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Thread: Two Services for one building

  1. #1
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    Two Services for one building

    I am working on a project that has two existing buildings (lets say building A and B) with their own services. The service for building A has maxed out but there is available capacity in the Main distribution board fed by Service for Building B. I know NEC only allows one service for one building (unless for exceptions stated) but I would like to know if there is a way I would be able to feed a load in building A from the Main distribution board in building B?

  2. #2
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    Not in any way that I think of.

    Unless this is a supervised industrial place, then maybe. IDK.
    "Electricity is really just organized lightning." George Carlin


    Derek

  3. #3
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    The one service per building... is that all buildings or is multiple dwelling different?
    Jamaica Utilities want the runs from the meter boxes up the meter pole separate for each meter to a location... and kept separate to the panels inside, of course. So, a few houses I have seen have a spaghetti nest at the top of the meter pole, since some people have as many as eight apartments in their homes. I always thought it would be better to do like in USA with one run to the pole and the bus system I see but...The Jamaican attitude is, it is easier to steal electricity if a bus system is used...
    still think it more dangerous their way..lol..

  4. #4
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    This might be more tricky than you would expect.

    230.6 says one service per building, and I don't think any of the "unless permitted by" statements apply to your situation.
    225.30 says one outside feeder per building, and I don't think any of the "unless permitted by" statements apply to your situation.

    However, you are not suggesting more than one service or more than one feeder. Rather, you are suggesting one of each. I don't think the code language, as written, forbids this. I suspect that the "one of each" installation is not in compliance with the intent of the code authors. But it is not in violation of the language they put into the code.
    Charles E. Beck, P.E., Seattle
    Comments based on 2017 NEC unless otherwise noted.

  5. #5
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    Quote Originally Posted by charlie b View Post
    This might be more tricky than you would expect.

    230.6 says one service per building, and I don't think any of the "unless permitted by" statements apply to your situation.
    225.30 says one outside feeder per building, and I don't think any of the "unless permitted by" statements apply to your situation.

    However, you are not suggesting more than one service or more than one feeder. Rather, you are suggesting one of each. I don't think the code language, as written, forbids this. I suspect that the "one of each" installation is not in compliance with the intent of the code authors. But it is not in violation of the language they put into the code.
    That is what I was thinking but I didn't want to comment without first checking the language. The code seems to want "one supply" but the combination of one service and one feeder doesn't seem to be specifically prohibited.
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  6. #6
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    Quote Originally Posted by charlie b View Post
    This might be more tricky than you would expect.

    230.6 says one service per building, and I don't think any of the "unless permitted by" statements apply to your situation.
    225.30 says one outside feeder per building, and I don't think any of the "unless permitted by" statements apply to your situation.

    However, you are not suggesting more than one service or more than one feeder. Rather, you are suggesting one of each. I don't think the code language, as written, forbids this. I suspect that the "one of each" installation is not in compliance with the intent of the code authors. But it is not in violation of the language they put into the code.
    Quote Originally Posted by electrofelon View Post
    That is what I was thinking but I didn't want to comment without first checking the language. The code seems to want "one supply" but the combination of one service and one feeder doesn't seem to be specifically prohibited.
    I’m sorry but I completely disagree with this concept.

    For this concept to be applicable it has to be ignored that the service location is indicated to be at first building or structure and the whole scope of article 225 is branch circuits and feeders to additional buildings or structures.

    Article 225 goes on to say the additional branch circuit or feeder supplies are on the load side of the premise service

    And this all has to be on the same property under single management

    ¬“225.30 Number of Supplies.
    Where more than one building or other structure is on the same property and under single management, each additional building or other structure”

  7. #7
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    Quote Originally Posted by david View Post
    I’m sorry but I completely disagree with this concept.
    You are certainly welcome to do so. But I do not understand the point you are trying to make. Here are three ways to provide power to buildings A and B. Ways #1 & 2 are clearly OK. Way #3 is the one in question.

    1. Utility provides service separately to each building.
    2. Utility provides service to building A. Then, a feeder originating within building A provides power to building B.
    3. Utility provides service separately to each building. In addition, a feeder originating within building A provides power to building B.


    For my part, I see nothing in either 225 or 230 that would forbid #3. Each of those two articles focuses solely on its own limits of applicability. Neither addresses any kind of interface with the other.
    Charles E. Beck, P.E., Seattle
    Comments based on 2017 NEC unless otherwise noted.

  8. #8
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    I never saw this coming, number #3 on charlie’s list is interesting.

    efelon saw it also.

    Slick.
    "Electricity is really just organized lightning." George Carlin


    Derek

  9. #9
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    225.1 Scope.
    This article covers requirements for outside branch circuits and feeders run on or between buildings, structures, or poles on the premises; and electrical equipment and wiring for the supply of utilization equipment that is located on or attached to the outside of buildings, structures, or poles.

    The scope of article 225 indicates outside wiring on the same premise from the premise service point forward. I am simply saying the service point is already established in article 225 to be on the premise and the article is addressing branch circuits and feeders from that established service point forward.

    All the article 225 branch circuits and feeders on the same premise are from the same service point

  10. #10
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    So it becomes strictly up the authority to say no, a building is to be supplied only once unless one of the exceptions in article 230 or article 225 indicate a second supply could be done safely

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