High Wattage, Double Step Waveform Device Identification

Trying to identity this strange double step waveform, these are the things I know:

  • It turns on when 3-6 times a day, time of day and quantity varies per day
  • Occurs when we are not at home as well.
  • Sense thinks that its a garage door, furnace, sump pump, pump, microwave, or washer. I can verify that non of those things are running at this time.
  • It runs for about 10-15 seconds then turns off (thanks jefflayman)
  • There are two steps, the first is ~350w and the second is ~750w
  • Does not have that distinctive “spike” at the start of the waveform indicating a motor

My thought is that Sense was just capturing the startup of something, say a motor in the hot tub, but then was loosing the rest of the signal but looking at the overall power during that time it truly is a spike in power, not just a misclassification by Sense.

Things that run in our house that use this kind of power levels:

*Electric Water Heater
*Heat Pump with Oil Backup
*Electric Hot Tub
*2x De-humidifiers

Device (First Step)

Device (Second Step)

Overall Power (Showing one spike)

Overall Power (Showing two spikes)

Anyone ever see this kind of waveform before? Cheers!

Sump pump. Although your description says your mystery device runs for 1.5 seconds, the traces on the power meter show it running for 10 or 15 seconds. My sump pump almost always empties its pit in 12 seconds. My pump uses about 700W, which is in the neighborhood of your mystery device. Sump pumps also turn themselves on when needed: they do not require user interaction, which matches how your mystery device sometimes runs when you are not home.

Your power meter views helped me reach this conclusion. They show a single step up of +797W. The device level power meter, which depicts a phased start at 350W, should be taken with a grain of salt because it is a reconstruction generated by the AI engine. Even though a start-up spike is not visible to the naked eye, the AI suggestions include several motor-driven devices, so there might be a spike that is too small to see.

Thanks for providing a complete set of clues.

Thanks for the response @jefflayman, appreciate the insight. I updated the timing, you are correct that it is on for 10-15 seconds, not 1.5 which I originally stated. Thanks!

Interesting to learn about the step up/AI construction, I’ll keep that in mind for future device identification.

I went and activated my sump pump with the float and it syncs with the device I already have labeled as Sump Pump (it also only draws 450w when activated).

While down there I also activated my pump for the basement bathroom sink/toilet and it was not that either unfortunately.

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I’m going with sump pump as well.
Turns on with no resistance, the water pressure causes resistance & slight spike/increase you see.

This is mine.

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@obscuredtrip my other device which was previously listed as “Sump Pump” looks similar. I just hit it manually with the float and here is the waveform…unfortunately its not my mystery device.

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Are you sure? I still see a low/high. The 2nd low appearing about the same as the brief 1st could have been caused if there was not enough water in the sump lowering the resistance on the motor when you turned it on manually.

I say keep an eye on it for more natural cycles.

I’m sure on the previously detected Sump Pump, I named it that after seeing the discharge of water every time it turned on (and manually firing it right now confirms it).

I can most certainly watch the new device as weather changes it rains, gets hot/cold etc.