ELECTRONIC MOTOR CIRCUIT PROTECTOR

摘要

A circuit breaker having a current transformer for powering trip unit electronics and sensing low and high currents includes a core with solid and gapped laminations. The breaker includes an adjustment assembly for translating dial settings to tripping levels stored in memory. A temperature compensation algorithm adjusts trip points in response to temperature variations. A redundant trip activation scheme requires at least one pre-trip condition to be satisfied before the trip solenoid is activated. A supply voltage regulation system includes a stored energy circuit. A reconfigurable microcontroller executes a time-synchronized trip algorithm. The breaker trips according to a trip curve split into three protection regions. Software for detecting whether primary current exceeds each region are run in parallel or simultaneously, providing redundant instantaneous trip detection. A calibration method utilizes a signal chain that includes a current transformer, a burden resistor, a stored energy circuit and a controller.