EmonTX4 with 3 phase VS, but single phase code

I just finish to install my 3phases setup, so I have a 3phases EmonVS, an emonTX4 and a emonPI.
The system seams working fine, I upgrade TX4 with the latest version, and configure the CT with what I have
3 100A for the main house supply, and 3 50A for some line.

But even that it’s not a 3phases code on any product, not yet available. how can I solve the issue of having some measure in minus instead of positive measurement.

Components: Emoncms Core v11.3.0 | App v2.6.10 | EmonHub Config v2.1.5 | Dashboard v2.3.3 | Device v2.2.2 | Graph v2.2.3 | Network Setup v1.0.2 | WiFi v2.1.1 | Backup v2.3.2 | Postprocess v2.2.7 | Sync v2.1.4 | Usefulscripts v2.3.10 | EmonScripts v1.6.7 | RFM2Pi v1.4.1 | Avrdude-rpi v1.0.1 | Emonhub v2.5.5 | EmonPi v2.9.5

You cannot. Whatever you do, the numbers for phases 2 & 3 (those NOT being measured by you single-phase code) will be wrong - because although your emonVs has access to the 3 voltages, the version of emonLibCM that you have cannot measure the other two voltages.

For a VERY approximate correction, multiply everything from phases 2 & 3 by -2.0 This will be a reasonable approximation for purely resistive loads, badly wrong if the power factor is not close to unity. (Look at a phasor diagram of the 3 phase voltages for your explanation - the other two projected onto the phase 1 axis are opposite (negative) and half the length of the phase 1 phasor.)

Remember to put everything as it was when the new library arrives. The good news is, it should not be long now.

Thanks, that what I was thinking. so I’m gona wait; I just plug my system, so if it’s not accurate for now it’s ok.

Did you know how the system will know which CT is on which phase ?

This is for you to determine from the wiring colours or numbers.

If you have a standard 3-phase, 4-wire system, then as long as you assign the current’power channels to the correct voltage, you will read the power & energy correctly. Unlike the emonTx V3 “approximate” 3-phase sketch, phase rotation does not matter, it treats each pair of current and voltage as a single phase.

Therefore, you must still know the phase of each circuit you are measuring, so that you can allocate the correct voltage to it.

Ok I understand the part of the association of the CT with the phase I know which is where. But that will come with the 3phase version of the TX4 software right ?
Because for now I can’t find where it’s suppose to be.

If it’s any help, I sent Trystan what I think is a working version an hour or so ago. I need him to check it on a real 3-phase supply before releasing it.

I don’t understand what you mean. The version of emonLib that I think you are using simply does not read the 2nd & 3rd voltages. It needs a very different library (internally) to do what you need.

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Ok thanks for the input
I understand about the emonLib.

Any news on the 3-phases version ?


I have no news, I don’t know whether or how far he’s got with testing it. I live in an ordinary UK house, with only a single phase 240 V supply. I understand the Megni workshop has a 3-phase 240/415 V supply, and he has done some initial tests.