Recent weird behavior with solar

I have been using Sense with solar generation since mid-2019. With the exception of the occasional server issue, which Sense is good at reporting, it has been working great. For the last couple of months I have seen some weird behavior… several times per day for up to an hour or two, the energy usage drops to zero and the Solar generation reports the NET difference between solar generation and usage. (see attached). Has anytime else seen this and does anyone know what is going on?

Hi

I have looked into your issue, and it appears that one of your solar CTs may either be receiving a lot of interference, possibly broken, or, in the best case - simply open or not connected properly.

If you can check your Sense setup and make sure it is connected and looks good, nothing is open, nothing is pressing up against hard on the CTs, or there is no strong magnetic interference.

Once you make some adjustments, let me know, and I can review your signals and see if the issue has cleared up.

Thanks for your patience while I work to help you. Please let me know if you have any questions. I am always happy to help.

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James

Wow, I can’t believe the level of detailed personal support you gave me! Thank you so much!

I went in and checked the CT’s and made sure there was no dirt/spider webs between the ends of the contacts, and then I also unplugged and re-plugged in the connectors to make sure there wasn’t a loose or dirty connection somewhere. There was nothing that was apparently loose or not making a connection.

A couple of photos of the CT’s attached.

Regards
Neil

IMG_9926.jpegIMG_9925.jpegIMG_9924.jpeg

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Oh and by the way, those downward spikes are caused by my 220v well pump which turns on for a minute or so a few times a day. It is the only significant thing not fed by the “house” circuit and it was way too complicated to figure out how to include that. So I live with the occasional negative solar readings which always go away in under a minute. It doesn’t affect my average readings very much.

Regards
Neil

Help me understand your setup for the “house” circuit vs the solar feed-in. If I had to guess, you have two parallel panels, one with most of your home’s circuits connected to the Sense mains CTs. Then you have a second panel with just the well pump and the solar feed-in and that entire panel is monitored by the Sense Solar CTs ? So when the well pump kicks in, the Sense Solar CTs see the current flowing from your meter and the grid, to the well pump ?

@JamesDrewAtSense

Thank you for this excellent explanation of the signals Sense is seeing on their end and how the are related.

I had a similar problem many many years ago and it turned out the printed circuit board of the sense where the CT connector are were damaged by humidity and caused it to measure the wrong info.
Unfortunately my PCB back then had no plastic layer over it so humidity collected at those pins and made a mess. I was then offered to exchange my Sense for a refurbished one, but lost all my data till that time since I wanted to use the same email address for the new unit.

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Kevin, yes that is exactly correct. I have all of the panels mounted on the side of a building that contains my well. The only circuits not fed by the main panel are the well pump, the light for the pump house and a water softener. So not much and I don’t care that I am not accurately measuring the consumption of those devices. In comparison to my 2 electrical vehicles, my 3 mini-splits for heat and air, my hot tub, my electric clothes dryer, my electric stove… they are a minimal percentage!

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