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Thread: Ground Bushings for rooftop arrays

  1. #1
    Join Date
    Aug 2004
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    Irvine California
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    Ground Bushings for rooftop arrays

    California here.

    What are you guys using on rooftop jumpers from array to array on your ground bushings? Underneath the panels?

  2. #2
    Join Date
    Oct 2009
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    Austin, TX, USA
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    Quote Originally Posted by harborrick View Post
    California here.

    What are you guys using on rooftop jumpers from array to array on your ground bushings? Underneath the panels?
    Underneath the modules there is no need for conduit.

  3. #3
    Join Date
    Aug 2004
    Location
    Irvine California
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    From Rooftop Array To Rooftop Array

    Quote Originally Posted by ggunn View Post
    Underneath the modules there is no need for conduit.
    I am running conduit from array to array and stubbing about a foot on each side
    So we end conduit with connecting conduits on both ends with entire connector and gr bushing.
    Thank You

  4. #4
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    Quote Originally Posted by harborrick View Post
    I am running conduit from array to array and stubbing about a foot on each side
    So we end conduit with connecting conduits on both ends with entire connector and gr bushing.
    Thank You
    We run EMT grounded on one end between sections of an array. If DC no more than 10' under NEC 2014 and no more than 1' under NEC 2017.

  5. #5
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    Feb 2005
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    Quote Originally Posted by harborrick View Post
    California here.

    What are you guys using on rooftop jumpers from array to array on your ground bushings? Underneath the panels?
    The issue with ground bushings is that they are not outdoor rated.

  6. #6
    Join Date
    Jan 2012
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    CA
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    Quote Originally Posted by shortcircuit2 View Post
    The issue with ground bushings is that they are not outdoor rated.
    Late reply here.

    I use two methods for jumpers between arrays:
    1. SHORT gaps (one or two feet).
    Split a piece of non-metallic flexible conduit (gray) (AKA liquid tight) lengthwise with a knife (like gutting a fish ) and snap it around wire and use fat black zipties to close.
    Benefit: No gr. bushing,
    no connectors,
    no reaming cut ends,
    no pipe bending
    ....because no metal!
    This works great on short and intact lengths of IQ Cable.
    For PV wire and field wireables on IQ Cable, you don't even need to "gut the fish".

    2. LONG jumpers.
    EMT as per you.
    I do have a special kit of
    -stainless steel bolts (small 10-24, 10-32, etc) to match the threads on the gr. bushing setcrews
    -s.st. starwashers
    -direct burial rated lay-in-lugs.

    I replace everything but the steel bushing itself.

    Small parts, but bonding is important to get right.
    Benefit: you feel good.

  7. #7
    Join Date
    Jun 2004
    Location
    Cherry Valley NY, Seattle, WA
    Posts
    4,523
    Several jobs I worked on they used pipe bonding clamps on the EMT to bond instead of connectors and bonding bushings. I guess it is arguable if that is acceptable.

    As an installer, I used to dread running PV wire through conduit between array sections - it is such a PIA and a time suck when you have several hundred feet on each side. I proposed using a piece of strut and laying the conductors in it like a mini cable tray, but it was shot down. Of course actual cable tray would work too, but probably only practical from a cost standpoint if you have a large number of conductors.
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

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