Low power solid state three-phase overcurrent/undercurrent protection circuit

A three-phase current sensing fault detection network has been developed employing an all solid state design. Systems equipped with such a network will be deprived of three-phase power in the event that either excessive or insufficient current is monitored in any or all of the three-phase power lines. The system design can be expanded to include a system shutdown capability for any number of sensing inputs from various critical portions of the circuit being monitored.