In this video
- Where the electrical connections live under the mini split's access panel, and which knockout to use for the 110/120V power and control wiring
- How to match control wire order (black, blue, brown) between the outdoor and indoor units
- How to connect line, neutral, and ground for the 110/115/120V power supply, including grounding to the green screw
- Why the two MC4 solar connectors are set aside for now and hooked up later
- Powering on the unit for the first time and watching the coil temperature drop to confirm it's working
Questions this video answers
What voltage does an Airspool mini split need for the electrical hookup?
Most Airspool indoor units run on standard 110-120 volt household power, sometimes labeled 115V - all names for the same standard US outlet voltage. You'll wire a normal line, neutral, and ground, just like a regular outlet plug.
How do I wire the control wires between the outdoor and indoor mini split units?
Keep the wire order consistent at both ends. Airspool's control wires run black, blue, brown, and as long as you connect them in the same order at the outdoor unit as they are at the indoor unit, the exact sequence doesn't matter.
Where do the solar MC4 connectors go on the mini split, and are they used in this step?
The two MC4 positive and negative connectors sit under the same electrical access panel as the power wiring, but they're set aside during this step and connected later when the solar panels are hooked up.
How can I tell my mini split is actually working right after I turn it on?
Watch the coil temperature drop once you power on the unit - in this demo it fell from 64 degrees down through the low 60s and kept heading toward the 30-35 degree range, which is a good sign the system is running.
What temperature difference should I expect between the return air and the supply air?
Expect the supply air coming out of the unit to run about 20 degrees cooler than the return air going in. So if the room is 85 degrees when you turn the unit on, you should feel roughly 65 degree air coming out.
Where does the ground wire connect on the mini split electrical panel?
Both the ground from the power cord and the ground from the control/power wiring connect to a single green ground screw, which should be tightened securely before you put the access cover back on.
Transcript
Read the full transcript
Okay, so our line set's all connected now, and the next step is going to be accessing all the electrical goodies that happen underneath this panel here. First, you need to remove typically four screws. For this Airspool unit, they're actually going to have — which we'll talk about a little bit later — these two MC4 positive and negative connections to connect solar panels. But we're setting those aside for now.
Instead, for right now we're going to talk about the volt power coming in here, along with the control power going from the outside unit to the inside unit. So we're going to knock one of these plugs out. In this case, this unit runs on 110 volt power — 115, 120 volt, whatever you want to call it — so you should have a nice straight ground here on your plug. You'll have a normal outlet, USA 110 volt plug, with a positive, negative, and a ground wire. Those are going to feed through here, and then you also have the control/power wire that goes to the inside unit, and we'll feed that through the same hole. Alternatively, you could feed it through the side port here, but we're only going to use this bottom one — these two ports are going to be for the solar later on.
So now we're all set up, and these wires are going to fit underneath this mount here. What this does is keep them from being pulled away from the screws they're going to be tied into. You'll notice we took one of the screws of this flange out, so it's just sitting like this. But before mounting the screws in this base, in this channel here, we're going to mount the round screws — there's two of them, one from the power cord, one from the power/control wire.
Now the power/control wires are mounted, and the ground's done. Same as the inside unit — we're doing them in alphabetical order, though it doesn't really matter, they're just copper control wires and power wires. We're doing black, blue, brown, which is alphabetical order.
Now the control wires are in the same order on the outside unit as they are on the inside unit: one, two, three — black, blue, brown. Now we're hooking up the power wires. Remember, the neutral's already hooked up. We're doing black for line, and neutral is white, and these connectors go underneath, beneath the metal plate here — that's true for all of them, so make sure you slide everything underneath the metal plate.
The last step is putting the mounting flange in. For this unit, it helps to have the control wires a little bit to the left of the power wires, and then everything is done here: one, two, three, black, blue, brown, line, and neutral. Both of the grounds go to this green screw — tighten that up all the way — and then we're just going to put this cover back on the same way it came off.
So that's just finalizing the plate, and now everything is nice and tidy. The final step we'll do momentarily — we'll be turning this on. Everything is clean and hooked up, so this is the last step. In this case, it's a 120 volt, 110 volt, 115 volt unit. Normally you wouldn't have it sitting on the ground like this, but for experimental purposes, we're turning it on now.
It should power up here momentarily... there we go. The anticipation! This coil right now is 64 degrees, 63, 62, 60 — it's heading in the right direction. The coil itself will get down into the 30, 35 degree range or so. The supply air here will be about 20 degrees different than your return air, so if it's 85 degrees in the space when you turn the unit on, you'll probably feel about 65 degree air coming out of here. Anyway, it's working — thanks for watching and following along.
