I have a semi-offgrid three phase setup consisting of three Multi RS Solar in 3-phase configuration (no AC input) connected to pylontech battery and solar panels (L1 no solar, L2 4kW, L3 4kW solar) and a MultiPlus 48/2000 that is connected to AC input and the same pylontech battery as the Multi RS Solar. Everything has been running ok, but recently I noticed that one of the MPPT:s is going on and off with its charging. In VRM it shos as current or voltage limiting. I’m loosing substantial amount of energy due to this. Reboot of the Multi RS in question helped remove it for a few moments, but then it started limiting again. The battery SOC is 75% and temps are normal. Any idea what might be causing this and how to fix it?
You have built a complicated and unsupported system by having a multi sharing batteries with the RS.
Anything could be happening and without a detailed wiring and comms diagram, settings, customisations etc it would be difficult to even guess.
Its always best to go back to basics, remove any complications and mods and see where it breaks.
Good luck.
Hi @punin
If I understood correctly, this ESS with 3× Multi RS Solar has no connection to the AC grid, and only the MultiPlus 48/2000 is connected to it? Is that last Multi used only as a AC charger? And is it connected to the Cerbo via VE.Bus?
Yes, correct. I had to do it this way because Multi RS Solar doesn’t support parallel operation nor connecting only 1 AC input phase to one of the Multi RS Solars. The system has been running for over a year now without any issues. The MultiPlus is connected via VE.BUS to Ekrano and is used in charger only mode.
Verify that all equpments in the system are reporting the same battery voltage: battery’s BMS, Multiplus and all 3 Multi RSes.
A MPPT from the Multi RS could enter limited mode when its measured battery voltage gets near its set target voltage.