Split system

[Gaffen99]

For a multi city split system A/C with 5 indoor units, the indoor units are DC, can you run THHN? I've heard of people doing this concealed in residential walls, and it doesn't seem right to me. Has anyone seen this, it is low voltage, I guess? But free conductors like that in a wall? They say that it is run with the line set, any comments?

 

[hbiss]

What does the manual say? I have always run UF to connect with the outdoor unit. I suspect that yours with 5 zones uses intermediate distribution within the building in which case I would use Romex. Even for low voltage individual THHN conductors are not permitted to be run within walls or ceilings.

-Hal

 

[GoldDigger]

For a multi city split system A/C with 5 indoor units, the indoor units are DC, can you run THHN? I've heard of people doing this concealed in residential walls, and it doesn't seem right to me. Has anyone seen this, it is low voltage, I guess? But free conductors like that in a wall? They say that it is run with the line set, any comments?

I have not seen any specifications for systems which use DC between units as power wiring, but if they do I would not assume that it is low voltage DC.

 

[hbiss]

I think the OP assumes it's DC but it really doesn't matter what it is. You need to read the manual to see what the manufacturer requires as far as field wiring and installation. What manufacturer is this? I suspect that the THHN was run by the HVAC installers who are not exactly qualified to be doing electrical work.


-Hal