Hi All,
I found a forum post explaining how to setup inputs to record grid import / export when setting up the emonTX v3 in a 'type 2' Solar PV installation.
However I'm having some issues with a couple of my feeds that I hope you can tell me where I'm going wrong. This is my input configuration for my CT clamp on my mains line;
+ input: 2 is my Solar PV CT clamp which reports the correct values.
The allow negative check seems to be working with the PV exported figures reporting correctly. However problems are introduced from the first Allow Positive, where Power Imported always has a 0 value.
Subsequently my values for Household Power Consumption always report the same as the PV output because the +input: 2 has just taken 0 + Solar PV.
Can anyone suggest what I'm doing wrong?
Thanks,
James
Re: inputs not behaving correctly
Hi James, using "allow negative" effectively withholds positives so when you then use "allow positive" it will withhold the negatives and allow the positives of which there are none as they where previously withheld by the initial "allow negative".
As the result at line 6 will always be 0 you can leave lines 1-6 as is and introduce "add input" 1 and then filter this with another "allow positive" this will have the desired result. I don't think you need the "allow positive" at line 11 so you could just move that up and just add the "add input 1"
Paul
Re: inputs not behaving correctly
Hi Paul - thank you so much for taking the time to help. I think you've nailed it on the head. So far it seems to be behaving as expected though I'll need to wait for tomorrow when the sun comes back up again so I can generate some -ve values on the grid :)
The whole input processing side of things doesn't appear to be well documented so for a newbie it's all very confusing :)
Thanks,
James
Re: inputs not behaving correctly
The documentation is a little thin in places, but it is a difficult topic to document and the best way to learn is to just dive in.:-)
To help learn & debug I created dummy feeds in each input process that i could move up and down at will to expose the values in the process lists eg debugGrid, debugSolar etc
Looking closer at your original process list I don't think you are going to get what you are expecting.
"Household Power Consumption" is only going to report import + solar without any consideration for export.
Maybe on the solar input process list you should add input 1 and log to feed "Household Power Consumption" instead, Solar + Grid = usage regardless of whether you are importing or exporting as export is a negative value.
Paul