Abstract: A zone arc fault detection system for detecting arcing faults in a defined zone of an electrical circuit, such as an aircraft circuit, includes a pair of substantially identical parallel insulated conductors for each zone in which arcing is to be detected. A detection zone is defined by the parallel conductors between end points where the two conductors are coupled together. A current sensor is operatively associated with each pair of parallel conductors. The current sensor and conductors are respectively configured and arranged such that the current sensor produces a signal representative of a difference in current between the two conductors.

Abstract: A circuit breaker for interrupting the flow of current upon the detection of excess current or temperature is provided which comprises a housing, a trip armature plate, a trip armature frame, and a bias spring. The trip armature plate has at least two pivot tabs extending laterally on opposite edges that are inserted into a pivot elongated slot, which is located at an open end of the trip armature frame, and a pivot aperture, which is located at the opposite end of the trip armature frame, respectively. A bias spring is used for securing the pivot tabs into the pivot elongated slot and the pivot aperture, and for urging the trip armature plate pivotably outwardly about the pivot tabs away from the trip armature frame. The circuit breaker also comprises a trip cross bar having at least two fingers that are used to engage optional circuit breaker accessories and that are located asymmetrically to allow the interchangeability of the accessories.

Abstract: The present invention provides diode bridge and a parallel type, capacitor based, phase to phase surge suppressor. The suppressor acts to suppress transient energy as soon as the spike exceeds the prevailing peak of the ac waveform. The system dissipates the spike by drawing current through the system impedance between the suppressor sand the source of the surge.

Abstract: An anti-rotation device for preventing the pivotal rotation of a circuit breaker required for removal of that circuit breaker from electrical distribution equipment in which it is installed is disclosed.

Abstract: An electrical transformer is disclosed. The electrical transformer comprises a central axis, a first modular section, and a second modular section. The first modular section is positioned about the central axis and comprises a first support, a first winding of a conductive element, and a first insulating material. The first winding of a conductive element is located about the first support. The first insulating material covers a portion of the first modular section. The second modular section is axially aligned with the first modular section and electrically connected to the first modular section. The second modular section comprises a second support, a second winding of a conductive element, and a second insulating material. The second winding of a conductive element is located about the second support. The second insulating material covers a portion of the second modular section.

Abstract: A bus cooling fan that operates without an external electrical power supply. The fan is positioned proximate two bus bars of a polyphase electrical system. The fan includes a rotor supporting fan blades and mounted on an axle. The axle is supported by cross-braces in a shroud surrounding the rotor. The shroud is open at the ends. The fan is fabricated of non-ferrous, non-conducting material with the exception of the rotor. The bent rods which interact with the electromagnetic field created by the current-carrying bus bars of the polyphase electrical system to make the rotor function as an induction motor when the fan is placed proximate two bus bars.

Abstract: A medium voltage controller for electrical equipment, such as motors, transformers, reactors, and capacitors, having a load discharge device. The load discharge device is compact and provides fast earthing of the load-side cables. The device has a scissors-type linkage and is charged by compressing at least one spring. The scissors-linkage, when in an almost-straight-line alignment, holds the compressed springs. An actuator moves one member of the scissors-linkage, thereby removing the holding alignment of the scissors-linkage. The springs move an earthing bar at high acceleration to ground the line-side cables.

Abstract: An apparatus and method for detecting motor bearing defects obtains motor current transient data during motor start-up, analyzes the motor current transient data via discrete wavelet transform, and compares the wavelet sub-bands to a baseline signature of a bearing-defect-free motor to detect bearing defects.

Abstract: A bi-directional torque-limiting interface for rotary operating devices is shown and described. The interface includes a first section receiving torque from a source, a second section delivering the received torque to a rotary operating device and a coupler operably connecting the first and second sections. The coupler is preloaded to a predetermined value and maintains a particular angular relationship between the first and second sections under normal operating conditions.

