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mvanrensburg asked

Solar gen limitation on Multiplus

My system: Multiplus 48|5000|70, MPPT 150|100 TR, CCGX, BMV700, 404 Ah Revov LiFePO4 batteries. ESS is active. Solar panels feed MPPT, which feed DC bus, with Multiplus connected to DC bus and grid. The limit on charging the batteries is 100A (not reached). I have solar panels of 7 kWp installed, which are more than 10 years old and degraded to about 5200 Wp. About 4 months ago I got more than 5 kWp from it, but one day the output dropped to 3800 Wp. I do not know what changed, although I have tried to recollect, but I cannot get the reason. I tried to roll back updates and installation files, but to no avail. I have updated all software and firmware, as I thought it might be an automatic software update. And no, the limit on the CCGX is not set.

If the limit is the Multiplus, than at least the MPPT should at least charge the batteries at full capacity till full.

The solar-gen curve show clearly a limit from about 10 am to 2 pm when the curve does not follow the normal solar pattern,

I have read wide, consult wide, but cannot find the solution. Any help will be appreciated.


MPPT Controllers
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snoobler avatar image snoobler commented ·


ESS overrides MPPT settings.


Worth checking your actual array performance. Verify each string is actually moving current with a clamp ammeter.


If you're in the northern hemisphere, solar 4 months ago was better than it is now, but that would have been a gradual change.

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mvanrensburg avatar image mvanrensburg snoobler commented ·
Thanks a lot for the response.


I have done that, and all of them generate current in the correct direction. I can can actually disconnect any array/string and get the same total output.
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Alexandra avatar image Alexandra ♦ mvanrensburg commented ·

@MvanRensburg

Check your connections. Possibly one has gotten hot and is not making good contact. Not just at the mppt but through all the strings

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mvanrensburg answered ·

Thanks for the advice - no, See my response above. Somewhere there is a setting that cause a definite limit on the solar generation.

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snoobler answered ·

3 places to check:


1) MPPT settings.

2) CCGX DVCC setting.

3) ESS settings

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mvanrensburg answered ·

Thanks for the response. Check all those and nothing changed there.

I then took a clean ESS file, reload same settings, upload it again, and what a surprise - it is working again!

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nickdb avatar image nickdb ♦♦ commented ·
Short of an accidental config change, given the old setup, reloading the config may just be a lucky coincidence. Your issue is likely to return if it is indeed panel related.

The MPPTs will throttle for various reasons, tired panels present plenty of opportunity.

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