Abstract: A solid state overload relay mechanism designed for minimizing the forces required to open an electrical contact associated therewith in the event of a current overload in a protected circuit, and further designed for overcoming residual magnetism in a solenoid initiating the opening of the contact. The contact includes a pair of stationary contacts supported by a base and a pair of movable contact supported by a contact carrier. A latch defines a notch which is normally engaged with a lever. When so engaged, the contact carrier is positioned such that the movable contacts are in contact with the stationary contacts. When the lever becomes disengaged from the latch, the contact carrier is moved and contact between the movable contacts and stationary contacts is broken. The latch is provided with a counterbalance weight to aid in minimizing the force required to return the latch to its original position after the mechanism is tripped.

Abstract: A handle assembly for a circuit breaker comprises a handle, a handle arm, an inner shield, and an outer shield. The handle includes a base, a shaft, and a first pair of locking members. The shaft extends from an upper surface of the base and the first pair of locking members extend from a lower surface of the base. The handle arm includes a pair of legs and a lateral plate bridging the pair of legs. The pair of legs include a respective second pair of locking members. The second pair of locking members are constructed and arranged to interlock with respective ones of the first pair of locking members so as to lock the handle to the handle arm. The inner and outer shields include respective apertures therein to permit the shields to be disposed over the shaft against the upper surface of the base.

Abstract: A code reading device for use in an industrial flexible automation track system is disclosed wherein a code reading device reads codes stored in a code storing device attached to a work piece carrier. The code reading device includes a multiple sensor sensing head in which any one or all of the enclosed sensors may be easily replaced. Each sensor is slidably received within a pocket in the sensing head and provided with a plug-on electrical connector such that it may be easily replaced should a failure occur or should a different type of sensor be required.

Abstract: An arc stack for receiving a circuit breaker blade moveable between a closed position and an open position, includes a plurality of generally rectangular are plates having substantially similar length and width dimensions and positioned substantially parallel to one another. The straight edges of the arc plates are in line with one another so that the are stack is generally rectangular in shape. The arc plates have respective arc throats formed therein having a plurality of sizes so as to form a longitudinal passageway extending through the arc throats following the arc generated by the blade moving between the closed and open positions. The arc plates include sets of arc plates with the arc plates in each set having identical arc throats. The sets of arc plates are arranged in order of decreasing arc throat size with the set having the largest arc throats being positioned adjacent the circuit breaker blade in the closed position.

Abstract: The present invention provides an arrangement for automatic selective circuit interruption in response to detection of a fault in a multi-phase distribution system feeding a plurality of network branches. The arrangement includes a plurality of line monitoring devices which are programmed to alarm a control station in response to detection of a fault in the system. In response to being alarmed by one or more line monitoring devices, the control station activates a specialized signal generator which produces a specialized signal along one of the lines of the multi-phase system. Each line monitoring device is co-located with and communicatively coupled to a circuit interrupter which, when actuated, prevents the flow of current in lines of the system positioned downstream from the actuated circuit interrupter. Each line monitoring device automatically actuates the coupled circuit interrupter within a prescribed period of time following detection of the specialized signal.

Abstract: The present invention converts an alternating current input into a direct current output by switching a current load at high speeds to create a voltage envelope having a maximum allowed voltage and a minimum allowed voltage. Complementary switching elements are employed to take advantage of both the positive and negative portions of an AC cycle. Load switching is arranged so that the current vector which represents the load is nearly coincident with the voltage vector which represents the power source. The system can operate in an open loop mode at a constant frequency, in a closed loop mode, or in a hysteresis mode. During open loop operation, the voltage envelope is not rigidly defined as the switching frequency remains constant. During hysteresis mode control, the voltage envelope remains fixed and the current switching frequency varies.

Abstract: The present invention provides a cover for an exposed electrical terminal mounted on an electrical distribution device. The cover includes a generally planar body member having sufficient size to substantially cover the exposed terminal. The cover demountably secures to the device so that contact with a person's finger or equipment is prevented while access to the remainder of the device is allowed. The body is manually attached and detached from the device. The cover is also integrally formed with the body.The present invention also includes a method of safely protecting an exposed terminal mounted on an electrical distribution device. The method includes the step of demountably securing a cover to the device so that contact with a person's finger or equipment is prevented while access to the remainder of the device is allowed. The cover is manually attached and detached from the device.

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 substantially cylindrical enclosure capable of being easily cut with a hand saw. The enclosure also provides support and protection from physical damage to a plurality of electrical conductors which are disposed within the enclosure. The conductors are held firmly in place by a number of electrically insulating supports which snugly fit inside the enclosure. Each conductor can be easily cut with a metal cutting hand saw, and is enclosed in an electrically insulating sheath 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. A joint cover connects the two adjacent enclosures together and provides additional protection for the joint connecting member.

