There is voltage drop in any conductor, that will show up as ground shift.
When you have wye distribution there is also voltage drop in the grounded conductor on the pole. Some current has to be returning through the earth.
Since I have a 13kv distribution line that runs pretty close to a tidal river (that I assume might be as close to true ground as possible) I may extend this experiment along the line of about 20 transformers. I just need to come up with a 150 foot meter lead and a decent electrode.
