Eaton Corporation

Rockwell Automation Technologies Incorporated

Westinghouse Electric Corporation

Mark E Innes

Rick A Hurley

Gregory A Helton

John Herman Blakely

Roger Alan Plemmons

John H Blakely

Nelson R Palmer

Ricky A Hurley

Nicholas G Muskovac

Marlan L Winter

John Stephen Clark

Parker A Bollinger, Jr

Michael G Early

Pamela S Combs

Lee E Smith

Ralph Rosa

John S Clark

An apparatus for electrical safety is disclosed. A system and an alternate apparatus also perform the functions of the apparatus. The apparatus includes a test point accessible from an exterior of an enclosure while the enclosure is in a closed state. The enclosure houses one or more electrical components and the closed state prevents a user from touching the one or more electrical components. The apparatus includes a test conductor connected to a point on a conductor connected to an electrical component of the one or more electrical components where the test conductor is within the enclosure. The apparatus includes an impedance connecting the test point to the test conductor. The impedance is within the enclosure. The test point meets an Ingress Protection code rating of 20.

Apparatus to verify an electrically safe work condition

An apparatus for dynamic braking is disclosed. The apparatus includes a first switch connected to a first connection of a dynamic braking resistor and to a first power bus of a motor controller. The apparatus includes a second switch connected to a second connection of the dynamic braking resistor and to a second power bus of the motor controller. The motor controller provides power to and controls a motor. The apparatus includes a switch control module that controls the first and second switches to connect the dynamic braking resistor to the first and second power buses. The switch control module controls the first and second switches in response to a signal from the motor controller.

Self protected dynamic braking

An apparatus for protecting a motor includes two or more motor overloads, within a motor overload enclosure, protecting two or more motors. Each motor overload includes one or more current sensors where each current sensor includes a magnetic core and each current sensor includes a conductor positioned within the magnetic core where the conductor providing power to a motor protected by the two or more motor overloads ('protected motor'). Each motor overload includes a motor trip module that stops current flow to the protected motor in response determining that a thermal state of the protected motor has reached a thermal limit. Determining that the protected motor has reached a thermal limit includes using a current signal from at least one current sensor of the one or more current sensors that senses current of the protected motor to determine a thermal state of the protected motor.

Multimotor variable frequency overload

An electrical control module provides a plastic insert fitting inside a housing and compressed by assembly of the housing lid and base to be held securely therein. Elastic components on the plastic insert are compressed during the assembly provide a secure retention in the face of normal manufacturing tolerances. The plastic insert includes features for attaching electrical components such as electrical contactors, motor starters, disconnect switches, circuit breakers, and overload switches without conventional screw fasteners or the like through channels and elastic detents.

Housing-captured component carrier for reducing fasteners

A sensing and switching device, such as an overload relay, is provided which includes a processor configured to make measurements and control operation (e.g., tripping) of the device. The processor regulates measurement of voltage and/or current, and the supply of power to power supplies. The power supplies store charge to provide operational power for the processor and that can be used for tripping and resetting contacts within the device. The processor opens a burden resistor measurement circuit when charge is being stored in the power supplies, and opens switches in the power supplies while closing the burden resistor switch to permit measurements. By alternatively switching for charging of the power supplies and making of measurements, the processor is able to reliably make measurements, control the device, and store sufficient power for operation of the device despite a demanding power budget.

Self powered electronic overload method and system

A technique is provided for controlling operation of motors of different sized or ratings. Components used to apply and interrupt current to the motors may be shared in control devices for the different motors. The components may include contactors or circuit interrupters, and instantaneous trip devices. The components may be sized for the higher rated motors, and be oversized for the lower rated motors. Control circuitry permits the devices to be controlled in accordance with the characteristics of the particular motor to which the devices are applied, providing accurate circuit interruption while reducing the number of different components and component packages in a product family for the various motors.

Motor overload tripping system and method with multi-function circuit interrupter

A technique is provided for controlling and protecting loads such as electric motors. In the technique, current sensing circuitry detects electrical current applied to the load. Device thermal modeling circuitry, such as circuitry for modeling heating of a motor, determines heating based upon the sensed current, and generates a first trip signal in a first range based upon the current. Conductor thermal modeling circuitry estimates heating of conductors that supply current to the load, and generates a second trip signal in a second range based upon the conductor heating. The system provides an extended range of operation for a wide range of loads by effectively modeling conventional thermal overload and instantaneous trip devices.

