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Thread: ideal setup for 3 Phase 208V 43.2KW SolarEdge Inverter 175-200 OCPD

  1. #21
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    Building has 3@ Delta 4 wire 240V. POCO can change to 208V Y 3$ for lots of $. Thinking about using Federal Transformer instead. Possibly 45KVa (125A calculated) T24SH2Y-45. Max output of PV inverter is 125A. Thoughts on using a 45KVA inverter?


    Probably use MDP and feed 225A panel and then 45KVA transformer to inverter.

  2. #22
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    Quote Originally Posted by hevnbnd View Post
    Building has 3@ Delta 4 wire 240V. POCO can change to 208V Y 3$ for lots of $. Thinking about using Federal Transformer instead. Possibly 45KVa (125A calculated) T24SH2Y-45. Max output of PV inverter is 125A. Thoughts on using a 45KVA inverter?


    Probably use MDP and feed 225A panel and then 45KVA transformer to inverter.
    3P4W 240V may mean high leg. If so and if it's open delta it might not be a good idea to connect to the B phase.

  3. #23
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    Quote Originally Posted by ggunn View Post
    3P4W 240V sometimes means high leg. If so and if it's open delta it might not be a good idea to connect to the B phase.
    Yes it has a high leg. 235v phase to phase

  4. #24
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    Quote Originally Posted by hevnbnd View Post
    Yes it has a high leg. 235v phase to phase
    You need to be sure that you won't overload the transformer feeding the high leg. Many times it is much smaller than what feeds the others.

    Many AHJ's will not allow you to connect three phase to a service like that but are OK with you connecting to the A and C phases just as you would a 120V - 0V - 120V single phase service. I'd advise talking to them before you get too far into the design process.

    Free advice, worth every penny.

  5. #25
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    Quote Originally Posted by ggunn View Post
    I haven't tried any sort of end run around their policies; they just say no and we obey. Except for CPS (San Antonio) they all allow IPC connections to the service conductors in the MDP, so that's pretty easy. Most of them, anyway; one of them allows no supply side interconnections, period.
    Quote Originally Posted by pv_n00b View Post
    The local muni utility in my town says no PV supply-side interconnections, and that's the end of the discussion with them. Never been a supply-side interconnection here and they have PV systems from residential up to I think 700kW commercial. All load-side.

    I am sure I am preaching to the choir about the ridiculousness of these "no line side tap" rules. My point is that, depending on a few specifics, there may not be any difference between a "supply side connection" and a 230.40 exception 2 or 3 install with a load side connection. I doubt they disallow 230.40 exception 2 or 3 so I don't see how you couldn't do a "supply side" connection this way. (is that a triple negative? Did I get that right?).
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  6. #26
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    Quote Originally Posted by electrofelon View Post
    I am sure I am preaching to the choir about the ridiculousness of these "no line side tap" rules. My point is that, depending on a few specifics, there may not be any difference between a "supply side connection" and a 230.40 exception 2 or 3 install with a load side connection. I doubt they disallow 230.40 exception 2 or 3 so I don't see how you couldn't do a "supply side" connection this way. (is that a triple negative? Did I get that right?).
    Where I have encountered this I don't believe that calling it something else would make any difference.

  7. #27
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    Quote Originally Posted by electrofelon View Post
    I am sure I am preaching to the choir about the ridiculousness of these "no line side tap" rules. My point is that, depending on a few specifics, there may not be any difference between a "supply side connection" and a 230.40 exception 2 or 3 install with a load side connection. I doubt they disallow 230.40 exception 2 or 3 so I don't see how you couldn't do a "supply side" connection this way. (is that a triple negative? Did I get that right?).
    You are trying to use logic on the NEC, silly PV person.

    Keep in mind that when a utility says no supply side interconnections they are not required to refer to the NEC. They live in an NEC free world. So all those words in 230.40 don't mean squat to them.

  8. #28
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    My supply house got the following message from Federal Pacific after asking them about using the T24SH2Y-45 Isolation Transformer FT0616.

    From factory.

    "That unit is suitable to reverse feed. However their mention of the Grid makes me think this is Solar application.

    We will not recommend stock units for Solar. If it solar I can custom quote you a unit for this."

    So my question would be what is different from a Solar Transformer vs a stock unit... Also anyone have an reason why not to use a 45KVa Transformer for a max output 125A from my Solar array?

  9. #29
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    Quote Originally Posted by ggunn View Post
    Where I have encountered this I don't believe that calling it something else would make any difference.
    Quote Originally Posted by pv_n00b View Post
    You are trying to use logic on the NEC, silly PV person.

    Keep in mind that when a utility says no supply side interconnections they are not required to refer to the NEC. They live in an NEC free world. So all those words in 230.40 don't mean squat to them.
    So say I have the super common setup of two service panels side by side (230.40 ex 2). I'm sure you can do a load side connecton to a breaker in one. So at what point does the POCO consider it a supply side? If there are no non solar loads in one of the panels?
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  10. #30
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    Quote Originally Posted by ggunn View Post
    ......a 120V - 0V - 120V single phase service....
    You inviting me into this thread gunny?
    "Electricity is really just organized lightning." George Carlin


    Derek

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