We've recently split an upstairs and downstairs space in a commercial building into separate leases, and encountered problems putting them on separate utility bills because of the way the two floors are wired. This building has been around for about 70 years, so there's a certain amount of... interesting... infrastructure.

There are two separate services with shut-offs at the meters outside, apparently relatively new, each with its own large conduit leading to the panels. However, not all of the circuits for each floor are on the correct service. Correcting this would be a relatively simple job of rerouting the wiring to the other box.

A bigger problem is that the panels for both services are in a utility room on the first floor, and the second-floor tenant doesn't have access. We'd like to move the panel upstairs...

So a couple questions/proposed solutions.

First, if we have a new panel installed upstairs, can we just pull out the and circuit breakers from the original panel and splice new wiring to run up conduit to the new panel? What's the best way to do that in terms of type of wire and conduit size?

I know the supply has to run in separate conduit from the load circuits, but can we just splice it at the old box along with the rest of the circuits, or does it have to be pulled directly from the meter in a single run?

Finally, the previous use of the space required a lot of high-amp circuits, such that after ripping out the equipment and rewiring to just outlet boxes, there is a 20 amp breaker for each outlet(!), of which there are 10 in a relatively small office space. Obviously this is overkill, and it would simplify things to combine some of the circuits at the original box and run less wires to the new box. Can these just be ganged with wire nuts like a normal two-wire splice within the old panel?

I've talked to a couple electricians, but they never follow up with written quotes, and I'd like to do the simpler parts myself and then try again when just the "heavy lifting" is left. Perhaps the local professionals will be less likely to turn tail and run with a bit less of a mess on their hands here. :)


Edit: Thanks for comments so far. Access to the utility room is only through the downstairs space, so giving upstairs tenant access isn't very desirable, but could possibly be arranged. The one thing that absolutely has to happen, though, is to sort out the circuits so that upstairs can be made to pay for their A/C condenser usage (currently on the downstairs service).

You are talking to the wrong electricians. Try again, there are many who would enjoy correcting the minor problems you describe.
Be aware, you cannot legally do this work unless you are licensed. (I assume you are in the USA)
Depending on the occupancy and size of this building you may be required to hire an Architect / Engineer...
Whatever, do it right.

My suggestion is that you bid this work out.

Far and away, the easiest thing would be to allow the tenant access to the panelboard.

Since the wiring is already in place, why go through the heartache of changing it. While it is somewhat impractical, it is transparent. It will make no difference as far as the over-all operation. It is wiser to leave it alone and add more receptacles on an as needed basis.

As to the grouping of the outlets, typically, you can put up to 10 receptacles on one breaker in a commercial environment. In the commercial world receptacles are calculated at 180 VA (volts/amps) per breaker.