I just completed a Multiplus-II 5000/48 installation.
The grid is on AC-in, while all loads are on AC1-out. The MPII is connected to a DC BUS, where two SmartSolars and a bunch of LFP batteries are also connected. There is no GX device on the installation, for now.
The goal is to be able to use all available solar production (4kWp installed) and have the grid as support, for when the solar production is slim. Since there is no GX device, smart shunt, nor can-connected batteries, I have adjusted "DC input" voltages accordingly in "Inverter Settings", so as to not run down the batteries excessively.
However, it seems like this setup doesn't work exactly the way I want it to: Starting up the MPII with no AC-in works fine, however as soon as AC-in is electrified, the MPII goes into "Passthrough" mode and inverting stops, hence not using any of the solar production.
Only way I was able to make it work (kind of) the way I want, is to fiddle with the "AC Input Control" settings, in which case my loads are being fed by either the inverter, or the grid. I was aiming for true parallel feed from inverter and the grid at the same time.
I suspect that I will be able to make more adjustments if I put a GX Cerbo into the mix, but I was hoping I could set it up as originally intended without one. Is there something I miss? Some secret setting, or a jumper cable I missed somehow during installation?