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Thread: 4160 Delta Secondary Grounded or Ungrounded

  1. #21
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    Quote Originally Posted by don_resqcapt19 View Post
    I think the grounding electrode system and GECs are required. The only real difference between the rules for a grounded and ungrounded transformer is that the ungrounded one does not have a system bonding jumper.
    Where would the requirement for a GEC be in the NEC for an ungrounded Delta and where would you connect it?
    Rob

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    All responses based on the 2014 NEC unless otherwise noted

  2. #22
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    Quote Originally Posted by infinity View Post
    Where would the requirement for a GEC be in the NEC for an ungrounded Delta and where would you connect it?
    Metal parts likely to become energized, I imagine. As mentioned, the case of the step up transformer would be connected to the primary EGC, while the case of the step down transformer would be bonded to the GEC of the resulting separately derived system. If the run is connecting two buildings, IMHO there is no requirement to bond the two GESs together. If in the same building there must be a wire bond between all ground electrodes, probably in the form of an EGC connecting the two ends, even though there is no grounded conductor.

  3. #23
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    Quote Originally Posted by infinity View Post
    Where would the requirement for a GEC be in the NEC for an ungrounded Delta and where would you connect it?
    IT is analogous to a detached structure under current code with separate N-G. The GEC lands on the ground bar, but doesnt hit a conductor of the system. See 250.30(B)
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  4. #24
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    Sounds like a waste of time. There are 8-500 kcmil EGC's run to the primary and since the secondary is #2 a #8 GEC landed with those 8-500's would be a joke.
    Rob

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    All responses based on the 2014 NEC unless otherwise noted

  5. #25
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    Quote Originally Posted by infinity View Post
    Where would the requirement for a GEC be in the NEC for an ungrounded Delta and where would you connect it?
    250.30(B)
    Don, Illinois
    Ego is the anesthesia that deadens the pain of stupidity. Dr. Rick Rigsby
    (All code citations are 2017 unless otherwise noted)

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