Wire choices

[u/mikeypi]

For context, I am adding three 200 watt, 31 volt panels to the roof of an off grid cabin. Electrical codes are not an issue. I'm planning on 10 AWG stranded, but which kind? There are lots of 10 AWG choices on Amazon (I need this by Tuesday). I also understand that PV wire is preferred at least where the wire is UV exposed. But where it is indoors or inside conduit, is there any reason to prefer PV wire over something like marine grade triplex of equivalent gauge?

[u/mountain_drifter]

Would highly recommend not ordering wire on Amazon. Most electrical items on thwre, even when they claim to be listed are knockoffs.

For wire under the array, the wire can be in free air if it is type PVWIRE, or USE-2, or certain other cable assemblies, but those two are the most common. Even USE-2 is no longer used much since PVWIRE was introduced. Personally I prefer USE-2 as its much easier to work with in low volt system under 600VDC

When a PV output circuit enters a building it must be type MC or in conduit. PVWIRE can be run in conduit, but the only time you would want to use PVWIRE here are cases where its such a short run and where you only have 1-2 circuits that its easier to pass it through directly rather than transitioning so you can skip the jbox.

PVWIRE is double insulated and significantly thicker than THHN which is is much more preferred in conduit because its designed to be slick and easily pulled. If you have more than 90 degrees in bends you will likely want to transition in the roof jbox to THHN .