Multiple Services for one Building (NEC 230.2)

[a larky]

I have a building that was previously two parcels but has since been combined into one single address and tenant. There are (2) existing 200A, 120/240V, 1PH services (1 on each side) and we are currently proposing to add an additional 800A, 480V, 3PH service. This additional service would typically be allowed under NEC 230.2 (D), but the AHJ is stating the already existing 200A services need to be brought into compliance and we cannot have 3 services. How does this work with the code if we have a building that falls under 2 APN's which already have these 200A services existing?

 

[petersonra]

You combine them into a single 400 amp service

 

[charlie b]

You combine them into a single 400 amp service

That could be tricky since they are on opposite sides of the building. I suppose you could convert one to a 400 amp panel and run a 200 amp feeder to the other. The problem is that the first one is presently fed by a 200 amp utility line.

 

[petersonra]

That could be tricky since they are on opposite sides of the building. I suppose you could convert one to a 400 amp panel and run a 200 amp feeder to the other. The problem is that the first one is presently fed by a 200 amp utility line.

Sounds expensive but if the AHJ is right that he cannot have three services, and that is probably the case, what else can he do?

 

[a larky]

That could be tricky since they are on opposite sides of the building. I suppose you could convert one to a 400 amp panel and run a 200 amp feeder to the other. The problem is that the first one is presently fed by a 200 amp utility line.

Can we argue that we have 2 APN numbers and therefore we have (1) service for one side and (2) services for the other?

 

[Elect117]

Use a dry type to refeed one of the old 120/240V services. Less voltage drop and is a quicker fix than trying to get a 400A 120/240V panel and utility transformer changed out.

I am of the opinion that you can remove all the old 120/240V services by this method and have just one utility serivce. The AHJ is correct. I would argue that the utility will probably require the same. Usually when you are requesting a 3rd service they will tell you to combine them if they are on the smaller side which they are.

 

[petersonra]

I don't see the need for a 400 A panel at all. You are going to likely need an outside disconnect now so get a 400 A fused disconnect and string two feeders from it to feed the existing panels. It's likely all outside so running conduit to the other end if the building is while not cheap, not difficult

 

[jaggedben]

Can we argue that we have 2 APN numbers and therefore we have (1) service for one side and (2) services for the other?

Not really, at least under the NEC.

The only thing in the NEC that might help you in this regard is that the NEC defines a service as serving a 'premises'. So you could argue you have two premises. However the rule in 230.2 applies to buildings, not premises. Moreover the NEC basically does not care about ownership or lot lines and leaves all its rules very intentionally agnostic of such issues. An APN number, whatever that is, is something the NEC never heard of. So if you're AHJ has already determined that you have one premise or building and you can't change their mind about that, nothing in the NEC is really going to help you.

Now, if the two spaces are separated by a firewall, then you can argue you have two buildings. See the NEC definition of a building.

 

[Knightryder12]

Just make your new 480 volt service a little bigger and provide step down transformers to feed both of the existing 200A single phase services. You may not even need that big of a transformer if you can do a load calc. or get a 30 day peak demand from the utility on the existing services.