Abstract: The toggle mechanism of a circuit breaker is connected at one end to the pivoted contact arm and at the other end to a pivoted latch lever which is engaged to latch the toggle mechanism by a latch member pivoted for movement in a plane perpendicular to the plane of the toggle mechanism. The latch member serves as an armature for a trip motor energized by a trip circuit responsive to an arc fault and/or a ground fault to unlatch the toggle mechanism and trip the circuit breaker open. The latch member is also tripped by a helical bimetal responsive to persistent overcurrents and coupled to the latch member through an ambient compensator bimetal cantilevered from the latch member. A flexible shunt connected between the helical bimetal and contact arm passes through an extension of the magnetic circuit of the trip motor to generate a magnetic field of sufficient strength to trip the latch member instantaneously in response to a short circuit.

Abstract: An arcing fault detection circuit breaker (10) with strain relieved electrical tap comprises an electronic trip unit (68) to detect arcing from line (30) to neutral (80). Arcing is detected by measuring the voltage drop across a bimetal (32). Voltage drop across the bimetal (32) is sensed by a twisted pair conductor (62), which is electrically connected across the bimetal (32). The bimetal (32) has a fixed end (34) and an opposing free end (54), which is free to move. A strain relief element in the form of stepped eyelet (92) is used to affix one conductor (64) of the twisted pair conductor (62) to the bimetal (32) so that the conductor (64) remains affixed to the free end (54) of the bimetal (32) during movement of the bimetal (32).

Abstract: A modular circuit breaker system includes a plurality of modules mounted side-by-side. The modules include electrical terminals for connection to live and neutral conductors of an electrical supply. Rigid metallic conductors extend between the modules for connecting electrical circuitry of one module to the electrical circuitry of the other module. Each conductor is removably engaged with electrical contacts mounted within the respective modules.

Abstract: In an exemplary embodiment of the invention, a dual test mechanism is presented for use in a circuit breaker. More specifically, the dual test mechanism includes a dual test button which comprises a single switch for testing both the AFCI and GFCI circuits of the breaker. The test mechanism includes a circuit board, which forms a part of the circuit breaker, and a test button assembly which includes a test button and signaling components which are electrically connected to the circuit board.

Abstract: An arc fault circuit breaker comprising an electronics portion that is interconnected with a mechanical portion is presented. A plunger arm affixed to the end of a plunger shaft of a solenoid connects the electronics portion with the mechanical portion. A protrusion is provided to assist in assembly of the circuit breaker. The protrusion depends from the plunger arm. An assembler applies a light downward force with one finger on the protrusion and the plunger arm tends to assume a position at right angles to the surface of the printed circuit board. When the electronics portion is connected with the mechanical portion, the plunger arm is properly aligned and it enters into the slot. If the electronics portion is slightly offset, the assembler's finger on the protrusion can move the plunger arm slightly to align the plunger arm. Thus, the invention enables an assembler to hold and guide the plunger arm into the correct position with one hand while assembling the circuit breaker.

Abstract: A current detector includes a Hall-effect device 18 for detecting a magnetic field generated by a current flowing across a conducting portion; a magnetic core 19 having a first end face for concentrating a magnetic flux and a second end face having a smaller area than the first end face, only the second end face being disposed at a position in close proximity to or in abutment against a magnetic field detecting surface of the Hall-effect device; and a signal processing circuit 26 for processing an output signal from the Hall-effect sensor 18 into a signal representing the current flowing across the conducting portion.

Abstract: An apparatus for use in arcing fault detection systems within circuit breakers and which is adapted for automated production by top-down assembly. In one embodiment, the apparatus includes a circuit board and a two-piece sensing coil within a two piece housing with its center oriented horizontally relative to the circuit board. In other embodiments the sensing coil is one-piece and is either preassembled with a sensing bus and oriented horizontally or oriented vertically relative to the circuit board. Also included are several methods for making electrical connections to the circuit breakers.

