Sum power consumption since given time

I installed the Fluxo a couple of days ago. I use the three sensors to get the energy consumption of the three incoming phases. I did not bundle them to one sensor reading, as I want to identify energy leaks.
OK, now I'm trying to compare the Flukso's kWh count against my provider's meter. For this purpose I wrote a script fetching the data with hourly resolution from flukso.net for all three phases since my last reading (20:00 28.01.13) with some simple awk additions to these readings.
A day later Flukso's reading was 10% under, 3 days later Flukso matched ok, but today (6 days later) it's reading is over 30% over (provider's meter: 82, Flukso: 110).
Obviously, I'm doing something wrong. Is there anybody with a similar script, just to give me an idea how to do this right?
The monthly dashboard gives me plausible results, but I need midnight readings for this.

michi's picture

Do you have any reactive loads? Fridge, air conditioner, switching power supplies? The difference in readings may be due to the power factor.

Michi.

holgerG's picture

Sure I have some reactive loads, but I don't expect them to have this much influence. I will go more into details with my calculations as soons as I've time to do so.

the_roggy's picture

30% difference is a lot on the entire load... but I have one 60 cm TL light in my house, and it read 80W using the clamps... and 25 Watt using a DIN kWh meter.

I had a look around on the the internet, and apparently a cos phi that bad is pretty regular with normal, cheap TL lights... even if you have just a lot of TL lights... it could make a difference...

Still... 30% on your entire consumption is a lot...