High Voltage post storm - Massachusetts

Hi All,

Anyone else in MA or in an area affected by the storm? I’m Upper Cape / Eversource.

We only lost power for about an hour, but about an hour after it came back, we have been running quite hot voltage wise. I’ve called the power company, but of course they are more concerned about people without any power (which I can mostly understand).

Due to the high voltage and my fear of frying electronics, I have killed breakers to just about everything except a few light circuits that are LED that won’t care about the excess voltage. UPS’s are saving the day currently on networking gear so we can at least stay online and keep watching Netflix.

Anything anyone thinks I should keep an extra eye on? I’ll see what happens when everything settles down and I can see if we lost anything. I’m just assuming we’ll lose a control board in the fridge or maybe the heating system.

For a potential “Sense Saves” story - because 98% of the house is LED, I didn’t even notice the over voltage at first. it was only because I was curious to see if we were getting spikes that I saw where things were at which is what caused me to unplug and or turn off breakers to try to protect things.

I’ll post the Labs voltage graph tomorrow when it updates


Most low-voltage DC electronics these days have power supplies capable of handling 100-240V (for use in a broad range of countries, with only passive adapters) – so, they may operate just fine on that higher voltage, and you might be able to get away without the UPS (assuming that they are in fact rated for that voltage range.) That said, if there are other, more hidden power quality issues aside from a constant 140V, that could cause other problems…

I actually don’t think it’s a given that LED light bulbs can handle arbitrary voltages: Some cheaper ones have much simpler driving electronics that do care about the input voltage.

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I’m in Franklin MA which is National Grid - all normal here, never lost power though.

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We hope you survived the storm with no additional problems. Your story and this event is another reason why SENSE users have been requesting immediate alert notifications when there is a voltage surge or voltage drop. Also the users have been requesting an actual real-time voltage graph, not graphs that are two days old. We are interested to hear how you knew to check the SENSE voltage during this time and if you experienced any home electronic device failures due to the over-voltage.



So far, it seems no damage that I can find, but I don’t know if thats because I turned most things off, or luck, or most electronics these days are more capable of handing the higher voltages.
The bad news - my Sense is unhappy. Voltage stayed high all night (I caught it at 145 at one point). Around 10 this morning (I think) we lost power again, and then it was up and out for a while. During one of the dips, the Sense went offline and it hasn’t come back after a few resets of the breaker. I gave up on it for the night and will try some more troubleshooting tomorrow or open a ticket with support.

To your point @Dcdyer , I would love to see more access to the voltage data. I am one of the people you can find in some chain from probably many years ago, and especially once the labs Voltage graph appeared asking for this info. What is frustrating is that as of this moment, my labs voltage graph is still showing to about 3pm yesterday which is right when things started to climb (you can see it in the below graph).
I also don’t fully believe the max sustained. While the info bubble says 7 seconds, I know I was above 135 for more than 7 second.

As to why I checked Sense in the first place? Honestly it was curiosity. We have had weird voltage things in the past, so its second nature to me to check the labs voltage graph every couple days and surrounding storms and outages.

Once the chart updates, I’ll post back for those that are curious, but as mentioned above, it seems we manage to make it through unscathed.
The current untested system is the Solar. The panels all shut down due to over voltage, but are currently covered with snow, so I’m un clear on if its all working properly. All 23 micro inverters are reporting back, but with various error messages, so I think I need some proper generation for them to get back in sync. Maybe tomorrow I’ll get the long broom out.


Alright - Unfortunately it seems that when the power company cut power to fix the voltage issue, it confused the Sense and caused it to lose wifi. Unfortunately I assumed that it was a brownout issue, so I power cycled it which may have lost 8 hours of data, but so it goes. It ends up it just needed to re run network setup and it rejoined and was happy.

Anyway, for those following along - updated graph attached.
I can’t explain the big hole in the middle. We only lost power from about 11:15am to 1:20pm which is confirmed by the gap in the main power meter. So I’m not sure why there is no voltage readings from what looks to be around 8am until 2:45pm.

@JustinAtSense , a friendly nudge again at getting better access to Voltage Data. While I’m glad there is the previous button now on the voltage chart, this whole screen is still a bit of a mess. Why when i took a screenshot yesterday could I see Jan 27 2:58 - Jan 28 2:58pm, but now I have Jan 28 7:58pm to Jan 29 7:58 pm. If I hit previous, it loads the previous 24 hours, but it seems depending on what time I view the graph varies what 24 hour span it renders.

I can appreciate that maybe adding another “live” meter may be taxing to the servers, but clearly these charts are being drawn on something, so if there was any way to get that data, even if its minute data or 5 minute data, its better than nothing.

And to the point about notifications - all of the dips / spikes only appeared today even though they occurred yesterday, so it seems the dip/spike analysis occurs on the same schedule as the chart being rendered, not realtime. So while its useful to know I had a spike yesterday, but the time you see it, the damage may be long done.


Thanks for sharing your experience with this @ben. I’m going to share this feedback with our team.

Thanks for all the details @ben, this has been a fascinating thread.

I posted this elsewhere recently

There you also have context for the Northeast ISO realtime dashboard.

I don’t pretend to understand the geeky and wonky (politics!) inter- and intra-state i/o of the national power grid but something I wonder about is the relationship between household feeds and higher level transmission decisions. A blackout is a good test of course.

There is “Chinatown” but there are also long term grid decisions that can result in “too much power”, so to speak. Though I suppose P still equals IV.

One last update here.

With the “delayed” data from Sense - a new screen shot that covers more of the high voltage times (and i’m now up to 1000x more dips/spikes than other users).