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

Abstract: A knockout providing either bundled wiring or multiple electrical conduit connector access to an electrical enclosure. The knockout provides one large knockout for use with bundled wiring or a large conduit connector when activated and a number of small knockouts, each for use with one small conduit connector when activated. The small knockouts are arranged tangentially within the larger knockout in a radial pattern.

Abstract: A hybrid transformer core assembly having a first leg having a first end and a second end, a second leg having a first end and a second end, and opposing first and second yokes coupling the first and second legs to the first and second yokes to create a closed core. The first leg and second legs are made of a plurality of packets of laminations having a high grain orientation, and the first and second yokes are made of a plurality of packets of laminations having a lower grain orientation than the material of the first and second legs. Alternating laminations of the first and second legs are staggered to alternately extend beyond adjacent laminations of the respective leg at first and second ends thereof. A portion of the laminations of the first and second legs which extend beyond adjacent laminations of the first and second legs, respectively, overlaps portions of alternating laminations of the yokes and couples with notches of alternating laminations of the yokes.

Abstract: An alternating current sensing apparatus includes at least two coils, each having a plurality of turns of wire around a core which defines a linear axis. The coils are mounted in spaced relation on a support surface so as to define an intermediate space, and the coils are electrically coupled additively in series. The coils produce a detectable signal in response to an alternating electrical current passing through a conductor which extends through the intermediate space.

Abstract: A weld controller maintains an internal dynamic model of load impedance, which tracks normal impedance variations that occur as the weld tooling degrades. The weld controller contains a weld process monitor function that tests an estimated load impedance of a weld schedule presently under execution against an internal dynamic model and generates events when characteristics of the estimated load impedance of the present weld falls outside an operator definable band, indicating a problem with the workpiece presently being welded. The weld controller further includes the capability to accept a static model of the load impedance that is used as the reference impedance for the weld control and tooling. The weld controller also includes means to declare an event when characteristics of the dynamic model differ from the static model by an operator-defined amount.

Abstract: A programmable data link module is used on a time division multiplex data bus. The module is functional as an input device, an output device, or both as an input and output device. It can receive data from the data bus during the selected time slot for a selected number of frames to control output devices connected to it. The data link module includes an input circuit for generating a data output signal data to the data bus in response to the input signals from an input device coupled to the module. The input circuit includes a programmable input communication mode selector, allowing the data bus and the data link module to function with or without a host computer. The mode selector provides simplex or duplex.

Abstract: The present invention provides a concealed hinge for a removable cover and includes an integrally formed locking mechanism which prevents vertical movement of the cover when it is in the closed position. The hinge is made from two parts, one being welded to the cover and one being welded to the enclosure. One of the parts includes an integrally formed locking arm which continuously engages the other hinge part except when the cover is completely open, thus preventing any vertical movement of the cover which might defeat a cover safety interlock. The hinge is completely concealed by a flange of the cover to which it attached.

Abstract: A medium to high voltage load circuit interrupter and method for breaking the flow of electric current in a line having a load and a source. A main switch is connected in series with the line. A metal resistor having a positive temperature coefficient of resistivity (PTC element) is connected in series to the arcing switch, wherein the metal resistor and arcing switch are connected in parallel with the main switch. The main switch moves from the closed position to the open position prior to the arcing switch moving from the closed position to the open position. The circuit interrupter further includes an arc chute having a channel and electrically coupled to the arcing switch wherein the arcing switch is positioned within the channel when the arcing switch is in a closed position. In one embodiment, the PTC element is positioned on an insulator positioned between a ground and the main switch and an arcing switch. In another embodiment, the PTC element is positioned within a channel in the arc chute.

Abstract: A method of making a surge protection system for use on sectionalized electrical busway distribution system housings. The surge protection system includes a number of surge clamps; each cut to a particular length from an extruded rawstock. The extruded rawstock is of a length easily manipulated by one person. The extruded rawstock defines at least one generally flat longitudinal surface and a passage extending along its longitudinal axis. When each surge clamp is installed the generally flat longitudinal surface engages a generally flat surface of a top or bottom of the busway housing. Each end of the surge clamp engages one of two generally parallel sides of the busway housing. Apertures are defined in the sides at the point of engagement with the surge clamp ends. Fastening devices such a screw pass through the apertures and into the passage defined by the surge clamps thus providing a means for attaching the surge clamp to the busway housing.

