I've found bits and pieces that answer most of my project questions, but still a bit unclear. I have about 50' of UF-B and about 25' of NM-B, all 10/3. My project is to run a dedicated circuit from exterior panel (30amp 2-pole breaker w/interlock) from one side of the house to the other out to an exterior 30 amp power inlet box.
My plan is to run 1" PVC with UF-B from panel up through soffit and then exit cable after the 90deg turn into attic. From there i would run to a suitable location in the attic for a junction box where i would splice the NM-B. From there I would go to the other side of house and transition through another junction box back to UF-B. Pop through soffit again to exit attic and run 1" PVC conduit to outlet. There is no plan to use conduit through attic other than section that breaks the soffit plane. I would attach wire to rafter/studs as appropriate. Is this reasonable/meet code?
My second option, is to minimize junction boxes and go UF-B from panel to NM-B through attic in one junction box. From there, run remainder of distance with NM-B and come through garage ceiling and run inside of garage/block. Run some EMT for NM-B wire coming down and drill a hole through concrete, out to outlet box. Per my understanding I would need some type of conduit for NM-B through concrete? (which I'm still not clear if that puts NM-B into a "wet"-type of location…?)
Attached is my interpretation of what this would look like. Appreciate any insight, corrections, and what the…?
Best Answer
Option 1 looks good. For my understanding you still need to transition to a wet-rated wire going back out the wall in option 2, so you don't really "save" anything there. Since the conduit appears to be (at least partly) below 8 feet (thus "subject to damage"), you'll want schedule 80, (if PVC) so you'd want to go with 1-1/4" minimum.
You could also use 1 inch EMT, though you might appreciate having more space, in practice. It is generally "not fun" to get anything very close to the maximum fill through a conduit - but you've basically got straight sections to LBs, so it should not be that bad. Though you have drawn elbows (which should be sweeps if doing that, and sweeps don't go though walls nicely, which is why we normally use LBs or a "pulling elbow" for the most minimal accessible connector.)