oldspark said:
I think it was touched on before, you create a parallel path for the returning current (neutral) even under normal conditions it can cause all sorts of weird things espicially if you are using metal conduit and have loose connections that can over heat, the fact of the matter is you may never have a problem wiring it that way but it is not worth the risk. I hope that is the answer you are looking for.
Hello oldspark
Well thanks again, I looked up more detail and found a better explanation that I was looking for.
Also thanks for being honest in saying that it may never happen in my small shed in the back yard since I did not use metal conduit.
It seems Electro-Magnetic Interference (EMI) can cause these stray voltages you are refering to.
It seems the major cause is:
1. Older local electric utilities that do not distinguish between ground and neutral like in the old days!
2. Old Motors in farm equipment with excessive leakage currents.
Quote from link below
1.
"The electrical utilities do all of the wrong things relative to stray voltage. They consider ground to be the same as neutral and they connect the primary neutral and the secondary neutral together at their distribution transformers."
2.
"Farmers need to select electrical equipment, including lights, that will not generate excessive ground currents. Lighting ballast, electrical motors and auto-transformers are primary sources of leakage current even when they are UL approved and working correctly. All electrical equipment needs to be tested for leakage before it is installed. If the leakage currents is in excess of 1 milliamps (0.001 Amps), then the equipment should not be used. If you must use it, then special precautions must be taken in the electrical system design."
See
http://www.bassengineering.com/SV_Cause.htm