LG LMU245HV mini split 3 zone heat pump DIY

[AC_Hacker]

Originally Posted by rgoltsch

...would anyone recommend or not recommend a particular brand?

What I mean is, if you had to do it all over again, would you buy a Mitsubishi, LG, Sanyo or Shinco again?

Ron,

Thanks for dropping in...

I installed a Sanyo 9000 BTU mini-split at my place and I haven't had any problems at all.

There is the vacuuming down part of the install, but almost all of the units require that. Harbor freight sells a couple of HVAC vacuum pumps that don't cost too much (I bought the 2-stage model, $160 for myself... works good. If I was a pro and was doing this kind of thing for a living, I'd invest some bucks $600 in one that could stand up to relentless punishment). If you don't have a micron gauge, but you have a new vac pump and have done everything correctly, let the pump run for a couple of hours, to be certain. If you are using a used or unknown pump, you should use a micron gauge.

But getting back to your question, if I was doing it over again, I'd get a Fujitsu Halcyon 9RLS (9,000 BTU) or 12RLS (12,000 BTU), because they are the most efficient to run.

One thing I didn't quit appreciate is that most sales people just want to talk about the SEER rating, which is the most appropriate rating when buying an air conditioner. If you are buying your mini-split primarily for home heating, as I was, then the Heating Seasonal Performance Factor (AKA: HSPF) is the most important figure to you. You might have to do a bit of digging to find out the HSPF, but that's what you're after. Higher is better.

There are a few models that advertise that no pump-down is required, because they use special connectors. I have no experience with these models, I also don't know what the efficiency rating is.

The parts you'll need are:

• Mini-Split outside unit
• Mini-Split inside unit
• Line set to connect inside to outside
• Disconnect box located at the outside unit
• Remote Control
• Thru-Wall adapter (or what ever they call it)

... make sure you are getting all this stuff. Some shysters leave some of these parts out and sell them separate at inflated prices. Dont' be fooled.

You'll still need to supply:

• Dedicated breaker of the correct amp rating for your mini-split
• Correctly-sized electrical wire to run from breaker-box to mini-split
• Concrete pad (or equivalent) to bolt outside unit to.

-AC_Hacker



As far as I can tell,

[Vern2]

I need two zones. That pushes cost above $2,500, even with a 1 ton.

Have clean room on left, dirty room on right.

Offen one zone may not be used.



Will have to install mine, either installers want to much for install or wont touch mini split.

[Jumpmaster]

I found this site about two months ago and after reading this string of post decided to buy an LG 245 system with three heads to replace an old trane 10 seer heatpump in my retirement home. I now have all the parts sitting in the garage and have been reading the manuals. I have run the power and have the disconnect installed. I will wire the pigtail last. My question involves wiring the com line between the inside units and outside unit. My diagram shows three wires for each unit but the wire that came with the units has four wires. Besides L1, L2, and L3, do I use the fourth wire to run to the ground lug? Everything else seams pretty straight foward, I just am puzzled over wiring the com wire. I have an HVAC guy that will purge the lines and do the initial startup once I get the system wired.

Scott

[Mobile Master Tech]

Forget the heat pumps, I lust after Vern2's shop toys!

[AC_Hacker]

Originally Posted by Jumpmaster

Besides L1, L2, and L3, do I use the fourth wire to run to the ground lug? Everything else seams pretty straight foward, I just am puzzled over wiring the com wire.

What color is the 4th wire?

-AC

[Xringer]

Originally Posted by Jumpmaster

I found this site about two months ago and after reading this string of post decided to buy an LG 245 system with three heads to replace an old trane 10 seer heatpump in my retirement home. I now have all the parts sitting in the garage and have been reading the manuals. I have run the power and have the disconnect installed. I will wire the pigtail last. My question involves wiring the com line between the inside units and outside unit. My diagram shows three wires for each unit but the wire that came with the units has four wires. Besides L1, L2, and L3, do I use the fourth wire to run to the ground lug? Everything else seams pretty straight foward, I just am puzzled over wiring the com wire. I have an HVAC guy that will purge the lines and do the initial startup once I get the system wired.

Scott

Hi Scott,
My old Sanyo cabling has a ground line..
http://i46.photobucket.com/albums/f1...indoorunit.jpg
http://i46.photobucket.com/albums/f1...CL/outdoor.jpg

Marked as GND..

It's the green wire going to the chassis.

I had to find some terminal lugs for the wires, that were small enough to fit on the (narrow) terminals.
The screw hole is pretty large, but the lug is small.. At least on the old Sanyo units.

[Jumpmaster]

Xringer,

Thanks for the information. I thought that the fourth wire would go to ground but this is the first heat pump that I have ever installed and I did not want to mess it up.

Scott

[Xringer]

Great Scott!
Be sure not to mix up the order of those lines going into the indoor unit.
On the Sanyos, two of them are 230vac and the other one is the low-voltage DC signal line.
I believe the signal line needs that ground wire to work right.

Anyways, if you stick one side of the 230vac on that signal line, it could smoke the comms.

I've heard, mixing up these lines, is the most common reason why new installs fail to work.

I've also heard of one case where the unit would only cool.. No heat..
Turned out to be a bad 230vac install. The electrician only provided 120vac.

Good Luck!

[Jumpmaster]

Xringer,
I have got the three inside units mounted on the brackets and I am ready to bend the copper tubes away from the unit. The instructions say to bend the tubes down and away from the unit. Then it gives instructions on bending the tubing left if you are running the lines to the left. My lines will run straight back into a wall. I am thinking it would be better to bend the tubes straight back from the unit in one movement. How did you bend your tubing on your installation? Thanks.
Scott

[Vern2]

Jumpmaster,

I was a flying Crew Chief. I can't find an installer, well be doing the same thing as you. I need two in door units.


In blue between the two rooms are the in door units. Bottom of picture I have ran the disconnect box.

I have to learn to do it my self, thanks for showing your build, it helps more people then you think.

Here is a build of my own, not a heat pump but a cool project, here.

Vern