Frequency dip in the power grid -> ESS switches off

Question

question

drmi asked Aug 6, '22

I am asking for support with a problem that I cannot solve on my own.

Two ESS systems are installed on two separate power connections:

System 1: 6x Multiplus 48/5000 3ph with 1280Ah OPZS, AC coupled PV inverter, the ground floor of the house is connected to the AC-OUT.

System 2: 3x Multiplus 48/5000 3ph with Victron-LiFePo4 400Ah, 3x MPPT 150/75, the upper floor of the house is connected to the AC-OUT.

Yesterday there was a drop in the power supply three times; the mains frequency went down to approx. 40Hz. The following happened:

- System 1 switched to "island

- Installation 2 switched off the AC-OUT power and restarted (three times).

My questions: Why did system 2 switch off? What settings are wrong with this installation?

In the screenshot you can see system 2.

Thank you very much for your support.

Michael

frequency

stromausfall.jpg (160.5 KiB)

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Answer 1 · 2022-08-10T09:45:41Z

Paul B answered · Aug 10, 2022 at 09:45 AM

sound like system 2 may have had a battery issue or the load on one phase was higher than the units capacity to deliver.

as you have a cerbo GX connected to the units then go and look at the graphs on the vrm. and see if you can see the cause.

if you have cant see it in the graphs then its a guessing game and you will need to try to recreate the issue with the same load and find the cause

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