Sense is under reporting usage


#1

Don’t know if this is a case of the issue someone else brought up as solar causing under reporting of consumption or something different.

Right now my systems shows the following:

Solar - 6792 watts

Unknown motor 214 watts
Kitchen Fridge 199 watts
1st floor Fridge 109 watts
Unknown 61 watts
Always on 68 watts

The problem is I am on my computer system right now and the Kill-A-Watt meter it is plugged into is showing usage of 285 watts, which is significantly more than Unknown and Always on combined :frowning:


#2

Always On is just a number though, it doesn’t actually represent any “current” usage (pun intended). It is a display of the average draw from the past 24 hours (or some measurable amount of time, hypothesized to be 24 hours). Could it be the Unknown Motor and Unknown? That gets you pretty close to the 285.


#3

While you are correct about Always on I believe it is balanced out by unknown. What I mean is Sense measures the total draw. From that number I believe it subtracts the identified loads and the Always On and the remainder is labelled as Unknown. My computer is normally in the unknown portion, that was the issue here as while it was on there was not enough power in Always on plus Unknown to account for it


#4

I’m not sure about that. I don’t think it does any math with “Always On” for “Unknown”, though I may be wrong. My understanding is Always On represents an average of the draw that was unattributed to devices within the last 24 hours. Unknown is the current draw of things that it thinks are devices (just unable to determine type). Since one is an average, and the other is the current draw, I don’t think they are related.

This furthers my questions about Always On. I really do wonder what happens if a device runs for more than 24 hours. If that was an identified device, does the power consumption of that device get reported twice (part of the “always on” from the previous 24 hours, and part of the named device). Either that happens, or Always On can some how differentiate and subtract out the “named devices”, but that doesn’t seem right either. Maybe Always On subtracts out the Unknown, and Unknown somehow subtracts out Always On, how does that idea work with this scenario? Maybe your initial hypothesis of “Under Reporting” is true, and I’d bet if you caught it right, there are times when it over reports (though I have yet to see someone bring that to the table with graphs supporting the notion).


#5

I’m almost positive it works the way I said because typically when I add everything up it comes out to what the total is from the CT. It only makes “sense” to do it that way. While you are correct that the Always on is some sort of a moving average I don’t think Unknown actually represents things that are running at the moment that are unknown. You have to have one degree of freedom for this to make sense. I believe that Uknown is just a fudged number to make the sum of the identified loads plus the Always on estimate come out to the total of what the CTs are reading. IT WOULD BE INTERESTING TO HEAR FROM TECHNICAL SUPPORT TO VERIFY THIS.


closed #6