AC network as a TN-S system and its supervising

Fault connections and leakages often occur in the TN-S partly due to the network itself and partly due to defective devices. These faults do not cause disturbances in the energy supply but do cause other disturbing influences, e.g. large potential differences between distinct equipment earths, electromagnetic disturbances, and the possibility that high-frequency disturbance voltages in the neutral conductor may penetrate into the protective earthing. By the continuous supervision of the TN-S network the disturbances mentioned before can be eliminated and a fault connection or a faulty device located easily. For the continuous supervision of the TN-S network, several supervising devices have been developed, which use sum current transformers. Good results have been achieved by the correct placement of the supervising devices and a detailed analysis of the network.<>