A protective device is provided comprising a microswitch which is serially connected to a fuse or a circuit breaker, a current measuring unit, a storage unit, and a control unit. At least one current value range is stored on the storage unit. The current measuring unit is designed to measure current intensities in the protective device and to generate current values which represent the measured current intensities. The control unit is designed to process the current values, to open the microswitch if a current value lies in the current value range, and to reclose the microswitch after being opened. Also provided is a protective system for electrical circuits with multiple protective devices of the aforementioned type and to a method for controlling the protective system.