Mini Split wiring woes

[votum]

Hey all,

I have two senville 24k units I'm wiring in right now - The linesets and wires are in the wall because I have the walls open and it's far nicer that way. I'm also installing one on a second floor and one on a first floor addition so hiding them in the wall now makes sense to me.

Inspector told me under no circumstance is flexible wiring allowed in the wall. Issue I'm having is how the F do I get the wire from the condenser to the indoor units?

My current plan is to run 14/3NM into the AC disconnect outside then wire nut it to the flexible control wire which is 16ga and run that through the whip with the power to the condenser.

For the indoor units though I can't figure out how to get the NM to the unit - I feel like the easy answer is just connect the NM directly to the indoor unit - is this code compliant?

Can I run the NM into the cable management area of the indoor unit and change to the flex cable for the connection to the unit itself?

I'd really prefer not to have a lineset running 15' up my exterior wall if I can help it.

 

[pcmeiners]

What I did was run the lineset and wire together in the wall ( carved out each beam to regulation depth) with steel plates protecting them from screws. Sounds like your inspector is being a *****, see if BX flexible metallic conduit will satisfy him.

Metal flexible conduit referred to as BX for in the wall, (watch out for regs regarding protection from screws/nails) then for the exterior transition to non metallic liquid tight conduit. In NYC they want the power and control wiring separate, so up here I ran 2 non metallic conduits on the exterior.

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[klassenl]

Usually you can run the wire right into the connection point on the unit. It's never fun or nice but it can be done.

 

[rlitman]

...Inspector told me under no circumstance is flexible wiring allowed in the wall...

Clarification please. Many Asian kits ship with SO or SJ type cable, and that flexible wiring is not at all allowed in the walls. If NM cable such as Romex is allowed in your jurisdiction, then you want a "mini-split hookup cable". This is a tray cable "TC" that is rated for in-wall use, as well as is sunlight resistant and rated to be used outdoors. Cables with the same rating can be found as either NM, or armored if you need metallic.

If you need real conduit all the way, you could use EMT into the back of the unit and transition to LFMC Armaflex where it goes outside. That's what I did on my first DIY mini-split install before tray cable for this purpose became readily available.

 

[Poolshark314]

14/3 for 24k mini split? I would think you would need a 20 amp circuit at a minimum, so 12/2 to the disconnect

 

[Heiny57]

Are you talking about the control wire between the inside unit and outside unit? Or line voltage to run the outside compressor?

 

[fitter30]

14/3 with ground runs from condenser to inside unit. 2 power, 1 communication and ground wire
Power for condenser 12/2 with ground
Greenfield is bx/mc without the wire can put stranded instead of solid wire.

 

[pcmeiners]

See if the inspector has an issue with this 14/4 for the control run, if he does he is an a-hole.....(cheaper from Home Depot)

https://www.supplyhouse.com/Southwire-59351203-EZ-IN-Shielded-Mini-Split-Cable-14-4-Stranded-600V-50