Electronic fuses permanently monitor the 24 V secondary circuit and reliably switch it off in the event of a failure. These electronic circuit breakers will also switch off circuits in cases where mechanical circuit breakers often do not trigger, e.g. in case of overload of a circuit with long cables. The system has a modular structure and consists of a feed module and side-by-side mountable fuse modules. These modules can be mounted next to the head module via a simple clip mechanism, completely without any bridges or jumpers. Easy mounting and minimised wiring complexity save cost and time. With the standard version the user can connect up to 10 and with the IO-Link version up to 8 safety modules to the feed module. The fuse modules feature an LED for signalling if the module has triggered, if it is active and in how far it is utilised. Each module is equipped with two channels. By means of a pushbutton, each channel of a fuse module can be activated, deactivated or reset individually. The IO-Link version allows remote configuration and operation of the modules.