Oscillating on a delta grid connection (3x230 without neutral)

DIY
22

Good evening,

Belgium is not the only country with a Delta power supply, e.g. Norway as well, etc.

When you want a Victron install you need a neutral, so, how to do that?

Easy, a bi-directional autotransformer (Delta/star config), see link, these can be purchased actually quite cheap, 12Kw for 400-isch euro (they have many scalable models, one certainly will fit your install), and bomb proof,

https://adajusa.es/en/single-phase-and-three-phase-autotransformers/4466-three-phase-230-400v-125-kva-reversible-autotransformer-with-box-8435532844662.html

As can be seen from this site, delta goes in and star comes out, and yes they work on 133V in and 230V out as well and bi-directional, just send a mail to that company with your desires and the issue is solved, Victron works, net meters work, etc, many colleagues of mine have those in Norway and yes, with Victron (and other inverters), no issues at all.

Regards, Jeroen.

23

it costs money, it produced heat - for what reason?

12kW - thats 4 per phase - for many way to less

24

Good evening,

@kr0815 , You didn’t look at the site, this is a three phase trafo, they have them up to 160Kva and can make what you want, they hardly produce heat (no fan needed on the casing btw) nor have significant losses, we install these all the time, please check the site, and if wanting to know, send a mail to them…

Regards, Jeroen.

25

You are correct. If there are money and space, is indeed best solution. Can be archived something “good enough”? Yes, it can. And that is what I’ve tried to prove.
Also as per kr0815, does the gain cover the effort? Not me to judge.

26

a transformer always will have losses - if there is no need for it, why install it?

Be also aware of the transformation losses:
Example: a 2:1 Transformer - theoretically 230V-115V - in reality 230V - 112V - so far not mission critical

But now the PV System needs to feed to the net - 110V - 225V - to low , Inverter has to raise the voltage, shuts off

(Values are just an example)

27

Hello, I use an elgris P1 meter in combo with the official meter from fluvius in Belgium. It gives the correct power management to the cerbo as it is the same of my invoice of fluvius. I’ve tried all meters and they all given a wrong power result to the cerbo as the cerbo get or an 0 volt on one phase or 135v on the 3 phases. The cerbo use only the total power of the elgris p1 which is correct because it is the same one of the fluvius meter. It works very fine. I’ve also have 2 pv converters on ac in. Not good for a good balance between the 3 phases with mono out but I connect my heat pump,… to the same phases. Further I use node-red to decrease the power current to load the battery as at night this cause unnecessary power from the grid to the battery and so on to the devices.

28

@maarten16 If you say this meter is recognized by Victron, then that would be a good solution indeed.
The L2 0 V and 0 kw, is indeed correct and is as such indicated in the manual of the meter.

Personally, I can’t go for this solution, while my wife would go in near future for an electric car on her company. Then the connection shall be after the official energy meter, but before a meter which would give a decent reading that PV, Victron and batteries would work with.

So, you see… each house has particularities ….

But, back to your proposal. Yes, for those interested on use of energy private only, would be probably a good solution.
Many thanks for posting your experience.

29

AC in only means the same 2 phases as the MP2 - your system will also work if PV is connected to other phases

why can´t you just use a power meter that counts what goes into the car?

My company pays my car energy costs with my official supplier price, regardless if the power was from the net or my PV system

30

Good evening,

@kr0815 , Most Adajusa (and many other brands) bi-directional transformers to make from a Delta a Star have only 0.3-0.5% loss, that’s nothing, your inverter is way worse keeping it on Delta, mostly 3-5% less than on Star….

It’s cheaper and better for your inverters to have a Star connection, Victrons need a neutral, point clear, and such cheap transformer out ways the extra costs and hassle you have with all kinds of secundaire equipments and the terrible efficiency of your inverter on Delta.

That’s why we installers put these trafos, cheaper overall, no hassle, no special equipment, single and three phase alike, more power, etc.

Than, payback time between Delta and Star, this is about 4% improvement and will last for ever, calculate it with your power, and this trafo is payed back in mostly of the systems in about 1-2 years only, so, also financially the best option.

Secundaire equipments are never improving efficiency and are extra initial costs which takes way longer to be payed back in the overall investment, but a trafo will!

Regards, Jeroen.

31

sorry, i don´t get what you are trying to say

I understand you from the side of an installer

But it´s mot done with the transformer, it needs cables, screws, time,….

What will you bill the client fpr such a transformer? what is the financial benefit for the customer?

32

I dont see the point of putting the MP on a transformer just to have it connected to a neutral. The gridmeter will still measure delta values.

If you really want to make it correct, you would need to use the transformer on the grid input, then put everything including gridmeter and house/loads behind it on 3x230/400 with N, making a rewire of the entire house necessary to convert it to having a neutral now.

