Today, since my work was closed to do the tropical storm, I decided to undergo a project I’ve been meaning to do for a while; relabel the circuits in my breaker box. The writing on it is faded and some of the labels don’t match anymore. So I turned everything off except Sense and my network rack (which just happens to have a dedicated circuit) and went through breaker by breaker and documenting what was on the circuit and also plugging and unplugging devices to see the always on power usage.
I saved the AC for last. This is a screenshot with the only device in the house besides Sense that has power is my outside unit and the air handler in the attic. My network rack is on a UPS that can run everything for about 20ish minutes. You can see in the screenshot where I unplugged it.
At first, I thought things just needed to settle some. So I made sure the temperature is set above the current temperature by a few degrees and have been waiting, but it’s still sitting at 117/118W 10 minutes later.
It’s a Trane variable speed system. I can get the exact models if it’s helpful. We had it installed in 2017 I think.
Well… I had a suspicion and it was right. I turned the temperature down so the AC would run and let it run for a bit before turning the air back up and turning al the other breakers off. The always on for the AC dropped down to about 20W. Still seems a little high, but it’s much better.
So I’m not sure what it was doing using 115W for about 15 minutes before. My guess was some sort of initialization, but that shouldn’t take so long, or use that much power I’d think.
After doing the whole house I have a big list of items to enter into Sense’s always on, but I should have most of it classified now.
That xv18 Trane variable speed AC will draw 1-2 amps while idle. For an inductive load such as a motor we can calculate that out to:
watts = 0.8 × 1A × 230V = 184W