Controlling the installation during a power outage/internet failure

[Juergen_Buerger]

I operate a local installation with the following core components:

• 10 kWh solar array

• 2x Solarcharger 250/85

• 3 Multiplus inverters, configured as a 3-phase system

• Cerbo GX inverter

• 28.8 kWh battery

The system is installed in parallel with the grid. Although technically possible, no power is fed into the public grid (target feed-in = 0W). In conjunction with a dynamic electricity tariff, this reduces my electricity costs by approximately 70%.

Depending on the actual cost per kWh, I frequently switches between grid power and PV/battery power, sometimes several times a day. This is achieved using the function in the VRM app to switch the inverter between ON and CHARGE ONLY modes:

This is also the only way I know to switch between grid power and self-generation.

In the case of a blackout, the installation allows to disconnect our house from the grid and supply it with power from the battery during a power outage. However, depending on which setting (ON / CHARGE ONLY) the power outage is in, I have a problem.

If ON is selected, the Multiplus units initially shut down correctly during a grid outage. I disconnect the house from the grid using a coupling switch and can then continue to supply it with power via AC1.

If CHARGE ONLY is selected, nothing happens after the grid outage because the Multiplus units are deactivated by software. However, I can’t switch to ON because the internet connection, necessary for VRM, is no longer available. Ultimately, all routers and repeaters in the house are without power.

After this long introduction, my question is: how can I switch the Multiplus units from CHARGE ONLY to ON independently of the VRM tool?

Victron Connect isn’t a solution, unfortunately, especially since the inverters are configured as a 3-phase system.

Does anyone have any ideas?

[nickdb (Nick)]

As long as the GX remains powered by battery, you could use nodered and create a watchdog flow that checks inverter switch state and grid supply. If the wrong combination of grid and state exists it can switch the inverters to ON or invert.
That way it is fully automated and runs locally.

I usually leave my systems in invert only, but have a flow that checks SOC and if it gets too low moves the system back to ON.

Nodered is part of the large venus image and has a dedicated sub-forum here.

[DuivertNL (Marc)]

Another option is to keep the cerbo running from battery and to connect to the gx local wifi connection and use remote console to switch it

[Juergen_Buerger]

Hi Marc,

the Cerbo is running permanently on battery power, that’s the easy part.

“… to connect to the gx local wifi connection …”: I think, you suggest to create an access point with the Cerbo an then connect with a notebook to this new network? That mayby a solution, I have to check this. But: there is no way to switch the multiplus via remote console. Simply there is no such menu available. It is only possible via the dashboard of the VRM-App.

But perhaps you have made a good point. I have to check, wether it is possible to connect via loacal access point with the VRM instead of the remote console.

THX

JB

[DuivertNL (Marc)]

Yes You can switch with remote console

Both old and new gui

[Juergen_Buerger]

Hi Marc,

I apologize!!! You are my hero. I was looking at the wrong places in the remote console - stupid. So most likely you found the solution. Let me check this, I will report on it.

Many thanks

JB

[Juergen_Buerger]

Hi Marc,

it works, you make my day. Thanks a lot

JB

[DuivertNL (Marc)]

Thanx!