Multiplus 2 three phase system and single phase generator

My current setup:

1x Venus OS Large on Raspberry Pi 4 with Node-RED

3x Multiplus II 5000 in a three-phase system

6x Pylontech US5000

1x Fronius Symo 10 connected to the AC output

1x switch before the Multiplus between grid/off/generator

(Only L1 can be supplied by the generator)

1x 8 kVA single-phase inverter generator

All loads are connected to the AC output!

Hello everyone,

I have a question about the individual configuration options of the Multiplus and the Assistants:

What I want is the following:

Feed-in to the grid should be prevented; the grid should only be used if the state of charge (SOC) drops below 20%, for example, and cannot be charged by PV.

Ideally, the grid would then be directly connected and not used for battery charging, but would supply the loads directly.

Alternatively, the generator can be manually switched on using the switch (of course, the generator must be started up beforehand, etc.).

Since the generator is single-phase, only the first Multiplus can charge the batteries in this case, so that energy is available for the entire system again.

I have the state of the switch position in Node-RED and can program my own logic for it if necessary to extend the functionality of the assistants.

Is my plan feasible with the existing components?

Which assistant is the right one here?

To operate the Symo at the output, I need either the PV Inverter Assistant or the ESS Assistant with the appropriate settings. This enables frequency shifting.

Feed-in to the grid should be prevented; this can also be configured in the ESS.

So far, so good… With the ESS Assistant and generator, it doesn’t detect the grid; I suspect this is because only one phase is connected.

It shouldn’t be due to the grid code, as I have set it to “other” and accept a wide range.

I’ve read many posts about using separate chargers for the generator, etc., but I wanted to avoid that.

You can only have an asymmetrical grid config if the system is configured to not switch as a group when it is originally setup as 3-phase. This prevents ESS being used.
It’s one or the other.

1 Like

Thank you for your quick reply.

Did I understand correctly?

In my case, I wouldn’t be able to use the ESS function.

Without the ESS Assistant, it’s possible to charge the batteries using both single-phase and three-phase power.

Switching the power through the grid as in ESS mode isn’t possible then, unfortunately?!

If ESS operation is necessary, would a separate charger or a three-phase generator be required?