AC-related device turns on shortly before AC turns off

This new device was detected a few days ago. Sense had already detected my AC a few days prior.

This device turns on about a minute before the AC stops blowing, and then turns off (EDIT:) about a minute after the AC stops blowing. I’m not very familiar with the inner workings of HVAC systems, so this could be something obvious I’m missing.

My system is a central AC, with (hopefully I’m getting these terms right) an outdoor compressor/cooling unit and an indoor furnace/air handler.

Do you happen to have a Carrier unit with enhanced humidity control? I ask because this particular unit has a function where if you have approached your desired temperature but you humidity level is higher than the desired level, the fan in your HVAC unit will turn on a lower speed setting. This flows the air more slowly over the AC coil and extracts more moisture out of the air before it continues on into your AC vents. The idea is to reduce humidity without going too far below your desired temperature.

This could be Sense picking up the low speed fan separately. It is also common for an AC unit to run the fan for a minute or two after the system shuts off to extract the last of the cooling out of the coil, this also keeps from condensation from building up on the coil.

Just a random thought that may apply. There could be other manufacture AC systems that have this feature, I am only familiar with the Carrier as this is the unit I have in my home.

Both in indoor and outdoor units are Trane, but I’ve had a similar hypothesis (if I’m understanding you correctly) that it might not be a different device but just a different behavior within the same one. I’ll keep the idea of humidity control in mind, and I might also ask around some more HVAC specific forums too.