Multiple Services to 3 buildings (230.2)

[elecshop]

Looking at 230.2(A) through (D) about when multiple services are allowed, can someone please explain the following sentences from parts (B) and (C):
(B): "A single building or other structure sufficiently large to make two or more services necessary."
(C): "Where the capacity requirements are in excess of 2000 amperes at a supply voltage of 1000 volts or less"

This means that either the building has to be large enough to save conduit and wire runs, or the service has to exceed 2000A to allow multiple services, right?

I have this project I'm working on, that has two separate buildings and each has its own utility transformer and service (and generator). We are adding a new building in the middle to connect the two, and the plan is to provide a new service (1200A 480V) and utilize it to power the new building + backfeed to the original distribution in the two existing buildings, that are being renovated too, thereby demolishing the existing services in the two existing buildings, and have a new transformer in the middle exterior to the middle building.
However, this might be a very expensive option and a lot of money can be saved by just adding a new service for the new building which is small, and keep all 3 services separate for each building.

Is there any requirement that I'm not aware of that prevents multiple services to the same building? I only found article 230.2 that references multiple services, but I think there is some other requirement related to fire protection, if I'm not mistaken?

Thank you!

 

[JoeStillman]

I would start by looking at the electric bills for the two existing buildings. There's a good chance you have existing capacity somewhere for the addition, or possibly reduce the size of the backfeeds to the old services.

 

[elecshop]

I would start by looking at the electric bills for the two existing buildings. There's a good chance you have existing capacity somewhere for the addition, or possibly reduce the size of the backfeeds to the old services.

If it turns out that the capacity for the 1st building + the capacity of the 2nd building is enough to service the new building in the middle, we would have two services for one building comprised of 3 combined buildings open to each other. Does the code allow two services for 1 building?

 

[elecshop]

And by the way, the current capacity is not enough. Mechanical units are added so we are definitely going to need a larger service, but the question is, if three services are allowed to one building.

 

[JoeStillman]

And by the way, the current capacity is not enough. Mechanical units are added so we are definitely going to need a larger service, but the question is, if three services are allowed to one building.

I would say, in this case, no. But it sounds like you could back-feed the older services with something smaller.