Device Off detection


#1

A couple of weeks ago Sense found a new device “unnamed heat 2” Through some reading and sleuthing i finally worked out that its the defrost heater on the fridge/freeze. It uses 500W it comes on for ~10 minutes every so often. But if i look back in the usage history there’a a couple of times where Sense thinks it was on for over 24hours! But i go back and look at the overall power chart for those days, I can see the spike where it turned on, and can see that no more than an hour later it was off. (total usage dropped down to ~400 for everything).

Are there issues with how sense decides a device has turned of?


#2

Here’s a chart from the overall power meter for the time period i mentioned.


#3

And here’s what device history claims


#4

Sense has to recognize both on-events and off-events separately. Sometimes it misses or conflates each one, though conflating off-events with other devices is lower probability shot since the incorrectly identified off-event device must also be already on for that type of error to occur (same for erroneously-detected off-events for devices that are already off)

If Sense misses or misconstrues an on-event, the power gets attributed to some other device or always on.

If Sense misses an off event, Sense eventually times out the on-cyle, presumably in a time period based on device type. That’s why we see occasional issues on this forum where long-running devices get turned off before their actual off-events (Sense times them out).