PowerPact™ P-frame and Compact™ NS630b-NS3200 electronic trip molded case circuit breakers are designed to protect electrical systems from damage caused by overloads, short circuits and ground faults. All circuit breakers are designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent. Electronic trip molded case circuit breakers use an electronic trip system to signal the circuit breaker to open automatically.