|>I could, in theory, have the service drop come in with no |>neutral at all from the utility transformer, and it would measure correctly. |>Safety would be a different issue. |>
| | 250.24(B) says you will bring the grounded conductor to the service disconnect | enclosure.
However, 250.24(B) is not a statement of theory. And I believe it is quite possible that the NEC and most engineers have it wrong. I am only saying possible. I have made no conclusions, yet. But what I do know is that a hazard I am studying is one where there is controversy and vested interests in the status quo.
What I will be doing is exploring all possible solutions and then trying to rule each out as to whether it is practical and/or poses new hazards that would make a worse tradeoff. The question I posted was to know if the watthour meter could impose an impracticality to what might (or might not) be a simple solution. That a watthour meter won't be an issue lets me explore this further to see if it is a practical solution. But it may not be for other reasons. At least I can focus on them.
| The only ungrounded services are going to be 3p delta and they are very rare, | usually needing special permission. | We used to keep the neutral out of computer room panels, using only line to | line loads, most 3 phase but the neutral was still in the service disconnnect | at the "star" grounding point.
The fact that many loads can be connected 2-wire (or 3-wire three phase) shows that there is no fundamental need for one of the current carrying conductors to be a groundED conductor at zero potential relative to the ground bond point. Some loads do need the groundED conductor for legacy reasons (for example the design of typical light bulb sockets makes it especially easy to touch one of the conductors, so we make that be the groundED conductor for safety reasons). But aside from legacy reasons, I think we do not need an actual groundED conductor; what we need are all conductors having system voltages relative to the ground plane, as a delta utilized wye transformer would be (the star point being bonded to an earth ground electrode or the whole grounding system, but not fed as a current carrying conductor).
BTW, the reason I don't just toss the broad issue here (yet) is that I do not believe it will be thoroughly studied that way. It is way too common for people here (and in other areas as well ... it being human nature) to just post the conclusions they have found or learned. In many cases people don't know why the "best" answer they have is the best, but that it is simply what they lerned or what everyone does. But that is not what I want for this issue; I want a thorough exploration of alternatives that might even "fly in the face" of what we (think we) know.
If I conclude that current practice is in fact the best, then there won't be any need for me to post it anyway. If I conclude something else, or just can't reach a conclusion, then I probably will post it, eventually.