System Neutral Grounding or System Ground

With respect to surge arresters, the type of earthing or grounding of the system neutral determines the maximum voltage reached during a fault on the system. There are several types of neutral grounding scenarios:

1. Solidly grounded: where the neutral is tied to earth or ground in many places along the power system. Sometimes referred to as effectively grounded.



2. Impedance grounded: where the neutral of the system is connected to earth through a low or high impedance at the source transformer. Sometimes referred to as non-effectively grounded



3. Ungrounded: where the neutral is not tied to earth or ground in any way. This can be a wye or delta system.