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Thread: need to know whats wrong

  1. #1
    Join Date
    May 2012
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    Greenwood, S.C.
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    2

    need to know whats wrong

    50 kva transformer, 106' 1/0 al xlp neritina triplex southwire then spliced, to 80' 2/0 al xlp underground to my meter 200 amp service. the neighbor served by the same 1/0 al xlp, spliced to 50' #2 al triplex service drop to meter 100 amp service. this is one branch curcit for two homes in south carolina there is a diversity factor of .85 per cpw being the utility company.

  2. #2
    Join Date
    Dec 2006
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    Chapel Hill, NC
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    25,714
    I am re-opening the thread as the op just wants to know what we think of the configuration. He thinks it is unsafe but the utility says it is fine. Since this is not a how-to or diy question I am allowing it.

  3. #3
    Join Date
    Feb 2003
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    Massachusetts
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    48,183
    It is fine, nothing to worry about in the least.

  4. #4
    Join Date
    May 2003
    Location
    Leesburg, VA
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    6,931
    Do you have light flicker?
    Do you have any low voltage issues?

    Do you have any issues?


    If so the utility most likely won't do anything to help so you have to live with it.


    If you do not have any issues you still have to live with it.

    But as installed there is not issue.
    Brian John
    Leesburg, VA

  5. #5
    Join Date
    Jan 2009
    Location
    Easton, Maryland NEC: 2011
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    Sounds like typical residential POCO install.

    What does "diversity factor of .85 per cpw" mean?
    "Electricity is really just organized lightning." George Carlin


    Derék

  6. #6
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    I agree with the rest of the crowd, nothing wrong with that installation. In fact, I am surprised that there is 1/0 in the span at all considering the distance, and the 50 kVa pot is oversized if there is only two houses on it, especially in SC.(winter loading)

  7. #7
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    Quote Originally Posted by jumper View Post

    What does "diversity factor of .85 per cpw" mean?
    I was curious about that too. I thought the diversity factor would be closer to 1.5 or higher with two houses.

  8. #8
    Join Date
    Jan 2009
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    Easton, Maryland NEC: 2011
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    Quote Originally Posted by Hv&Lv View Post
    I was curious about that too. I thought the diversity factor would be closer to 1.5 or higher with two houses.
    Actually I am trying to figure what diversity factor the OP is talking about period, It might something you POCO guys look at, but me and my NEC are clueless.

    As far as OP worrying about what POCO does in a resi install, I say tell HOs to not worry about it. If it breaks or is wrong, POCO has to fix it, so not a problem.
    "Electricity is really just organized lightning." George Carlin


    Derék

  9. #9
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    Quote Originally Posted by jumper View Post
    Actually I am trying to figure what diversity factor the OP is talking about period, It might something you POCO guys look at, but me and my NEC are clueless.

    As far as OP worrying about what POCO does in a resi install, I say tell HOs to not worry about it. If it breaks or is wrong, POCO has to fix it, so not a problem.
    the house demands would be 42 kW, and the XF is 50 so 42/50 =.84
    I would expect the house demands to be 42kW, and the xf to be 25 so 42/25= diversity factor of 1.68. Not everything in the house will run at once, except on cold load pickup after an extended outage. Of course, the XF can double capacity for a couple of hours and be fine. The constant switching of loads in a house or houses is what we look at when sizing. I have seen (5) 2500 sq.ft. houses ran from a 25 kVa transformer for a couple of years. We changed it when the internal fuse blew after a week of 90+ temperatures. Put a new fuse in it and set it somewhere else to serve 1-2 houses
    houses..

    Rule of thumb around here, 1 house w/ electric heat and air conditioning= about 12-15 kW

  10. #10
    Join Date
    Jan 2009
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    Easton, Maryland NEC: 2011
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    Quote Originally Posted by Hv&Lv View Post
    the house demands would be 42 kW, and the XF is 50 so 42/50 =.84
    I would expect the house demands to be 42kW, and the xf to be 25 so 42/25= diversity factor of 1.68. Not everything in the house will run at once, except on cold load pickup after an extended outage. Of course, the XF can double capacity for a couple of hours and be fine. The constant switching of loads in a house or houses is what we look at when sizing. I have seen (5) 2500 sq.ft. houses ran from a 25 kVa transformer for a couple of years. We changed it when the internal fuse blew after a week of 90+ temperatures. Put a new fuse in it and set it somewhere else to serve 1-2 houses
    houses..

    Rule of thumb around here, 1 house w/ electric heat and air conditioning= about 12-15 kW
    That's cool info, I had no clue about how POCO sizes resi XFMRs.
    "Electricity is really just organized lightning." George Carlin


    Derék

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