Tree-phases 230V without neutral - to 3x mono 230V - Possible ?

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Johann PILARCZYK asked May 31, '23

Tree-phases 230V without neutral - to 3x mono 230V - Possible ?

Hello,

After quite a bit of research on the community in French and English, I can't find a precise answer because the idea that always comes up is three-phase with neutral and so the answer is "NO, that's not possible".
However, in Belgium, we also have 3x 230V without a neutral (it's impossible for me to install tetraphases, which many people also call three-phase but with a neutral).
My idea is not to end up with three-phase but to decompose everything...
From my 3 lines of APSYSTEMS microinverters, I connect to my three-phase installation. All my loads have been balanced as they should be (see diagram 1).

Wouldn't it be possible to do the same with the Victron devices? I connect them as if they were single-phase, and the loads are distributed for each Victron device as if they were in my electrical distribution panel (see diagram 2).

Thank you for your answers and suggestions.

Translated with www.DeepL.com/Translator (free version)

installation

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matthias-nagel commented · Sep 15, 2023 at 04:47 PM

Are you sure that you don't have a neutral? A would assume that what you designate as "PE" is actually a "PEN", i.e. a combined protective earth and neutral wire. From my training (but that is 20 years ago), I learned that Germany and most northern European countries have a so-called TN-C-S net, while Spain, France but also parts of Belgium use TT (see https://en.wikipedia.org/wiki/Earthing_system#IEC_terminology).

What voltages do you read if you measure between Lx and Ly (y,x = 1,2,3) and between Lx and "PE"? Do you get 400V/230V? Or do you get 230V/132V? If you get the latter, you are out of luck, but that would be rather odd. I bet you get the former.

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Alexandra answered · May 31, 2023 at 08:23 AM

@UUSSPRL

The answer is no. Because the Victron inverters reference neutral.

What you are describing is a delta connection. While victron support delta loads they cannot use the delta connection for power.

It is stated clearly in the online training in Victron professional and in the three phase manuals.

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Answer 1 · 2023-05-31T08:32:42Z

Johann PILARCZYK answered · May 31, 2023 at 08:32 AM

Hi Alexandra,
I've seen the online training and the problem is that's always speaking about 3 phases with neutral.
With my 3 phases without neutral, I can make 3 mono installations.

The Victron appliance could'nt be installed in mono ? With L1 & L2, I have 230V mono, like L1 & N for 3 phases with neutral.

Why it should'nt work ? All my device in my house are mono (except my electric car) and all works fine.

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Alexandra ♦ commented · May 31, 2023 at 08:40 AM

Because the way the units are designed and built (even some of the safety mechanisms) they need the neutral.

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Johann PILARCZYK commented · Jun 02, 2023 at 09:30 AM

Hi Alexandra,

In my other post in French, Michele write me it was possible.
The idea is to come from 3phases in the fusebox and from there, making 3 times mono 230V (like my other house devices) balanced connected to 3 separated circuit breaker of 40A. Then from them, go to each Victron appliance in mono 230V. From solar panel it's already in 230V mono, then each line solar panel for each Victron.

If you always not agree with that (you are actually better than me about Victron products), could you tell me the difference between separated 3phases without neutral that give 230V mono and mono 230V ? The PE (ground) cable always connected and separated from the 2 other cables (see scheme)

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Alexandra ♦ Johann PILARCZYK commented · Jun 06, 2023 at 07:20 PM

@Johann PILARCZYK

I am going to say I have never tried it, I do know that if a three phase installation done here looses neutral reference we get 380V and all our safety goes down, so not good. The only way to get 230 is between line and neutral.

Some guys have and do connect two lives to their inverters (230v between the two) so do not have the ground relay engaged ever as the case of the inverter goes live when inverting. (it is not a supported set up.)

Then there is a way with a zig zag transformer to create a neutral. Again I have no personal experience with the set up, just theory for me. The best is contact a local distributor who probably has more experience with your Grid needs.

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Johann PILARCZYK Alexandra ♦ commented · Jun 07, 2023 at 07:34 AM

Hi Alexandra,

In Belgium, there 3 installations possible depending on GRD. Mono 230V, treephases 3x230V without Neutral (delta), and tetraphases 3x380V or 3x230V with neutral (Y), also called treephases.

It's nothing really special, I have 230V between phases. It's all.
Thanks for participation to my question.
Have a nice day (or night) :D

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Answer 2 · 2023-06-05T07:41:56Z

gerardg answered · Jun 05, 2023 at 07:41 AM

Bonjour Johann.

vous pouvez nous contacter pour en parler, on est distributeur victron:

www.offgridservices.be

info@offgridservices.be

On aimerait tester ce montage pour avancer sur cette problématique, on a tous les jours des demandes et ça nous bloque dans notre développement... le mieux est de faire un vrai test.

Je pense aussi que le montage tel que proposé peut fonctionné... en tout cas pour la partie sortie, si on ne lie pas les neutres (phases) ensemble... mais peut-être que c'est nécessaire pour le bon fonctionnement de l synchronisation.

Je sais qu'en monophasé avec victron ça fonctionne sur du 3X230, même si quelques problèmes de lecture du voltage... on doit travailler dessus.

bonne journée

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Johann PILARCZYK commented · Jun 07, 2023 at 07:49 AM

Bonjour Gérard,

C'est tout nouveau pour moi. J'avais commencé à prendre des contacts avec Ysebaert mais ils sont restés sur leur acquis sur le fait que c'était impossible. Peux-être la barrière de la langue ? Mais en aucun cas, je n'essaie de recréer un triphasé en sortie. L'idée étant de rester équilibré avec les appareils comme cela devrait l'être avant l'ajout des appareils Victron.

Actuellement, je suis en contact avec un autre distributeur Victron. Comme c'est nouveau, je ne connais pas la valeur de leur service mais j'ai déjà eu un échange prometteur au téléphone. Je suis assez fidèle en business. Mais je note tes infos (parfois le stock est plus important pour contenter le client malheureusement).

Dès que ce sera d'application, je t'en ferai part.

Bonne journée.

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Answer 3 · 2023-09-15T12:49:39Z

tokke answered · Sep 15, 2023 at 12:49 PM

@Johann PILARCZYK
Did you find a setup that works?
I skipped victron for this reason and have my doubts about my current setup. Wish victron was more helpful about this.

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Answer 4 · 2023-09-16T15:43:50Z

sharpener answered · Sep 16, 2023 at 03:43 PM

From other postings the clue is in the instructions that the live and neutral connections cannot be interchanged. I think this is because at start-up the grid sensing and/or earthing relay tests the voltage between the neutral connection and ground, in the 3-phase delta system this will be ~133 volts so it will fail the tests and not connect to the grid.

This is consistent with what @Alexandra says above about it working in an unsupported configuration with the case live while inverting (!). I do not think a zig-zag transformer will help, it would create a neutral point OK but then you would need 3x 133V input inverters in a star configuration. Not sure if the 120V nom inverters will cope with this voltage.

Having installed a 3-phase laser scanning system in Mons/Bergen in the '70s I have long known about this particular setup in Belgium. Personally I am surprised that Victron do not have a solution for this market.

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