The application of neutral earthing reactors is to increase the impedance in the neutral point of a transformer or a shunt reactor. During single phase faults the reactor limits the fault current in the neutral and the restoration of the power line is improved.
The losses in the reactor are without economic importance. The designed current density in the winding is determined by the reactor´s ability to withstand the mechanical forces due to the short-time fault current. The design can be dry-type or oil-immersed.