[Project] Fault Detection: Power Quality

I have only recently seen this problem. I do not remember seeing this issue on an earlier version.

Don’t know how to find what device is causing a spike?? Graph shows spike happening at exact time, but how do you find exact device or breaker that is spiking? If you can’t this thing is complete waste of money.

The voltage drop or spike can be occurring for many reasons. The majority of the time, they are because of something occurring externally; e.g., a lightning strike, transformer issue, or a wiring issue in the breaker box. There’s no device to tie it to, in this case.

Some drops can occur because of a device suddenly drawing a large amount of current. If you think that is the case, you could hop on over to the power meter and the device-specific sections to see if you can identify a potential source.

I think Sense provides enough context to make some educated guesses and do research, but I don’t think it would be capable of identifying a source in the general case just because of the origin of these events.

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As @whee mentioned above, there are a variety of reasons that a voltage drop or spike could be happening. The resource that was provided shows just a few of these.

As far as providing value from the data provided, we’ve had an abundance of cases where users have utilized the data provided to come to a solution. Below are 15 different users that have used Power Quality to isolate an issue and worked with either the utility or an electrician to fix their Power Quality, with steps on how they came to their resolution. We have even more responses/feedback from users that have utilized Power Quality in one way or another.


I think the challenge for some people is the perception that this is the tool for all issues. I’d suggest that its a tool to make you more effective at identifying issues and resolving them quicker.


Greetings all. I have been playing with the Power Quality feature for about a year now.

I have been trying to download a CSV of the power quality data for the past few days. Each time I download it, I get a CSV with blank data, just header entries.

Is there a new bug with this feature?

The graphing feature shows data is being recorded

Do you actually have some power quality events listed ? I don’t have any events logger, and when try to download, I see the same thing as you in Safari - no downloaded data and just the CSV column headings in the browser.

Wonder if people are seeing different results when they have some events logged, unlike me.

ps: If you are actually looking at downloading the full L1/L2 waveforms in the graph, that’s not available as CSV. You might want to consider trying Home Assistant and the Sense integration if you want that. From there you can indirectly pull minute-by-minute L1/L2 voltage data like @whee is showing.

pss: I get different behaviors from Safari, Chrome and Firefox when I attempt to download CSV for no events. Safari shows the header but doesn’t download a file, Chrome gives an XML error and Firefox actually downloads a CSV of jet the headers.

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I have

More than most Sense users

Dips & Spikes (30x) and when I click on the CSV i get real data:

Linux OS with brave browser btw


BTW - I’m guessing that very big power users in your house could cause a dip in line voltages, outside the band. I can see 1-2V dips when my EV charger kicks in at 80A (19kW)

But this happens whether we’re home or not, usually between 7 pm & 9 pm. Happens every day. Were on vacation 2 weeks & still happened. I biught Sense so I could figure out which breaker is bad. But it doesn’t tell me anything

Not sure why your are thinking it might be a bad breaker. Per @JustinAtSense’s list, more likely that power quality issue is happening because of a problem in your breaker box, the wires that run to your house, your distribution transformer, or even your neighbors behavior (EV charging). If it is happening when you aren’t home, even more likely it is outside your house. Read some of the items in Justin’s list to see how they were resolved.

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3 posts were split to a new topic: Help - Mystery Loads Causing Outrageous Bills

I love your Power Quality “diagnosis” summary here:

It probably deserves a more prominent place in the forums, or even in the support docs. But that raises the question of where an interested or in-need users is most likely to find it.

ps: I may try to do the same kind of synopsis on Sense accuracy.