Abstract: A molded plastic current limiting circuit breaker includes an interrupter assembly that includes an over-molded magnet, arc stack, baffle stack, and a chamber liner in which a trip unit is described.

Abstract: An in-depth review of a product line is conducted, including customer interviews, in order to identify customer specifications that are more complex than customer needs. Customer needs are quantified, and a reduced set of standard product configuration classes are selected so that about 80% of customer orders based on actual customer needs can be satisfied by the standard product configuration classes, and the remaining orders can be satisfied by custom design. Major components in the standard products are themselves standardized. Manufacture of the standard product is optimized for a one-day manufacturing cycle and separated from the manufacture of the custom designed product. A sales office and manufacturing plant roll-out schedule is implemented and managed by computer-based spreadsheet tools.

Abstract: A circuit breaker and method for interrupting the flow of electric current in a line includes connecting separable contacts to a conductor in the circuit. An actuating device, actuated by an activating signal, is connected to the separable contacts to effect separation of the contacts wherein the flow of electric current in the circuit is interrupted. A current sensor, such as an iron core current transformer, senses the current in the circuit to provide a first sinusoidal signal. A bridge rectifier is connected to the current sensor wherein the first sinusoidal signal is converted to a rectified signal and power is derived from the rectified signal. An interface circuit connected to the rectifying network converts the rectified signal into a second sinusoidal signal for providing the activating signal to the actuating device at a predetermined magnitude of the first sinusoidal signal. The interface circuit includes generating a sign bit indicative of the polarity of the first sinusoidal signal.

Abstract: An in-depth review of the switchboard business, including customer interviews, revealed that customer specifications were more complex than customer needs. Customer needs were quantified, and a reduced set of standard switchboard configuration classes was selected so that about 80% of customer orders based on actual customer needs could be satisfied by the standard switchboard configuration classes, and the remaining orders would be satisfied by custom designed switchboards. Major components in the standard switchboards were themselves standardized. A standard switchboard, for example, has a continuous current capacity of no more than 4000 Amps, a maximum voltage rating of 480 Vac, a short circuit current rating of no more than 200 kA, and an aluminum or copper bus. The manufacture of the standard switchboards was optimized for a one-day manufacturing cycle and separated from the manufacture of the custom designed switchboards.

Abstract: A number of methods can be used for zone arc protection to detect series and/or shunt arcing faults in various electrical components and/or circuits. A differential current detector, or a di/dt based detector, may be used to detect shunt arcs, while a differential voltage detector or a zero-sequence voltage detector, is used to detect series arcs. A differential phase current detection scheme may be used for both shunt arcs and series arcs. Series arcs may also be detected using a voltage drop system or a line power loss system. Detection of arcing in joints may be monitored directly. A ground fault detector may be combined with one or more of these systems for detecting a ground fault in the circuit to be protected. Two or more of the above systems or detectors may be combined for arc monitoring and detection.

Abstract: A circuit protection apparatus includes a circuit breaker coupled in series with a circuit to be protected. The circuit breaker has a trip input and is responsive to a trip signal at the trip input for changing from a closed circuit condition to an open circuit condition to thereby remove electrical current from the circuit to be protected. A thermal trip element is coupled in series with the circuit to be protected and is responsive to a predetermined current/time characteristic of current flow in the circuit for delivering the trip signal through the thermal trip element to the trip input.

Abstract: A circuit breaker for interrupting electrical current flowing through a line conductor to a load terminal in response to the detection of a current overload, ground fault and/or arcing fault. The circuit breaker has a trip circuit to generate a trip signal, a releasably latchable trip lever, and a latching mechanism. The trip lever is moveable between a latched position and a tripped position. In the latched position, the trip lever engages the latching mechanism and the electrical current flows through said circuit breaker. When a fault is detected by the trip circuit, a trip signal is send to the latching mechanism. Upon receiving the trip signal, the latching mechanism disengages the trip lever allowing the trip lever to slide into the tripped position and interrupting the current flow through the circuit breaker.

