I installed a sense Flex 400A almost 2 weeks ago. The first few days ,sense matched what the power company listed each day usage. After about 5 or 6 days it began not matching (4kwh less than the power company listed for each day usage). I have checked and rechecked the Ct’s to ensure they were still clamped with no obstructions. Today and yesterday it was 2.5 kwh off. It doesn,t seem like much but it adds up and it really doesn,t tell me where the “extra” power is being used. Sense has detected my Stage 1 AC (not stage 2 as it looks to be in the other bubble when it kicks in) refrigerator, hot water heater,microwave,oven (not stove top). My question is, should I just start all over or just reset the data?
At first it was spot on, but then it began not logging all power use. Really weird.
Interesting. Sounds like you are comparing daily Sense vs. daily Utility ? My take is that you should do a little more investigation before reseting.
You might have already read this, but it gives a good idea of expected accuracy as well as the reasons why people weren’t initially seeing a high-degree of accuracy WRT to their meter (everything from a hidden additional sub-panel, to estimated reads by the utility, to reversed billing with the townhouse next door).
One useful thing to try would be to compare hourly usage if your utility provides that data (min provides 15 min data). A time-of-day based discrepancy might give some clues.
Does the power company reset its data for collecting daily usage at the same time that Sense starts calculating daily usage? I have been using sense for a few years and and two different countries with two different grid voltages and Sense has always been within a few kwh of what my billing cycle was. My last two bills were both within 4kwh of what Sense said I used and this is because of the time of the meter reading by the electric company and the fact that Sense calculates per day and rolls over to a new day at midnight for your given location.
Thanks for the reply. Since it seemed just sensible to reset and restart Sense, since it has only been used for less than 2 weeks I did reset it. I also moved the CT’s. They were placed initially “after”the 200A breaker in the panel for the house. It looked almost impossible to connect them in front of the breaker as there was not much room. I did get it to work. I moved them before the 200A breaker. I also disconnected the other set of CT’s (400A Flex) as the panel it is feeding is still utilizing the same cables from the power company on what appears to be some type of Bar? as the first set of CT’s that are now in front of the 200A breaker. I feel this description is confusing but it is working now and I will have to wait for items to be found again.
So in conclusion, I have a panel with 2- 200A breakers. One is for the house and the other is for a shops. I reconnected the house CT’s and disconnected the shop’s CT’s. I tested the power usage from the shop and saw a spike in power use when I turned on the compressor in the shop. So it is registering power use, albeit on one set of CT’s.
It sounds like you have moved the main set of CTs ahead of both parallel subpanels ? That’s how I’m set up as well, but it took some work. Hoping you’ll see good and accurate results and the same good detection history ! Sounds like you will also have a spare set of sensors to use for dedicated circuit monitoring, and/or future solar.