Running 240V for mini split through exterior wall in conduit from indoor unit to outdoor unit.

Cable supplied by mfg is SJOW 16/4 105c 251603 3/8" O.D.

Can use 3/4" non metalic flex conduit (blue) and run it through the lineset cover with the appropriate termenating ends on both sides OR Is placing it in the lineset cover a bad idea because although it will be protected from the elements the linset could be considered a wet location (due to the possibility of insulation deterioration sweat could occur) and just run outside the lineset covers and use liquid tight non metallic?

  • And not sure why the mfg would call it a signal cable when it's 240v.
    – Louis
    Sep 20, 2021 at 5:27
  • Is that SJOW cable supplied by the manufacturer, or something they expect you to provide? Sep 20, 2021 at 11:43
  • Welcome. Please take the tour and read about how to get good answers to good questions. I recommend you ask a couple of more focused questions. For example, how to retrofit liquid tight conduit to an already-installed inside unit. For that, include a link to the instructions, pictures including what entries or breakouts are available to the unit, your wall construction, etc. That would be a good standalone question. If you have a question about system drainage you should ask it more fully in a separate Question.
    – jay613
    Sep 20, 2021 at 12:44
  • 1
    It was supplied, already attached to the indoor unit.
    – Louis
    Sep 20, 2021 at 12:45
  • @Louis -- just how long of a cord did they put on that indoor unit?! Sep 21, 2021 at 1:13

2 Answers 2


Most minis that I have installed use TC cable. The compressor and controls are 240v but the voltage on the inside unit can be different.

If the unit is listed by UL / or another 3rd party agency and they specify the SJOW it is legal to use the cable/cord.

The W in sjow is for water resistance water will not be a problem with this cable.

Last make sure you are not using ENT electrical non metallic tubing outside it is not listed for that but liquid tight flexible non metallic conduit is.

I have seen some DIY not know this


The cord gets stuffed directly down the lineset cover, because the manufacturer doesn't give us any better option

Normally, stuffing cordage through a wall is a major no-no (NEC 400.12, point 1 in this case). However, the manufacturer hardwired the cord to the indoor unit, and worse yet, CSA listed it this way. So, since it's an outdoor-rated cordage type, I'd just stick it directly in the lineset cover as the instructions direct us to; there isn't enough room in there I reckon for a conduit anyway!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.