Questions about LABS- Power Quality

A few months ago I start receiving alerts that there might be a installation issue with my sense meter. When I opened the notification it brought me - settings/monitor then I could see the voltage on L2 was 102.0v and L1 was 123.2v. I contacted the power company who sent out a truck and said they replaced the connector for the drop line. I haven’t received any alerts but I started looking thru the Labs section in the mobile app which has a section that has a ! power quality. I opened it and it says I have 967 voltage dips and spikes in the last 30 days. Seems to mainly be L2 in the charts.
I put a multimeter on the mains and never seen anything drop for about 10 mins. So I attached the meter to the breaker and a few mins into it… I seen it drop to 106v, then right back to 120v. But I dont know if the whole system dropped the voltage or just at the breaker. So I made sure my CT’s were on there good and switched out the breaker feeding the sense last night. I couldn’t find any loose connection on the mains.

I’ve been watching the live voltage on the web app (only works in chromium) which appears to have fixed it but the voltage chart wont update. My latest chart that show 6:58am-6:58am ends yesterday morning. My main questions are … Has anyone seen this before? Is there a way to setup an alert like I got before? What If the breaker wasn’t the issue?

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No way to do alerts for Sense Lab features. My take on your issue is that you have rust/corrosion/connection issue on your L2 similar to this situation.

If you want me to chart, like I did in this gent’s post, upload the .csv file available from the Labs part of the Sense web app.

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My box looks clean, its a Square D residential QO box that’s mounted in a finished basement. The contacts of the old breaker looked new and were tight. The bus bar looks good and the breaker snaps in tightly. I also moved the breaker to a different slot and technical had to move L1/L2 so that it would recognize the devices that were already learned. Im going to move it back as soon as I figure out it it was the breaker.

I’ve had no flickering/ resetting of modems/switches/ lights/ TV’s/ hubs. I dont have anything on a ups and I even have 2 sengled z-wave bulbs which are very temperamental. If the power goes off or even just flashes, they come on and stay on until I turn them off.

The labs section that Ive been watching hasnt had any drops that Ive seen. Its been 119-122 since I posted earlier… But my time line still hasnt updated since 6:58am yesterday.

Here is my csv file though
power_quality_raw.csv (75.9 KB)

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I’m assuming “time line”, do you mean the Sense Labs Power Quality Timeline ? I ask because the window below is referred to as the “Timeline” in Sense-speak.

If you are talking about the Power Quality “meter” (below), I think that that only updates once a day. So I have nothing for today, yet. Only 3:58AM Pacific through 3:58AM for previous couple days. (same as 6:58 through 6:58 Eastern for you).

As for your quality issues, it looks like, they were mostly clustered into a couple days, mostly on the second leg.

But power quality issues can come from stuff beyond your breaker box as well. You probably share a distribution transformer with 4-5 other households, so the issue could be tied to that transformer or one of your neighbors shorting that same leg to neutral or ground… Saw one interesting story about a garage gutter connected to a hot wire here.


The labs chart still hasnt updated since I posted yet. But… We had a big storm the other night and the transformer a the end of my driveway blew. Not just the fuse. It burned up my modem (on a surge protector), blew one of the 3 fuses in my solar disconnect (600v/20amp), a switch, 2 cameras, and flipped every GFIC outlet in the house. Not sure how it fired 1 of the cameras since its POE, it got the managed switch it was plugged into and 1 of the 6 cameras. Here is my latest data.
power_quality_raw.csv (76.8 KB)


minimum 12.52 (not sustained) = 10.4% of nominal
maximum 149.29 (not sustained) = 124% of nominal

Was it really only the solar disconnect, the inverter(s) survived?
That is pretty impressive. What brand inverter do you have?

Yes one of the 2 hot legs blew and the N has a black mark down the side/ maybe a crack. AEP (APPCO) requires to have a 3 phase/3 pole disconnect for the inverter to be mounted on the same wall and near the meter. They don’t require the fuses bought a fused one anyways. I have a SMA sunnyboy 5.0… its a transformerless string inverter that is rated for 5200watts. I was lucky it didnt harm it.


Im now showing 1000 spikes/dips for the month. My 24 hour window is now on 7-2… 3 days ago. The CVS doesnt have anything past 7-2, so IDK if its current data or data from 7-2 back

My PQ lab reading currently says July 3 6:58pm - July 4 6:58pm
It seems to be a few days behind in general

Mine remains a little more than one day behind the current day.

But the CSV should be for the entire past month ? I only had one on 6/19 but it is coming up in the CSV.

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I believe the breaker feeding the sense meter was causing the dips. They have finally fell off my 30 day history.

I think the day we had the storm, surging and transformer blow … is still on there showing 18 dips and surges. Im hoping after the 7/2/21 evening drops out of my history, I will only have a few dips. My lights don’t flicker when something large kicks on or anything


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