I’m just installing my first system. Multiplus ii 48/5000/70, single phase 230V. System is running in ESS mode with a grid setpoint of 20W and all appears to be working as expected apart from the indicated AC Loads power value.
I have a separate AC coupled solar inverter connected to the AC input side of the Multi along with all the house loads so nothing is connected to the AC out 1 or 2.
The first issue is that although I’ve set the position of the AC loads to be “input only”, they’re still shown on the output side of the Multi in the system overview (and on the VRM).
The second issue is that, because the solar is AC coupled, the AC loads power value is not showing the true power value. It’s showing the effective load power as seen by the system (true load power minus the output of the solar system). Is there a way to configure this to show the true AC load power (grid power + battery output power + solar power)?
Just to add, I’m using a CT for the grid measurement connected directly to the CT input on the Multi. I’m using a “40A Victron Current Sensor” to monitor the Solar production via AUX#2 input.
Your system does not know there is a PV inverter, you need a dedicated current sensor or meter configured for the right PV role (unless it supports modbus).
Suggest you brush up on the relevant manual sections or even Victron Energy - Victron Professional
The gui has a logical layout that won’t change for AC loads if they are only on the input and there is no AC out (critical) loads.
Thanks for getting back. I’m using the standard 100A:50mA Victron CT. This is around the live meter tail inside the consumer unit / fuse box. This seems to be measuring fine. Grid CT setting is “Inverter/Charger”, not “External” (I have a 3 pin connector block for the CT connection).
I was going to use AUX#1 for the PV current sensor but I’ve set the grid code to UK:G98 which then forces you to use AUX#1 for the “Disable feed-in” signal. Like I say though, the actual indicated power of the PV appears correct using this meter and AUX#2.
I can understand if the Multi doesn’t know the AC PV power it will have to calculate the AC load based on its inverting output power + grid power. If however it knows the AC PV power and knows that it’s grid-tied on the input side, the AC loads should be the sum of all three (Grid + PV + Inverter output).
As an example I’ve disabled the ESS in the screenshot below. There’s no inverter power in this case so AC loads should equal Grid + Solar but they don’t. The Solar power is not being added onto the AC loads power.
Could the Status of the “PV Inverter on input 1” being “Startup(0)” be the problem? This code seems to suggest that the device is not ready yet which may explain why the system isn’t using its power reading in the AC loads calculation?
The two versions of the GUI show the same PV production values however the grid power is different for some reason. If I had to guess I’d say the PV is being deducted from the grid reading in V1 but not in V2? I’ll have to confirm this once I have zero PV generation.
System was in the middle of a scheduled mains charge when I took these…
I’ve now updated the MP2 to v556 but no change re the AC Loads power value from what I can see. The PV generation connected to AC In-1 is not being accounted for in the AC loads power value.
Below shows the system with ESS disabled so no inverter power. The grid is supplying 326W but the loads in the house are being supplemented with 201W of solar so the true AC loads value should be the sum of both, 527W.
The grid values show in the VRM are even more confusing. The L1 value shown in the Grid power box is correct (-38W due to higher solar so feeding-in slightly) but the main value of -608W makes no sense. Is this the 239V x 2.5A shown in the L1 section?? If so, these power values are mixed up.
Just to further clarify the issue. The following screenshot shows the system running with ESS enabled and an excess of PV generation.
AC Loads is shown as 0W where it should be GRID + SOLAR + INVERTER. In this case that would be 17 + 974 - 469 (negative because the Multi is consuming power to charge the battery). The result should be 522W.
