Trouble finding unmonitored usage, negative readings?

Hi All,

I am trying to find the non-metered usage, however I am running into an issue where it seems IoTaWatt is measuring more usage than what I am consuming which I don’t think is possible? Any suggestions on how I can track down where the extra power is coming from? Does the power factor have anything to do with ?


First, can I get a high res picture of the panel? Why does the output “grid” not factor in solar2?

Hi overeasy,

Thanks for pointing out that grid was missing solar2, forgot to add it while troubleshooting. Below are pics of the panel.

Breaking it down, the basic problem is either that the supply is understand or the load is overstated.

The supply is the mains and solar. I think the solar is probably OK as both legs appear to match, as they should, notwithstanding that one uses a 100A CT and the other a 50A CT.

The mains are a different story. They are vastly different. Main1 is importing 25 Watts and Main2 is exporting 977 Watts. That could very well be the case, but possibly one is understating. Can you plot the power Watts and Power Factors for both mains for an hour or so when there was no solar?

The load would need to be overstated to cause this problem. It’s hard to get a CT to overstate power. Overstated voltage would do it, and you appear to have a very imbalanced load with almost all of the load on the main1 leg and hardly any load on the main2 leg. Do you know which leg the VT is connected to?

Another possibility is that the kitchen CT is a 50A CT and not a 100A. That would cause the kitchen power to be doubled and your unmetered in the status above would be 10W.

Kitchen CT is 100A, it has about 4 wires going through it, in the panel it’s the CT in the bottom left. The VT is on the bottom left breaker and on Main1 leg. Here is the chart , hopefully it’s helpful ?

I don’t see anything obvious that would cause the problem that you are reporting. The next thing I would like to do is to check the mains. This will take a few days. Can you please read your meter and note the data and time of the reading. In a couple of days, do it again and then compare to the sum of your two mains. You can set a custom start and end date/time. Plot the two and then add the kWh in the Sum/Integral column of the statistics tab in Graph+.

Aside from that, I have a couple of observations that probably don’t cause this problem

You have one CT on your dryer and have the value “doubled”. Dryers should use the three-wire techniques from the docs.

When you pass several wires through one CT, are you observing which leg they emanate from and passing them in the corresponding directions? (see split-phase docs).

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Thank you very much, I think I found my issue(still waiting to gather more data to verify). I think my issue was due to one of the several wires running through the kitchen CT actually already having another CT on it so it was being counted twice. I will fix my dryer as you mentioned also, thank you again for your help. This product is really neat/fun.

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