4

I recently installed a run for a mini-split from my panel to a disconnect box. The run is 12/3 NM-B cable from the panel, under the house in a crawlspace suspended from a rat track, through a hole in the siding to an L-fitting on the exterior, then exterior to 3' of PVC conduit, then to the disconnect.

To be clear, the parts that are exposed to weather are the L-fitting, PVC conduit and the disconnect. These are all less than 3' from the mini-split.

I'll add that the crawlspace is tight, considered nominally 'inaccessible' (I managed it ok, but someone more rotund than me would not.) This rules out a crawlspace junction box to transition to THHN.

Given that the exterior parts of the run (L-fitting, PVC, disconnect box) are exposed, they are considered 'wet', and thus not allowed for NM-B, right?

I realize it's a bit nit-picky, but I'd like to know how can I make this run code-legal.

I was considering enlarging the hole in the siding to fit a junction box, transitioning to THHN inside this box to a flush-mount wet location outlet box, then making the run from the outlet to the mini-split disconnect. Then I get a utility outlet for my trouble.

Would what I propose be compliant? I'd rather do that than re-run this with UF or THHN in conduit all the way back to the panel.

hacktastical
  • 1,346
  • 3
  • 17

1 Answers1

4

I believe you best solution is your idea of an outlet box on the siding and converting to THHN from there. This depends on how far away the compressor is.

In some areas an outlet within 6 feet of the outside HVAC unit is code. It is the way I have done my mini splits and they meet code here in Fla. If the outlet box is not within 6 feet and your area demands it be, add another box to be within the 6 feet and run the THHN to that and then the disconnect.

RMDman
  • 52,615
  • 3
  • 36
  • 113