Abstract: An arc fault circuit breaker (10) conducting an electric current to a protected load is presented. The circuit breaker (10) has a first (mechanical) compartment (24) and a second (electrical) compartment (62). A bimetal resistor (50) is disposed within the first compartment (24) and conducts the current therethrough. The bimetal resistor (50) has a stud (56) extending into the second compartment (62). A single sense line (60) is electrically connected to the bimetal resistor (50) and routed into the second compartment (62). The sense line (60) and said stud (56) conduct a voltage signal indicative of arcing of the current. A circuit board (84) is disposed within the second compartment (62) and is connected to the sense line (60) and stud (56) within the second compartment (62) to process the voltage signal. The circuit board (84) has a first conductive path (104) electrically connected to the stud (56), and a second conductive path (106) electrically connected to the sense line (60).

Abstract: A miniature circuit breaker has an arc fault detector and a ground fault detector each with its own test circuit. Test switches for the two test circuits are mounted on a printed circuit board and share a common test contact formed by a flat U-shaped leaf spring. The common test contact is deflected into engagement with another test contact for one or the other of the two test switches by a remotely mounted common test button through a common test actuating member which is moved generally rectilinearly by rocking the common test button.

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

Abstract: A method for assembling a modular current transformer (17) includes providing a first bobbin (40A) having a first aperture (32A) disposed therein and a second bobbin (40B) having a second aperture (32B) disposed therein. The first axial aperture (32A) is aligned with the second axial aperture (32B), and a xontinuous wire (21) is wrapped sround the first bobbin (40A) in a first direction. With the first and second axial apertures (32A, 32B) still aligned, the continuous wire (21) is then wrapped around the second bobbin (40B) in a second direction opposite the first direction. The first bobbin (40A) is then inverted by pivoting the first bobbin (40A) about a flexible tab (33) that connects the first and second bobbins (40A, 40B). A transformer core (22) is then disposed through the first and second axial apertures (32A, 32B). The windings on the first and second bobbins (32A, 32B) form the secondary windings (20A, 20B) for the current transformer (17).

Abstract: A trip device comprises a removable module for determining long delay tripping parameters, designed to be fixed to a front panel of the trip device. In the fixed position, the removable module exerts a pressure, via an auxiliary part, on a movable part so as to move the latter to a position in which it performs voltage connection of the processing circuit of the trip device to the conductors of a power system to be protected. In an unlocked position of the removable module, the movable part is urged to the disconnected position by a spring. The part can be movable in rotation or in translation.

Abstract: A tester for an arc fault circuit breaker plugs into a socket in the protected branch circuit. An actuator includes a first spring biasing a moveable contact carried by a pivoted contact arm away from a fixed contact and a momentary closer for momentarily closing the contacts. The momentary closer includes a push button and a second spring coupling the push button to the pivoted contact arm to close the contacts when actuated. Closing of the contacts completes a circuit across the branch circuit resulting in a current producing a magnetic repulsion force which blows the contacts open thereby striking an arc. The arc, which should trip the arc fault circuit breaker is visible through a translucent or transparent section of the molded tester housing. A fuse interrupts any overcurrent and a test light verifies initial energization of the protected circuit and operation of the arc fault circuit breaker.

Abstract: An electromagnetic starter with an overload relay having magnetic flux shielding is disclosed for use in industrial contactor applications. The starter includes a multi-pole DC controlled contactor which is interlockingly coupled to an overload relay. The overload relay has a simplified interlocking connection to the contactor, which when made, corresponds to an abutting electrical connection between the contactor and the overload relay also being made. The contactor further has a guiding pin that promotes even contact closure within the contactor.

Abstract: An electrical shorting block has a molded body with a plurality of side-by-side recesses in which terminal members having first, tapped apertures are secured. A shorting bar supported in the molded body extends across but is spaced from the terminal numbers and has second apertures aligned with the first apertures. For the hot side terminal members, shorting connectors slidable through but captured by the apertures in the shorting bar have threaded ends which can be selectively threaded into the tapped first apertures of those terminal members. Helical compression springs bias the captured shorting connectors away from the terminal members when not used to short the terminal. Common terminal members are connected to the shorting bar by shorting screws which remain threaded into the first apertures. The terminal members preferably have both screw terminations and male fast-on terminations.