Abstract: An anti-regeneration circuit for preventing a regenerated current produced by an overhauling DC motor from setting a series brake. The anti-regeneration circuit includes a current blocking device 90 which blocks the flow of regenerated current in the crane control circuit 10 and a surge suppresser 94 for protecting the current blocking device 90 from a high inverse peak voltage produced by de-excitation of a crane control circuit 10 upon the sudden loss of power.

Abstract: A solenoid operated remote resetting device with a protective solenoid activation circuit is disclosed. The device includes a housing for enclosing and protecting a solenoid with a movable plunger, a movable mechanical operator having an operator arm extending through an opening defined in the housing and a circuit board on which a solenoid activation circuit is mounted. The solenoid activation circuit includes circuitry for protecting the solenoid from overheating due to intentional or unintentional prolonged current flow in the solenoid.

Abstract: The present invention provides an electrical power distribution system which contains a primary load-center (100) having a common data bus (124) that is adapted to provide two-way digital communication. A number of circuit breakers (120) are coupled to the common data bus (124). Each circuit breaker (120) has a first contact and second movable contact which is moved between a closed position and an open position by an actuator (216). The circuit breaker contains a microcontroller based control circuit (210), which controls the operation of the actuator (216) according to programmed instructions, which may be stored in a memory (234) contained in the circuit breaker or which are communicated to the circuit breaker over the common data bus (124). A status detection circuit (218) coupled to certain nodes within the circuit breaker provides status information about various contacts and current paths contained in the circuit breaker.

Abstract: An electrical isolation device for use in an electrical distribution network having a plurality of branch circuits each defined by line and neutral conductors connected between a power source and a load, the line conductor being electrically connected to one of a plurality of line buses at an electrical distribution panelboard, the neutral conductor being electrically connected to a neutral bus at the electrical distribution panelboard. The isolation device includes a filter coupled between a selected number of line buses and the neutral bus at the panelboard and is designed to provide a low impedance path for an arcing fault occurring on either of the selected number of line buses. In another embodiment, the isolation device is comprised of a filter coupled between the line and neutral conductor of a selected one of the branch circuits and is designed to provide a low impedance path for an arcing fault occurring on the line conductor of the selected branch circuit.

Abstract: A sectionalized electrical distribution feeder system for carrying electrical power from a source point to a use point or a distribution point. Each section of the distribution system includes a cylindrical enclosure capable of being easily cut with a handsaw. The enclosure also provides support and protection from physical damage to a plurality of electrical conductors that are disposed within the enclosure. The conductors are held firmly in place by a continuous electrically insulating support that snugly fits inside the enclosure. Each conductor can be easily cut with a metal cutting hand saw, and is enclosed in an electrically insulating sheath, a portion of which can be removed from a newly cut end to provide a contact surface. A joint connecting member is provided for electrically connecting the conductors of adjacent sections of the electrical distribution feeder system.

Abstract: A circuit breaker for interrupting the flow of electric current in a line includes a switch connected in series with the line, the switch having an open position and a closed position. At least one positive temperature coefficient resistivity element (PTC element) is connected in series with the line. A first magnetic coil is positioned around a yoke, for example, an iron core, and connected in parallel with the PTC element and a second magnetic coil is positioned around the yoke and connected in series with the line and the switch. A voltage limiting device, such as a metal oxide varistor, is connected in parallel with the at least one PTC element. An armature is pivotally mounted in relation to the yoke wherein the yoke and the armature form a magnetic circuit with the first magnetic coil and the second magnetic coil.

Abstract: A phase controlled weld controller system uses an internal model of weld line and load impedance and of open circuit weld input voltage to develop a nominal firing angle sequence to maintain a desired weld current sequence. The weld controller computes a nominal firing angle sequence based on estimated models of line impedance, open circuit line voltage, and an estimated relation between the load current and conduction angle and the mathematical relation between firing angle, conduction angle and load circuit power that will achieve a desired weld sequence if the models are accurate. The weld controller subsequently uses measured values received in real time while the weld sequence is being executed to modify the nominal firing angle to better achieve the desired objective. This approach allows the weld controller to quickly achieve the desired weld sequence with the actual load, while permitting low feedback gains, resulting in a system that is quick and accurate in response without being overly sensitive.

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: 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 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.