That sounds like a workable plan to me. That is installing the 400 amp panel
now, then later making the other panels subpanels.

Just be sure you have plenty of breaker slots in your 400 amp panel. I have
a 40 slot 200 amp panel for example.

So in the future, you could have the electric service disconnected and meter
removed from one of the other panels. Then wire that panel into the 400 amp
panel with an appropriate breaker.

Then on the subpanel, you would then need isolated grounds from the
neutrals. This would just be adding a separate grounding bar most likely,
ask the electrician about this. If the subpanel is an old congested panel,
you might need to get a new panel.

Otherwise sounds like a good plan to me.


"MASTERCHIEF" wrote in message

....I think this will be the easiest way to accomplish my goal:

1. Upgrade #1 to 400A
2. When I want to run #2 and / or #3 off the 400A panel I will shut off
the utility (won't be on anyway if there is no tenant) and remove the
SE cable from the panel.
3. I should then be able to wire it in such a manner to make it a
subpanel of #1. I know code does not require a main breaker, but I
could leave it in there I do believe. My feeder cable will come from
the 400A panel and be wired to a 100A breaker.

This will require some work since I cannot leave an unused wire in
place when I am not using it.
The only big question. When I rewire floors #2 and #3 I will be
running ONE CABLE from the basement to subpanels on the 2nd and 3rd
floors. When I go to single-family it will mean my two main panels (#2
and #3) become subpanels of #1. This means I will have TWO SUBPANELS
in that configuration and I do not know if that will meet code.

Frank