100/20 MPPT PV Bluesolar cut offs

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johnh1917 asked Oct 15, '23

100/20 MPPT PV Bluesolar cut offs

Hi,

I have 100/20 MPPT connected to 4x100w panels. Nominal open circuit voltage is 96.4v and VRM portal and charger daily history have recorded as high as 98v.

The system is experiencing cut offs from time to time like in in the graph below.

While I acknowledge that I am very much on the edge of the charger capabilities, based on data I have not crossed it and in example case below, faults started at around 80v range.

If I access the daily history through the Victron connect, it shows no errors, same in case of VRM alarm logs, no logged faults. However, if I access the Gerbo GX notifications page, it lists some high input voltage errors but only aligned with later part of the day, once the voltage has peaked to open voltage, close to 100v.

Any idea how can I review the fault shown in the status graph? and why isn't VRM portal alarm logs showing anything?

Has anyone experienced issues like this with 100/20 MPPT?

Thanks,

MPPT Controllers fault

1697370127918.png (87.6 KiB)

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grahamwood commented · Oct 15, 2023 at 12:21 PM

If you go into your remote console on VRM, go to your MPPT Controller, overall history, what does it say for your Maximum PV voltage?

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johnh1917 grahamwood commented · Oct 15, 2023 at 02:52 PM

Hi,

Since current PV panel configuration 98.05v. All time high is 114v which happened due to some external component failure and was only momentary (happened about 6 months ago).

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Answer 1 · 2023-10-15T14:05:32Z

snoobler answered · Oct 15, 2023 at 02:05 PM

Nothing in notifications in the GX console?

There is absolutely, positively no good reason to run your panels in that configuration.

Re-wire for 2S2P.

VRM only logs in 1m intervals (15m default) if set that way. It may not capture peaks.

With VC through VRM, pull open the trends tab and display PV voltage/current. With a live view and short interval, you get data every two seconds.

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johnh1917 commented · Oct 15, 2023 at 02:52 PM

I should have mentioned, it is 48V system. 2S2P is really not an option (LIFEPO4).

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grahamwood commented · Oct 16, 2023 at 11:15 AM

I run 2 banks of 4s2p 12v panels through 2 100/20 controllers and have never had a problem since installation. Highest ever recorded voltage was 90.8v.

I don't know what the manufacturing tolerances on panels are but they don't normally exceed around 22v VOC. The highest voltages you would normally get would be when the chargers go to absorption/float mode when there is still full sunlight.

Maybe you have a rogue panel that's kicking out more voltage than it should. Perhaps test the output voltage under no load on each panel. They should all be the same.

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