x0 to ground
x0 to ground
I assume that your transformer is connected delta on the H1-H2-H3 windings and wye connected on the x1-x2-x3 windings. By definition the primary of the transformer is the source of supply side. In this case you have formed what is called a "Grounding Bank" by tying down the x0 or the wye tie you allow the currents of the 208/120V system to flow into the X0 bushing and be distributed by the delta windings on the high side.
Always float the X0 bushing in this cast. A wye-delta connection should be avoided in this case.
Don