Sense going offline until power is cycled

So this has happened a few times now - perhaps once every couple of months, and there doesn’t appear to be a common factor I can pin it on. It happened yesterday, and I’m pretty sure that there wasn’t a power outage, or a network outage because I have data coming in reliably from the Enphase system all day.
What puzzles me though is that Sense doesn’t recover from this. While it was offline, I attempted to use the phone app to communicate with it - and there was nothing - no communications at all. Once I cycled the breaker, all was hunky dory.
My question is - do you have a resource watchdog running here? In my line of work (embedded software for consumer appliances) whenever there is some resource that is essential for operation like the network connection in Sense we have a watchdog in the software that resets the device after the resource has been absent for some period of time. It sure feels like somewhere in your code you have a lockup situation that it can’t get out of…

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Do you live in an area prone to brownouts? There’s a hardware issue with some monitors where a brownout occurs and some monitors will not come back online after it. This has since been resolved. If you think this may be the culprit, definitely reach out to Support. https://www.sense.com/contact

There’s a long thread about it here: RESOLVED: 1/10 Second Power Outage = Sense Offline

Hmmm…so I went and looked at the Enphase data for that period…and lo and behold…

Very interesting. Do you you see other voltage drops like that historically?

Well, dunno. I extracted this one because I knew when you look…but the other events I just cycled the breaker when I got home.

This one is interesting because it corresponds very nicely with the start of the Sense going offline - which I know happened at 9.15am.

What might be REALLY interesting is that my neighbor has just installed a Sense (based on me showing mine off :)) and so I imagine he would have experienced exactly the same power glitch that I did. I just asked if his unit went offline yesterday - I’ll update you when I hear back from him…

Just keep in mind that this doesn’t affect all Sense monitors (only a small subset), so he might not have experienced it for that reason. I’d still recommend reaching out to Support on this. They can better diagnose than I.

Well, support basically shrugged:

Hi Paul,

Thanks for reaching out.

Looking at the thread on the Community forum, it seems like your monitor went offline due to the brownout (voltage drop). Power interrupts can have a weird impact on some electronics. If there is a brief interruption of power, Sense may not always be able to naturally get back online by itself. In these situations, the monitor should be able to get back online simply by power cycling the device. Unfortunately, there is not a lot we can do to resolve this particular issue from our end.

I hope this helps. Let me know if you have any questions.

Thank you,
Maxim
Sense Customer Support

Also, my neighbor said that his unit dropped out at that time but was back online after about 10 minutes…

I’m going to shoot you a quick PM about this.

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Interesting, I’ve has my Sense for 2 years and in the last month or so my Sense has gone “permanently” offline twice where I had to power-cycle to bring it back online.

How long does the Sense need to be offline before the email notification is sent? I’m trying to look back at UPS logs to determine if a brownout occurred around the time the Sense went offline.

It needs to be disconnected for 30 minutes. However, the process that sends out the notifications runs once an hour, so it could be 30 minutes to 1.5 hours before you get the notification.

Interesting, one of the days (June 9th) I got the email Sense was offline an hour and ten minutes after my UPS switched to battery for 2 seconds due to distorted input. The other times there were brownouts the same day but the UPS emails and Sense emails were significantly more then 1.5 hours apart.

We had a real quick brownout today due to power company re-routing power to repair recent wind damage. Sense hasn’t recovered on its own so I reached out to support.

I intentionally turn off my mains power twice a day to connect and disconnect my battery back inverter and my sense monitor restarts everytime with no issues.

Power truly being off and then on hasn’t been a problem in the past for my early 2018 purchased device. It seems to be when there’s a momentary interruption or partial loss of voltage, picture an interruption quick enough to not need to reset device clocks, where the earlier devices don’t seem to recover.

Just a bummer a $300 device can’t recover the same as a $20 smart outlet.

Support suggested not replacing mine since you lose your data/devices on replacement.

ok gotcha, my power cycle takes about 15 seconds. Luckily I live in an area that is semi-desert so we have virtually no large trees around and therefore my power only glitches once every 5 years maybe.

Review this old blog. I had the same problems you are currently having. All you need to do is install a TD-69 relay. You only need to connect the black wire on SENSE. That is the power connection to the SENSE computer. You don’t need the elaborate setup that I installed. I have not had any problems with power glitches since I installed this device. It saved me a lot of headaches. Just an idea…

So this relay will turn a glitch into an actual on/off event of a specified time?

The TD-69 is a delay timer. Google it.

You will see that many appliances have this installed. Example would be a A/C unit. You don’t want to immediately restart the compressor or you may damage it. You need to wait for the system to stabilize before a restart.

If power is lost, then you can set the ‘wait period’ until the relay enables. I started with a delay of 8 minutes, then slowly decreased my timer to 3 minutes. If a brief power outage occurs, then I lose 5 minutes of data (3-minutes for the delay + 2-minutes for SENSE to reboot and reconnect) that SENSE does not record. That’s better than me having to manually trip the breaker or lose hours of data because I am not home. Look at the example PSWIRED shows in the same blog. He took my idea and made it simpler.

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