User-Calibrated Voltage


#1

Provide the ability for users to designate a voltage offset value to calibrate the voltage to a locally measured value. Example: Sense device reports 125v, but measurements with multiple other trusted devices measure 119.5. User would designate -5.5v as a calibration offset.

Sense apps would use this offset to calculate the wattage more accurately (live displays, historical reports and graphs). Raw sense data would remain unchanged (therefore no need to start over with device detection, etc), but this value would simply make the displayed/reported data more accurate. Of course, all the reporting apps would need to be modified to be aware of this offset…but that would be just a 1-time effort.

Requesting this because my Sense monitor overstates the voltage and also the wattage and kWh values. This seems like a relatively simple way to resolve it without costly hardware changes and without the need to start monitoring/discovering from scratch.


#2

That is strange that you are seeing this as I identified this problem several months ago and they issued a fix for it. I wonder if your unit did not receive the fix.


#3

It sounds like @joe 's issue is the opposite - where his unit is reporting more than he is actually seeing at his voltmeter.

The question then is whether the 119.5V reading is at the mains where the Sense is reading or at an outlet.

The second question is whether there are correctly calibrated units that came out shortly after the “fix,” which also got that software-side adjustment effectively making them over report.


#4

My bad, I read that the wrong way. You are right the issue I had Sense was showing a lower voltage at the panel than multiple meters showed downstream which violates the laws of physics. As far as new units, my replacement unit seems to be correct and I assume it received the patch just like any other unit.


#5

My voltage variance is at the mains. Same voltage also on an outlet that is 1 foot from the panel. Of course it’s always varying slightly and it’s hard to tell just how realtime the Sense voltage display is in the app, but it’s in the neighborhood of 5v+ overstated on Sense. And the daily usage reported by Sense vs electric utility is appx 4-5% over as well (that’s why I presume the wattage is overstated).

I have the latest firmware so if that was where the issue was resolved I should have it already I installed appx Nov 16, 2016.


#6

The voltage reported by some Sense meters (early production run) is set to be higher than what the actual voltage for a reason. Basically, my understanding is that there was a calibration error during production, and as a consequence, power use (watts) was being under-reported.

To compensate for this and properly calculate power draw, the voltage detected by Sense was set at being higher than what it actually is (because Power = Volts x Amps).


#7

To provide a little clarification, there was a calibration error in earlier units that was corrected. It should not, however, have made your voltage read 5V more than your actual voltage.

@joe, with your permission, we’d love to take a closer look at your monitor’s data and see what may be going on. Let me know if you’re okay with this!