P1 Meter - Wrong Daily Return values?

[baustromverteiler]

Hello Everybody!

I just integrated a solar setup into domoticz and I'm reading power consumption/return directly from the smartmeter. The Smartmeter is a Landis&Gyr E450 which is connected via M-Bus to a Raspi Zero running a pyhton script that sends the readings via MQTT, the readings from the Meter are processed in Node-Red and then send via a JSON update in the for the P1 Meter expected format (so Usage2,Usage1,Return1,Return2,Con,Prod) which works as expected.

While my "Today Consumption" is shown correctly the "Today Return" shows a total different value thats way too high, also I have no idea how it's calculated:

I was thinking maybe it's because my Usage 1 / Usage 2 values are in the wrong order, but then the calculation of the consumption also shouldn't work? I'm not too keen on correcting my Usage 2/1 errer becaus there's already about 2 years of consumption data in the database.

any hints appreciated!

[waltervl]

You better check your Node-red calculations. Usage2,Usage1,Return1,Return2 should be in Wh.

Edit: Could also be that your smart meter already did measure from the past and put that in today as first value and that tomorrow the normal expected values will be shown.

[willemd]

This is a very recent addition I assume ? Since your return2 is still zero, so no return yet during a weekend?

The overall return value on the icon does add up with the return values shown in the device list (so the domoticz calculation seems o.k.), but it already seems to be a very high value, so not only your today value but also your overall value seems too high. Somewhere your feed seems to be wrong.

It also noticed you have two values displayed on top of the icon. Don't know whether this has anything to do with it. I only get one value, i.e. the nett return or usage of that moment.

[baustromverteiler]

walterevl: thanks I'll check that! from the top of my head the meter shows around 13 000 kWh consumption so I think the readings are already in Wh

willemd: yes the addition is recent, after having some problems with wrong data formats I manually deleted the values from the DB. My power company seems to use only Return1 for return measurement, regardless of the weekday. Consumption tarifs change from 1 -> 2 at 10:00 pm so maybe it's the same with production.

I think the two values displayed on top of the powermeter have something to do with on which phase of the 3 phase setup power is consumed, so eg. two phaeses are returning power while a appliance on the third phase consumes power two values show up. As the smartmeter is balanced / cumulative that shouldn't matter in overall electricty usage.

[willemd]

Manual deleting from the database might mess up the daily switchover routine and the calculation of counterToday(), depending how and when it was done. Maybe you need to wait a day to see whether it corrects itself. You can also inspect the values in the devicestatus, multimeter and the multimeter_calendar table to see whether those explain the current calculation.

[baustromverteiler]

I think I've found the issue. The smart Meter outputs the return as 123,45 kwh, but when the last digit is a 0, as in the jump from 123,99 to 124,0 the output is one digit less which I think causes a wrong return value display because the value is calculated from yesterdays return + actual daily increase in return. Screenshot is in the attachment ... I need to think about how I'll solve this issue ... maybe just use 4 digits instead of 5 instead the first hand?

[waltervl]

Just multiply the result by 1000 and it should give good results in Domoticz. Do not try to add extra zeros to get from kWh to Wh.
123.99 * 1000 = 123990 and 1234.0 * 1000 = 124000 so matching values.

[baustromverteiler]

Thanks, for pointing out the obvious, apparently too late for my brain yesterday to function properly ... Today the return meter shows correct values, looks like this did the trick!