Long story short. I’ve had an emonPi and emonTX running for some years now, feeding a table on the wall in the kitchen. After upgrading a while back, I lost all the power readings from the emonPi, but those from the emonTX were fine (via wifi). After much perusal of the forums, I eventually found that the baud rate had changed (to 115200), but my install had not. It also took some time to find the correct emonhub config for node 5 (the emonpi), and that’s all ok too now.
It was clear that my understanding of the ‘input’ section of EmonCMS was severly lacking - I couldn’t find clear info that this will auto-populate - I’ve lived with multiple pages of empty readings that I guess were pre-populated when I bought it - I’ve now deleted everything and ony the active readings are there (great).
OK - a question. In the Admin section of EmonCMS it says I’m running “emoncms core Version: low-write 11.5.6”, but on github Releases · emoncms/emoncms · GitHub it says the latest version is 11.4.2. I’m confused.
The other question I have is about the difference in power reading between emonPi and emonTX on the same cable. I’m using the original supplied blue clamps (although they may have been swapped around) from openenergymonitor. One says 392W and the other says 477W. One is always 20% lower than the other. Any thoughts on that.
I did read a comment that suggested all the latest information was available in this forum, but perhaps the original documentation on openenergymonitor.org could have a couple of comments to that effect.
Finally, I appreciate all the hard work that goes into this system, so thank you.
20% is close to the absolute worst case you can have by virtue of component tolerances, it’s not usual to see that much difference, even at a power as low as this - remember you’re at 2% of the full-scale reading, and c.t’s are inherently inaccurate at low power. Your YHDC c.t. is specified at ±3% linearity, but only down to 10% (2.4 kW as you’re in the UK). Have you any idea what the correct power is? Is it still 20% at much higher powers, or ‘only’ 85 W?
The first thing I’d do is check that the mating faces of the ferrite core are scrupulously clean and seating together with absolutely no possibility of an air gap, and of course make sure both halves of the core are intact and not cracked.
If everything appears OK, did you ever calibrate either the emonTx (which version?) or the emonPi, either in the device itself or in “scales = …” in emonhub.conf? Are both reading the mains voltage correctly?
Yes - you can always delete entries on the “Inputs” page, they’ll pop up again as soon as valid data comes in.
If only you knew how easily useful stuff gets buried in the forum, I think you might revise this view,
Thank you for your suggestions. With my glasses on, I could see a foreign object in one of the clamps. With that removed, I am now seeing a fairly constant 20W difference (at different power levels) between the two clamps, which is I expect more normal.
I’ve not done any calibration and it’s an emonTX3.
The Vrms readings for the emonPi and emonTX3 are 252V and 254V (a little higher that I expected). I am using USB power on both, with the power block for voltage detection.
There was a second question in yesterday’s post (as the title suggested).
“In the Admin section of EmonCMS it says I’m running “emoncms core Version: low-write 11.5.6”, but on github Releases · emoncms/emoncms · GitHub it says the latest version is 11.4.2. I’m confused.” I’m probably showing my lack of knowledge here (again).
I’m afraid I can’t help you with emonCMS versions. There seems to be no rhyme nor reason to how the various versions and releases relate. One of my emonCMS here says “low write 11.4.5” across the bottom of the screen, and for the “Version” and “emonCMS core” in System Information on the Admin page, while the download version is emonSD-10Nov22. The other says it’s “low write 11.4.11” and the download version is emonSD-24Jul20. Yet if you look here: emonSD Download — OpenEnergyMonitor 0.0.1 documentation, expand the top item in the list of versions (emonSD-01Feb24) and diligently scour the screen prints, a long way down ( 2+ screens-full) you’ll find
Emoncms
Version : low-write 11.4.11
so it looks as if you’ve found yet another case where “Latest version” isn’t - which is why I don’t trust Github. I’m sure it’s of some use to somebody, but I’m too long in the tooth to waste days and weeks trying to find out what use it is. I’m afraid I’ve no idea where your 11.5.6 version has come from.
I don’t always create a release that shows up in latest as changes can be minor, that said it’s been a while so it’s probably about time I did another release
