This is a new installation. You didn't change out a meter base. You removed a meter base and installed a meter/main with provisions for additional circuits ( new main panel ).
You can change out the meter base as a repair without bringing the whole system up to code. what makes you think that you are not doing new work? You have changed the location of the main panel.
I concede all points relating to what the code says and that it needs to be fixed. The following questions I ask not to be stubborn, but I really want to understand what is happening with the system and why it is dangerous. It was never fully addressed while I was in training, and it seems that my understanding is lacking, so I really want to know. If I seem frustrated, it's because I hate doing things just because "it's what the book says" when it seems to fly in the face of common sense. I have seen many conflicting and contradictory things in the code that even my teachers conceded were self defeating. I just want to know how it makes sense. So, bearing in mind that I'm not trying to be snarky--I just really want to understand--here is my new question:
How is it functionally different? Isn't this, on a smaller scale, exactly how the power grid in general is set up? At each residential transformer, power is stepped down to usable voltages and then sent out with only two hots and a grounding conductor. There is no grounded conductor that carries current back to the transformer. My understanding is that a true neutral, not a grounded conductor, only exists in three-phase electrical systems where it carries the imbalanced load between the three different phases. (As I deal only with residential systems, I confess my grasp on three-phase is weak). So, regarding single phase, residential systems: what is the danger of combining the grounded and grounding conductors? And if there is a danger inherent in combining the neutral (
grounded) conductor and the
grounding conductors in the panels, why not bring 4 wires from the transformers? Why, if all the load is carried on the grounding conductor back to the transformer, is it less safe in my scenario? They are all tied together, regardless of weather in the main panel or any sub-panels. Thus, being of equal electrical potential, any current carried by the neutrals/grounded wires is fed into the grounding conductor. The only physical way that I see electricity can back-feed from the grounding conductor into the grounded conductor is if the grounding conductor from the utility's side is damaged or impeded. Otherwise, it has a clear and unimpeded pathway back to its source regardless of if the neutrals are bonded together with the grounds.
Again--I'm not trying to be snarky. I know we all read things without the speakers intended tone of voice. Please help me see where I am misunderstanding what I think is basic theory.