Abstract: A switchable adaptor for receptacles includes a manually settable switch that may be manually tripped or tripped by a solenoid in response to a signal. The switch is readily converted to be normally ON or normally OFF, and to be unipolar or multipolar. The adaptor may conveniently be in the form of a power bar or a power block, and will normally include a circuit board which may incorporate a circuit suitable for generating a signal responsive to a predetermined input condition.

Abstract: Problems with inaccuracies in selecting the relay trip current in an overload relay are eliminated in an overload relay employing a custom potentiometer having a resistance that varies at multiple rates to set the trip current value. The dial markings on the trip current adjustment dial are sufficiently spaced to allow for a more precise selection of the relay trip current at the higher ampere settings of the relay.

Abstract: A ground fault circuit interrupter has a pair of stationary contacts and a pair of movable contacts mounted in a housing. Also included is an electromagnetic coil mounted in the housing for generating an electromagnetic field. The interrupter also has a plunger and an armature, each slidably mounted at least partially within the electromagnetic coil. The armature can be magnetically driven by the coil against the plunger. A latch means is included for releasably holding the pair of movable contacts against the pair of stationary contacts. A fault detector can detect a fault in an electrical distribution system in order to actuate the electromagnetic coil.

Abstract: A multi-pole circuit breaker assembly for interrupting AC power to a load upon the detection of an earth leakage fault or an overcurrent condition includes a pair of circuit breaker units mounted adjacent to an earth leakage module. The earth leakage module includes an electronic circuit that senses a current imbalance between the power line lead and the neutral line lead using a differential transformer. In response to a current imbalance greater than a predetermined value, the electronic circuit periodically energizes a switching circuit that provides power across a solenoid. The solenoid, when actuated, engages a common trip mechanism to open concurrently the contacts of the circuit breakers units. The common trip mechanism includes an elongated bar that extends through the casing of the earth leakage module and the circuit breaker units. The elongated bar engages a U-shaped trip member pivotally disposed in each circuit breaker.

Abstract: A transient voltage surge suppressor (TVSS) receptacle having front and rear matable casings including a plurality of through openings for receiving the blades of an electrical plug; an electrical circuit within the receptacle having at least one element adapted to clamp high transient voltages imposed thereon to a lower level; an alarm electrically connected to the at least one element for indicating the failure of the at least one element; and a switch connected to the alarm for disabling the alarm, is described. The switch includes a moveable on-off element and a generally U-shaped, metal switch blade having a first leg for contacting the moveable element; a second leg for contacting a contact of the alarm in response to travel of the first leg caused by the moveable element, the second leg; an integral U-shaped portion connecting the first and the second legs; and a non-linear intermediate portion in the second leg extending toward the first leg for absorbing over-travel of the switch blade.

Abstract: A molded case circuit breaker is provided with ground fault protection by a modular unit which drops into a pole compartment in the molded casing in place of a pole assembly. The modular unit includes a housing forming an open faced cavity across which is mounted a printed circuit board with the ground fault circuit components and trip solenoid projecting into the cavity. The housing also supports the ground fault sensing toroid in a position for the appropriate conductors to pass through the coil. A bell switch and auxiliary switch are positioned by the housing for actuation by levers mounted on the cradle pin and crossbar, respectively. An integral leaf spring molded into the housing accommodates for manufacturing tolerances and fixes the positions of the various components.

Abstract: A compact current transformer is formed by arranging a pair of secondary windings on opposite sides of a single turn primary winding. A core is then wound about the primary winding and part of the secondary winding coils from a continuous roll of metal strap. The secondary windings are arranged on a pair of bobbins on opposite sides of the transformer core. A modular twin bobbin arrangement allows the secondary windings to be wound from a continuous source of transformer wire. The continuous wound core eliminates air gaps and improves magnetic transfer between the primary winding and the secondary winding. The continuous transformer wire eliminates the need for soldering or welding to connect between the two secondary windings.

