Patent attributes
A redundant trip activation scheme whereby at least one pre-trip condition must be satisfied before a trip signal is sent to a trip solenoid of a motor circuit protector. To provide a layer of protection against spurious or nuisance tripping caused by software errors or external events such as EMF effects, a trip module sets a trip variable upon detection of a trip signal. Instead of tripping the MCP, the trip module requires at least an additional trip signal to be detected. The next time a trip signal is detected, the trip module checks whether the trip variable has been set, and, if so, sends a trip signal to a trip circuit, causing the solenoid to be activated. To ensure that a trip actually occurs, the solenoid can be tripped from the microcontroller via the trip circuit or from an over-voltage protection circuit in the event of a system failure, which operates independently of the trip circuit.
