I have just bought my first emonPI and my first emonTXv3.
Both have the standard AC to AC adaptor.
The emonPI shows the mains voltage as 235-237V, with the adaptor plugged into a socket which is 2 feet from a consumer unit and itself 6 feet from the main consumer unit and Henley block.
The emonTX shows the voltage as 254V. It is plugged into a 30 foot extension lead from a socket off the main consumer board. there is nothing else plugged into that lead.
Is this an expected level of difference between the two devices? 10% seems like a high inaccuracy to me and I therefore wonder whether something is faulty.
Re: Mains Voltage Consistency
I suggest you read the pieces in Resources about manufacturing tolerances and calibration.
Re: Mains Voltage Consistency
thank you - I have read pages on the subject. What is unclear to me (a newbie) is how i actually access the parameters it suggests i adjust. the GUI for the emonPI has the EmonHub page to amend certain parameters; the ones we would need to change are not there for either the emonPI or the emonTX.
As a newcomer, it is really hard to find out where to go to find that basic information. any advice would be welcome.
Re: Mains Voltage Consistency
For the emonTx, everything you need to know to calibrate it is spelled out in detail in Resources > Building Blocks > Calibration
For the Pi, changing the numbers in the "scale = " line of emonhub.conf will work, but you cannot access the phase error calibration that way. For that, you need to change the sketch - see your other thread.
Re: Mains Voltage Consistency
Hello Averyone
Complete newbie so please be gentle ;-)
Installed emonTX V3 with 4 ct clips on my weird system (solar, grid, etc)
Most is running smooth with the pi and emoncms on my webserver ... all is communicating and I'm mostly with the RTFM problems as every newbie. Only thing that is bothering me is the voltage returned from the ac adapter on the emontx.
Let me say all hardware is brand new ordered here and I just plugged everything. I did read most on this forum regarding voltage and calibration but is it normal that the adapter shows on average 15 to 16 V above grid ? I can understand a few volts but that much ?
We have fluctuations over a day from 230 to 246 (rural) but the reading on emon shows on average 16 to 16V above ...
I understand already that there is no simple/quick way to solve this except the calibration process and reprogramming the emontx ?
thanks for the feedback
Re: Mains Voltage Consistency
You've done the RTFM bit about calibration, component tolerances and the voltage input, but you don't actually say what you've bought. Judging by your name, I'm guessing that you have the Euro adapter ( 77DE-06-09 ), and that requires a slightly different calibration constant to the UK version, which is the default value in your emonTx.
You could either calibrate your emonTx (this is the 'correct' solution), or you could change the "scales=" value in emonhub.conf so that emonCMS displays the correct voltage. Changing the number for the voltage will leave the power wrong (because power is calculated in the emonTx), so you will need to change the number for the power(s) also.
Re: Mains Voltage Consistency
tue forgot to give the full details
In France so yes Euro adapter ACACEU euro plug. And you do confirm my best guess, learn to compile etc .... But I'm going to take it step by step. As I know Voltage is on average 15V higher then real ... that's not a problem, power is not best possible neither but I can already learn ... Once I feel confident enough I'll attack that little emonTx thing though I need to figure out how to attack it from a Mac .. first thing to do is to get the adapter to USB ....
But for now I let it gather data .... and I'll play with widgets/visualisations ... there is already quite some to do there
Thanks Robert
Re: Mains Voltage Consistency
You can do the emonHub.conf editing via your web browser! That is why I told you that method.