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ac coupling

Phoenix Inverters with AC-coupled PV

I have an off-grid system with PVs and Phoenix inverters C 12/2000 working in parallel. I would like to add a grid-tie inverter to the AC output of the Phoenix inverters to increase power. What I have learned so for from previous discussions is that this should work, Phoenix inverter is the same as MultiPlus just without AC input for the grid connection and can charge the batteries? Is this right? If yes, then the 1:1 rule applies.

So this setup will work only with grid-tie inverters that support frequency shifting. How can you know if a certain inverter has this feature? I can get Fuji FU-SUN 3kW inverter or FUJI Microinverter 2kW at great prices, but I don't know if they support frequency shifting.

tuky asked
tuky answered ·

1 Answer

ESS Multiplus-2 AC-Coupling: Inverter on AC-Out 2?

Is it possible to connect a grid-inverter to AC-Out 2 on the Multiplus?

My idea is to save the EM24 compared to connenct the inverter on AC-In.
(Multi is measuring the currents but kick the inverter out if grid lost)

puitl asked
Sander Stolk commented ·

1 Answer

Groupe sans neutre sur Multiplus 2

J'effectue une installation solaire hors réseau, Multiplus 2 48/5000, RS Solar 450/100, batteries Pylontech US5000. Nous avons prévus un groupe électrogène de secours, je viens de constater que ce groupe (SDMO Kohler 6000 AVR) ne possède pas de neutre (les deux plots alimentent en 230), est-ce que le Multiplus 2 va accepter ces caractéristiques? S'il n'accepte pas, est-ce que relier un des deux plots à la terre pourrait résoudre la question? Il faudrait également que la protection différentielle de la maison fonctionne en mode groupe.

En vous remerciant,
Très cordialement.


jacques-v asked
jacques-v answered ·

6 Answers

AC Coupling offgrid with zero injection

Hi, I have an off grid installation with a DC Coupling via Victron Smart Solar, Victron Multiplus and OPZS batteries. I want expand it via AC Coupling, but until April there aren't Fronius Primo on market, for this reason I bought a Solax inverter.

Multiplus communicates to Solax increasing frequency, but I'm afraid this increase may damage the appliances or may lead to a malfunction of these.

I have a Smart Meter Chint DDSU666-D 80A 1Ph, it's an export limiting meter.

I want install it between the AC Out Multiplus and the house loads, so that it regulates the Solax according to the loads and no energy is sent to the Multiplus.

There are any problem with this configuration?

Maybe I could set the Multiplus to very low frequencies such as 50.01 instead of 50.20 to start the Solax output reduction, 50.03 instead of 52.70 to minimize and 50.05 instead of 53Hz to stop the Solax?

If I don't configure the Solax it will be regulated by the Smart Meter regardless of the frequency sent by the Multiplus, right?

What will happen when the Multiplus detects that the Solax has not stopped?

With my DC Coupling system, now I can charge overnight consume and batteries stay on float almost all day.

I attach a simple diagram.



kyuketsuki asked
kyuketsuki answered ·

4 Answers

Multiplus 2 ESS, Fronius Symo on AC-Out 1 and grid-lost: Symo turns off for 2 minutes


In my ESS with 3x MP2 and an Fronius Symo on AC-Out 1 the Symo turns of for about 2 minutes if the grid is lost.

After the 2 minutes it restart´s and run´s on the micro-grid of the Multi´s.

Why is that?
I assumed that the Symo is running without a brake in this case...

puitl asked
puitl answered ·

3 Answers

AC coupling on Multiplus II with micro Inverter

Hi Guys,

I am googling for long time now and maybe I just use the wrong key words or dont understand what I am reading, so I try to ask here. Maybe someone can help.

We have an Offgrid PV System based on Multiplus II, 3kWp Solar panels (DC coupled with Victron MPPT) and 10kWh battery from pylontech.

The setup works very good, but we want to increase the photovoltaik power.

The setup is installed in an old farm and the orientation towards the sun is not optimal, so we think about installing PV modules all around the area to get good energy all over the day...

Now the question:

It would be ideal if I could just take micro inverter for every PV module and couple them via AC coupling to the system. I know the 1:1 rules and so on. But I dont find micro inverters which support frequency shifting as SolarEdge, ABB or Fronius do.

Is there a working and tested combination of Multiplus II together with microinverters which supports frequency shift for this setup?

Which microinverters can be used here?

I am very thankfull for ideas or help so

Thanks an best regards


richard-offgrid asked
Michelle Konzack answered ·

1 Answer

Off-grid PV Inverter support on AC IN - respond to frequency changes

In all of my searching, I can only find configuration options to modify the behavior of Multis/Quattros by changing the frequency on the AC Output. But I'm still a novice in the Victron world, so maybe I've overlooked something?

What I'd like to achieve is change battery charge/discharge parameters based on the frequency of AC Input. As far as I can see, this isn't possible, but I'd appreciate being corrected if I'm mistaken!

My goal is to use Multi to:

  • keep SoC > XX% (or keep a minimum DC Voltage)
  • if frequency > XX, charge batteries (ideally, current increases with frequency)
  • if frequency < XX, discharge batteries (via PowerAssist or Ignore AC?)

