Hi All,
I have a weird one, my installation comprises of the following components Victron MultiPlus II GX, 2 x Smart MPPT's, Smart Shunt and a 3 phase Fronius Inverter.
The Fronius is connected to the AC1 input, the loads I want to run off batteries are connected to AC1 out, nothing is connected to AC2 out and the MPPT's are connected between the Multi and the Smart Shunt.
All was working ok via ESS, however I purchased a Victron 3 Phase Meter and installed it to see how this would change the way the system operates now that it knows exactly what happening. If I leave the setting in ESS to use the Multi for the metering everything seems ok however the Multi doesn't use the Fronius power at all, this is all exported. The batteries only get charge by the MPPT's everything else seems to work as expected.
If I change the setting to use external meter I notice a few, what I think are strange things and one good. The first thing I noticed was that the Multi had started to utilise some of the Fronius power to also charge the batteries, which I though was great as they are the priority over export.
The second thing I noticed was that in the evening when we turned our 3 phase air-con on, the Multi would try to assist one of the phases by supplying power out its input AC1 in from the batteries, which isn't what should happen as this is why its connected on the input side and not the output.
The third thing I notice was also toward the end of the day when the batteries were full, the Multi would go into alarm because the voltage of my 48V system had gotten up to 60V. Using lithium ion batteries I found this to be very concerning. The other thing that happened at this point was the Smart Shunt would indicate a 15% difference between the top and bottom sections of the battery bank.
The other thing I thought was unfortunate was the inability to export excess DC.
Would love to hear anyone else that has had similar experience in these issues.
Regards,
Nathan