MPPT 150/35 PV Overvoltage Warning / but Voltage is well within Range

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Meine_Energiewende asked Apr 28, '23

MPPT 150/35 PV Overvoltage Warning / but Voltage is well within Range

Hi Community !

I've a Problem with a MPPT 150/35. I got PV overvoltage Alarms.

As you see most of the Alarms last only 1s but some are longer. I've got 3 Panels in Series and 2 Strings in parallel (6 Panels in total). This worked für 3 years without a problem. The PV Voltage stays well within the allowed range.

I only get this alarm but the charger works well without any problems. Any idea why the charger is complaining about high voltage ?

Thanks a lot !

Jens

PS: my battery is nearly full at 11:00 .... so no current is going to the battery .... works a designed :D

MPPT Controllers mppt overvoltage 150/35

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snoobler commented · Apr 28, 2023 at 02:31 PM

What's your string rated Voc?

What happens to the voltage when you turn off the charger in settings immediately before sun hits the panels in the morning and get a true Voc reading? Leave it off for the first hour or so and see if you get anywhere near Voc limite. If you actually observe it, burn it back on quick and reconfigure your array.

You may want to use the Trends tab in VC to monitor the PV voltage. VRM only updates once a minute at its fastest, but the trends tab updates every 1-2 seconds or so.

If charging a LFP battery, is there any chance the BMS is cutting off the charge?

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Meine_Energiewende snoobler commented · Apr 30, 2023 at 02:59 PM

voltage if charger is turned of: 113,33 volts.

Error #33 raises even then.

As far a i know the VC Tab i've posted above catches the max values per day.

Jens

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snoobler Meine_Energiewende commented · Apr 30, 2023 at 04:17 PM

Sounds like there's a problem with the charger.

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thanar Meine_Energiewende commented · Apr 30, 2023 at 06:05 PM

I believe the vrm graphs smooth out the readings. The history tab in Victron Connect app does indeed display the maximum values; however, a maximum voltage needs to stay at the highest point for at least 5-10 to get registered. I've had better luck with the trends tab, when trying to debug fast-evolving phenomena.

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snoobler thanar commented · Apr 30, 2023 at 06:40 PM

Voltage with the charger off is 113.33V. That's an 81°C safety margin before they hit 150V. Doubt the temps are -56°C.

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thanar snoobler commented · Apr 30, 2023 at 06:45 PM

not all sunny days are created equal... you'll observe highest voltage during a cloudy spring day, as soon as the sun comes through an opening and the rest of the sky is overcast with white clouds, maximising reflected ambient light, which gets added to the direct sun. What's the panels' Voc?

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Answer 1 · 2023-04-29T22:51:57Z

Paul B answered · Apr 29, 2023 at 10:51 PM

This is saying that your PV panel array is to hi a open circuit voltage for the regulator at some point in the day, so you will need to change the pv wiring setup to 3 strings of 2, by the times on the error report its in the afternoon so is this peak output time.

what are the panel oc voltage figures on its spec plate, also low ambient temps will increase panel oc voltage's .

also look for a bad connection in the pv array wiring as you may have a string thats coming in and out of connection due to a bad connection somewhere, unlikely but possible.

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Meine_Energiewende commented · Apr 30, 2023 at 02:54 PM

I know what it is saying .... :D But i dont know why. As you see in the above graphs (and the output of Victron Connect -> which gets the maximum of the day from the charge controller) i've Vmax at this day of 111 Volt. At the moment the error is active i've got 91,82 Volt. (see screenshot above).

Ambient Temp at is about 10-15 degrees at the moment. VOC is about 39 Volts.

btw: at 19:30 the sun is nearly completely gone .... (no direct sun from 16:00 on).

What do you mean with the bad connnections ? how can the influence the voltage ?(getting higher).

Jens

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Answer 2 · 2023-04-30T17:20:18Z

z-zk-z answered · Apr 30, 2023 at 05:20 PM

I was getting similar errors which were due to the individual cells in my EG4-LL V1 battery over charging and activating the Over Voltage alarm. I had to lower my MPPT (default) absorption voltage from 56.8 to 55.2-volt.

https://diysolarforum.com/threads/eg4-ll-v1-sending-high-voltage-alarm-warnings-to-victron-100-soc.55542/

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snoobler commented · Apr 30, 2023 at 09:29 PM

Those are battery voltage warning errors and are common with BMS over-voltage protection triggers. These are PV voltage errors implying the MPPT is being subjected to >150V input from the PV.

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