Abstract: The present invention provides a distribution system for audio and video services from a centralized source using lightwave signals generated from terminal equipment through an optical carrier to multiple locations in a facility. The terminal equipment reversibly convert audio, video, and control signals from electrical into lightwave signals. The terminal equipment also provide for electrical output at the remote locations with the appropriate format for various audio and video speakers and displays. A controller selects and converts audio communication signal into a standard audio format and directs the signal to the desired remote location in response to the control signal.

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 racking assembly is provided for racking a circuit breaker into and out of electrical switchgear having a cell adapted to receive the circuit breaker and a cell door for enclosing the circuit breaker within the cell, the racking assembly includes a shaft having a first end adapted to be coupled to the circuit breaker and a motor coupled to a second end of the shaft for applying a rotational torque to the shaft. An anti-rotation assembly is coupled to the motor for preventing the motor from rotating when it is applying the rotational torque to the shaft.

Abstract: An associative current interrupter system provides improved circuit protection and electrical safety. A test control unit (200) applies a regulated series of input voltage levels to the appliance (300) which is to be subsequently protected under a series of minimum and maximum load sequences. The resulting data series is logged and compressed into a format suitable for downloading into a programmable interrupter (100). A remote interface (217) is provided to allow device-specific data series to be input from alternative sources. When the appliance is connected in series with the interrupter (100), load current, line voltage, and time constraints are sampled and compared to the data series, thus providing a continuous solution to the determination of normal vs. abnormal currents. An output relay (103) provides a switching element and an internally accessible calibration port (111) allows monitoring combined non-linearities for correction during manufacture.

Abstract: An insulation stripping tool of the present invention removes insulation from the free ends of a substantially rigid electrical conductor. The tool has a barrel at one end and a handle at the other end. The barrel is generally tubular in shape and longitudinally receives a free end of the substantially rigid insulated electrical conductor. An insulation cutter is captivated within the barrel for cutting off a predetermined length of insulation from the free end of the conductor.

Abstract: A non-ferrous current sensor is used to continuously measure the charging current magnitude in step-graded foil and paper insulation systems used on high voltage measurement and control apparatus such as instrument transformers and on the condenser bushings of power transformers and circuit breakers. The low voltage measured signal is conditioned by an electronic circuit such that it modulates a DC signal in a system current control loop to provide continuous remote monitoring and alarm functions. Remote power is supplied to the sensor and conversion circuits through the current loop. Alarm level thresholds and alarm time delay are embodied in a control device which may be located in a remote location, away from the high voltage equipment. Step-graded insulation systems form a capacitively divided circuit between the high potential and ground. As the dielectric between the foil layers breaks down, the total capacitance of the insulation system increases, producing an increase in the charging current.

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: Firmware is downloaded to a metering unit located in a distributed power network carrying a power-related waveform, where the metering unit senses power-related parameters associated with the power-related waveform and generates and transmits data representative thereof. The metering unit is provided with a sector-erasable flash EEPROM having a first section for storing main functionality firmware and a second section for storing boot code. The boot code includes a reset portion for resetting the metering unit and a firmware update section for downloading external firmware to the first section. The firmware update section includes a writing routine for writing the external firmware to the first section. The metering unit is also provided with a volatile RAM. The external firmware is downloaded to the first section of the EEPROM by executing the firmware update section.

Abstract: A microprocessor based uninterruptible power supply generates an AC electrical output power from an AC input source when the AC input source is within settable voltage limits and from an auxiliary source of DC power when the AC input source is outside said the voltage limits. The microprocessor provides monitoring of the AC input voltage to determine its amplitude and frequency, and uses this information to set the magnitude and frequency of the AC output voltage and to select the source of the AC output power. A power factor improvement circuit boosts the selected source to a high DC voltage which is inverted by a chopper circuit to produce a high frequency AC voltage is rectified and sent to a PWM inverter to produce the AC output power. An average current feedback loop provides the output voltage regulation and utilizes current limiting to provide output current limiting for protection against short circuits and overloads.

Abstract: The present invention provides an integrator 5 with switched hysteresis for inductive proximity switches comprising a reference current source IREF connected between a reference voltage supply rail and a first side of a current mirror, a second side of the current mirror being connected to a proximity switch rectifier, the first side of the current mirror being connected to a capacitor CINT and to one input of a two input comparator, the other input of the comparator being held at a threshold level, wherein a fixed hysteresis current source IHYST is provided in parallel with the current reference source IREF, the fixed hysteresis current source IHYST producing a switchable current which is a fixed proportion of the current of the current reference source IREF, the fixed hysteresis current source IHYST being switched on (off) when a target is detected and off (on) when no target is detected. This invention provides for reduction of effects detrimental to the speed of operation of the switch.