lead-out side cables.

Abstract: An electrical enclosure wherein an electrical component can be moved between various positions (e.g., connected, disconnected, test, etc.) without opening an enclosure door. The electrical enclosure supports a component for movement between a withdrawn position, a test position, and an inserted position. A handle is accessible by an operator from an exterior of the enclosure and is configured to move the component between the respective positions without having to open the enclosure. The handle is integral with the enclosure and thus an operator needs no special tool or other device to effect movement of the electrical component between its respective positions.

Abstract: A gas-insulated switchgear assembly is provided that includes a housing having an interior containing insulating gas. A disconnector is disposed in the housing and includes a movable contact, as well as fixed contacts that are spaced apart and arranged linearly in a direction perpendicular to a wall of the housing. The movable contact has a colored or topographical marking and is linearly movable among a plurality of positions. The wall of the housing is provided with an inspection window that permits a person to see the colored or topographical marking in relation to the fixed contacts, thereby permitting the person to determine the position of the movable contact.

Abstract: A circuit breaker system includes a circuit breaker that includes an electrical input for a power circuit and positioned on a first holder in a housing of the circuit breaker system; a cooling device positioned on a second holder adjacent to the first holder in the housing, the cooling device configured to dissipate heat generated by the circuit breaker; and a control system coupled to the circuit breaker and the cooling device, the control system configured to determine a temperature condition of the circuit breaker and control the cooling device based at least in part on the determined temperature condition.

Abstract: A drive shaft extension assembly is provided for an electrical switching apparatus which is removably disposed in a cassette. The electrical switching apparatus includes a levering assembly with a drive shaft. The drive shaft extension assembly includes a housing assembly, a shaft extension including an elongated body, and a racking gear. The shaft extension is structured to be coupled to the drive shaft in a fixed orientation, thereby increasing the width of the levering assembly.

Abstract: A system and method are provided for coordinating the installation and removal a motor control center subunit with the power connection and interruption thereof. A system of interlocks and indicators causes an operator to install a motor control center subunit into a motor control center, and connect supply and control power thereto, in a particular order. Embodiments of the invention may prevent actuation of line contacts of the bucket, and shield the line contacts, until the bucket is fully installed in the motor control center. Other embodiments also prevent circuit breaker closure until the line contacts are engaged with a bus of the motor control center.

Abstract: A removable contactor drawer including a transitional chamber receivable in a fixed casing. The transitional chamber including electrical components for an electrical feeder circuit. The fixed casing being designed to be mounted and used within a power distribution center and has input connectors for the incoming electrical power. Source power may be channeled through the electrical components via the fixed casing and delivered to a power outlet on a front face of the transitional chamber. The transitional chamber may optionally contain equipment to monitor and report operational faults within the contactor drawer. A front-mounted motor drive allows a remotely located operator to perform removal of the transitional chamber while under power, thus providing protection against the danger of arc flash.

Abstract: A disconnect mechanism, an electrical component assembly including the disconnect mechanism, and an electrical circuit protector in turn including the electrical component assembly. The disconnect mechanism includes a carriage, as well as a switch actuator connected to the carriage for moving the carriage between a switch-closed position and a switch-open position. A contactor is mounted to the carriage so as to move with the carriage, the contactor including first and second contactor terminals and providing selective electrical connection between the contactor terminals. A movable disconnect switch contact is connected to the first contactor terminal, and is movable with the carriage and the contactor. A fixed disconnect switch contact is positioned for selective engagement with the movable disconnect switch contact as the carriage moves to the switch-closed position.

Abstract: A power connection system includes a power attachment assembly (PAA) to house power cables that transport electrical power, where the cables are terminated by a connector associated with the PAA; and a power supply to provide the power to a network device, where the power supply includes another connector and a group of circuit breakers that correspond to the cables. The PAA and the power supply permit the cables to be connected to the power supply, and permit the connector and the other connector to be connected to form a junction via which the power is transported. The circuit breakers, when turned on, permit the power to be received from the cables via the PAA. The system also includes a handle to disconnect the PAA from the power supply in a manner that turns off the circuit breakers prior to disconnecting the PAA from the power supply.

