Running wire through attic (AC, Microinverters)

[dapug]

I'm running THWN-2 through the attic to get it from the Soladeck JB to my Enphase Combiner 3 (Microinverter setup, AC solar). My plans call for EMT, but that is not easy/fun to do inside the attic, seems like overkill, and... I happen to have tons of LFNC available... hoping to give it a purpose. My questions are thus:

Can I run LFNC in the attic? (Liquid Tight Flexible Non-metallic Conduit, PVC) I'm unclear on code here, but I suspect something to do with high heat temp in attic space is a factor.

Or must I use LFMC (Liquid Tight Flexible Metalic Conduit)?

Still not sure why Romex would need to be in conduit rather than just attached via wire staples, but that is my understanding, so no advantage there.

[foo1bar]

Still not sure why Romex would need to be in conduit rather than just attached via wire staples, but that is my understanding, so no advantage there.

You may be able to use Romex (without conduit) for the in-attic/in-house wiring for an enphase system.
I don't know for sure, but it is something you can look at.
I'd probably ask the AHJ to confirm that your plan of using NM-B inside without conduit was good with their interpretation of the code.

You'd probably have to transition to something rated for outdoor / wet location (ex. thwn2) in a jbox inside the house, as NM-B isn't rated for wet environment, and conduit/jbox on the roof is going to be considered as a wet env.

If you want to use LFNC, I'd also ask the AHJ.
Also, IIRC, there's a limit on 360 degrees of bend you can have before having a pull station. And sags in flexible conduit add up to a lot of degrees of bend pretty quickly. Not to mention it would look weird, and I would try to avoid anything that looks weird in my house.

Good luck.

[PVAndy]

You may be able to use Romex (without conduit) for the in-attic/in-house wiring for an enphase system.
I don't know for sure, but it is something you can look at.
I'd probably ask the AHJ to confirm that your plan of using NM-B inside without conduit was good with their interpretation of the code.

You'd probably have to transition to something rated for outdoor / wet location (ex. thwn2) in a jbox inside the house, as NM-B isn't rated for wet environment, and conduit/jbox on the roof is going to be considered as a wet env.

If you want to use LFNC, I'd also ask the AHJ.
Also, IIRC, there's a limit on 360 degrees of bend you can have before having a pull station. And sags in flexible conduit add up to a lot of degrees of bend pretty quickly. Not to mention it would look weird, and I would try to avoid anything that looks weird in my house.

Good luck.

We use Romex without conduit all the time for microinverters in attics & basements. Totally code compliant

Andy

[bob-n]

Andy,
Do you need to label the Romex with reflective stickers?

[PVAndy]

Probably depends on the inspector. Technically it is not a PV Source Circuit. There are labels available to label. PV AC Output Circuits

Andy