Signature anomalies - flat lines


I see this sort of question on the Facebook page a lot ( so thought I’d post something here in case anyone might stumble across it later.

If you have an unidentified device with a flatline, don’t waste a lot of time wondering what it might be that’s drawing a constant amount of power for so long. Sometimes It’s not. What you may be seeing is a shutoff anomaly - Sense hasn’t figured out that the device has shut off, perhaps because of noise around the time it actually shut off.

Here’s an example from my refrigerator signature:

It seems like sometimes Sense will latch on to some power draw, either always on or perhaps even non-existent, and ascribe it to a device until it falls off or you tell it that it’s not on. So far, I don’t think human intervention from tech support has managed to come up with a solution for this, it’s purely an unpreventable A.I. failure.

And here’s an example of the actual device signature, which Sense gets right maybe 75% of the time:


I’ve always found the straight line odd but I dont think you can make the assumption that Sense misses the turn off. In some cases, yes, but not always.

I have a light for an aquarium that turns on at 7:30am and goes off at 4:00pm every day. Its power draw looks like this:

Even though it’s straight lined, it always turns off exactly at the time it should turn off. My fridge is the same way. It goes straight line but it always turns off when the compressor stops.

I dont know what causes it, but at least in my case, its not because of a missed turn off. For the aquarium light, it always goes straight line at the exact same spot every time. It’s like Sense is doing it on purpose and it’s not randomly losing track of things.


Corrected to say: Sometimes it’s not

closed #4