Sharp edge of aluminum siding and NM wire


Old 01-09-15, 09:28 AM
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Sharp edge of aluminum siding and NM wire

I have an outdoor light fixture with a work box that's fed NM wire through a hole in aluminum siding. Is there anything I can put around the rim of the hole in the siding to keep it from cutting through the sheathing on the wire?
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Old 01-09-15, 09:32 AM
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Not sure what size hole you have, but a conduit fitting bushing Halex 3/8 in. Flexible Metal Conduit (FMC) Anti-Short Bushing (35-Pack)-75401 - The Home Depot would be one solution. Of course you need to protect the NM. Does it go all the way through the wall? Or just inside it?
Old 01-09-15, 09:38 AM
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You have an old work box for the fixture but the cable is coming through the siding? can you post a pic of that? The box should be cut through the siding and the cable brought into the box.
Old 01-09-15, 10:26 AM
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There's an inch-wide square hole in the aluminum siding with the NM coming through it. The NM runs inside the wall, stapled just inside the hole and then pops out the hole.

There's a wooden mounting plate that's cut in on the back to fit over the siding. And then a metal pancake box fits into the wooden plate.

I think I can use a clamp (should I use metal or plastic?) in the knockout in the back of the mounting box, but there's the 2nd hole in the siding about an 3/4" back behind the box. Is there something I can place on the sharp siding edge?

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Old 01-09-15, 10:35 AM
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You could pull the pancake box off, stick a short piece of 1/2" pvc conduit through the back KO, and replace the box. That will protect the cable transitioning to the outside of the house. Caulk up the hole.
Old 01-09-15, 11:05 AM
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Take a razor knife and cut the hole in the siding larger.

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