Abstract: In a circuit breaker, a power source current transformer (2) comprises: a secondary coil (6) arranged between two legs (1a and 1b) of a U-shaped part of a main circuit conductor (1), and an iron core (7) including an iron core leg (7a) which penetrates the secondary coil, and yokes (7b and 7b) which embrace the two legs (1a and 1b) of the U-shaped part of the main circuit conductor, the power source current transform supporting the current detecting means. As a result, the power source current transformer (2) is arranged compact inside the main circuit conductor (1), and the main circuit current, when flowing in each of the legs (1a and 1b) of the U-shaped part, produces the magnetic flux output acting on the secondary coil. Hence, even if the main circuit current is small, a great power source output can be obtained.

Abstract: A ground fault/rating plug for molded case circuit breakers is inserted within the circuit breaker cover for electrical connection with the circuit breaker electronic trip unit. A rating resistor within the ground fault/rating plug enclosure sets the circuit breaker ampere rating. Rotary switches on the outer surface of the ground fault/rating plug enclosure configures the trip unit for ground fault protection.

Abstract: A module for use with the circuit breaker, the module being arranged to be mounted on an end of the circuit breaker and to monitor and/or control the circuit breaker and/or an electrical circuit control thereby in use. The module can be active or passive, and, where circuit breakers are ganged in side-by-side relationship, the module can be equal in width to the width of the gang breaker unit to which the module is mounted. The invention also resides in the combination of a module and a circuit breaker.

Abstract: An electric switch (1) includes a switching device (4), movable between its ON position and OFF position, for switching a current circuit. The switch (1) is combined with a magnetic circuit (28, 29) for electromagnetic undervoltage tripping. In the event of undervoltage, the magnetic circuit (28, 29), as it opens, shifts the switching device (4) to its OFF position. The switching device (4) shifted to its OFF position closes the magnetic circuit (28, 29) again. A linearly movable fixing slide (24) couples the switching device (4) with the magnet armature (28) of the magnetic circuit and fixes the magnet armature (28) on the magnet core (29) in the OFF position of the switching device (4).

Abstract: A low resistance current interrupter for detecting the occurrence of an unsafe condition and terminating power to an electrical circuit. The current interrupter comprises two in-line connectors having a gap formed therebetween. An electrically conductive pin is disposed in the gap for movement between a first, extended position, wherein the pin bridges the gap to establish electrical contact between the connectors, to a second, retracted position wherein electrical contact is broken. The device further includes means for sensing the occurrence of an unsafe condition and generating a signal indicative thereof, and an electromechanical means such as a solenoid which, upon receiving said electrical signal, is activated and causes the pin to move to the second position.

Abstract: Methods and apparatus for switching a load between first and second sources is shown to include first and second solid state switches connected to the load. First and second mechanical breakers are connected between the switches and the sources so that each source is connected to the load through a circuit breaker and solid state switch. A controller is connected to sense the voltage from the first and second sources. The controller is connected to the first and second switches and the first and second mechanical breakers. The controller senses the phase difference between the voltages from the first and second sources. The controller causes the first and second mechanical breakers to open and close in response to sensing the phase difference between the sources. The first and second mechanical breakers can include medium voltage vacuum breakers.

Abstract: A field-installable circuit breaker trip actuator unit includes a flux shifter unit that interfaces with the circuit breaker operating mechanism and is installable without dismantling the circuit breaker components. The flux shifter unit responds to an electronic trip unit to articulate the circuit breaker operating mechanism and separate the circuit breaker contacts upon occurrence of an overcurrent condition. A reset arrangement allows the trip actuator unit to be automatically reset upon completion of the contact separation process.

