So, what happens if you lose power during the first 24 hours?

Technical Questions
#1

Hi there. My sense was installed yesterday finally (hooray!) Aaand, of course we have a massive unexpected windstorm that knocks out power the next day. Near as I can tell it was still showing 0% initial device progress when things went down. So, my question is, will this unexpected power outage negitivly affect the initial detection process, or will it just resume and go on its merry way assuming power comes back at some point. Which I really hope it does before my ups dies and I lose internet.

Thanks for any insight!
Tim

#2

If it completed its initial signal checks and had started reporting basic voltage readings and the power graph, I would think you are fine.

But if you are worried about it at all, since its a new install and there isn’t any historical data to really lose, you can reset the data and start from scratch again just to be sure.
From the App, navigate to Settings> My Home > Sense Monitor > Then tap Reset Data

That should wipe everything data wise and have it start searching again.

You can of course also submit a ticket to Sense Support and I’m sure they can take a look and see if anything seems out of place.

#3

Power came back on an hour ago, it looks like it’s showing power signal checks in progress 0% again. So I guess that’s good? Thanks for the reassurance

#4

I think you should be fine, accordingly.

If you don’t see any forward progress on the signal check within the expected time you can of course perform the reset process ben mentioned above.

#5

Sounds like everything is proceeding normally. If you’re not fully through signal check in 48 hours, reach out to the Support team.

#6

It finished its checks eventually, and its detected my HVAC system so far. So thats good. There is a bit of weirdness yet, its detecting my general usage with a large 3d printer, 2 high wattage gaming computers with 5 monitors between them and a 60 inch led TV running as 65 watts. With those off and the lights off it goes to 56 watts. When my hvac system kicks on it shows 560 watts with spikes up to 2000 when the electrical heat strips kick in. Its like it’s not seeing any of the wattage from the sub panel. The sub panel is fed from the main panel via a breaker, and in turn feeds a tertiary panel. My solar panels feed into the tertiary panel and aren’t being monitored by the sense due to wiring logistics yet. So I think its seeing all the electricity in use, but the magnitude seems off based off what I expect from the meter readings and electrical bills. The 3d printer alone should be drawing at least 125 watts.

The 2 panels in the house aren’t dual fed. I double checked. The computer circuits and 3d printer are on the sub panel. I know that panel is fed via a breaker on the main panel, I know which breaker it is and can shut it off via that breaker.

So, knowing all that, any idea why I’m seeing less energy usage than I should? Especially at night when the panels aren’t doing anything? There is no battery backup present on the panels, though the computers and 3d printers are behind 1500va ups.

I’m still getting a useful amount of information, there seems to be a missing component though.

#7

Two thoughts…

  • your power might be reading low if Sense is experiencing data dropouts - look at your power meter waveforms for places where power drops to zero.
  • Sense unlikely to identify/detect computers and monitors for a while. Too content / compute dependent.
#8

I see a periodic 5 watt drop every 10 seconds or so, which seems unusual. The wireless signal over by the sense is pretty good outside the wall, though I suppose the wall itself where the antenna is could have more interference. I have an asus mesh network set up so I can install a closer node if needed. Does the sense unit have anywhere it displays what it is seeing for wireless signal strength? I haven’t been able to find that if it does.

Edit: i’m not worried about it detecting the computers or monitors as devices per say, I’m more concerned that those devices are online and using what should be a few hundred watts of power that the unit isn’t seeing. or if it is, its seeing at the wrong scale.

#9

No visible signal strength metering from the Sense monitor today. But if you aren’t seeing drops to 0W, then Sense is likely to be incredibly accurate, within +/- 2% of your revenue power meter.

Mu experience with accuracy vs. power company here:

#10

Well, this one isn’t for some reason.

#11

OK,
If you are not experiencing data dropouts, I’m betting Sense is accurate for whatever you are actually measuring.

#12

I know for a fact the heat bed for a Lulzbot Taz 12" 15 amp bed draws 125 watts. The sense isn’t seeing it. Its not seeing either of my 1000 watt computer power supplies either, during boot or at idle. During boot they should both be using at least 200 watts for a sustained 1 minute period when the fans and drives are run up to full. Its not seeing those either. I dunno why it isn’t seeing it, but I do know those wattage numbers are real and accurate based off other monitoring I have available.

