Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A technique for reducing nuisance tripping is disclosed in which a desired limit temperature is determined for a component of a motor system. The limit is compared to actual temperature signals, or signals indicative of temperature of the component. The component may be the conductor or conductors providing power to the motor. A counter is augmented when the actual temperature exceeds the limit. The limit may be computed, such as based on a heating model. A trip signal is generated only when the actual temperature has exceeded the limit for a predetermined number of periods. The counter may be reset if the actual temperature drops below the desired limit.

Abstract: 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.

Abstract: A sealed modular control and monitoring system is provided which affords location of electrical control and monitoring components adjacent to an application. The system comprises modular components which are mounted on a shared thermal base. The base is sealed to the components and presents thermal exchange features on interior and exterior surfaces thereof. Forced convection within the modular system is afforded by a circulating fan that directs air through the component circuitry and adjacent to the thermal base to remove heat from the circuitry during operation.

Abstract: 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.

Abstract: A motor control technique is disclosed in which a first algorithm controls interruption of power to a motor in a first current range. A second algorithm controls interruption of power in a second, higher current range. The algorithms may be adapted to specific motor sizes, ratings or classes. The extended range may extend from a transition point (e.g., 6–10 times the FLC of the motor) to an upper limit. The upper limit may be determined based upon a current rating of an instantaneous trip device.

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 method and device for immunizing a contactor circuit from the inductive effects of a holding coil derived power supply, including: sensing a voltage signal from a power supply, the voltage signal having a switching range comprising an upper voltage and a lower voltage; providing a drive output responsive to the upper voltage; holding the drive output at a constant level as the voltage signal remains above the lower voltage; and, disabling the drive output in response to the voltage signal droppings below the lower voltage.

Abstract: A method for providing electrical current to a contactor circuit, by providing a power supply circuit having a power supply resistor, the power supply circuit supplies electrical current to the contactor circuit in response to the electrical specifications of the contactor; selecting a value for the power supply resistor in response to the contactor's electrical specifications and requirements of the contactor circuit; and, inserting the selected power supply resistor into the power supply circuit.

Abstract: A self-powered circuit interrupter arrangement for interrupting current in a circuit path uses a current-blocking component to ensure that an insufficient amount of accumulated power for actuating and completing interruption of the circuit path is not misused in an unwarranted attempt to interrupt the current path. The arrangement includes a current inducer circuit for providing a current signal having a magnitude corresponding to the current in the circuit path and a power supply operating from the current signal to provide a voltage signal of a predetermined value relative to common. A trip command circuit, in response to a fault detected in the circuit path, sends an electrical signal commanding that the circuit path be interrupted by using the voltage signal. The electrical signal is sent to an electrical latch located electrically in series with a coil of a solenoid mechanism.