I have a project where they want to convert an existing home and a second building (some 60' away) to a preschool. My problem is that the existing service is a 400A "all in one" mounted on the smaller building (1500sf), and the larger home (4000sf) only has a 200A feeder from the service. These all-in-ones only have two 200A disconnects. The home is all electric - stovetop, oven, laundry, WH. It probably barely meets load calcs as a house, but as a commercial structure, it does not (more A/C's needed for fresh air). NEC 225.30 says there can be only one supply unless (A)(1)- or (6) special condition is met. I don't think any of these are met. Is there a chance that two buildings 60' away could be considered one? Any other ideas for getting more power (short of moving the service entrance or adding a new service)? As it stands, I'm recommending that they remove the cooking equipment and laundry. Their budjet is really low.
More than one building issue (No. of supplies)
- Thread starter donw
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inspector 102
Senior Member
- Location
- Northern Indiana
It sounds like you have one service with 2 load side panels fed by feeders, not service conductors. Based on the square footage you quoted, I don't know why a 200 amp at each location would not be enough. Am I missing something?
inspector, I should also have given you the voltage/phase. It is 240V/single phase. With a 5-ton, 4-ton, & 3-ton A/Cs, 8KVA for stove/oven, 4.5KVA for WH, 5KVA for dryer, 1.2KVA refrig, 1.2 microwave. If you figure merely 3VA/ft for lighting+recept, I'm over 200A.
John Valdes
Senior Member
- Location
- SC.
- Occupation
- Retired Electrician
Article 225.30
(B) Special Occupancies. By special permission, additional
feeders or branch circuits shall be permitted for either
of the following:
(1) Multiple-occupancy buildings where there is no space
available for supply equipment accessible to all occupants
(2) A single building or other structure sufficiently large to
make two or more supplies necessary
Talk to the AHJ. I am certain one of these exceptions is valid for your circumstance. People get around this article all the time. Additionally, interpreting the article and exceptions is almost an impossible task. IMHO.
(B) Special Occupancies. By special permission, additional
feeders or branch circuits shall be permitted for either
of the following:
(1) Multiple-occupancy buildings where there is no space
available for supply equipment accessible to all occupants
(2) A single building or other structure sufficiently large to
make two or more supplies necessary
Talk to the AHJ. I am certain one of these exceptions is valid for your circumstance. People get around this article all the time. Additionally, interpreting the article and exceptions is almost an impossible task. IMHO.
John, thanks for the reply. I don't think any of those exceptions apply. But I did have an idea. What if I routed a feeder over to a new panel mounted on unistrut to feed the air conditioners that sit on the ground? That would be a separate structure with its own grounding system.
e57
Senior Member
- Location
- San Francisco, CA
Gas appliances (stove/dryer) - but that plumbing.... Otherwise it sounds like the AC's are pushing the envelope for the 200 on only one building? Pulling a feeder or two from the other building for AC loads an option via 225.30B2 and some talking to the AHJ.... Since the compressors could be separated from the condensor and air handling by just LV control wiring I would not see an issue.
Or build a 'hallway' from one building to the next.
And put all the new feeders in it....SmithBuilt
Senior Member
- Location
- Foothills of NC
What would be wrong with removing the 200 amp feeder that goes from the small building to the house and installing a new 400 amp service on the house.
e57, I am thinking that I'll be able to send another feeder over to a new structure (unistrut), dedicated to some A/C load (like you said). But I don't think it'll fall under "...sufficiently large to make two or more supplies necessary".
SmithBuilt, having to replace the 200A panel with a new 400A service would probably be a project killer, financially.
SmithBuilt, having to replace the 200A panel with a new 400A service would probably be a project killer, financially.
e57
Senior Member
- Location
- San Francisco, CA
"Large" is subject to the AHJ - never hurts to ask....
IMO (not knowing the particulars - assuming over-head) demo'ing an existing panel with some care to relocate - then use the feeder in the opposite direction would only be labor and misc. mat.'s AND a 200A panel to extract what you need for equipment then feed out of that to the other building - may be equal to running a new set of feeders. POCO replaces the drop....
If UG or not feasible or allowed - I would say get some $ for the time and effort you're putting in to cost engineer this thing - even if it cant be done....
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