MSG,
Current on the ground indicates a ground fault. This could be very
dangerous. If there is little to no load with current on the ground you may
have circulating current. This happens when there are more than one ground
location separated my more than about 3 feet. The potential at one ground
point is different than the other. Current flows because of the potential
difference. Hot-to-ground voltage. This reading should be the highest of
the three readings. The ground circuit, under normal, non-fault conditions,
should have no current