33

Hey, thx for the reply. I’ve also have an evc and I use the charger from victron. It’s also on the ac in and it’s work fine in combo with the net/grid meter elgris p1. In case of the victron charger you don’t need an extra energy meter. In case of another charger you can use an em24 for instance and in particular you can put two phases through the evc energy meter and the 3 one directly to the charger. For the car it does’t Mather if you use 2P, 3P, 3PN. So as long the netmeter gives the correct power and with a delta net the load is good balanced, it will work fine. Best Regards.

34

Good evening,

@kr0815 , no you do not, just a minor change in your main switch board, that’s all, 5 minutes work, and maybe less than 10 euro on materials, I really give up, as so many of installers here, you buy equipment without planning nor asking a Victron distributer and/or installer and then, when it doesn’t work, post here…and then complain.

We help, utmost, as much as possible here, install facts, rules, laws, instruction manuals, etc, need to be followed first, if you do otherwise at first your warrantee is lost, your insurance company will not pay out, and worse something might get fire.

Regards, Jeroen.

36

Fair question. For now, I do not have a clear picture how this car charge tarif works. So, I will decide when the time comes. As personal intention now is to keep battery for house only. But, time will tell. I might change my mind.
I fully agree that official meter has more stable reading of power (rather than installed EM540) and using that data for victron would solve a lot of problems in power management. I just need to build an arduino to interface with Victron, as one of my topics on this web site. It will take time.
Moreover, I have a hot water boiler using excess / export power to make accommodation hot water to spare gas. So, energy from battery would have a different purpose.
You see … complicated equation to put together… And again general rule: there is no one solution to fit all… :rofl:

37

On the manual of official energy meter L2 voltage is mentioned as 0. Also there, it is mentioned that the meter is taking L2 “as reference”. In same time, any so called official answer from Victron on how to connect a Multiplus on a 3x230 without neutral network, it is always mentioned L1 to L and L2 to N.
Question: have anyone tried to wire up electric panel in sequence L1-L2 and L3-L2 (no connection L1-L3) and use an external current transformer for Multiplus. Would that tell to Multiplus cumulated current so it shall compensate that at all time? Is the system better in stability and compensation with ESS?

grid-connections-3-phase-meters-behavior-of-p1values.pdf (807.7 KB)

38

Got it stabile and with all 3 phases indicated.

What I’ve done is below. Also somehow in line with above document.

So, I’ve started from the principle that L2 is reference and set PV inverter and Victron on same phases. Also, aligned with Victron recommandations: L1 to L, L2 to N. (Yes, if your cables are not colored as per standard (in my case also not) I took first wire coming from official energy meter as base of being L1.)
Then I’ve checked my electricity incoming and defined the rotation. I needed to arrange the incoming lines. With this, also the meter connected to Victron correctly reported L1-L2-L3. (Before the work, was L1-L3-L2).

Then, took time and calm, I’ve checked the phases used by PV inverter and also by Victron. And here is the trick. I’ve made them to be the same for both units.

Then, I’ve started the PV and let him start completely. (~10min)

Then, started the batteries and Victron.

Set reading of meter for all 3 phases: At Integration set the meter as Multiphase. PV inverter linked to phase L1, as is in real. At ESS - Multiphase regulation. (MP-2 would report as alarm Phase rotation unknown. Probably this one is ok, while I have single MP in the net.)

I could not believe it. It is running for several hours already and it does stay nice. Also now is balancing full power.

Conclusion: Instability in 3x230 without neutral would come from the fact that PV and batteries are actually fighting each other, as being on different connections. Check and correct the connections. Make them exactly same. Start one unit at a time. Happy days!

PS. A resistor of 120ohm on EM540 side might help for stability.
For now, settings of EM540 are reset to default each time modbus protocol is restarted (restarting Multiplus or reconnecting USB to Multiplus). I am in discussion with Carlo Gavazzi how to solve.

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39

Wife cooking test passed. System stabile.

Case closed.

40

Powering a 1-Phase Device in a 3 Phase System- regardless if Star or Delta, it doesn´t matter what is L1, L2 or L3

Only the MP2 has to be connected to same phase / pair what the meter sees as L1 - or just ignore everything, gibe the Venus System just total Watt

41

ATTENTION!!!
Stupid of me.
Victron is using IP 192.168.0.1 to communicate with energy meter (in my case EM540).

Guess what. Most of routers on market have same IP (unless not changed by the user). And that was the case for me.
The main IP of house router was also 192.168.0.1.

And from here most likely a conflict with impact on EM540 reports to Victron and most likely the explanation of the oscillations.
So, keep in mind. Make sure that there are no IP conflicts in the house.

42

Dear @nickdb,
Any clue from where this discrepancy may come? (The discrepancy is for each day.)

It is not a big deal as what I pay is less than what Victron reports. Just asking. Yes, it is in a system 3P (3x230 without neutral).

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