Mppt are scaling back voltage due to 70 amp limit with muitiplus 48/5000 splitphase

Q&A and troubleshooting
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1

My MPPT’s are cutting down my voltage i’m assuming due to the 70 amp charging limit that my splitphase multiplus 48/5000 . I have two mppts capable of 200 volts , my 8 series panels are outputting 160-170 volts but one mppt is limited to 40 amps and the other is around 30 amps. Two mppts wired into system.
I have a total of 5 eight series string around 8000 watts potential. The system seems like it is limiting voltage down to 120-130 volts and only producing 4000-5000 watts.

I increased watt demand assuming that additional demand would allow for additional wattage from panels.

Am I missing a setting in ve configure? I have checked the settings in the mppts and have it set to max 100 Amps,

I know the multiplus restricts charging to 70 amps but if my demand exceeds that I thought I would be able to pull in more watts from my overpaneled system.

Any thoughts would be appreciated. I was going to add another 8 series string but I don’t think this will help.

2

Which MPPT’s are you using??
DC coupled charging is not restricted by the inverter ac charging limit..

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3

4000 to 5000w equates to 72a to 92a @ 55v(assumed battery charge voltage).

You state mppt’s are limited to 49a & 30a, how have you determined this?

Is battery bms in comunication with inverter? If it is battery bms may be communicating to system to limit mppt’s due to settings/parameters such as temp / soc ect ect.

Mppt’s will balance pv voltage / current to give best output, so voltage isn’t being limited.

What mppt’s do you have? As 200v doesn’t sound like a victron.

4

All MPPT‘s are Victron one is a 250/100 and the other one is a 250/60

A measured voltage at each series string and each eight panel string is bringing in between 160 and 170 V, but on the victron dashboard it’s only showing 130-140v

My batteries only have an internal BMS and are not communicating with the system.
What DC to DC charger would you recommend? Will this dc charger communicate along side mppt?

5

If you need 8 panels in series to get an open circuit voltage of 180v, these must be low voltage panels (20v).
If your current is being restricted, this may be poor illumination, or a bad connection somewhere. The short circuit current of each module should be tested individually. It is not recommended to operate high energy lithium systems WITHOUT BMS control of the charging.
Victron MPPT’s are DC coupled chargers.