question

sahkovirta avatar image
sahkovirta asked

Victron ESS low output voltage when grid voltage low

I have a Victron ESS system with MultiPlus-II inverters and a Cerbo GX, and I live in a country with unreliable grid power. Today the grid voltage has been 103-109V, and I noticed that the ESS system has also been outputting 103-109V. This is with batteries full and power coming from the batteries/panels and nothing being drawn from the grid. If I switch off the breaker that disconnects my system from the grid, the voltage immediately stabilizes to 120V (still coming from the batteries).

I was expecting the Victron system to regulate voltage to 120V, especially when drawing from the batteries and not the grid. But it looks like as long as the grid is physically connected, the Victron system outputs the same low voltage that's present on the grid. Is this expected behavior? If so, is there anything we can configure to avoid this situation (maybe setting a limit to auto-disconnect the grid at 110V or so)?

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2 Answers
Mike Dorsett avatar image
Mike Dorsett answered ·

While the inverter is in charge mode - as in connected to the grid, then you will see the grid voltage on the output of the inverter. If this voltage is too low for you, then you need to raise the minimum grid voltage disconnect setting of the system.

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·

1684005553996.png

As long as the Grid is connected the MultiPlus is synchronized to that voltage and frequency. The MultiPlus can't change/stabilize the voltage/frequency of the grid.

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sahkovirta avatar image
sahkovirta answered ·

Thanks, that explains what I was seeing. Are those values that can be adjusted via VRM or the remote console? Or would the dealer need to come and physically plug in a cable to change them?

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