Abstract: A medium voltage controller for electrical equipment, having cast fuse holders, a disconnect switch, a switch illuminator, low power current transformers, and an optical temperature measuring system. The fuse holder includes a cast housing with smooth rounded surfaces that reduce corona. The disconnect switch has cast components that provide terminal points, mounting surfaces, and contact surfaces. The switch illuminator provides illumination of the disconnect switch internals. The contactor assembly is mounted in a truck and moves on a rail system that includes a pull-down handle with rails. The truck rolls out of the cabinet on the extended rails for easy removal from the cabinet. The truck, and contactor assembly, is racked in by pushing the truck into the cabinet and then raising the handle, which forces the draw-out fingers to engage the contact stabs.

Abstract: A metering module for use in a power circuit monitoring system including a circuit monitor having a processor for processing data related to power signals, said metering module comprising at least one sensor for sensing a predetermined property of a power signal and for producing a corresponding sensor signal, and a modular metering circuit for producing data corresponding to said sensor signal for input into said circuit monitor, wherein said metering module is selectively detachable and replaceable relative to said circuit monitor to permit one or more of testing, calibration and repair of said metering module thereby minimizing any interruption in operation of said circuit monitor.

Abstract: A method for time reference compensation in a power metering system, the method comprising monitoring a time-dependent characteristic of incoming AC power over a predetermined local time interval, comparing the monitored characteristic over the predetermined local time interval with the expected value of the characteristic based upon the nominal frequency of the AC power, and calculating a correction to one or more of local real-time and time-based measurements of the power metering system, based on the comparing.

Abstract: A method of manufacturing an improved comb for a disk wound transformer. The method comprises the steps of providing a web of cellulose material; removing a portion of the cellulose material to create a plurality of longitudinal slits along the length of the web, wherein the longitudinal slits have a fixed length and width; and folding the web along a line proximate the midpoint of the length of each of the longitudinal slits such that the cellulose material adjacent the longitudinal slits defines a plurality of tooth members.

Abstract: An on-board self test system for an electrical power monitoring device includes a test signal circuit in an electronic circuit of the monitoring device, and responsive to a programmable test input signal for producing an analog signal simulating an electrical power waveform, and a programmable memory in an electronic circuit of the monitoring device and operatively coupled with the test signal circuit for storing and reproducing upon command, one or more of the programmable test input signals.

Abstract: An impulsive transient detection and data acquisition coprocessor for use with a power monitoring device having a processor for performing data sampling and reporting at a given rate. The coprocessor has a processor, an interface for accessing data from the processor, a plurality of channels for monitoring for transients, and at least two independent, switchable memory banks for simultaneous real-time storage and analyses of an incoming transient data stream.

Abstract: A switch-lock assembly for securing a circuit breaker in one of a plurality of circuit breaker positions, comprising a switch-lock attachment and an anti-twist insert. The switch-lock attachment includes a spring member adapted to engage a retaining area of the circuit breaker, a support member adapted to accommodate the spring member, and a locking member connected with the support member via the spring member. The insert includes a securing end adapted to engage a first area of the circuit breaker for limiting the movement of the insert relative to the circuit breaker, and an interface area adapted to engage the switch-lock attachment for limiting the movement of the switch-lock attachment relative to the insert.

Abstract: An enclosure and operating handle apparatus for a double throw switch is disclosed. An operating handle support defines two distinct switch compartments within the enclosure and supports an operating handle apparatus configured for selectively operating only one of two switches inside the enclosure at a time.

Abstract: A method of rapidly dissipating energy from a contactor controlled by a switching device, the steps comprising: operably connecting a metal oxide varistor to the switching device; interrupting electrical current to the contactor; absorbing energy from the contactor; and, limiting the amount of voltage across the switching device.

Abstract: A field convertible tap-off base for an electrical busway distribution fitting. The field convertible tap-off base includes an AC phase termination side and a field configurable side having first and second configurable electrical terminals. The AC phase termination side provides terminals for connecting three AC phase conductors of a busway electrical distribution system to any one of a number of load bases configured for electrical components such as circuit breakers, switches, fuses, lugs or other special functions. The first and second configurable terminals permit two additional busway electrical conductors to be used for neutral, high current capacity neutral, secondary ground, DC current or other special functions which might be defined in the busway electrical distribution system.

Abstract: A sprinkler and drip resistant tap-off base for an electrical busway distribution system. The tap-off base includes an overmolded perimeter seal providing a liquid resistant seal between the busway housing and the tap-off base and between the tap-off base and a tap-off unit installed on the tap-off base.