Abstract: A self-powered self-contained ground fault protective device including a current monitor, an electronic circuit for amplifying the output of the current monitor, a relay connected to the amplifying circuit and adapted to operate whenever ground fault current through the current monitor rises above a predetermined level, and an interchangeable rating plug including means for activating a circuit board switch. The current monitor, amplifying circuit, and relay are all supported and enclosed by a molded insulating housing. The rating plug is inserted into a socket on the exterior of the housing.

Abstract: A circuit interrupter having a fixed elongated contact arm, with a fixed contact disposed at the end thereof, and an elongated movable contact arm, with a movable contact disposed at the end thereof, and a magnetic driving device for rapidly separating the contacts. The magnetic driving device is formed of a ferromagnetic material and has a slot formed therein which is magnetically open on one end. The fixed contact arm is partially disposed in the slot near the closed end and the movable contact arm is partially disposed within the slot towards the open end. The magnetic drive or slot motor rapidly separates the contacts upon a predetermined overload. Divergent arc rails lying in the same general plane extend from the fixed contact and the movable contact.

Abstract: Apparatus for protecting power distribution networks from damage due to ground faults comprises a plurality of groups of zero sequence current monitors, each group surrounding all branches of the network which enter a zone of protection. Each group is electrically connected to produce an output signal corresponding to the vector sum of differential currents flowing into and out of the zone. Each group is connected to a ground fault relay which will trip when the vector sum of the differential currents entering or leaving a zone is above a predetermined level.

Abstract: A circuit breaker includes a slotted magnetic device having a plurality of spaced slotted conductive plates and a moving contact arm positioned within the slot when the circuit breaker is in a closed circuit position so that current flowing through the contact arm has a component in a vertical direction with respect to the slot. An overcurrent condition through the circuit breaker causes magnetic flux to be generated within the slotted magnetic device which develops a force to drive the moving contact arm from the front to the rear of the slot in a direction generally parallel to the bottom of the slot, thereby actuating the circuit breaker from a closed circuit position to an open circuit position. The circuit breaker also includes an arc-extinguishing device including a plurality of apertured conductive plates. The moving contact arm includes a probe member extending into the apertures of the plates when the circuit breaker is in a closed circuit position.

Abstract: A molded case circuit breaker having thermal and magnetic trip means. A moving contact support structure is disposed about the magnetic trip means so as to cause current flowing through the circuit breaker contacts to pass twice through the magnetic circuit of the magnetic trip means. The moving contact support structure includes resistance material operable upon overcurrent conditions through the contacts to aid in heating the thermal trip means. An operating mechanism includes an operating spring in compression which acts as one leg of a toggle linkage and stores energy to operate the contacts with a snap action.

Abstract: A system for interrupting high-voltage circuits including a surge-limiting resistor, a resistor switching interrupter and a power interrupter. The resistor and resistor switching interrupter are connected in series and the series combination connected in parallel with the power interrupter. The resistor switching interrupter includes a hollow rotative gas-conducting crossarm assembly carrying two pairs of moving contacts which cooperate with two pairs of stationary contacts to form four breaks. On an interruption operation, the gas conducting arm is rotated to initiate four arcs and a valve admits high pressure arc-extinguishing gas through the arm and against the arcs.

Abstract: A combination motor-starter circuit breaker comprising a single set of separable contacts and providing the function of motor starting, circuit interruption, and current limiting. The combination employs three separate means for separating the contacts to provide these functions; a solenoid, an overcurrent trip mechanism, and a magnetic drive device for high overcurrent conditions. Arc rails and spaced conductive plates are provided to aid in extinguishing any arcs established. Movable contacts are mounted on a bridging contact arm which can be provided with two open positions, a first position for use during motor control wherein the contacts are separated by a relatively small distance and a second position for use during circuit interruption and current limiting.

Abstract: A multi-pole circuit breaker system includes a plurality of individual circuit breakers and at least one tripping action transfer device disposed between adjacent circuit breakers. The tripping action transfer device includes a lever pivotally supported at one end and carrying a rod shaped transfer member at its other end. The transfer member extends into the interior of the housings of adjacent circuit breakers and cooperates with their tripping mechanisms. A tripping operation of one circuit breaker engages the transfer member and causes actuation of the tripping mechanism of the adjacent breaker to initiate simultaneous tripping thereof.

Abstract: A motor controller providing a disconnect and a single set of movable contacts, to provide operation and protection of a motor and associated circuitry over a complete range of possible currents. Plug-in modules for a circuit disconnect, a solid state overload relay, and an instantaneous trip unit are provided. The disclosed integral modular motor controller consists of five major components: (1) an isolator switch, (2) arc chambers, (3) a linear slot motor drive, (4) a drive operator, and (5) a solid state control. For a normal motor starting operation and for fault currents up to a predetermined value, such as 1200 amperes, an electromagnetic actuator is used to open the contacts a relatively small distance such as 0.25 inch. For higher fault currents a drive or linear slot motor opens the contacts to a greater separation such as 1 inch.

Abstract: A circuit breaker comprises a stored energy mechanism and a solid state overcurrent sensing trip circuit. The circuit breaker also includes a remotely operable shunt trip device having a zener diode for operation from high voltage control circuits without the necessity for a stepdown transformer.

