Ductless Mini Split Wiring

[Old Red]

In reading through this thread it is apparent the OP is not really knowledgeable enough in either electrical work or refrigeration work to tackle this project as DIY W/O a lot of technical advice. Hope you can separate the wheat from the chaff of all the advice given here or that he has some good friends in those trades.

In my early life as an AC&R technician we would not come into a partially assembled system and complete it. No way to warrant the work ethically. Some guys would go tackle it on their own W/O the bosses blessing. They would virtually reinstall the system to fix all the things done wrong. Those homeowners wound up paying more in the end than if they would have contracted the project to start with. Sears sold home units to the DIY community that had pre-charged lines and pre-assembled electrical harnesses. Should be easy for anyone who can read to install; Murphy's law prevailed; failures were still common and Sears contracted for us to go fix the screw-ups and they ate the cost.

Today I am retired, still have all my equipment, and planning a remote heat pump for my house. Just had a new furnace installed and had the coil installed for the future. I have discussed doing part of the work my self with 3 contractors, they all said "forget it" we will not be involved in something we cannot warrant. All three stated that it was very difficult to get warranty replacements from manufacturers when they are called out on a service call for a failure. Imagine the run around a home owner would get. End of story I will do the concrete slab and the rack to mount the refrig lines and electrical conduit on.

Since HF now sells vacuum pumps, leak detectors and gauges for a couple hundred bucks, every body is now an expert refrigeration technician. Only their 2 stage vacuum pump will get the 5 micron vacuum required to evacuate and dry out a system. It takes a special gauge to read down to 5 microns. (expensive) Their gauges have special connectors on the hoses unique to the auto AC stems and the pressure/temp conversions is probably not for the same refrigerant either.

Refrigeration 101, Ron

The DIY models are back on the shelf my friend. Head on over to Home Depot and get you a pre-charged Mr. Cool mini split. They do have nuts for the line set connections you must tighten down to install.

The is also the climate rite 1 ton Mini Split actually comes with a nifty quick connect coupler. Runs on 110, no hvac tech needed. Just plug it in a 110 source, run your line sets mount the hardware, connect the quick connect coupler and presto, your done.

 

[MNBobcat]

Old Red,

That is true to a degree. If you need to cut excess length off the line sets though, you can't use a Home Depot flaring tool. R410 requires a special flaring tool that leaves a thicker flare on the end. Also, its best to still pressurize the lines with nitrogen and leak check and then evacuate the lines to remove moisture. That will make the units last longer. I have an A/C tech coming out Monday to do the final hook up of the line sets at the compressor.

What I get tired of is these guys thinking their work is worth gold. I had a quote of $6,200 to install these (but Fujitsu brand) and they must have had over $2,000 in labor and I had to do the electric. I didn't just fall off the boat. Its at most a 1 day job for 1 guy and he ain't worth $2,000 or more. And any competent home owner can do it themselves. At least 90% of it. I'd do the whole thing if I wanted to buy the right tools but I also just don't have the time to do everything myself.

A couple years back I had a guy quote $10,000 to make 2 custom doors, trim and install. I did it for $300.

I just got back from Menards. Turns out I had a 30 amp breaker in the panel that I don't need as it was for a tannning bed the previous owners had. I'm running 10/3 from the breaker panel to the disconnect and then I picked up a couple of 20 amp slow burn fuses for the disconnect panel. I'll run 12 gauge thhn from there to the unit.

I'll be labeling the line sets and power lines to the indoor units so that the tech on Monday will know which set goes to which. I have two 12,000k units going in each of the upstairs bedrooms.

 

[Rustyiron]

What I get tired of is these guys thinking their work is worth gold. I had a quote of $6,200 to install these (but Fujitsu brand) and they must have had over $2,000 in labor and I had to do the electric. I didn't just fall off the boat. Its at most a 1 day job for 1 guy and he ain't worth $2,000 or more.

That's right where I am Bobcat, and virtually the same $ numbers.
I don't mind paying a grand or so for the techs wage, costs, overhead & profit, but over 2k for a days work (8-10 man hours) is going to make me shop hard, real hard.

 

[SirReal63]

What I get tired of is these guys thinking their work is worth gold. I had a quote of $6,200 to install these (but Fujitsu brand) and they must have had over $2,000 in labor and I had to do the electric. I didn't just fall off the boat. Its at most a 1 day job for 1 guy and he ain't worth $2,000 or more. And any competent home owner can do it themselves.

Way too much money! We had 6 tons of Mitsubishi mini's installed for 15k. That is two 3 ton outside units, 8 inside units, 8 line runs with electrical. Yes that includes the units themselves and all labor.

 

[3Ts]

I was quoted $2k for connecting the 2 units. I didn't feel that price was worth it. For that I could buy another set of units. I did buy a good vacuum pump, a digital gauge, and some hoses and did it myself and still saved $1500. No warranty since it was DIY, but it's been running 2.5 years now without a problem.

 

[3Ts]

The hardest part of the installation is hanging the inside unit and getting the pipes thru the hole in the wall all at the same time while holding a 35# box in the air and trying to line it up on the hanger. Works better with 2 people.

The hardest part of on going maintenance is moving the washer and dryer to get to the filters to clean them. (The inside unit is 8' up on a 10' tall wall above the washer & dryer)

 

[MNBobcat]

I set the unit on my head to hold it while I shoved the lines through the wall.

But the hardest part of the installation depends on your situation. My lines all ran from the room into an attic. So for me the hardest part was being in the sweltering heat of the attic and breathing in the insulation dust. Total miserable horrible job. Had it been a normal install with lines going out the wall to the outside that would have been a piece of cake.

The hardest part of the installation is hanging the inside unit and getting the pipes thru the hole in the wall all at the same time while holding a 35# box in the air and trying to line it up on the hanger. Works better with 2 people.

 

[MNBobcat]

To anyone doing an install stay away from the Diversitech wall mount bracket. Get the rectorseal WBB-300 wall mount bracket instead. The Diversitech is total crap. It's two L brackets and no mounting hardware. If you're unit's feat aren't 32 inches apart then the Diversitech bracket wouldn't be mounted to a stud. Horrible design. In addition, if you have Lap Siding the diversitech requires you to fab up something to make it work.

The rectorseal has a horizontal bracket that will hit 3 studs. Then the vertical "L" brackets can slide back and forth on the horizontal bracket and adjust to the width you need. In addition, it has a pad that you can unscrew which will space out the bottom of the bracket to get it to sit plumb on your lap siding.

Just trust me and get the rectorseal bracket and you'll be glad you did. It even comes with a level and anchors for installing it on a concrete wall.