A modular protection system was developed for DC radial microgrids. The novelty of the realised protection system is based on the combination of different fault detection, characterisation and localisation criteria. The protection system was developed based on real-time monitoring of voltages and currents at different positions within smart modular switches in the DC system. Intelligent modular DC switches were developed for the setup. On the basis of fault detection criteria, protective measures are initiated and appropriate switching signals are sent to the appropriate switches in order to isolate the faulty part. Different fault locations and types have been tested in the laboratory for a 24 V DC test setup. Hence, the selectivity of the new protection concept has been verified.