Abstract: A circuit breaker including a solid-state circuit for providing regulated current to operate a holding coil for an undervoltage release mechanism. An alternating current control line feeds a full wave bridge rectifier in the control circuit to provide pulsating direct current to a reference voltage supply circuit, a current regulating circuit, and the holding coil of an undervoltage release mechanism. The current regulating circuit comprises two series connected units of an integrated circuit quad current differential operational amplifier. The output of the second unit controls the base current of a regulating transistor which is series connected to the holding coil. The reference voltage supply circuit includes a transistor connected as a variable resistor to provide operation of the circuit over a wide range of input voltages without excessive heat generation.

Abstract: An automatic punch press and monitoring system. The monitoring system includes a piezoelectric accelerometer mounted within the stationary die shoe of the punch press, and electronic circuitry including a variable gain amplifier, a detector, an integrator, and a comparator. The monitoring system is manually placed in a "LEARN" mode whereupon the signal produced by the accelerometer during normal operation of the punch press is amplified, detected, and integrated over the time period of one stroke to produce a test function. The gain of the amplifier is automatically adjusted during successive normal strokes of the punch press until the test function is equal to an arbitrary set point, thereby establishing a reference function. The monitoring system is then automatically placed in an "AUTO CONTROL" mode whereupon on each succeeding stroke, with the gain of the amplifier fixed, the test function produced is compared with the reference function.

Abstract: A circuit breaker including a flux transfer trip mechanism and a solid state passive overcurrent sensing device having a temperature-dependent switching resistor of resistance material such as vanadium dioxide or lanthanum cobalt oxide.

Abstract: A circuit interrupter includes an automatic circuit breaker in a draw-out unit removably mounted within an enclosure. A levering mechanism is provided to lever out the draw-out unit on rails to permit complete disengagement of the circuit breaker from load and line terminals mounted within the enclosure without requiring unbolting operations. The circuit breaker includes an interrupter module, an operating module, and a control module, each of which includes a sub-frame supporting all module components. Each module is removably mounted in a main support structure and can be separately removed therefrom without removing the other two modules. Interlocks prevent removal of any module until the draw-out unit is levered out to the completely disengaged position.

Abstract: A multipole circuit breaker including a trip release actuator having a single coil coaxially surrounding a plunger and mounted within a hollow cylindrical actuator support frame. The actuator is mounted in association with a latch mechanism and includes a spring biasing the plunger toward release of the latch mechanism. The coil is responsive to an electronic sensing and control circuit and serves, when energized, to oppose the action of the bias spring and maintain the plunger in a position to prevent release of the latch mechanism during normal conditions. Upon either undervoltage or overcurrent conditions the sensing and control circuit deenergizes the coil, allowing the bias spring to move the plunger into engagement with the latch mechanism, effecting release of the latch mechanism and separation of the circuit breaker contacts.

Abstract: A current limiting circuit interrupter having a movable contact arm disposed within a magnetic drive structure and a pair of contacts disposed within a magnetic arc driving structure is provided. The magnetic drive or slot motor rapidly moves the movable contact arm to separate the contacts upon a predetermined overload. When high overload currents pass through the contactor arm extremely fast separating movement occurs between the contacts providing current limiting. In one embodiment there is provided a pair of relatively stationary spaced apart contacts bridged by an elongated movable contact arm which can be moved away from the stationary contacts to establish two serially related arcs. At each end of the bridging contact there is provided a surrounding magnetic structure or yoke which magnetically impels any arc formed during circuit interruption to move laterally outward into an arc extinguishing structure. The arc extinguishing structure can comprise non-magnetic metallic spaced apart plates.

Abstract: A multipole circuit breaker including a latch release actuator having a trip coil and a hold-in coil coaxially surrounding a plunger and mounted within a hollow cylindrical actuator support frame. The actuator is mounted in association with a latch mechanism and includes a spring biasing the plunger toward release of the latch mechanism. The hold-in coil is responsive to voltage conditions on an external control line and serves to oppose the action of the bias spring and maintain the plunger in a position to prevent release of the latch mechanism when the voltage on the control line is above a predetermined level.

Abstract: A fusible electric contactor having a plurality of cavities and a movable member having a path of movement into the cavities. A fuse assembly is removably inserted within the cavities to occupy a volume within the confines of the height, width, and length of the contactor.

Abstract: A latch for a circuit interrupter is provided wherein a movable member having a contact attached thereto is latched in a selected position by a spring member which is deflected by the movable member until a predetermined distance is exceeded at which time the spring member moves into a latching position with respect to a latching surface provided on the movable member. In its simplest form the latch uses a single piece of spring wire. As a movable member moves past, the spring wire moves aside and once the movable member has completely passed the wire, the wire springs back into place preventing the contacts from reclosing. A reset is provided which permits the contact arms to be closed by moving the spring member to one side. The disclosed latch is very fast acting, can be independently actuated for each phase, and can be positioned so as to not interfere with low current operation of the switching device on which it is employed.

Abstract: An indicator light circuit utilizing a single lamp and providing continuous illumination during normal operation and on and off flashing during an emergency condition. The circuit can also provide an indication wherein the lamp is continuously on but pulsating bright and dim. The indicator light circuit can thus provide four visual indications: (1) Off; (2) Normal on; (3) Flashing on and off; and, (4) On, but pulsating bright and dim. The invention is particularly adaptable for use to provide motor running and relay trip indication.