Abstract: A coupling is for a racking assembly for racking an electrical apparatus into and out of an enclosure with an actuator. The electrical apparatus includes a housing. The racking assembly includes a safety interlock, which is movable between a locked position, and an unlocked position corresponding to the racking assembly being operable to rack the electrical apparatus into or out of the enclosure. The coupling includes an adapter having a first portion coupled to the racking assembly, and a second portion coupled to the actuator. A sleeve is movably disposed on the adapter. The sleeve moves the safety interlock from the locked position to the unlocked position. When the safety interlock is disposed in the unlocked position, the adapter transfers movement of the actuator to the racking assembly to move the electrical apparatus.

Abstract: A system and method for connecting supply power to motor control components includes use of a motor control center subunit with moveable supply power contacts. After a motor control center subunit is secured into a motor control center compartment, the supply power contacts may be advanced to engage supply power buses. For disconnection, the supply power contacts may be retracted and isolated from the buses before physical removal of the subunit.

Abstract: A switchgear system includes rail structure having a base coupled to an interior sidewall of a frame. A first member extends from the base and has an upwardly facing surface. The first member has a second surface extending generally transversely to the upwardly facing surface to oppose a surface of the base. A second member extends from the base and has a downwardly facing surface spaced from the upwardly facing surface so as to define a wheel receiving channel there-between. A circuit breaker tuck includes wheels on exterior sidewalls. The wheels are received in the wheel receiving channel to be slidable along the upwardly facing surface, with the upwardly and downwardly facing surfaces limiting movement of the circuit breaker truck about the horizontal axis and the surface of the base and the second surface of the first member limiting movement of the circuit breaker truck about the vertical axis.

Abstract: A position locking device is disclosed for a draw-out circuit breaker. In at least one embodiment, the position locking device includes a screw rod, a catching plate, a positioning plate, a locking plate, and a push rod. The screw rod has key ways. The catching plate has a catching plate hole and a protrusion that can be inserted into the key ways. Positioning notches for limiting OFF, TEST, and ON positions of the circuit breaker are formed on the top surface of the positioning plate, and corresponding protruding platforms are disposed on the bottom surface. One end of the locking plate bears against the bottom surface of the positioning plate, and the other end is locked to or unlocked from an outward protruding platform of the catching plate. One end of the push rod passes through the catching plate hole, and has an inclined surface. When the push rod is pushed, the inclined surface makes the catching plate leave the key ways.

Abstract: A system and method for connecting supply power to motor control components includes use of a motor control center subunit with moveable supply power contacts. After a motor control center subunit is secured into a motor control center compartment, the supply power contacts may be advanced to engage supply power buses. For disconnection, the supply power contacts may be refracted and isolated from the buses before physical removal of the subunit.

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

Abstract: A plug-in housing module for forming an-explosion-proof switchgear/distribution panel including a number of plug-in points, where when the plug-in housing module is in a plugged-in position at a corresponding plug-in point of the number of plug-in points, the plug-in housing module is brought into contact with electrical connection devices and is detachably fixed to carrier rails of a frame of the switchgear/distribution panel, the plug-in housing module including at least one switching device for switching between a locking position and a release position, and when the at least one switching device is in the release position, the plug-in housing module can be moved out of the plugged-in position into a separation position, where in the separation position, the contact with the electrical connection devices is interrupted, while maintaining a flameproof mechanical connection.

Abstract: A locking device for an electric switch is disclosed which is movably guided in a withdrawable rack via an actuating shaft wherein the electric switch is placed in a preferred position, in particular in a disconnected position. In at least one embodiment, the locking device is movable from a release position in which the switch is displaceable in the withdrawable rack to a locking position in which the locking device blocks the switch displacement in a predetermined direction and the actuating shaft is actuated via an actuating crank. In order to safe the switch locking in the preferred position thereof, the locking device is movable to the locking position when the actuating crank actuation is blocked, only. The withdrawable rack, provided with the inventive locking device for the electric switch displaceable in the withdrawable rack via the actuating shaft, is also disclosed.

