Originally posted by sparky:
[b]parallel ground path
ah ha! key word Paul!
we cannot run #2 ( a 3-wire, hot , hot and dual usage N & G) with any mettallic pipe interconecting the mother & outbuilding here . [/B]
I can see how that makes sense; you don't want the part of the neutral current flowing through the pipework.
however, the utility will commonly run the same 3-wire configuration to 5 homes off the same X-former with city water lines to all.
I hadn't considered that before, but I certainly see your point. Typical bureaucracy I suppose: "Do as I say, not as I do."
There are a few special cases here where PME is not allowed to be used. One such place is in a petrol (gas) station where a broken neutral could result in the load current flowing through fuel lines.
