A grounding transformer or earthing transformer is a type of auxiliary transformer used in three-phase electric power systems to provide a ground path to either an ungrounded Y or a Δ connected system. Grounding transformers are part of an earthing system of the network. They let three-phase systems accommodate phase-to-neutral loads by providing a return path for current to a neutral.
Grounding transformers most commonly incorporate a single winding transformer with a zigzag winding configuration, but may also be created with a Δ-Y transformer.
In this case, the voltages are as follows:
Between phases 12,5kV;
Between phases and neutral 7,2kV.
Flip on the SPST switches to turn on primary high voltage.
Switch between the voltmeters to see the different voltages.