Abstract: Disclosed herein is a method of moving and altering movement of a breaker mounted spring discharge interlock lever during racking and unracking of a breaker with an enclosure. The method includes, rotating a racking screw to rack the breaker into or out of the enclosure, rotating a shaft in operable communication with the racking screw, translationally moving a cam with a link having one end disconnectably connected to the cam and an opposing end disconnectably connected to a crank, that is fixedly attached to the shaft, translationally moving a cam follower that is in operable communication with the cam, moving the breaker mounted spring discharge interlock lever that is in operable communication with the cam follower, and enabling removal and replacement of the cam by disconnecting the cam from the link, thereby enabling the movement of the breaker mounted spring discharge interlock lever to be altered.

Abstract: A subunit is provided for a motor control center including an enclosure, a number of compartments, a plurality of power lines, and a number of covers for covering the compartments. The subunit includes a housing removably disposed within a corresponding one of the compartments, a plurality of electrical contacts movably coupled to the housing, and an actuating assembly for moving the electrical contacts into and out of electrical contact with the power lines. The subunit further includes at least one of a locking assembly, a panel assembly, and a secondary disconnect assembly. The locking assembly locks the position of the electrical contacts and restricts access to the actuating assembly. The panel assembly is pivotable and translatable with respect to the subunit housing. The secondary disconnect assembly is independent from the actuating assembly in order that movement of the electrical contacts does not move the secondary disconnect assembly.

Abstract: A dampening mechanism for an electrical for an electrical switching apparatus, such as a draw-out circuit breaker, includes a mounting bracket coupled to the circuit breaker, a pivot member, at least one biasing element, and a damper. The circuit breaker is movable into and out of an installed position within a switchgear enclosure. The pivot member pivots between first and second positions corresponding to the circuit breaker not being fully installed and being disposed in the installed position, respectively. The biasing element biases the pivot member toward the first position. When the circuit breaker is moved toward the installed position, the second end of the pivot member engages at least one of a back panel and a ledge of the enclosure, thereby pivoting the pivot member toward the second position. When the pivot member is disposed in the second position, the damper is biased against the ledge of the enclosure to dampen undesired vertical motion of the circuit breaker.

Abstract: Disclosed is a racking mechanism for a drawout circuit breaker including a cross shaft movably positioned in an enclosure and at least one input link in operable communication with the cross shaft via at least one connecting link. At least one racking cam is movably positioned in the enclosure and is in operable communication with the input link. Each racking cam has at least one cam slot receptive of a portion of the circuit breaker. Movement of the cross shaft about an axis of the cross shaft is capable of moving the at least one racking cam from an open position toward a closed position with the portion of the circuit breaker disposed in the at least one cam slot, thereby securing the circuit breaker in the enclosure and the at least one racking cam is in the closed position. A method for securing a circuit breaker in an enclosure and a circuit breaker assembly are also disclosed.

Abstract: An electrical distribution device assembly includes a drawout substructure having at least first and second opposing side portions. The electrical distribution device assembly also includes a telescoping rail unit mounted to one of the first and second opposing side portions. The telescoping rail unit includes a carrier rail having a carrier rail support surface and a loading rail having a loading rail support surface. The loading rail is slidably supported by the carrier rail to define an extended deployed configuration and a retracted stowed configuration. The electrical distribution device assembly also includes an electrical device is supported upon at least one of the carrier rail and the loading rail and is selectively shiftable into and out from the drawout substructure.

Abstract: The invention relates to a frequency converter, comprising: a power electronics part provided with wheels on the lower part thereof; an installation cabinet for receiving the power electronics part movable on the wheels; and connectors arranged to the power electronics part and the installation cabinet, a contact being created between the connectors when the power electronics part is installed into the installation cabinet. To facilitate electrical installation works, the power electronics part is divided at least into a base part provided with wheels and a power stage part arranged thereon, the two being detachably attached together, whereby the base part, when detached from the power stage part, can be pulled out of the installation cabinet whereas the power stage part remains in place in the installation cabinet.

