Patent ID: 8665574
Filing Date: 2014-03-04
Classification: H02H

Abstract:
1. A circuit breaker for protecting a load, comprising a temperature sensor that measures an ambient temperature of the circuit breaker; a primary conductor for conducting a primary current from a power source, through the circuit breaker, to a load being protected by the circuit breaker; a current transformer coupled to the primary conductor; a secondary conductor coupled to the current transformer such that a secondary current is induced in the secondary conductor in response to the primary current flowing in the primary conductor; an energy storage device that stores energy related to the secondary current in response to the primary current passing through the primary conductor; a trip module that includes a controller programmed to continuously process a thermal model of the primary conductor while the primary current is passing through the primary conductor and, if the primary current is not passing through the primary conductor, until the thermal model indicates that the temperature of the primary conductor converges to about the ambient temperature measured by the temperature sensor as the controller is being powered by the energy stored in the energy storage device.