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Mini split wiring — dimensions

Trevor Lambert | Posted in General Questions on

I have run some wire above the ceiling to near where I will be having a mini split installed, likely a Fujitsu 9RLS3(H?). Is it possible to route the electrical wire through the same hole and service chase as the pipes and wires connecting the indoor and outdoor units, or does it need to go to a separate box on the outside? I have a guy coming to give me a quote this evening, but I’m not expecting him to know much on the technical side.

Is there a place I can get the dimensions for the Fujitsu unit? I thought I had found it at some point, but can’t find it again. Fujitsu’s website is no help.

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  1. Yupster | | #1

    Here is the submittal for the 9RLS3 with the unit dimensions and here is the link to the installation manual for the unit.

  2. Keith Gustafson | | #2

    The power wiring to the compressor does not come from the same place as the refrigerant pipes, unless accidentally. IOW, with wire from the electrical panel goes to the outdoor compressor and wires from the compressor to the inside unit run with the refrigerant pipes

    IF you have accidentally run the power wire to the inside unit, I would see no reason why they could not go out the same holes, but they probably need to get separated and put in flex conduit as soon as they get outside.

  3. Trevor Lambert | | #3

    The power ultimately comes from the breaker panel, which is inside the house. So to get it outside to the outdoor unit, in my case it goes right by the indoor unit. I guess this is more of an electrical code question than a mini split install question. It was actually an electrician friend who suggested it go out the same hole, but he's never installed a mini split before.

  4. Zephyr7 | | #4

    There shouldn’t be an issue running wires to the outdoor unit through the same hole as the refrigerant lines as long as those wires are in a conduit run. If the run is fairly long, I’d use EMT (thin wall metal conduit). If it’s a short run I’d use sealtite (flexible metal conduit with a waterproof plastic exterior layer). You could run sealtite the entire way, but it won’t make a clean install since it will say between supports. You could, however, tape the sealtite into the bundle with the refrigerant lines. You’ll need a junction box to split the wires between the supply, indoor, and outdoor units.

    What you really shouldn’t do is try to run NM (“Romex”) cable through the hole to the exterior along with the refrigerant lines. You need something that counts as armor, and plastic sheathed cable doesn’t.


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