Abstract: A portable ground fault interrupter is provided which includes a strong environmentally durable housing and plug inputs for plugging into an electrical outlet. The housing also contains receptacles to accept an electrical plug. A plurality of first electrical contacts are within the housing and stationary relative to the housing. A second plurality of electrical contacts corresponding to said first contacts are suspended within the housing by electrical conducting strips which biasingly move the second contacts away from the first contacts. A latching assembly selectively and operably engages said second contacts to overcome the force of the suspending strips to move the second contacts into electrical engagement with the first contacts. Occurrence of a ground fault removes the latching assembly from engagement with the second contacts breaking electrical contact between the first contacts and second contacts.

Abstract: A ground fault interrupter (gfi) wiring device in the form of a duplex wall receptacle. A pair of electrically conducting members in the form of small buss bars each carry two, spaced contacts. The buss bars are moveable to bring their respective contacts into and out of engagement with fixed contacts on the hot and neutral terminals on the line and load sides of the receptacle. The buss bars are biased toward movement to the circuit-breaking position by respective coil springs extending through openings in a separator member dividing the interior of the receptacle housing into front and rear compartments. One end of each spring rests upon a respective buss bar and the other end is contacted by an integral portion of the front housing section, the springs being compressed to apply a biasing force to the buss bars only upon placing the front housing section in mating engagement with the rear section.

Abstract: A dc power supply circuit connects a plurality of dc circuit breakers to a semi-conductor converter, returning again to the semi-conductor converter through a dc driving part such as an electric railcar connected to each dc circuit breaker. A second dc circuit breaker of larger capacity than the above-mentioned dc circuit breakers is provided in a return circuit and opened when a short circuit current is detected. A current decreasing means opens the second dc circuit breaker to decrease the short circuit current and includes, for example, a series-circuit of a resistor R and a reactor L. The dc power supply circuit has a large interruption capacity with low resistance loss.

Abstract: A compact current detection unit which detects a failure in a relay terminal and provides a relay terminal array which has a failure detection function and is compact and easy to assemble. The current detection unit includes two symmetrical bobbins; a core located within compartments of bobbins and has an air gap in it; holes in the bobbins which correspond to air gap in the core; coil wound on the compartments; and a circuit board fastened to the side of one of the bobbins on which a Hall element is mounted. A Hall element is inserted through and fixed in position by the holes in the bobbins and the air gap in the core. If a current is flowing through the coil, the lines of magnetic force generated in the core are detected by the Hall element located in the air gap. If no current is flowing, no lines of force are detected.

Abstract: A resettable circuit interrupter device includes a circuit board support, contact pairs for selectively opening or closing a circuit, one contact of a contact pair being positioned on the support, a solenoid actuator positioned on the opposite side of the support for selectively operating the contacts, and a solenoid plunger device extending from one side of the support to the other side of the support and a contact carrier mounted on the plunger and on which a movable contact is mounted, the plunger being movable to move the movable contact into engagement with the fixed contact in response to energization by the solenoid actuator.

Abstract: An auxiliary switch, mounted in a compartment in the molded housing of a circuit breaker separate from the compartment in which the circuit breaker mechanism is mounted, is actuated, when the circuit breaker contacts are open, by cascaded actuating members, one of which engages, through a housing panel dividing the compartments, the latchable cradle of the circuit breaker mechanism to actuate the auxiliary switch when the circuit breaker is tripped, and the second of which is spring biased against a cam surface on an operating member incorporating the circuit breaker handle to actuate the auxiliary switch when the handle is in the off position.

Abstract: A reverse wiring indicator for a GFCI receptacle alerts the installer in the event that the AC source has been improperly wired to the load or feedthrough terminals of the receptacle rather than to the source or input terminals. The reverse wiring indicator operates by open-circuiting one of the load or feedthrough terminals of the receptacle, and may take the form of a removable barrier which inhibits conduction through one of the power contact sets of the GFCI circuit breaker until the receptacle has been installed and successfully tested. The contact set through which conduction is inhibited is the one other than that to which the TEST switch is connected, and the other contact set is allowed to conduct in the normal manner.