Extended trip range motor control system and method

A method and apparatus is disclosed for complete three-phase sensing using two current transformers. Two phases of a three-phase system are used as the primary windings in each current transformer such that each current transformer produces a phasor representation of a sum of the two phases. A three phase sensor is provided to add the phasor representations produced by each of the current transformers and to produce a third phasor representation from the summation. The three phasor representations can then be applied to any conventional overload relay control to monitor each phase and produces a trip signal to open the three-phase system when a phasor representation exceeds some predetermined value, or the magnitudes of the phasors differ by more than a predefined value.

Method and apparatus for three-phase sensing using two current

A control circuit for electrical contactors, starters and the like which include one or more pairs of separable main contacts is controlled by an electromagnet assembly. In order to reduce, if not eliminate, audible noise generated by the electromagnet assembly, the electrical current to the electromagnetic assembly is regulated to minimize the rate of change of magnetic flux therethrough to thereby reduce, if not eliminate, audible noise. By regulating the electrical current to the electromagnet assembly, the power consumption of the electromagnet assembly is reduced which, in turn, reduces undesirable heating of a solenoid coil within the electromagnet assembly.

Ultrasonic coil current regulator

A unique combination of nonvolatile memory (16) with a visual indicator (18) to give a device an address display which adds very little cost or space to the device and its housing. A nonvolatile RAM incorporated into the device electronics is provided with a memory location sufficient for storing the identifier in binary form. A simple visual display in the form of an LED (18) is also provided in the device housing and electrically connected to the RAM for providing visual indication of the stored number according to a predefined code.

Devicenet address verification

A method and apparatus are disclosed to reconstruct a third phase for a three phase sensing system in which only two current transformers sense all three phases. Two phases of the three phase system are used as a single primary winding for each current transformer such that each current transformer produces a voltage representation of a sum of two phase currents. The present invention is directed toward reconstructing the third phase from the two discrete signals produced so that true RMS characteristics can be determined, as well as indicating any phase loss. Since all three phases can then be represented, this technique offers precise phase imbalance protection as well.

Third phase reconstruction from a two current transformer sensor with

An electromagnetic switch for opening and closing a set of contacts has a microprocessor which monitors coil current to determine the state of the contacts. The switch relies on the phenomenon that the inductance of the switch coil changes significantly between the open position of the contacts when the switch armature carrying the moveable contact is spaced by an air gap from the core of the electromagnet, and the closed position in which the armature abuts the core. For an AC energized coil, which is self-limiting in that the increase in inductance from closing of the contacts reduces the current to the holding value automatically, a coil current of less than about one/half of the nominal open contact value is an indication that the contacts are closed. For a DC coil, where the coil current is regulated by a current regulator to a closing value and a holding value, the coil current is measured and then the current regulator is turned off for an interval during which time the current is recirculated through a fly back diode connected across the coil. After a period of time, which in the preferred embodiment is one cold, open time constant of the coil, coil current is measured again. If the second value of coil current is less than about one/half of the initial value, the contacts are open, otherwise the contacts are closed.

Detection of contact position from coil current in electromagnetic

An electronic overload relay has an intrinsic power supply connected in parallel with the NC contact of the relay between wire attachment terminals. The power supply is a parallel connected zener diode and capacitor, connected to the processor in parallel with a low voltage sensing circuit that detects the charge on the capacitor, whereby the processor operates to turn on a unijunction transistor for low voltage coil applications to shunt the power supply during contactor closing and turn off a predetermined interval later by which time the contactor should have closed.

Electronic overload relay having intrinsic power supply operable from

A motor starter includes separable contacts; an operating mechanism for operating the separable contacts; an overload relay controller including a memory for storing the settings for a plurality of selectable operating features, and a microprocessor for retrieving the settings from the memory and employing the settings at least for controlling the operating mechanism; and a programmer module temporarily engaging the overload relay controller for changing the settings in the memory.

Programmer for starter

An electrical switching device such as a motor starter includes separable contacts; a coil for operating the separable contacts; two light emitting diode indicators having a plurality of states; a pushbutton switch; and a control circuit responsive to the pushbutton switch employing a plurality of parameters for controlling operation of the coil and the indicators, with the control circuit having a setup mode and including a microcomputer for detecting actuation of the pushbutton switch to enter the setup mode, indicating a first one of the states on the indicators corresponding to a first one of the parameters, and detecting de-actuation of the pushbutton switch to indicate a value of the first parameter on the indicators.

Growing community of inventors

Asheville, NC, United States of America

Mark E Innes