Repeat 200 watt spike

Any idea what could be going on here? This repeat 200w signal occurs every 18 seconds (start to start) when my a/c is running. The spike last for approx 7 seconds. Seems to go away when a/c isn’t running.

I have a 3 zone system with a 2 stage compressor and I’m trying to figure out if the spike only happens when aligned in one particular configuration.

Trying to determine if this is an equipment issue/ failure imminent.

have you watched it in the past and have seen it operate without that spike every 18 seconds?

I’ve been trying to go back and watch. Short answer is yes. For instance, look at this from last night/ early morning. Not present on the left, and then it comes back.

1 Like

that’s an interesting meter where the 18 second peaks match the previous cycle.
for 3 AC, zone you have 3 thermostats, right?
how many heat pumps do you have? or are any of these split units?

I have 1, 6 Ton Bosch Geothermal Unit. It serves all 3 zones. Yes, 1 thermostat per zone.

this may sound dumb, but i would attempt to see what combination of thermostat settings may provide this 18 second peak.
Thermostat 1 / Thermostat 2 / Thermostat 3 (1=on, 0=off)
001
011
111
110
100
010
101 ← EDITED 3 HRS LATER FOR THIS COMBO lol

1 Like

thats makes sense. The other thing i was just looking at is that the problem appears to go away late at night, early morning hours. That is the time of day when i ask the unit to work harder to drop the temp for sleeping purposes. this may be the only time stage 2 on the compressor is running. Maybe there is an issue with stage 1 on the compressor?

Experiment number one. I forced my unit to kick into 2nd stage by dropping my thermostat setting 7 degrees. You can see that it goes into stage 2 with no issue. The spikes continue for about 4 minutes and then…gone.

I have a similar problem: every 20 seconds or so, usage is swinging up and down by ~250w. In my case, it’s directly tied to a separate solar battery inverter system that I have powering a second sub-panel in my house (so I’m using the Flex sensor add-on with a 400a split setup). I have a transfer switch and can bypass the inverter, in which case readings are normal. The moment I engage the inverter, I start getting very similar swings. Sense has yet to figure this out (they only just got my Flex CTs reading positive usage!).

I’m a new poster, and I think my account is restricted, as it won’t allow me to upload a picture. But imagine regular, cyclical 250w swings peaking every 18-20 seconds. Suspiciously familiar to your situation with an entirely different setup.

1 Like

@roughcharacter I have a similar experience with a solar inverter

I have a Trace SP2524 (2500 watt 24 volt) inverter hooked up to 8kWh of lead acid batteries.
I am using it as a glorified UPS for my 19" rack with computer equipment.
I have 1200 watt of solar panels hooked up to the batteries and in case there is more solar then load usage it will even put it back in the grid. I see only a 61 Watt fluctuation but 22,000 times per month


Average runtime 11 seconds though

So your cycle is around 30 seconds, with a shorter peak.

I can’t imagine Sense would (at least on paper) have trouble with a decent battery-based inverter setup; the power that comes out of them can be cleaner than the utility. Besides, the Flex CTs add-on is supposed designed to monitor an external generator, which are notoriously noisy, unclean power with significant voltage fluctuations. If Sense can handle those, it certainly should be able to handle clean 240vac from an inverter.

It’s the mice getting rev’d up ((-:wink:

My geothermal has lots of moving parts, and Sense continues to struggle with detecting, much less accurately monitoring, the system

REALLY wish I had a 240v wire in monitor (like KASA with wires instead of plugs) to monitor the whole mess.

1 Like

@roughcharacter Sense had recognized my device as a light bulb. So we will have to assume the inverter is a nice non-out-of-phase load just like a resistance incandescent light bulb.
Since this inverter has both a load and sometimes I see it about 200 watt max into the grid but mostly is getting power from the grid Sense treats it like a regular load.
I am pretty sure frequency/distortion/pure sine wave is well within limits of clean power.

I’m curious is there is some sort of valve changing position or something. Like you said, lots of moving parts.