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alator avatar image
alator asked

Frequency jumping at night

I had a off grid install completed December 2021 my setup can generate up to 10kw and consists of:


2 x Quattro 48/15000/200

1 x SmartSolar MPPT VE.Can 250/100 rev2

1 x 6kw Solis

3 x 200a/10kwh Rosen power wall with inbuilt BMS

35 x 390w panels (15 connected to MPPT & 20 connected to Solis)

2.5kw dump load installed as attempt to prevent battery SOC reaching 100% to prevent frequency locking and needing manual intervention.


I have been having issues with the frequency jumping to 51 Hz or higher and remaining there which shuts down the Solis inverter. The only way to correct the frequency is to turn on the generator until the Quattro match the generator frequency. In reading the posts here I had believed it was a setting issue with the batteries combined with the configuration on the Quattro. However I am not so sure as the issue is not constant and I have had the system run smoothly during the day but then the frequency jumped to 51Hz at 1am and remain locked through to 2pm when i noticed the issue and turned on the generator. The batteries had not fully charged the previous day and were at 30% at the time this occurred.


I am not an engineer and am having difficultly getting support from my installer to address the issue. Since this is happening at low SOC and during the night would this be a configuration issue or a fault? Can anyone help me solve this problem?


thank you

quattro 10kvafrequency
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alator avatar image alator commented ·
My issue continues for now i have set the generator to turn on for 1 minute around 5am to ensure at the start of the day the frequency is not preventing solar generation.
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Alexandra avatar image Alexandra ♦ alator commented ·

What is programmed onto the system. ESS or PV inverter assistant?

What frequency range has been programmed in vs what the lockout is for the Solis?

Does the BMS control the system at all?


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Paul B avatar image
Paul B answered ·

Hi as a guess I would suspect that the batteries bms is connected incorrectly to the Quattros I suspect the BMS triggers a low cell voltage then the connection to the Quattro is seeing this as a high cell voltage and thus the hz is increased.

starting the generator then forces the hz to be correct at 50hz then the system charges the battery and the cell error reported by the bms stops.

so look in this area and see if youcan isolate the battery thats causing it plus corect the wiring so that a low cel voltage causes the inverters to turn OFF, as they should if wiring is correct.


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