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Thread: Getting outdoor panel branch wiring inside

  1. #1
    Join Date
    Jun 2016
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    Getting outdoor panel branch wiring inside

    I am rewiring a house that has a NEMA 3R outside panel. The existing installation has a riser out of the hub on the top of the panel that extends 22". All of the NM cables go through the riser, into the eave, and then distribute through the attic. There is a 6" wide U-shaped sheet metal chase over top of the cables and the riser that is fastened to the wall. The chase extends into the eave and down to 3" above the panel.

    I plan on redoing this in the same manner except I'm going to fan out the NM cables and fasten them prior to going into the eaves, and replace the chase with one that is panel width.

    This seems to be compliant with (2011) 312.5 exception however I'm concerned whether the inside of the chase and inside of the riser would be considered dry locations (required for the NM).

    also, just for curiosity,

    312.5 exc (b) makes reference to a structural ceiling I'm not allowed to penetrate directly with the riser. Is the plastic or metal vents covering the eave considered a structural ceiling?

  2. #2
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    Quote Originally Posted by Coppersmith View Post
    ...
    ...

    312.5 exc (b) makes reference to a structural ceiling I'm not allowed to penetrate directly with the riser. Is the plastic or metal vents covering the eave considered a structural ceiling?
    IMO, no. The roof sheathing and membrane is a structural component (but a roof, not a ceiling), supporting the weight of roofing and persons walking on the roof.
    The sheathing, vented or not, on the bottom side of the rafter tails is not structural in any way.

  3. #3
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    Anybody else want to comment on whether what I propose to do is code compliant. I'm really not sure. I'd like to ask an inspector, but they are all busy assessing hurricane damage.

  4. #4
    Join Date
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    You riser and if I understand your chase layout are both technically wet locations. Pretty minor IMO.

    300.9 Raceways in Wet Locations Above grade. Where
    raceways are installed in wet locations above grade, the interior
    of these raceways shall be considered to be a wet location.
    Insulated conductors and cables installed in raceways in wet
    locations above grade shall comply with 310.10(C).
    "Electricity is really just organized lightning." George Carlin


    Derek

  5. #5
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    Quote Originally Posted by jumper View Post
    You riser and if I understand your chase layout are both technically wet locations. Pretty minor IMO.

    300.9 Raceways in Wet Locations Above grade. Where
    raceways are installed in wet locations above grade, the interior
    of these raceways shall be considered to be a wet location.
    Insulated conductors and cables installed in raceways in wet
    locations above grade shall comply with 310.10(C).
    Location, wet - ... and in unprotected locations exposed to weather.
    Location, damp - Locations protected from weather and not subject to saturation...
    The chase, riser and panel are under an eave. But they are several feet below it. Is that a wet or damp location?

    Even if under the eave is a wet location, the outside of the chase will get wet just like the outside of the building will get wet. The inside of the building is dry. Seems to me the inside of the chase is dry as well. The chase will butt up against the eave venting so no water is going to get in the top.

    Location, dry - ... a location classified as dry may be temporarily subject to dampness or wetness, ...
    Based on the above definitions, I think the inside of the chase and the riser under it is a dry location. Where am I thinking wrong here?

  6. #6
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    Under an eave, which is 2 or 3 ft wide usually, is pretty exposed IMO, and is a wet location. Up to your AHJ to call it at best a damp one.

    300.9 Raceways in Wet Locations Above grade. Where
    raceways are installed in wet locations above grade, the interior
    of these raceways shall be considered to be a wet location.
    Insulated conductors and cables installed in raceways in wet
    locations above grade shall comply with 310.10(C).
    "Electricity is really just organized lightning." George Carlin


    Derek

  7. #7
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    Would it be possible w/o affecting working space to frame out or reframe the existing wall a bit so that that cables would then be in a dry location?
    Electricians do it until it Hertz!

  8. #8
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    Quote Originally Posted by JFletcher View Post
    Would it be possible w/o affecting working space to frame out or reframe the existing wall a bit so that that cables would then be in a dry location?
    I thought about that. I could run pressure-treated 2x4 on either side of the panel up to the eave and screw a metal cover over it, but that's about the same as the u-shaped metal pan that I already proposed using. I think either way would make the interior of that space a dry location. (Maybe not the top of the panel, but several inches above it, and definitely from the top of the riser to the eave.)

    How are the branch circuits normally brought into these exterior panels? I really can't come through the wall from the inside. The stove and cabinets are opposite the panel. I can go inside the block from right below the lintel, but that seems hard.

  9. #9
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    Quote Originally Posted by Coppersmith View Post
    I thought about that. I could run pressure-treated 2x4 on either side of the panel up to the eave and screw a metal cover over it, but that's about the same as the u-shaped metal pan that I already proposed using. I think either way would make the interior of that space a dry location. (Maybe not the top of the panel, but several inches above it, and definitely from the top of the riser to the eave.)

    How are the branch circuits normally brought into these exterior panels? I really can't come through the wall from the inside. The stove and cabinets are opposite the panel. I can go inside the block from right below the lintel, but that seems hard.
    I always come in thru the bottom if I can; coming in from the back or top tends to lead to corrosion issues. ofc I'd rather put the panel inside if possible, and I think most electricians here have done the same for ages. Exterior panels are extremely rare in this area, to the point that I once thought it was against code to locate them outdoors.
    Electricians do it until it Hertz!

  10. #10
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    Use UF cable.
    Use EMT and THWN to gutter or jboxes in attic.
    Tom
    TBLO

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