Abstract: A compact coil assembly is provided for protecting electrical components from transient voltage surges. The assembly includes a bobbin having a cylindrical core with two ends. A first and second flange are each perpendicularly mounted and extended outwardly from one of the ends. A lead pin is perpendicularly upstanding on the top surface of the first flange. The first flange has a parallel outer and inner wall defining a channel therebetween. The inner wall has a slot therethrough. The slot is open at one end to the top surface of the first flange and extends downward to the core. The slot is positioned on the top surface of the first flange opposite the lead pin. The channel extends from the lead pin across to the end of the slot near the core. The width of the channel and the slot are adapted for guiding a winding wire therethrough.

Abstract: A switch mechanism opens a contact set in the event of an electrical fault condition. The mechanism involves a contact lever biased by a spring for pivoting about one or other of two fulcrums to open or close the contacts respectively. The fault condition results in an out of balance current flow which causes a solenoid to release a plunger initiating operation about a fixed fulcrum to open the contacts. A reset device is used manually to initiate operation about a movable fulcrum to reclose the contact set, provided the fault condition has been removed. An arm is deflected by the plunger to shift the movable fulcrum and also acts to restore the plunger as the mechanism is tripped. The switch mechanism may be incorporated in a residual current device (ground fault circuit interrupter) which provides a detection circuit to trip the mechanism.

Abstract: A ground fault interrupter (gfi) wiring device includes a latch member having integral abutment, latching and spring portions. In the preferred embodiment, the latch member is formed from a unitary blank of springy sheet metal, the spring portion being a leaf spring formed at one end and biasing the latch member to a latching position to maintain the moveable contact(s) in circuit-making relation with the fixed contact(s) of the device. The latch member is released to permit circuit-breaking movement of the moveable contact(s) by a solenoid having an armature with a relatively enlarged head portion to enhance speed of operation. Optionally, a spring may be provided to maintain the otherwise freely-slidable armature with its end portion in spaced relation to the latch member abutment portion so that the armature gains momentum before contacting the abutment portion to effect unlatching movement of the latch member.

Abstract: A miniature ground fault circuit breaker having a housing assembled from molded sections has stiff conductors supporting the toroidal coils of the ground fault circuit in position in one molded section and aligning connectors secured to the stiff conductors for easier assembly of the molded housing sections.

Abstract: A miniature circuit breaker with two thermal-magnetic poles has an electronic trip device providing ground fault, and sputtering arc fault (if desired), protection located entirely in a large central compartment of a molded housing between compartments housing the two mechanical poles. The molded housing is assembled from a top base and top cover forming a compartment for the thermal-magnetic trip device of the first pole, and a bottom cover and a bottom base forming the compartment for the second mechanical pole. A hollow center piece mates with the top and bottom bases to form the single, large electronics compartment.

Abstract: A guidance system for an interrupter switcher comprising a first guide positioned in between the contact support and the movable contact system of the interrupter, and a second guide inserted into the stationary contact system of the interrupter. According to the invention the second guide is capable of receiving the nozzle of the movable contact system. An interrupter with the guidance system is assembled by positioning the first guide between the contact support and the movable contact system, positioning the second guide within the stationary contact system, inserting the nozzle of the movable contact system into the second guide, and mounting the stationary contact system in the interrupter housing. The assembly of an interrupter with a guidance system results in a self-adjusting switcher interrupter capable of maintaining a stable alignment between the interrupter's movable and stationary contacts while opening and closing the interrupter.

Abstract: A conducting spring is provided for exerting a biasing force against a test button to open a circuit interrupter test circuit. The spring includes a one-piece, elongated cantilever having a first and second end. The cantilever is formed from an electrically conducting material. One of the cantilever ends is adapted to directly secure to a first terminal of the test circuit. The other cantilever end is adapted to directly and reversibly contact a second terminal of the test circuit. The spring also includes means for resiliently flexing the second end of the cantilever in relation to the first end. The flexing means is integrally formed with the cantilever. Also provided is a ground fault circuit interrupter and a ground fault circuit module for protecting a circuit interrupter with a push-to-test feature.

