TN-S/TT system

Advanced warning prevents shutdown – Residual current monitoring in earthed systems

In earthed systems (TN-S/TT systems) one point or several points of a system, an electrical installation or electrical equipment are connected to earth for the purpose of electrical safety.

In TN systems, the star point of the feeding transformers is connected to earth through a low impedance and the exposed conductive parts of the electrical installation are connected to the protective earth (PE) of the system. In TT systems, the star point is also connected to earth through a low impedance but the exposed conductive parts of the electrical installation are earthed independently from the system earthing.

Melden statt Schalten – Differenzstromüberwachung im geerdeten System