Multiple Building Services

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bcorbin

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Guys, I am faced with an unexpected challenge.

I am doing design work in an old school building.

There are seven main lug only electrical panels in the building...most are 40-50 years old, so replacing them, at least on an as needed basis is probably a good idea.

I discovered all of the panels are fed from an 800-amp distribution panel, located outside, approx. 60 feet from the building. The dist. panel has an 800 amp main breaker, and is fed from a utility transformer 10 feet away.

It looks like all of the interior panels were re-fed like this no more than 10 years ago (dist. panel is new...conduits on side of the building are still pretty shiny, etc.)

So by my reasoning, I have a building with seven services to it. I'm not sure I can replace a panel and be grandfathered with existing conditions.

Do you agree I have seven services?

If so, any insights on how to deal with this? At the very least, I would call for a bunch of multiple service labels on all of the panels. That might appease the local inspector (assuming he isn't the inspector who approved this mess when it was built this way).
 
bcorbin said:
Guys, I am faced with an unexpected challenge.

I am doing design work in an old school building.

There are seven main lug only electrical panels in the building...most are 40-50 years old, so replacing them, at least on an as needed basis is probably a good idea.

I discovered all of the panels are fed from an 800-amp distribution panel, located outside, approx. 60 feet from the building. The dist. panel has an 800 amp main breaker, and is fed from a utility transformer 10 feet away.

It looks like all of the interior panels were re-fed like this no more than 10 years ago (dist. panel is new...conduits on side of the building are still pretty shiny, etc.)

So by my reasoning, I have a building with seven services to it. I'm not sure I can replace a panel and be grandfathered with existing conditions.

Do you agree I have seven services?

If so, any insights on how to deal with this? At the very least, I would call for a bunch of multiple service labels on all of the panels. That might appease the local inspector (assuming he isn't the inspector who approved this mess when it was built this way).
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I would say you have 7 feeders, not services. Art 225 is going to cause issues here. My first concern would be if the feeders have both a grounded conductor and EGC?
 
I agree with Texie, from your description sounds more like feeders... although the "code" gets you either way :). There are provisions in 225.30 where the AHJ may have allowed the initial install. First step I would think would be contact them/
 
I think you have 7 feeders as well.

I am not sure you actually have a problem, although it appears the building is being served by multiple feeders which is generally prohibited.

Does each of the feeders have its own CB in the distribution panel? if so, it would appear the panels would not need a main.

Does each feeder have its own EGC and neutral (if needed)?
 
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Unfortunately, this school is in a pretty rural area. I know for a fact no permit will be pulled and the work isn't going to be inspected. However, I'm sure that will provide me little cover in a court of law should something bad happen.
 
petersonra said:
I think you have 7 feeders as well.

I am not sure you actually have a problem.

Does each of the feeders have its own CB in the distribution panel? if so, it would appear the panels would not need a main.

Does each feeder have its own EGC and neutral (if needed)?
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Yes, they all have their own circuit breakers. But doesn't this still violate 225.30(A)? That sounds like only one feeder can go to each building fed by the distribution panel.
 
bcorbin said:
Yes, they all have their own circuit breakers. But doesn't this still violate 225.30(A)? That sounds like only one feeder can go to each building fed by the distribution panel.
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I was editing while you were replying to suggest that might be an issue.

I wonder why they did not install the distribution panel at the building.

[added]
I don't see any cost effective way to undo what is already there. The school district is going to have to decide if they want to pay a bunch of money to meet code or just live with what is there. I personally do not see a huge safety issue. Put a sign on each panel that says where the disconnecting means is at for the panel if there is not one already there, and let the school district worry about it. It is really their problem.

The most cost effective answer might be to just extend the building out to the pole.
 
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bcorbin said:
Unfortunately, this school is in a pretty rural area. I know for a fact no permit will be pulled and the work isn't going to be inspected. However, I'm sure that will provide me little cover in a court of law should something bad happen.
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Even if it was legal per code it would not help you all that much in court. You have liability insurance to deal with the legal problems.
 
Two questions:
1. Are the feeders protected by individual breakers or just the 800A main? That will determine the wire size required.
2. You may not need a wire EGC if the raceway EGC is complete. But you should not have a neutral to ground bond at the subpanels. If they were originally all "service" panels, then they may not even have an insulated neutral bar.
 
& - & - &

bcorbin,

Submit a code compliant design regardless of the costs.
Be sure to cite the applicable Articles in your applicable
edition of the NEC.

It should not matter if the location is in rural or not !
[ i.e. - design what is the right thing ] :happyyes:

& - & - &
 
petersonra said:
I personally do not see a huge safety issue.
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Huge? Debatable. Safety Issue? I think so. When the fire department arrives they will discover that they have to go 60 feet away and throw seven switches, in order to make the building safe for them to enter. I would not want to impose that on them.

I think you need to put a distribution panel inside the building, give it one feeder from the outdoor panel, and subfeed all the other panels from that point. You also need to make sure there is a grounding electrode system at the building, and you need to connect the new DP to it.

 
charlie b said:
Huge? Debatable. Safety Issue? I think so. When the fire department arrives they will discover that they have to go 60 feet away and throw seven switches, in order to make the building safe for them to enter. I would not want to impose that on them.
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IMHO this is not a huge safety issue as long as the FD is aware of the situation. Minimum code would require a single location for disconnection _inside_ of the building. The FD would have to _enter_ a burning building to turn off the power.

A code compliant setup would have the single disconnect on the outside of the building, which the FD could turn off.

I do not see a big difference in safety between a single disconnect on the outside of the building and a single disconnect 60 feet away from a building. I think that a single disconnect 60 feet away is arguably safer than a single disconnect inside the building.

I agree that having multiple feeders from a separate structure violates code as written.

-Jon
 
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