Reset of Energy calcs after deleting history log?


#1

Currently, I only log locally to my new Iotawatt unit, and read graphs using iotawatt.local. Yesterday, I finished hooking everything up and was happy with the readings. I then deleted the current and history logs. Now, I see that the accumulated Energy readings do not start at 0kWh. I monitor two sums Ph1+Ph2+Ph3 (main fuse, 3ph system) and sum of individual user loops. The sum of users should be a bit lower than the main fuse, since I have a few non-monitored loops.

I expected Energy for both of these to start at 0, but the main fuse starts at 239kWh and the sum of individual fuses at 90.5kWh. The difference is du to wrong hookups during installation period. But why were they not reset to 0 yesterday?


#2

Generally, it’s not a good idea to delete the logs. It’s better to look at the change in kWh over a period. Using the fixedxinterval and delta options in graph. For instance, here is my total kWh use over the past year, by month, with heat-Pump and hot water. Note the settings. You can set these up and save them for quick future use.

But back to your original question. You probably used the /command?deletelog=current and /command?deletelog=history to delete the logs. When you use uithervof those, the IoTaWatt restarts immediately and rebuilds the deleted log, using the totals in the other as a starting point so that they are in harmony and can be used interchangeably to retrieve data. A record of usage at a two minute interval in the history log must have the exact same total for each input as the corresponding current log entry.

So if you really want them both to have a zero starting point, you need to delete them simultaneously using /command?deletelog=both


#3

Thanks a lot, all of this very useful! I am on the flat part of the learning curve still, expecting to enter the steep section soon.

The reason why I want to start with blank log right now is that I logged just a bunch of c**p during the first days, and will forever need to filter these data if they persist. In general, though, I fully agree about the principle of sorting and filtering. Thanks again!