Abstract: A circuit breaker has a pair of poles, either of which can experience a ground fault. A sensing device senses an imbalance of current between the phases and neutral, and a trip device responsive to the sensing device simultaneously trips both of the poles when an imbalance of current (ground fault) is sensed in either of the poles. The trip device includes a trip lever engageable with each of the poles and a single solenoid for controlling operation of the trip lever.

Abstract: A circuit breaker includes a normally open switch having first and second contacts and a movable leaf spring supporting the first contact. The leaf spring is normally oriented in a first position wherein the first contact is not in electrical contact with the second contact. The leaf spring is deformable into a second position wherein the first contact is in electrical contact with the second contact. An armature is movable between an open and a closed position and is located adjacent an electric coil which generates a magnetic field which moves the armature into the closed position when the coil is energized. The leaf spring biases the armature into its open position when the coil is not energized. The armature causes the leaf spring to deform into the second position, so as to place the first contact into electrical contact with the second contact, when the coil is energized.

Abstract: A switch mechanism opens a contact set in the event of an undervoltage condition. The mechanism involves a lever assembly biased by a spring for pivoting about one or other of two fulcrums to open or close the contacts respectively. The undervoltage causes a solenoid to release a plunger which initiates operation about a fixed fulcrum. A reset device is used manually to initiate operation about a movable fulcrum, provided that the voltage is sufficient. An arm is deflected by the plunger to shift the movable fulcrum and also acts to restore the plunger during reset. The switch mechanism may be incorporated in a residual current device which provides the undervoltage condition on detecting an electrical fault.

Abstract: A miniature circuit breaker with two thermal-magnetic poles has an electronic trip device providing ground fault, and sputtering arc fault (if desired), protection located entirely in a large central compartment of a molded housing between compartments housing the two mechanical poles. The current rating of the circuit breaker is increased by a gas vent channel extending between the two mechanical pole compartments adjacent the respective breaker contacts which allows gases generated by arcing during current interruption to expand into both outer compartments, thereby permitting the circuit breaker to interrupt larger short circuit currents. The gas vent channel extends through, but does not communicate with, the central electronics compartment.

Abstract: A ground fault module is provided for protecting a circuit interrupter connected between the load and line terminals of a phase and neutral power line. The module includes a sensor for detecting a current imbalance between the phase and neutral power lines. A phase conductor having a rigid, elongated body made of solid, electrically-conducting material with a first and second end is adapted for connection to the load and line phase power line. A neutral conductor having a rigid, elongated body made of solid, electrically-conducting material with a first and second end is adapted for connection to the load and line neutral power line. Preferably, terminals are used to clamp the ends of the phase and neutral conductors to the load power line and load neutral line. The phase and neutral conductor are operatively connected to the sensor.

Abstract: A housing is provided for a circuit breaker. The circuit breaker has contacts capable of being in an open state or a closed state, of movement between the open and closed states, and of generating a hot gas in consequence of that movement. An electronics module is provided for controlling movement of the contacts from the closed state to the open state. The housing has a first portion housing the contacts and a second portion housing the electronics module. The second portion is formed of a material subject to damage by the hot gas, and the first portion is constructed to protect the second portion from damage by the hot gas. The first portion is ideally formed of a thermosetting material resistant to damage by the hot gas and the second portion is ideally formed of a thermoplastic material, which reduces the cost of manufacturing the housing. A quick-mounting construction for assembling the second portion with the first portion further reduces the cost of assembly.

Abstract: A magnet is fixed to the inner surface of the ceiling of a cylinder-like yoke which is closed at the top, and a holding plate is attached to the yoke through a slider. A coil and collet are unitedly attached to the holding plate. When a current is passed through the coil, a force proportional to the current acts on the coil so that a constant load is applied to the collet.