. . . I'm not ever going to say you can have too much ground wire, but the neutral wire connects to the ground bar and the ground bar connects to the ground rod and the ground rod connects to the kneebone..... point being the ground and neutral connect at the same junction. Seems to me if you have ANY voltage differance between ground and neutral, there is a bad connection on the lower voltage wire.
I'm sure I'll get corrected soundly for this post...
Not soundly!
The ground and neutral should only connect at the breaker box. The neutral and hot wires have current running through them when they are suppling power to a device. In a proper system, the ground wire should not have any current running through it. As a consequence, there will be a voltage drop across the neutral wire which will not occur on the ground wire. Thus, there will be a voltage difference between neutral and ground at the load end of the wires. On short runs of heavy gauge wire it should be barely noticeable. On long runs, like a few hundred feet of extension cord, it can be several volts.
