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This is a new one for me. The owner needs a new main panel in a wet location but wants the box inset in the wall. I cannot find a reason not to do it, other than it will be a bit harder to wire. The feeder is in conduit and the local AHJ allows the feed in conduit at the nearest point of connection. Has any one run into this before? I was thinking it would not be code compliant but the inspector said 230.70(A)(1) would allow if the service feeder was in conduit. Does anyone have tips or advice?

I think the box will protrude from the siding about 3/4" so the door will function.

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Leave yourself strategic access for future wiring, like access doors above and below the panel if the homeowner is game for that.

Otherwise, sounds pretty cool looking.

  • Not quite what I was looking for but thanks. The. Job was completed almost a year ago. – Ed Beal Aug 12 '17 at 23:50
  • Hahaha, saw the date on the edit, missed the OP date. – NPM Aug 12 '17 at 23:54
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Having completed this almost a year ago what I found to help was to have the panel protruding through the exterior wall an extra 3/4" and run some nailer plates so I could use the lower back and. Upper back area to install more holes for clamps. The space was to limited using just the top and bottom since I had to support the box between studs. Added a trim around the box that matched the Windows and the owner and inspector were happy.

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Make sure that things drain where you want them to

One problem with a semi-recessed NEMA 3R enclosure setup would be the potential for water to drain out of the enclosure and into the wall. A framed-in and pan-flashed sill, like that used when framing for a window, would be needed to drain that water back to the outside -- it'd have holes in it for the conduit, which would then be caulked around once the flashed sill's in place. See the figure below (from BSI-004) for details.

pan flashing/sill detailing

Of course, at least two 1/4" holes or knockouts should be open in the bottom of the box itself to allow it to drain and keep the seal from failing due to pressure differences -- there's not an explicit allowance in Art. 312 for doing this to a NEMA 3R cabinet, but 314.15 provides for it in the case of weatherproof junction boxes, which is enough of a parallel for me.

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