I have a system as per the attached “Solar-Battery-System.jpg” that incorporates and old Samil SolarRiver Grid-Tied inverter with a reasonable FIT of 13 years ago, so I need to keep it “as is”. The “House-Garage-Wiring.jpg” shows how the Samil is wired to the system which includes battery back-up for the low-load devices with the high-load devices connected direct to the grid… In the event of a grid failure (which we get quite often), the low-load devices remain powered while the high-load devices are disconnected. The Samil is configured using VE-Config as on the output (AC-Out) of the MultiPlus II 48/5000, so the MultiPlus will attempt (and fail) to moderate the Samil output using phase-shifting if/when the grid fails with Batteries SOC @ 100%, but I’ll deal with that if it occurs, the worst that can happen (I think) is that the Samil will shut-down with an error as the phase deviates beyond 50Hz.
The problem is that the Victron VRM (and the CerboGX LAN GUi) , attached “VRM-29-May-26.jpg”, seems to miss-report the Samil solar generation by seemingly adding it to the AC Loads readout, as the PV Inverter generation increases so does the AC Loads, showing a direct correlation. Difficult to capture the data so it’s exact but the screenshot shows the math error quite clearly: Total Solar 2176W minus Battery Charging 1697W = 479W while the consumption shows 989W with only 28W from the grid. In fact, the AC Loads should be zero as none of those devices are active while the Essential Loads should show a modest power draw (around 400w) with standby devices, couple of freezers, a fridge and this PC drawing power.
The actual loads are correct as measured at the various physical locations (i.e. the PV Inverter is generating, not consuming), it’s purely the data displayed and recorded that is incorrect.
The two CTs/Meters are for Grid and PV monitoring and they are configured as such in VE-Connect, they’re both showing the correct values and are the right-way-round as the Grid CT is positive when drawing from the Grid and negative when feeding to the grid. Same with the PV CT, positive when generating and zero when not. I’ve tried switching the PV CT and the value goes negative, so yes, the correct orientation.
The Grid CT is positioned after the incoming meter but before the Consumer unit. The PV CT is positioned on the Live AC-out of the Samil inverter, so it then feeds the AC-Out terminal of the MP2 and either charges the batteries or feeds back to the grid.
It looks to me like a bug in the Victron software/firmware but if anyone can throw any light on this I will appreciate it…
Edit: I’m an idiot… the PV CT/Meter was configured as on AC-In… obviously it is now corrected to AC-Out and all is as it should be.
