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Thread: P.V. & metal roofing

  1. #1
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    P.V. & metal roofing

    P.V. system installed on a standing seam roof. The roofing is painted or coated.
    ?'s Is the roof likely to become energized & does it need to be bonded?
    Thank you in advance.
    Ron

  2. #2
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    Quote Originally Posted by rcarroll View Post
    P.V. system installed on a standing seam roof. The roofing is painted or coated.
    ?'s Is the roof likely to become energized & does it need to be bonded?
    Thank you in advance.
    I'm curious to know how one would actually expect to bond the metal roofing. S-5! clamps are specifically designed with a rounded point set-screw, so they do not damage the protective coating on the roofing material. Any way that you would attach a grounding connection would have to cut through the coating, unless you have an unpainted roof like galvalume, bare copper, or zinc-coated copper.

    And if you do damage the coating on the metal roof, you ruin the leak protection performance of the roofing system.

    The only way I could see to bond the roofing panels, is to do so under the ridge cap, where it is already protected from the rain.

  3. #3
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    Thanks. But, in your opinion, is the roof "likely to become energized"? This is the first time I've come across this.
    I believe the building is wood framed. A metal building, I wouldn't have a question.
    Ron

  4. #4
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    I think bonding a metal roof would be silly. Here are my reasons:

    1. I have never heard of anyone having to do it, therefore the issue does not exist (kinda joking here)

    2. The roof is already bonded by the zillions of S5 clips and fasteners.

    3. We install electrical on metal buildings all the time, lights, plugs, RTU's, and don't go out of our way to bond the roofing or siding. Why should PV be different?
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  5. #5
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    Quote Originally Posted by electrofelon View Post

    2. The roof is already bonded by the zillions of S5 clips and fasteners.
    Is it? The S-5 clips are designed to not puncture the coating, and unless the coating is a different metal, the coating is probably an insulator.

  6. #6
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    Quote Originally Posted by Carultch View Post
    Is it? The S-5 clips are designed to not puncture the coating, and unless the coating is a different metal, the coating is probably an insulator.
    I'll bet you 10 dollars and a Reuben that roof is pretty well bonded
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  7. #7
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    I've been through this conversation a couple times with AHJs but have never actually done anything to specifically bond the roof or ultimately been required to. The sticking point is: okay, say I agree the roof needs to be bonded, can you show me a product to bond it with?

    With that said, I would not take electrofelon's bet unless I had $10 and sandwich I needed to get rid of.

  8. #8
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    this is like arguing over whether sheet metal studs should be bonded.

    Personally, I think all the zip screws do a perfectly acceptable job of bonding them together, even though the code does not allow sheet metal screws to be used for this purpose. So your first problem is how do you connect all the pieces of sheet metal together before connecting some kind of EGC to it.
    Bob

  9. #9
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    Quote Originally Posted by jaggedben View Post

    With that said, I would not take electrofelon's bet unless I had $10 and sandwich I needed to get rid of.
    Why would anyone in their right mind get rid of a Reuben sandwich?
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  10. #10
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    Quote Originally Posted by electrofelon View Post
    I'll bet you 10 dollars and a Reuben that roof is pretty well bonded
    I really want a Reuben now.

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