Abstract: A securing mechanism is provided for an electrical switching apparatus, such as a circuit breaker, which is movable into and out of an installed position within a switchgear enclosure. The securing mechanism includes a mount coupled to the circuit breaker, and a movable assembly movably coupled to the mount and including an engagement member. The movable assembly moves among first and second positions corresponding to the circuit breaker not being fully installed within the switchgear enclosure and being disposed in the installed position, respectively. When the circuit breaker is moved toward the installed position, the engagement member engages the switchgear enclosure and moves the movable assembly toward the second position, in which the engagement member securely engages the switchgear enclosure to resist undesired movement of the circuit breaker with respect to the switchgear enclosure.

Abstract: A modular racking system for an electrical switching apparatus is provided. The modular racking system includes a carriage assembly structured to support electrical switching apparatus and at least one cam follower structured to be removably coupled to the electrical switching apparatus.

Abstract: A closure device for a withdrawable rack adapted for receiving power circuit breaker includes a plate arrangement having at least two plates provided with openings and movable relative to one another so that the plate arrangement is changeable between an open position in which the openings of the plates are in alignment and a closed position in which the openings are out of alignment. An actuating mechanism is acted upon by the power circuit breaker as it is inserted to cause a movement of at least one of the plates to thereby change the plate arrangement between the closed and open positions. The actuating mechanism includes two V-shaped linkage assemblies. Each linkage assembly has two legs connected by a hinge to allow the linkage assembly to spread apart, with one of the legs having a free end which is connected to the at least one of the plates, and a coupler is connected to the hinge. Both couplers are jointly articulated to actuating element.

Abstract: An air circuit breaker is provided wherein a rotational force is accurately discontinued at a movement completion time of assuming a connected position, a test position or a disconnected position by a breaker body in the process of withdrawing in and withdrawing out the breaker body from a cradle whereas a driving connection is performed if necessary, the breaker including a coupling device capable of being moved to a position where a withdraw-in and withdraw-out driving force generated by a manipulating handle is transmitted to a withdraw in and withdraw out apparatus and to a position where the withdraw-in and withdraw-out driving force is stopped of transmission.

Abstract: A locking device for an electric switch is disclosed which is movably guided in a withdrawable rack via an actuating shaft wherein the electric switch is placed in a preferred position, in particular in a disconnected position. In at least one embodiment, the locking device is movable from a release position in which the switch is displaceable in the withdrawable rack to a locking position in which the locking device blocks the switch displacement in a predetermined direction and the actuating shaft is actuated via an actuating crank. In order to safe the switch locking in the preferred position thereof, the locking device is movable to the locking position when the actuating crank actuation is blocked, only. The withdrawable rack, provided with the inventive locking device for the electric switch displaceable in the withdrawable rack via the actuating shaft, is also disclosed.

Abstract: Methods and integrated apparatus are disclosed for electrically disconnecting and allowing external support and access for electrical devices in a power conversion system cabinet. The apparatus includes a support structure that translates a power conversion system component at least partially through a door or other cabinet opening between a first position with the component entirely within the cabinet and a second position with the component supported at least partially outside the cabinet, as well as a power disconnect apparatus operated by translation of the support structure to disconnect the component from electrical power when the support is translated from the first position to the second position.

Abstract: A connector assembly for an electronic device saves space and cost. It includes first and second sockets defining first and second insertion paths for receiving mating plugs. A pivoting keep-out member has first and second blocking surfaces and can be pivoted between first and second positions. In the first position, the first blocking member blocks at least a portion of the first insertion path, but the second blocking member clears the second insertion path. In the second position, the second blocking member blocks at least a portion of the second insertion path, but the first blocking member clears the first insertion path. Thus the connector assembly may receive a plug in either the first or the second socket, but not in both simultaneously.

Abstract: A hard disk support apparatus having a casing having an opening accommodate the hard disk; a main support body combined with the hard disk and accommodated in the opening; a lever provided in front of the main support body, having a first side rotatably combined to the main support body and a second side provided to be combined with the main support body; a control button provided either in the lever or in the main support body and releasing the second side of the lever from the main support body; and wherein the lever has a latch provided in an end side thereof, combined to or released from the opening by a rotation of the lever. With this configuration, the present invention provides a hard disk supporting apparatus readily installed and separated, and a computer having the same.

