I need to add a circuit and the my panel is outside. The easiest way to run the cable would be to run a conduit vertically from the panel and up through the soffit. Then I would properly run the cable through the attic to. I have two questions.
My question is, what is the proper way to install the conduit? Does the conduit need to extend a certain height up into the attic?
Second, it seems that with much debate, Romex shouldn't be run through a short conduit run. Is it OK to run it since it would be just 6' down to the panel or not? If the answer is no, would I just run the Romex in the attic to a junction box. Then have THHN wires run through the conduit to the exterior of the house and down to the panel?
Thank you
Best Answer
If you can't get the cable down the wall cavity, then use a junction box to transition to THHN in conduit and go down the wall that way from there
Normally, this run would be inside the wall cavity and then enter the panel from the back -- even if it's somewhat harder to run that way, it has the advantage that you don't have to mess with conduit. If that's not possible, though, the alternative would be to run the NM into a box in the attic, where you transition to THHN in conduit (1/2" EMT or PVC suffices for this) and then run a short length of conduit out the wall into a LB conduit body, then conduit down the wall to a point alongside the panel, where it uses a LL or LR (depends which side of the panel you're on; if you can't be sure when you're buying it, simply pick up an Arlington AnyBODY or equivalent configurable conduit body instead of the LL or LR) body to transition into a nipple into the side of the box -- do not enter the panel from the top! (NEMA 3R boxes require a hub fitting to enter from the top, and generally only have knockouts for a single hub atop the box.)