Now that the units are set in place and the line sets are all run in this MrCool Olympus Multi-Unit MiniSplit System I can get everything wired up. When we looked at how to heat and cool the Off-Grid Barndominium we first looked at traditional furnace options and even planned for it by building in a spot to place the unit. But we wanted to have the system more hidden and to open up the space for extra storage.
We looked at MiniSplit units but they are all typically set up for single room use with a unit hanging on the wall, which we didn't want. And alternative use was to get a ducted unit. These units could be hidden in the attic space and then ducted like a traditional system to each room. This means that one unit can heat and cool multiple rooms and we wouldn't have to see the unit hanging on the wall.
When I first look at the system it seemed like the power requirements were going to be extreme. It was old by MrCool that the system required a 60Amp breaker to the condenser and then individual 15Amp breakers for each air handler in the house. This is a LOT of power needed to run the system which seemed counter to what we've heard about how energy efficient the units are. So after a lot of research and not talking to MrCool because they really aren't any help at all, I found that I actually only needed one 50Amp breaker to run the whole system. This lowered my power needs to the level of a traditional furnace.
When I was told that each unit required it's own 15Amp breaker I was also told that a 14 gauge wire would need run to each unit to power it. So when we pulled the linesets we also pulled a 14/2 wire to each unit. When I went to wire them up it became very clear that a 14/2 was not correct. So after several more calls and emails with the company and not getting any clear answers I did my own research and found that I needed special weather proof wire with three leads and a ground. What you would typically see in a 14/3 wire but it was labeled as a 14/4.
So I had to pull out all the 14/2 I had already ran and install the 14/4 to each unit. Once I got the wires outside I ran into another problem in that the wire was to thick to be installed inside the whips I bought that would come from the house into the MrCool Olympus Multi-Unity Condenser. To get around this I stripped the four wires out of the rubber coating and ran them through the whip and joined them with Push-In Connectors (also known as WAGO's) inside a junction box mounted on the side of the house.
Next I had to hook up the main power supply to the condenser at which point I ran into another issue. A 50Amp breaker requires a 6 gauge wire but this wire was to thick to fit into the terminal provided on the condenser. I was able to find some adaptors that really worked great at Home Depot.
Over all I kept running into little issues here and there that seemed to me to be poor design flaws. The instructions really didn't help much and tech support wasn't much better. Most of the correct information I received was form the local commercial supply store where all the contractors for for parts, from my HVAC guy, and the internet. This is a good reason why I try to put more information in these videos about the process I'm going through. I realize some of the videos are a bit less flashy than others building their off-grid homes and borderline of boring. But I've watched a lot of other boring videos and have gotten the answers I need so I hope this helps others find answers to their questions.