Abstract: The present invention provides a terminal assembly 18 and method for connecting an electrical connector to an electrical distribution device. The device has a housing 12 with an interior surface defining an interior space 16. The terminal assembly 18 includes a clamp body 20 having a first surface 26 and a second surface 28. A portion of the first surface extends downward to define an interior wall 30 of a cylinder. The interior wall 30 extends perpendicularly to the first surface 26. A substantial portion of the interior wall 30 of the cylinder has threads 40. A fastener 24 has a head at one end of an elongated body and screw threads 60 near the opposite end. The screw threads 60 being adapted to engage the threads 40 on the interior wall of the cylinder of the clamp body 20. A clamp plate 22 has a plate body 50 which is partially defined by a top surface 52 and a bottom surface 54. The plate body 50 has a plate aperture 56 for accommodating the fastener 24 through the plate body.

Abstract: A circuit breaker including a switch having an open and a closed position connected to a line of the circuit breaker. A first actuating device, actuated by a first activating signal, is connected to the switch to move the switch from the closed position to the open position wherein the flow of electric current in the line is interrupted. A positive temperature coefficient resistivity element (PTC element) is tripped at least once wherein the tolerance of the PTC element is reduced and the PTC element is connected to the first actuating device for providing the first activating signal. In another embodiment of the present invention, a second actuating device, actuated by a second activating signal provided by the circuit breaker current, is connected to the switch to move the switch from the closed position to the open position wherein the flow of electric current in the line is interrupted.

Abstract: An arcing fault protection system for a switchgear enclosure includes a grounding device for rapidly grounding the source bus of an electrical distribution system in response to the detection of arcing faults in the system. The grounding device, which may comprise a mechanical switch, a solid-state switch or hybrid device, quickly diverts current carried on the source bus to ground to effectively extinguish arcing fault currents present in the distribution system, preventing the generation of gases at hazardous pressures and/or temperatures so as to protect the switchgear equipment from damage and to prevent injury to operating personnel.

Abstract: An improved latch mechanism is provided for use in a motor control center having a door and a frame which the door cooperatively closes onto. The latch mechanism is capable of securing the door against the frame and is rotatable between an OPEN position and a CLOSED position. The latch mechanism includes a body portion, rotatably coupled to the door, capable of engaging a slot disposed in the frame for securing the door against the frame. A stop, disposed on the body portion, is provided for limiting the rotation of the body portion.

Abstract: A current sensor has a closed loop magnetic hoop with a gap and a central aperture for receiving a conductor. An IC chip incorporating a Giant MagnetiResistive (GMR) sensor is positioned in the gap to provide a measure of the current in the conductor. A relatively small current transformer provides the necessary information about the direction of the current to an electronic trip unit for a circuit breaker as well as power supply for the IC chip and the trip unit. The trip unit operates in the presence of AC and DC faults. In a three phase power system, a single GMR chip in the proximity of three closely spaced phase conductors, together with a current measurement from the neutral line, enables trip units to operate on the occurrence of AC and DC faults.

Abstract: A method and apparatus for interrupting the flow of electrical current in a multiphase circuit path between at least one source and at least one load including a circuit breaker having an electro-mechanical assembly and a blade carrier corresponding to each phase of the multiphase circuit path and a phase barrier between each blade carrier. The blade carriers are interconnected, preferably, with a crossbar wherein, when one or more phases of the circuit path are interrupted, opening one or more of the blade carriers, the crossbar moves all of the blade carriers to open positions. The phase barrier is positioned circumferentially around the crossbar between each blade carrier and includes a thermoplastic material. The electro-mechanical assembly is housed within a circuit breaker enclosure having an insulating base wall and cover wall. The phase barrier has a main body planar surface perpendicular to the blade carriers and extending from the base wall to the cover wall.

