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Branch circuits in a “different” building than service.

Merry Christmas
Ok. So I am a facilities electrician at a company. We have a “group” of buildings we have added onto to make 1 big building. Each addition has a different address for the service. 7070, 7060, 7040.
No wires go in between buildings except fire alarm wires. The maintenance manager now wants to run a branch circuit between 7060 and 7040. The circuit will originate in 7040 and supply a work station in 7060.
We are pretty much out of power in 7060. The last load study I did revealed about 100 amp available on the 7060 buss bar, so he wants to bring it from the other building.
I’m not real fond of this idea, cause it will create a precedent going forward and we will have all kinds of branch circuits ran between buildings and it’s going to be a mess.
Is there a code article against this?
Thinking building supplies via another service would limit how many circuits could go in between.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Just one circuit? It doesn't seem worth it. As you said, when will it stop?

Seriously recommend an upgrade.
 
Upgrade is gonna be about 1/2 million dollars, in a down year, so that’s not gonna happen.
I did read 225.30 and it allows 1 circuit.
Which we already have. They pulled a 480V 1000 amp feeder circuit from 7040 to 7060 to feed a vacuum furnace.

So it’s gonna be anything new that is added is physically located in and fed from 7040.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Are the sections of the now one large building separated by firewall? If not I don't see any code issues and the street addresses have nothing to do with this issue.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)

Code cycle?? (2023 has reduced earlier restrictions even if they are applicable)
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Seems to me that the configuration in the OP will fall into one of compliance categories:

1) The multiple addresses are a single "building" per the NEC definition. In which case 230.2 applies, and having 3 services instead of one will require meeting one of the allowances in that section. Then once that hurdle is cleared, there is no NEC limitation on where branch circuits and feeders go within the building, or what service supplies them.

2) The multiple addresses are in fact 3 different "buildings" per the NEC definition. In which case there is only one service per building, so 230.2 is not an issue. However, 225.30 is a possible issue, as it limits the number of branch circuits or feeders supplying a building. Building 7060 already has a feeder supplying it in addition to the service, which is fine, as 230.2 and 225.30 are separate requirements. But the question is whether the additional branch circuit supplying Building 7060 would meet one of the allowances within 225.30.

There is also an argument that could be made that since the scope of 225.1 refers to "outside branch circuits and feeders run on or between buildings," in the case of two adjoining buildings, it would not apply to a branch circuit or feeder that never runs outside but passes between buildings while always staying inside. No comment on that argument, other than that on its face it is sufficiently valid that it requires consideration.

Cheers, Wayne
 
Yes. It all started as 1 building (7070) then they cut a hole in the wall and expanded(7060). Couple years ago we knocked that wall down and expanded again with 7040. There is a fire barrier.
Each address has it's own service and meter.

We may be able to slide in under 225.30 (D), but how do you determine all the power is shutoff in case of a fire in 7060? Unless you know to kill the switchgear in 7040, you'd be dumping water on live circuits.
 
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