Question about single phase Multiplus-II behavior on 3-phase home network

DIY
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1

Hi,

I’m currently planning the extension of my home PV-system with additional modules and a Multiplus-II connected battery. As I’m somewhat new to the topic, I could use some advise.

Background/current situation:

  • Home installation in Germany, connected to the grid (3-phases, loads on all of them)
  • Existing 2.4 kWp PV system with a 1-phase inverter (Solarmax 2000S)
  • All PV current is currently fed back to the grid (due to German subsidies).
  • But this subsidies are running out, thus I’m planning to rebuild

Planned changes:

  • Re-Connect existing 2.4 kWp PV system on the inner side of the grid-provided energy meter, so that I use the created wattage for my own loads with priority
  • Install one Multiplus II 48/3000 together with a ~5kWh battery pack and an EM24 in order store excess current for night use
  • Extend the PV system by 4 new modules (4*430W) and Hoymiles micro-Inverter (single phase)

My question:

  • does the Multiplus have to be connected to the same phase as the Solarmax and/or the Hoymiles inverters in order to get the excess wattage into the battery? If one PV inverter would be connected to a different phase (say: Multiplus on Phase A, Hoymiles on phase A and Solarmax on phase B): then, how does the excess wattage generated by the Solarmax and fed into phase B get into the battery? Would the current from the Solarmax actually go into the grid via phase B and in return the Multiplus would load the battery from the grid on phase A?

thanks in advance for the help!

2

Hi if you want it directly in the batteries, you must connect it to the ac out 1 of the multi, then your pv will also work when grid is down

However the pv inverters feed back to grid on phase A and you can charge at the same time from grid on Phase B, sum will be zero

depending on how your energy provider calculates your energy bill…