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mindaugas avatar image
mindaugas asked

Adding 3 phase Fronius to single phase Multiplus system

I have 3 phase grid. Curently I am running Multiplus 48/3000 with 4 kW solar and 15kWh battery. ESS assistance. Mainly critical load is powered.

I need more solar generation to power 3 phase heat pump. No plan to add more batteries , it is enough to be partly offgrid for 2 days and grid feed-in and storing is much cheaper than extra batteries.


How shall I expand?

Option 1. Adding 2 more Multiplus with more solar controlers and extra solar panels (total inverter power - 3×2.4 kW)

Option 2. Install 3 phase 10kW Fronius Symo PV inverter with extra solar and use AC coupling on Victron grid-in. (Tital inverter power - 10kW+2,4kW)


I am tent to go for option 2, but not sure if this is even feasible?

Can not find on Victron page.

Thanks


Mindaugas

ESSAC PV CouplingFronius
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2 Answers
Michelle Konzack avatar image
Michelle Konzack answered ·

I doubt, that you can add the Fronius with one phase on the ACout and the other two on the remaining two phases.


You would need probably one of the two solutions:


1) adding 2 additional MultiPlus-II hang the Fronius on the ACout and what you can not use life sell back, which would be the optimal solution


2) put the Fronius on the ACin side and keep the existing MultiPlus-II for your critical loads.

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mindaugas avatar image mindaugas commented ·

Thanks Michelle

My Option 2 is exactly:

2) put the Fronius on the ACin side and keep the existing MultiPlus-II for your critical loads

Will this work as separate systems or it will work as one managed by Victron? I haven't found any information regarding such configuration and implementation. How feed-in will be managed?

Have anyone done this implementation?

Thanks

Mindaugas

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Michelle Konzack avatar image Michelle Konzack mindaugas commented ·
100% unmanaged because if the Grid fail, the Fronius switch off anyway.
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sharpener avatar image
sharpener answered ·

Looks like two people have implemented your Option 2, see this thread https://community.victronenergy.com/questions/172902/fronius-pv-point-as-ac-in.html.

Option 1 more complicated but then you would be able to run the heat pump from the batteries when there is no sun. Though not for long, maybe a thermal store would be a useful addition.

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