sentences:  This gradient is low at points far away from the earth return connections, but increases near the ground rods where the metallic circuit enters the earth.In three phase four-wire ("wye") electrical power systems, when the load on the phases is not exactly equal, there is some current in the neutral conductor.Because both the primary and secondary of the distribution transformer are grounded, and the primary ground is grounded at more than one point, the earth forms a parallel return path for the neutral current, allowing part of the neutral current to continuously flow through the earth.