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Thread: Generator grounding

  1. #1
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    Generator grounding

    How should a commercial non portable generator be grounded that has
    case a - ats that switches neutral
    case b - ats that doesnt switch neutral

    do you have to put ground rod at generator in either case ?

  2. #2
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    There are many ways to skin this cat -- install instructions generally have detail schematics showing options to your examples
    CircuitRyder --- Unfortunately not all good ideas are code enforceable.

  3. #3
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    250.30 might help
    CircuitRyder --- Unfortunately not all good ideas are code enforceable.

  4. #4
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    Quote Originally Posted by mrkc949 View Post
    How should a commercial non portable generator be grounded that has
    case a - ats that switches neutral
    case b - ats that doesnt switch neutral

    do you have to put ground rod at generator in either case ?
    Case A: Must be installed as a SDS. Bonded neutral at genset main breaker. Must have a GES connected at that point. Must have EGC on load side of genset main breaker.
    Case B: Install as a non-SDS. Must NOT bond the neutral at genset. Must have EGC to genset. No GES required. You could optionally connect a GES to the the frame of the genset.

  5. #5
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    Quote Originally Posted by texie View Post
    Case A: Must be installed as a SDS. Bonded neutral at genset main breaker. Must have a GES connected at that point. Must have EGC on load side of genset main breaker.
    Case B: Install as a non-SDS. Must NOT bond the neutral at genset. Must have EGC to genset. No GES required. You could optionally connect a GES to the the frame of the genset.
    That is pretty succinct.

    This should be a sticky...
    Kirchoff and Ohm...the only laws that make sense

  6. #6
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    Quote Originally Posted by mrkc949 View Post
    How should a commercial non portable generator be grounded that has
    case a - ats that switches neutral
    case b - ats that doesnt switch neutral

    do you have to put ground rod at generator in either case ?
    Usually you are matching the ATS to the system (SDS or non SDS) more so then matching the system to the ATS.
    I live for today, I'm just a day behind.

  7. #7
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    Quote Originally Posted by mrkc949 View Post
    How should a commercial non portable generator be grounded that has
    case a - ats that switches neutral
    case b - ats that doesnt switch neutral

    do you have to put ground rod at generator in either case ?
    I seem to recall you are required to use the structure's GES if a connection to a GES is required.
    Bob

  8. #8
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    Quote Originally Posted by petersonra View Post
    I seem to recall you are required to use the structure's GES if a connection to a GES is required.
    You do need to tie into the structure's GES. Nothing prohibits installing an additional "supplemental electrode" though.
    I live for today, I'm just a day behind.

  9. #9
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    Quote Originally Posted by kwired View Post
    You do need to tie into the structure's GES. Nothing prohibits installing an additional "supplemental electrode" though.
    the OP asked if he HAD to put in ground rods. The answer to that is they would appear to be optional.

    but he does have to tie into the structure GES regardless of whether he adds ground rods or not. this is not optional IMO.
    Bob

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