Wiring for 9k btu mini split

[frank563]

Hello,
I have combed the forums and did not see any similar questions- I am looking to wire a 9000btu minisplit that draws115v/7-8amps.

It's a big house (3 levels, 6k square feet) so nothing is nearby in terms of the 2 electrical breaker boxes. My question is, rather than get a portable ac that draws 12 amps, 115v, and deal with their inefficient condensate handling, would it be possible to plug the mini split in an indoor socket 5' away then run 14/3 (outdoor rated) thru the wall with the other "stuff" pipes & control wiring, to the outside unit with a cutoff switch etc. The length is 25'.

There is a totally DIY 12kbtu unit today that does this (friederich breeze) but I do not need that big of a unit and current draw..

 

[Highbeam]

9000 btu is extremely small. Will this only be heating and cooling one room?

 

[frank563]

Yes, these are small rooms, I currently use a 9kbtu window unit and that cools perfectly.

 

[pattenp]

It really depends on what else uses the circuit. I assume the outlet circuit you are thinking of using is 20 amps and not 15 amps. If it's 20 amps then you should be fine. Also why does the wiring between the units need to be 14/3 and not 14/2 if it's only 115V? I'd think it would be better to use #12 between the units if it's being run off of a 20 amp circuit.

 

[frank563]

Yes, it's a 20 amp circuit. I was thing of running a ground so was thinking of 14/3. There isn't anything on the circuit except for a small table lamp but will flip the breaker and double check that to be sure. We have a central vac so the plugs in the room are seldom used. Thanks for the input & on using #12. Having this as an option to consider helps considerably-

 

[pattenp]

#14 UF or NM building cable the number scheme for 2 conductors and a ground is 14/2. If it has three conductors plus a ground then it's listed as 14/3. The ground wire is not counted in the number. On the other hand, flexible cord is listed by the total number of wires, so 14/3 is three wires total and 14/2 is two wires.

 

[alfredeneuman]

To plug into the receptacle you'll have to run cord. Cord caps aren't listed for UF (outdoor)
cable.

By Code, a cord can't penetrate walls, ceilings, floors, or roofs.

In addition, running it permanently through doorways or windows is prohibited.

 

[frank563]

Instead of the plug, I have been looking at white primed (paint to match) metal raceway channel & receptacle box where I would be able to run the #12/uf directly and wire it there, would look better than the plug and more permanent.

 

[Average_Joe]

Find an outlet inside the house close to where you will set the unit. Cut a hole in the outside wall in the same stud cavity as the inside outlet, at the same height. Tie a piece of 12/2 onto the circuit existing in the inside box and fish the wire into the new hole you have cut. Now you can either install a disconnect box or a weatherproof outlet box outside with an in-use cover.

 

[frank563]

Find an outlet inside the house close to where you will set the unit. Cut a hole in the outside wall in the same stud cavity as the inside outlet, at the same height. Tie a piece of 12/2 onto the circuit existing in the inside box and fish the wire into the new hole you have cut. Now you can either install a disconnect box or a weatherproof outlet box outside with an in-use cover.

good idea and less cable being run.

 

[wyliesdiesels]

#14 UF or NM building cable the number scheme for 2 conductors and a ground is 14/2. If it has three conductors plus a ground then it's listed as 14/3. The ground wire is not counted in the number. On the other hand, flexible cord is listed by the total number of wires, so 14/3 is three wires total and 14/2 is two wires.

I think he said 14/3 because he was thinking of using flexible cord!

Instead of the plug, I have been looking at white primed (paint to match) metal raceway channel & receptacle box where I would be able to run the #12/uf directly and wire it there, would look better than the plug and more permanent.

If you're going to hardwire your outside unit, it will need to have a disconnect located near the unit IIRCC!

 

[pattenp]

Well if he thinking flexible cord then that can't be run through the wall to the outside unit as he is saying. I thought he was talking about UF to the outside unit. I can understand the flex cord from the inside unit to plug into an inside outlet.

I think he said 14/3 because he was thinking of using flexible cord!.........

 

[wyliesdiesels]

Or maybe the outside unit needs 120v/240v, thus the reason he said 3 conductor? I've never worked on a split unit system...

 

[frank563]

Well if he thinking flexible cord then that can't be run through the wall to the outside unit as he is saying. I thought he was talking about UF to the outside unit. I can understand the flex cord from the inside unit to plug into an inside outlet.

Yes, I was originally thinking of plugging in to the inside outlet for 6' then tying into the uf solid core (12-2 , I originally said 14-3 but counted the ground) at the point the rest of the 'stuff' goes thru the wall and down 25'.

Got some good pointers from this forum and some info to chew on.

 

[Aceman]

The couple of mini splits I've worked on took power(12/14-2) to the inside unit and then a 3 conductor(12/14-3) from the inside unit to the outside one.