The purpose of this is to interact with an existing off-grid system in a supportive way. Grid-tied inverters will curtail their output in response to rising frequency. To avoid "wasting" that energy, I'd like my Multis to store power in the battery, until the excess condition is gone, then give this energy back again until the batteries approach empty.

I'd prefer to use an Assistant or Virtual Switch over something like Node Red, but I don't see the functionality there. Am I missing something?

randyoo asked
randyoo edited ·

0 Answers

Setting up an AC coupled system with string inverter Aurora 6 kW with Multiplus or Quattro


I have a customer which already has a grid tied system using 27 modules of 230W and 1 string inverter 6 kW Aurora model PVI-6000-OUTD-US.

I understand that CCGX has built in a FRONIUS module for AC coupled systems and I have the doubt for other models that can be compatible and if there is an specific software product from Victron to do it.


dgmar-ni asked
rgerber commented ·

2 Answers

Paraller phasing of two MultiplusII 5KVA for one phase system it is possible ???


I have a single phase off grid system on an MPII 5KVA using the SOC generator function to switch via ATS to the distribution network (I don't use it as a generator!!! If the PV is disconnected (SOC) the whole system is connected to the distribution network. "Please don't confuse this with a generator" ). I am satisfied with this solution.
But I would like to increase the 1 phase power from 20A to 40A by parallel wiring and keep the wiring I have (if possible). In the prospect documentation it is written that it is possible to connect up to 6 pieces of MP-II (parallel). Honestly, I'm not quite sure how to connect it :) So maybe you can guide me if I'm doing it right...
Question about connecting two pieces of MPII in parallel (one phase):

a) From MPII (Slave) AC OUT1 I bring the cables to MPII (Master) AC IN, since I do not use the distribution network via victron (we don't have to solve why).
b) Or MPII (Master) AC out I will send the cable to MPII (Slave) AC In - but here I have a feeling that the Master-Slave logic will change :)
How to actually wire it properly???
If I'm not mistaken, I have two options to connect and configure?
1) is a generator where additional MPii are connected from a certain load
2) parallel phasing - this seems like a more reasonable solution to me, but I haven't been able to find out how it works in practice yet.

Regarding the following configuration (ve.config), I found something regarding parallel connection via ve.config. I will document later.

Thanks for advice.

Juraj Nikolov asked
Juraj Nikolov commented ·

1 Answer

EasySolar 48/5000 and AC coupling with Multiplus II 48/5000

I have an off grid installation with an EasySolar 48/5000/70 MPPT 150/100 running at full output power. I've installed a new Multiplus II with its own PV and batteries so completely separated from the EasySolar. Is it possible to do AC Coupling with both installations ? AC Out 1A of the EasySolar with AC Out 2 of the Multiplus II or install the Multiplus II AC out as a power Assist to the EasySolar ?

benoit asked
wkirby answered ·

1 Answer

Solaredge SE27.6K on Multiplus-II AC-IN

a short questions about the Solaredge SE27.6K Inverters with 3Pcs Multiplus-II (3-Phase System with about 10kWh Battery).
Is it also possible to use the Solaredge SE27.6K on the AC-IN Port of the Multiplus-II ?

like here, but connected to AC-IN:


The PV System with the Solaredge SE27.6K is already installed, the ESS with Multiplus-II, Cerbo-GX etc. have to be added.

Because of the 1.0 Rule, the Solaredge SE27.6K can not add on the AC-OUT of the Multiplus-II.

I know if the Public Grid is down, then the PV Generators also not work, but this would be no problem for me.

joergsc asked
andreas-ziegenfeldt commented ·

2 Answers

micro-inverter and Victron on ac out

Olá a todos
Tenho um micro inversor que gostava de ligar no AC- OUT do Multiplus II 5000, mas não sei se tem frequency shifting, no caso de não ter, como se comporta o victron?

As especificações do micro inversor estão na imagem.



ditmarco asked

0 Answers

stable output of three phase AC output of Three Quatros AC Coupled

Three Quatro 8KVA inverters in Three phase configuration

with 27KW Fronius inverter (17 KW panels only will add more later )

with Victron MPPT 250/100 and 5 KW solar panels

when client does welding work with a AC welder 2KW single phase the AC Output is not stable and causes lights to Flicker

the load is mixed with lights and other electrical equipment on three phases

how can the output be made more stable

Willem asked

0 Answers

Is it possible to AC couple an 8kva growwatt inverter with a victron 10kva multiplus inverter

I have an existing system, 10kw of panels going through a growatt 8kva inverter tied to grid, feeding back 5kw. I want to install a victron 10kva multiplus inverter and 30kw of batteries, to try and run off batteries at night and reduce bill dramatically. And be sweet if grid goes down. Does anyone know if this is possible?

Thanks in advance

samnarly asked
sharpener answered ·

1 Answer

Victron Multi + Fronius Primo Hybrid system!


I am having the Fronius AC Coupled at Multi's AC Out1, and trying to set all for Grid Feed-in limited to a given value.

Should it be the Fronius discovered on the Modbus TCP device list? for me is not there. Scanning not helps.


zsolt asked
anthony answered ·

1 Answer

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