There are different grounding requirements for a main panel -vs- a subpanel.
So I don't know how you would get around that issue without a permanent
re-wiring job.

Also there is a safety issue. Someone might think power was off to one of
the panels when in fact it could be energized. Back-up generators have a
similar problem, and panels are made for that specific use. Might want to
look at some of those.

Check with your electric company about their being able to provide a 400 amp
service.

I would ask your local inspector what you can and can't do. In my area, I
can go in and ask the inspector questions before I do any work.


"MASTERCHIEF" wrote in message
BACKGROUND:
1910 Queen-Ann Victorian in Oil City, PA
Currently has three 100A panels, one for each floor.
I will add one more meter for the basement where I will put an
apartment, but for the sake of this discussion it is not of primary
importance.

OBJECTIVE:
I want the FLEXIBILITY to switch from multi-family to single-family. I
have already devised plans for gas and water. Now I want to do the same
for electrical.

I have the permit(s). I can have the inspector onsite for $55. I
wanted to have a tentative plan in place first.

I called to upgrade my service from 100A to 200A for 1st floor. But
after calculating AMPS for the entire house I do not believe 200A is
enough.
The 1st floor/meter/load center is the one I would like to be able to
use as the source for the ENTIRE house if/when I don't have tenants on
2nd and 3rd floor. or if the new owner wants to make it SINGLE FAMILY.

Yesterday I did a complete breakdown of my amperage requirements based
on a formula in Taunton's Wiring a House.

Floor #1: 119A
-General lighting 1920 sq. ft x 3 = 5760
-Kitchen 3000
-Disposal 900
-Stove 8000
-Dishwasher 1500
-Washer 1500
-Dryer 5000
-Hot Water Heater 4500
Total 30160-10000

AMPS Required
10000 (1st 10,000)
8064 40% of remainder (20160 X 40%)
10500 (heating based on 42' of baseboard heaters 42'x250)
Grand Total: 28564/240V=119A

Floor #2: 93A
Floor #3: 92A
This is approximated.

It seems a little high because I am migrating AWAY from gas to electric
due to predicted/continual price of gas.

It seems to me I will be better upgrading my service (floor #1) to 300A
or 400A. This will allow some room to grow and why do it TWICE?

I currently have 3 meters with a single SE cable coming from the
transformer on the utility pole into a box that houses the 3 meters
with the individual SE cables for each of the 3 100A service panels.

Should I upgrade my service to 400A for first floor to cover all
current/future needs?

How do I interconnect them? I think I need switches inbetween the
meter and service panels but cannot find out how to set this up.

Thanks,
Frank