question

kallenr avatar image
kallenr asked

2x Multiplus on 3phase grid, ESS

I have a customer who has a Multiplus 2 5000 gx with em24 (rs485).
Only the AC IN was connected, he has a 48V BYD premium 12.0 battery
The customer charges and discharges the battery with an external solar inverter connected to the home.

Everything has been inspected and works fine, but now a month later
He wants to be able to charge and discharge the battery faster and wants more battery capacity.

can I install a 2nd multiplus on phase 2 and mount 1 additional 4kWh module on its existing BYD battery?
so the system has double the charging and unloading capacity.
In Belgium you are not allowed to send more than 5000W on 1 phase
so a 2nd inverter parallel on phase 1 is not allowed.
Customer has 3 phases. (3 phase + zero)

should that be a Multiplus-II or Multiplus-II GX?

ESS
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larsea-dk avatar image larsea-dk commented ·

@KallenR Did you succeed with this and could you please do a short how to? I can't find the setup in the documentation from Victron, since this is mostly based on 3phase systems or 1 phase MP on 3 phase system.

Thanks in advance :-)

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4 Answers
kallenr avatar image
kallenr answered ·

@mvader (Victron Energy) kunt u mij helpen?

De andere beschikbare kanalen bieden geen antwoord.


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Alexandra avatar image
Alexandra answered ·

@KallenR

I think with your set up we will need more clarification to help you.

I understand you have three phase supply.

On the original setup one on L1 and one on L2?

And now you want to add another unit parallel on L2? Obviously increasing battery to suit.

Are you running ess?

You only need one GX in a system.

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gskalle avatar image
gskalle answered ·

I think kallenr has a 3phase grid with actual only one inverter on L1.

And he want to add a second inverter on L2. In summary: one inverter on L1, one inverter on L2 an no inverter on L3.


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shaneyake avatar image shaneyake commented ·

This is fine, you can do that.
Install a Multiplus-II not the GX version.

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kallenr avatar image
kallenr answered ·

@gskalle , indeed, that's exactly what I want to achieve.
@shaneyake are you sure about this?
how do i set up the system?
like a 2 phase system?
the supplier told me that this was not possible because a 2 phase Victron system is 180 degrees between the phases, my power supply is 3 phase and 120 degrees apart.

is there no problem with the setting "Total of all phases" ?
if i use 3000 watts on phase 3 in the house (with full batteries)
is the system going to send 1500 Watt to the grid via F1 and olso 1500 Watt via F2? (grid setpoint 0W)

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shaneyake avatar image shaneyake commented ·

Here are the options for Victron systems.
What you want is Dual Phase 120.

screen-shot-2022-03-31-at-112345-pm.png

if you have Total of all phases enabled and you use 3000W on phase 3 it should export 1500W on 1 and 2 so that the meter reads 0W. This can be changed to individual phases if you want. I haven't tested this but if it doesn't work then you can do this in software. This does required 3 phase meter if you don't already have one.

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Marco Nijholt avatar image Marco Nijholt shaneyake commented ·

Is this actually confirmed to work? And what L2 options would you select?

I am in somewhat of a similar situation.

I have a 3 fase setup with 3x multiplus II, however 1 of the multiplusses died. Its in RMA and i'm waiting on replacement. But i have 15kwp of solar and a 3 phase 25A grid connection. Currently it's running on only 1 multiplus II on single phase so my limit is +/- 6kw of supply to grid. With 30kwh batteries that buffer the PV coming from the MPPTs its not enough for the solar peak.

The certified victron specialist that originally commisioned the system says a dual phase is not possible, it's only for USA.

However I already had my reservations since i also saw the dual phase 120 option. But when he commissioned my system it was also the first Multiplus II he installed. So if its specific to that model then that would explain it maybe.

Would be nice to get confirmation. I'm located in the netherlands and its also 3 fase 120deg each + 0.

I assume if you want to connect L1 + L2 you select dual phase 120, and if you want to select L1 + L3 you do dual phase 240? In my case it'd be L1 + L2, L3 is the one that died.

Also to maybe clarify, untill i have my third multiplus II back, i'm not interested in putting any loads on the AC out, i'm purely interested in delivering the solar back to the grid. So the argument for not wanting 2 multis in 3 fase system incase of a 3 phase motor burning out when the third phase for some reason turns off is not relevant. My whole house is running on the bypass switch, meaning i run directly from the gird and not through the victron setup.

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Robert Boerescu avatar image Robert Boerescu Marco Nijholt commented ·

@Marco Nijholt

Did you manage to set it up as dual 120? Which option for L2? Thanks!
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