Abstract: A lightning protection device is provided. The device includes a lower field coupler, an upper field coupler, a lightning sensor, and a controller. The lightning sensor includes a differential voltage window comparator. The lower field coupler is capacitively coupled to the earth ground, and the upper field coupler is coupled to the local atmospheric electric field. If a ground potential rise (GPR) event occurs, the differential voltage window comparator trips. If the differential voltage window comparator trips or if a power line transient occurs, the controller disconnects the power phase, neutral, and ground wires to isolate sensitive equipment. In some embodiments, the controller also detects power line transients and disconnects the power, phase, neutral, and ground wires if a power line transient is detected.