AC & Blower Motor Combined Into One Device?

Hi community!

Question about my AC Condenser + blower motor.

My furnace blower motor is a variable speed ECM motor (which I understand are difficult to detect). However, my AC is only single stage, so the fan & condenser always operate at one speed in AC mode. Is it normal for Sense to combine the blower and condenser into one device called “AC”?

I defined my Always On devices and use smart plugs, so my “other” bubble is nonexistent when I have all my electronics, LED lighting and other undiscovered devices powered off. For this example, assume everything undetected is off or in standby. When my AC is operating normally, it looks something like this:

.

I was expecting it to only detect the electrical signal of the single stage condenser, and then associate the wattage of the fan as “other”, but it looks like they are combined. Is that expected or normal?

It’s standard for the fan to run for a few minutes after the condenser kicks off to disperse the cold air in the ducts… Sense knows my AC shuts off, and still shows the undetected blower:

Only reason I ask is that I just replaced my 16 year old furnace because my blower motor died (it was too expensive to just replace the motor in such old equipment, so I replaced it all). My condenser was coming on, but not the blower, and Sense still detected my AC, but at a lower wattage than normal. It was cooler at the time, so I didn’t notice anything was broken until I looked at Sense! When I saw this, it didn’t seem to add up:

How is it possible for the AC to be using 3066 watts but my whole house was using 2500 watts? I’m assuming there was some AI/ML algorithm going on, and it was making assumptions based on historical usage data. Regardless, in this state, I found I had an equipment issue! Sense still was able to detect the condenser, but at a lower wattage since the blower motor was broken. Either way, now that everything is replaced, it looks more like the first screenshot.

Any insights on how these devices are combined together? And how it knows the condenser shut off even if it’s combined with the fan?

PS - This was my first summer with Sense, so I don’t have an AC energy comparison data calculated yet. I’ve had sense since last December, and because my heat is two stages and the fan speed can vary, it only detects the furnace ignition sequence, but not the blower (which I’m fine with). I don’t have an ecobee, so it can’t learn from my Nest thermostat data.

I’ve pointed this out many times over the last 2 months.

My best guess is that there is an on/off transition being missed by Sense and a discrepancy in the offline and online events occurring, but Support would be able to confirm or deny this. If you haven’t already, please submit a ticket so we can take a further look:
https://help.sense.com/hc/en-us/requests/new

1 Like