Abstract: A semiconductor device is provided having a single-piece clip that interlocks into a lead frame using one or more forks on the clip that mate with one or more corresponding slots in the lead frame. A semiconductor die is mounted to a pad of the lead frame and the clip couples the die to a conductive lead of the lead frame. The interlocking coupling forms a lever that allows adjustment of a position of the clip relative to a region of the semiconductor die. Interference between the clip fork and a slot corresponding to the clip fork confines the lever motion or pivoting of the clip relative to the mounted semiconductor die. The coupling between the clip fork and the slot furthermore confines motion of the clip in each of a first dimension and a second dimension relative to a position of the lead frame.

Abstract: An interlock assembly for a circuit breaker housing assembly and a circuit breaker extraction device wherein the interlock assembly has a first and second component. The first component is coupled to a circuit breaker housing assembly and the second component is coupled to a circuit breaker extraction device. The first component includes a rail obstruction assembly that is structured to move between a first position, wherein the movable rail obstruction element blocks a circuit breaker wheel from traveling over a circuit breaker housing assembly rail, and a second position, wherein the movable rail obstruction element is spaced from the circuit breaker housing assembly rail so that a wheel may travel over the circuit breaker housing assembly rail. The second component is structured to engage the first component when the circuit breaker extraction device is brought adjacent to the circuit breaker housing assembly and to move the movable rail obstruction element from the first position to the second position.

Abstract: An interlock system is for a bypass transfer switch including first, second, third and fourth circuit breakers. First, second, third and fourth interlock assemblies each include a mounting bracket coupled on or proximate to a corresponding one of the circuit breakers, a transmitting member disposed on the mounting bracket and coupled to the poleshaft of the operating mechanism of the corresponding one of the circuit breakers, and a receiving mechanism disposed on the mounting bracket and structured to engage and actuate the circuit breaker trip lever in response to a trip condition. The transmitting member and receiving mechanism each include primary and secondary connections. A plurality of linkages are adapted to interconnect the connections among the circuit breakers in order to provide a predetermined automatic bypass interlock mechanism, without requiring a separate manual locking device.

Abstract: An apparatus for defeating an interlock for an electrical cabinet permits a technician qualified to service the equipment within the cabinet to defeat the interlock and open the cabinet while current is flowing through the equipment therein, while permitting the interlock to continue to resist unauthorized access to the interior of the cabinet.

Abstract: Disclosed is a main switch conveying apparatus for a vacuum circuit breaker.

Abstract: A mechanism for mounting and removing a data storage device, such as detachable hard disk or optical disc driver, into and from a computer according to the present invention includes a lever pivotally mounted in the middle front of the data storage device; an engaging portion formed on one end of the lever; and a guiding rail formed on a carrier to be engaged with the engaging portion of the lever. The guiding rail is so designed to transform the movements of the lever into assistant forces of pushing and pulling the data storage device into and from the carrier. Moreover, the engagement of the lever to the guiding rail restricts the moving speed of the data storage device and prevents it from being bumped or damaged.

Abstract: An automatically operating interlock device prevents connection of an electrical device within a cabinet unless the cabinet door is closed. The interlock is particularly useful for circuit breakers contained within arc resistant cabinets. The interlock includes a spring-biased brake bar controlling the position of a brake. The brake bar is biased so that it pulls the brake against one of the wheels of the circuit breaker, thereby preventing movement of the circuit breaker towards its rear, connected position. Closing the door causes the door to push against the brake bar, thereby causing the brake bar to pivot the brake away from the wheel. The circuit breaker may then be moved rearward towards this connected position.

Abstract: An object is to provide a key protection structure for an electronic apparatus which can prevent a preset value of a switch from being intentionally changed by the user or the like. When setting of a first switch 21 is ended, a tool shutter operation portion 72 of a lock key 70 is inserted into a first shutter operation hole 61. The tool shutter operation portion 72 is then engaged with an engaging recess 45 of a first shutter 40. Thereafter, the lock key 70 is rotated, so that the first shutter 40 is rotated. A covering portion 44 of the shutter is therefore moved immediately above the first switch 21 to close a first switch operation hole 58, whereby the first switch 21 can be locked (key-protected) so as not to be externally operated.