Abstract: An improved overload relay includes a number of current transformers that draw power from a circuit it protects to power itself. The current transformers charge a capacitor which powers a processor and which can energize a solenoid to initiate the interruption of the circuit. The overload relay further includes a capacitor analysis circuit which detects an operational parameter of the capacitor and enables a processor to determine when the energy storage capability of the capacitor has dropped to a predetermined threshold. In the event of such a determination, the overload relay can perform any of a number of actions.

Abstract: The disclosed concept provides for an operating mechanism in a overload relay assembly having a solenoid with a permanent magnet. The solenoid includes a ferrous output member. The solenoid moves the output member between a first retracted position and a second extended position. When the output member is in the first retracted position, the permanent magnet maintains the output member in the first retracted position. Thus, in a system wherein the overload relay assembly interrupts power to its own operating mechanism solenoid, the permanent magnet maintains the output member in the first retracted position even when the solenoid is de-energized.

Abstract: An improved overload relay includes a number of current transformers that draw power from a circuit it protects to power itself. The current transformers charge a capacitor which powers a processor and which can energize a solenoid to initiate the interruption of the circuit. The overload relay further includes a capacitor analysis circuit which detects an operational parameter of the capacitor and enables a processor to determine when the energy storage capability of the capacitor has dropped to a predetermined threshold. In the event of such a determination, the overload relay can perform any of a number of actions.

Abstract: The disclosed concept provides for an operating mechanism in a overload relay assembly having a solenoid with a permanent magnet. The solenoid includes a ferrous output member. The solenoid moves the output member between a first retracted position and a second extended position. When the output member is in the first retracted position, the permanent magnet maintains the output member in the first retracted position. Thus, in a system wherein the overload relay assembly interrupts power to its own operating mechanism solenoid, the permanent magnet maintains the output member in the first retracted position even when the solenoid is de-energized.

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.