jw1848h
New User
- Location
- Baldwin, NY
- Occupation
- Retired Electrical Engineer
This is about clamping cables entering a junction box via conduit.
I plan to use an exterior PVC junction box, for example an E989NNJ-CAR found here: https://carlonsales.com/techinfo/brochures/conduit/Junction_Boxes_Brochure.pdf, with PVC conduit. I plan to drill holes, one in the back and another in the bottom, and use conduit adapters, for example https://www.acehardware.com/departm...fittings-and-conduit/conduit-connectors/33220
Two cables will enter the junction box, one will be interior NM 10-3 in ½ inch conduit, and the other a buried-rated NM 10-3 (it’s flat, not round) in 1 inch conduit. The interior NM will enter at the back of the box through a very short piece of conduct, maybe 1 inch long, to pass through vinyl siding, it then will pass exposed (not in conduit), through a wall and then perpendicular through several floor joists over a crawl space, completely inaccessible (there is an existing cable there, I plan to pull it out and then pull-through the new cable. The buried NM cable will enter the box at the bottom, through maybe 1 foot section of conduit extending out of a concrete driveway.
My first question is, with this arrangement, how do I satisfy the requirement to clamp cables inside the box? I can’t clamp them anywhere within 12 inches outside the box. Or maybe they don’t need to be clamped inside the box in this situation?
My second question is, do I even need that short piece of conduit protecting the interior NM cable as it passes through the siding? Maybe if I caulk all around the back of the box, it isn't needed.
I plan to use an exterior PVC junction box, for example an E989NNJ-CAR found here: https://carlonsales.com/techinfo/brochures/conduit/Junction_Boxes_Brochure.pdf, with PVC conduit. I plan to drill holes, one in the back and another in the bottom, and use conduit adapters, for example https://www.acehardware.com/departm...fittings-and-conduit/conduit-connectors/33220
Two cables will enter the junction box, one will be interior NM 10-3 in ½ inch conduit, and the other a buried-rated NM 10-3 (it’s flat, not round) in 1 inch conduit. The interior NM will enter at the back of the box through a very short piece of conduct, maybe 1 inch long, to pass through vinyl siding, it then will pass exposed (not in conduit), through a wall and then perpendicular through several floor joists over a crawl space, completely inaccessible (there is an existing cable there, I plan to pull it out and then pull-through the new cable. The buried NM cable will enter the box at the bottom, through maybe 1 foot section of conduit extending out of a concrete driveway.
My first question is, with this arrangement, how do I satisfy the requirement to clamp cables inside the box? I can’t clamp them anywhere within 12 inches outside the box. Or maybe they don’t need to be clamped inside the box in this situation?
My second question is, do I even need that short piece of conduit protecting the interior NM cable as it passes through the siding? Maybe if I caulk all around the back of the box, it isn't needed.
