Run Thhn Through Attic

I have a 20 amp feed on 12 amg romex terminating in a metal 4 x 4 junction box in the basement.

Run thhn through attic.

I have a bunch of 12 awg red black white green thhn. From this i. The reason i wanted to use the cable is because i already have 75 of it and didnt want to have to buy something else also. I am thinking about using it for some indoor wiring projects and i don t know if i need to run in through plastic metal conduit or not.

Nm through to soffit in non accessible attic junction box under soffit to transition from nm to 10awg thwn grounds crimped thwn in 3 4 metal conduit down to switch or 2 circuit solar load center through the wall into the basement and into the subpanel sized for at least 5760w if using a load center or 3840w if using switch. I should say thhn thwn 2 wire. If the sites that you want to run wire to are on the outside of the house you should not need to drill a new hole. The national electrical code which is the basis for all local building codes has specific regulations for installing electrical wires so that they are protected from damage.

A favorite target of electrical inspectors is the improper use of non metallic cable nm in exposed locations such as basement foundation walls or along the face of studs and joists in unfinished framed spaces. If the wires are within 7 of the attic access hole or along any attic flooring you ll need to protect the wiring from damage with furring strips along each side of the wire run. When cutting through drywall from the interior of a room use a utility knife and cut carefully you don t want to drill through a hidden wire or the paper backing of the attic insulation. If you drill holes in the joists and run wire through those holes you ll be disturbing the insulation.

Which is jacketed cable to be run through the attic without conduit because it is packaged together already with a jacket around it they consider the attic to be inaccessible indoor location.