choices besides UF-B wet damp location not inside conduit

Question

I have a situation where 2" PVC provides a conduit from basement to attic via outside of the house. As such if that classifies as a wet or damp location and NM-B wire cannot be used in that section of conduit, then what choice is there currently other than UF-B ?

Just one run needed for 240 volt 3-wire (red/black/neutral/ground) either 12 gauge or 10-gauge, currently on 20 amp breaker, do not foresee need to ever go above 30 amp need, this is for AC air handler in attic.

The conduit is 2", and wish to keep the ends of conduit open so runs of RG-6 coax or CAT-6 cabling can be done to reach attic then down to second floor rooms. Only the one run of 12/3 or 10/3 is needed from basement up to attic through exterior 2" conduit to reach AC air handler in attic. Only possible space issue is at one 2" LB conduit body.

From exit of top of load center to entrance of 2" conduit in basement ceiling the wire would not be in conduit. And in attic from conduit exit to Jbox on AC unit wire would not be in conduit

Answer 1

You use individual wires in conduit, not a cable

Pulling cable through conduit is a miserable job -- NM and UF cables use solid wire, making them awful stiff, and the jacket just makes them stiffer and harder to pull still, especially around bends. Instead, you want to take some single wires rated for wet location service (you can get THHN/THWN-2 dual-rated single conductors basically anywhere building supplies are sold) and pull an appropriate bundle of those through your conduit instead of a cable.

This will make your pull easier then and there because said bundle's less stiff and snag-prone due to not having a jacket; furthermore, you can get stranded THHN/THWN-2 wire in most places, which will make your pull easier still as stranded wire beats solid wire of equal size on flexibility, every time. Just do not ever try to get away with shucking the jacket off a cable to get at the wires inside -- wires inside cables are not marked for use outside the cable jacket!

At the ends of the conduit, you'd put a box and transition to a cable wiring method there

With individual wires in conduit, the conduit run needs to be complete between boxes. So, this simply means you need a suitable box at each end of the run, mounted indoors, that you can make splices in to transition between NM and wires-in-conduit.

Run another conduit for the networking wires

You can't put network or coax cables in the same conduit as power wires -- this is governed by 800.133(A) and 820.133(A), not 300.3(C).

Answer 2

Conduit can be used two ways:

• as raceway for individual wires like THWN that are required to run in some kind of raceway. This is the conduit wiring method. The conduit must be continuous throughout the use of this method. You can transition to another wiring method at a junction box. You are also allowed to pull cable through the conduit if you really, really want the exercise!
• as a mere protective shield. In this case conduit is not a wiring method. You're actual!y using another wiring method such as UF cable. You can enter and exit conduit at will, gaps allowed, and you don't need a junction box at the end of conduit because you're not actually transitioning wiring methods, you are in UF wiring method (or whichever) the whole way and must comply with that method's rules.

"Wire", as you refer to it, is actually muticonductor cable containing several actual wires, such as NM, UF and the like. Generally pulling cable through conduit is an act of masochism. However #12 or #10 solid cable will pull easily through 2" conduit because it is wildly oversized for a single #10 circuit (oversize is good). Certainly easier than the #0000 aluminum THWN single-strand one typically puts in 2".

You cannot put low voltage or comms wires in the same conduit with mains power. Not even a question.

Edit:

Sigh... OK... yeah, there's one exception, but it's completely useless to your goal, hence my hasty armwave. What you want to do is come out of the mains+data conduit to a cover plate with an ethernet, cable TV etc. socket, then onto your cable box or PC. That's the thing you can't do because it means the circuit is not entirely in Class 1 wiring methods. Run two conduits if you want that.

The exception is intended for industrial controls, 24V-based office lighting controls, that sort of thing.

There's one more exception, but it involves running entirely non-metallic fiber optic cable inside mains conduit.

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