What does the TN grounding method refer to?

The TN grounding method refers to a system where the Wye or star point of a three-phase system is connected to ground. In this setup, the connection allows for fault protection and enhances the safety of the electrical system. There are three variations of the TN system: TN-C, where the neutral and protective earth conductors are combined; TN-S, where they are separate; and TN-C-S, which is a combination of both.

The grounding of the star point plays a crucial role in ensuring that the system remains stable and that any fault current can safely return to ground, minimizing the danger to equipment and personnel. This method is widely adopted in various electrical installations due to its effectiveness in providing a reliable grounding path. Other choices are not valid as they describe different configurations or grounding methods that do not pertain to the TN grounding method.