#13

Not doubting your assessment of the power usage of devices in your household. Just questioning what Sense is actually measuring. I don’t know your power company offers hour-by-hour net metering data, but it would be interesting to see them graphed side by side or in a scatter plot.

#14

Do you have any pictures of your installation and maybe a single line diagram of your panel layout?

Have you checked the per-phase instantaneous power readout in settings > my home> sense monitor? If either of those values are negative, you’ve got a CT backward and the auto-calibration process didn’t correct for it.

#15

I don’t yet, but I’ll take some this weekend. The Per-Phase instantaneous power readings are both showing positive values. Also the stickers on the CT’s are both facing up and the hinge is facing the same way on the main leads. The simple description of the panel setup is Panel 1 has the main leads coming into the top, Panel 2 is fed from panel 1 via a large breaker, panel 3 feeds into panel 2 via another breaker, and the solar panels feed into panel 3 which is out in the shop. There is also a freezer out in the shop along with lights and power tools, but the lights are the only other thing out there that has been used since the Sense unit was installed. For electricity monitoring the 3rd panel is of low concern to me. The computers and 3d printers tie into panel 2.

#16

Ah, I think I see now. So, do you have Sense solar CTs anywhere in your configuration? I suspect that your solar production is causing the artificially low usage, since with your current configuration, Sense is only able to measure the portion of your household loads that’s being fulfilled by the utility connection. All of your solar production is going directly to your loads without being measured by Sense.

Are you able to get a set of solar CTs wired out to the inverter location using the new Sense CT extension cables? Or, even though this will introduce some error when loads are used in the garage, can you get a set of CTs on the feed to your 3rd panel from the 2nd panel?

#17

I’ll repeat this with more details… You can sort this out, but it will take detective work, plus a little help from your utility.

If your utility offers hour-by-hour downloads, try downloading/exporting from them and from Sense, then do a scatter plot of utility (x axis) vs. Sense (y-axis) for the same hour. That plot should inform you of your issue.

  1. It should be a 45 degree (slope=1) line with minor variations (maybe 2%).
  2. If you see a 45 degree pattern, with a bunch of points that are lower on y-axis from the 45 degree unity slope line, you are likely seeing data dropout from Sense, during a number of hours.
  3. If you have a nice line, but it is less steep than 45 degrees, then you have a systemic calibration problem.
  4. If you have an 45 degree nice line, but it appears offset on the x or y axis, then you have some kind of additional feed or drain problem, where Sense is accounting for incomplete (or extra in the case of some kind of feed-in) usage.
  5. Some combination of above…

Here’s what I discovered when I did the comparisons.

Does anybody have any cool graphs or analytics using Sense data - Please share! Data Analysis

#18

I own the solar CT’s but they aren’t installed yet due to logistics. There isn’t a good unobstructed path from panel 1 to panel 2 yet. adding that in is likely going to require opening the wall so I;ve been avoiding it. I’ll clamp them around the 3rd panel feed breaker. The inverter itself is 40 feet away so difficult to get to with the sense where it is. Though i haven’t looked at the extension cables so it might be far enough away. Adding an additional sense closer someday may be in the cards, but not for now.

I don’t believe my utility allows downloading of usage data at this time. I’ll double check though.

1 Like
#19

Oh hi.

Best thing would likely to be able to write into the support team really. Then I could take a look at the readings and see anything strange that might be going on.

One thing of note that stands out though is that you haven’t said that you see anything weird in terms of the readings from Sense beyond missing device wattage but you have solar power which feeds into panels but no solar monitoring.

Either all of that power goes into batteries which then feeds out only to devices in your home or you never produce more solar power than you consume. Without the solar monitoring, Sense will never report any of the usage that comes from your solar power at all since it will never reach the main sensors.

If you fed any solar power back to the grid, then you would be seeing negative power usage data on the main lines. As you aren’t noticing any negative wattage, this probably means you use all your solar instead.

That or your Sense is installed in a different panel than you think or your panels aren’t setup how they were described.

#20

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