Abstract: For use within an electrical distribution to control current paths through a plurality of associated circuit breakers, a circuit arrangement comprises a plurality of circuit breakers, each having a status related to open contact position and a closed contact position. An informational display is included within the load-center to display the plurality of statuses at a user access side of the display, and a control circuit, coupled to the circuit breakers and the informational display, automatically monitors the contact status of the circuit breakers and drives the informational display so that a display of the statuses is provided.

Abstract: A circuit breaker interconnect arrangement and a method for selective interruption of electrical circuits includes at least one upstream circuit breaker having an upstream electronic trip unit and a microprocessor and a plurality of downstream circuit breakers connected to the upstream circuit breaker. The microprocessor transmits a trip command signal to the downstream electronic trip units at the occurrence of a predetermined load condition, such as an overload condition, through the upstream circuit. One or more downstream circuit breakers are tripped after the predetermined time delay for tripping according to a predetermined priority until the load condition through the upstream circuit is reduced below the predetermined load condition whereby the upstream circuit breaker is deterred from interrupting current in the upstream circuit.

Abstract: The present invention provides an assembly and method for mounting a plurality of circuit breakers for electrical and mechanical connection to a bus bar in a module of a distribution board. The mounting assembly includes each circuit breaker having a housing which is defined by a contact end for connecting to the bus bar, a mounting end for securing to the cell of the distribution board, and side panels extending therebetween. Each housing has a top surface and a bottom surface. The connect end of each housing has a bus bar terminal for connecting to the bus bar. At least one spacer is located between at least two of the circuit breakers. The spacer has a predetermined width between the side panels of adjacent circuit breakers. The spacer width is sufficient to spread the circuit breakers apart from each other and align the bus bar terminal of each housing with the busbar.

Abstract: An electrical distribution system having a load center for programmably and remotely controlling a plurality of circuit breakers, an expander unit coupled to the load center and a plurality of external switches for providing signals to the load center representative of the status of the switches. The load center contains a control module that continually receives inputs from the expander unit via an interface module. It also contains a keyboard and display for programming instructions for closing and opening the individual circuit breakers and for displaying the status of the circuit breakers. The interface module, coupled to the control module, causes the circuit breakers to open and close according to programmed instructions received from the control module or another external device. The expander unit contains a plurality of input circuits coupled to external switches.

Abstract: A Positive Temperature Coefficient Resistivity (PTC) element has a resistivity that increases as the temperature increases. Circuit breakers having PTC elements can achieve better overload and short circuit protection than existing products. Breakers with PTC elements can also be combined with ground fault detection circuits to activate the circuit breaker under ground fault conditions that are less severe than the overcurrent conditions that would normally activate the circuit breaker. A shunt trip assembly incorporating a PTC resistor reduces the required power rating of the clearing switch.

Abstract: The present invention includes a control device and a control center having at least one cell defining an interior space with a front face for receiving and electrically connecting the control device therein. The cell and control device have mounting for mounting at least one electrical component thereon. The control device pivots on a pivotal axis within the cell so that a rear mounting surface pivots away from a cell mounting surface to provide access to the rear mounting surface and the cell mounting surface through the front face of the cell. The control device is releasably fastened to the cell to prevent pivoting the control device while the control device is electrically connected. A method is included with the present invention for providing access to the interior space through a front face of a cell in a control center with a control device inserted therein.

Abstract: A reverse deflection prevention arrangement is provided for use in a circuit breaker for preventing a bimetal from bending in a direction opposite its normal thermal deflection. The reverse deflection prevention arrangement includes a tab portion extending from a yoke and a corresponding block member disposed on the inside surface of a circuit breaker cover. The tab portion engages the block member when the bimetal is forced to deflect in the direction opposite its normal deflection. An alternate embodiment of the reverse deflection prevention arrangement includes a reinforcement member secured to one end of the bimetal. The reinforcement member strengthens and supports the bimetal so that it is prevented from bending in the direction opposite its normal thermal deflection.