Fronius has been detected at the very moment of starting GX, I suppose this means that the two are communicating.
Inverter is Multiplus-II 48/5000/70-50 GX and during first tests by cutting the grid, I have seen Status 560 on Fronius. Being outside and MP inside, I did not notice any strange MP behavior.
Is it essential to have Modbus enabled on Fronius, for throttle, or Multiplus is doing it solely by frequency shifting ?
My initial understanding was that Modbus is used only for feed-in limiting, which is not my case, the system can feed-in all available PV.
Having a look on ESS Assistant configuration, 2 points are not clear for me, assistant description kind of ambiguous:
Restart PV Inverters when the DC voltage becomes lower than 40.00 V (community search did not really help). Why restart Fronius ? When battery is too low, Fronius should work as hard as possible.
Total installed PV panel power. My PV is only on Fronius, 4500W total. I wonder if the field is asking about a possible extra DC coupled panels ? Should that field be also 3000W ?
It did looked like a short grid failure but at the same time, the AC Out has been cut for a moment, “VE.Bus System [275] - Low battery: Alarm” and few minutes later “System overview [275] - Grid alarm: Grid lost”
I have an alarm system that announces me about in-house AC power loss.
The in-house power loss was very short but should not happend, considering that system was hapily inverting from battery all night, house consumption being 50-150W, with spikes from the fridge motor.
Having a look on Fronius Solarweb history, lthe grid failure has not been recorded, probably due to 5 minutes chart resolution. But the Victron “AC Input Frequency” did recorded a short fall.
Is it supposed from the ESS to have a short AC Out power cut at the moment of grid failure ?
What could produce a Low Battery Alarm, out of the nowhere ?
The battery voltage has been down adjusted to absorption 54.5V and float 54V. Many thanks for Cluj Napoca, Victron dealer for great support.
The Fronius frequency shift values adjusted in ESS Assistant to: 51.00 / 53.10 / 53.20, after reading this post
Up to now it has tested OK during grid removal and restore, though with a 50% SoC battery.
Will do more test after reaching 100% SoC and still PV production.
I also activated the Modbus but not the power limit as I am allowed to inject to grid all Fronius production.
Better reading of Fronius related documentation, Modbus is required only for Feed In control.
I do hope it is so, time will tell.
Surprising for me too. Actually, the old and new values do not make much difference in terms of frequency shift as Derating Gradient is 60%/Hz, giving control from 51.00 to about 52.70.
The difference is for disconnect frequency which has to be higher than 53.10Hz.
From all tests, I do have a strong feeling that only the charging values, being a it high (though Dyness proposed), probably along with some DC spikes at switching from Inverter<->Charger (discussed in this community and also producing Low battery Alarm), led to a very short BMS disconnection and system restart.
Can you please elaborate a bit?
Thank you, again, for your support and involvement !
It seems each battery for comms has a different method for aet up (dips etc) yours already has comms so that isn’t the issue for you.
(The thought was triggered your mention of having to be told to change charge voltages it means the information is not readily available)
Something simple like the voltages is a silky thing to not make known. I had attended a training day for them and wondered what the point was if for most of everything they want you to contact a team for support.
Most compatible battery pages have at least the basics such as charged absorption and bank sizing with how to do comms.
Found a post, on powerforum.co.za, mentioning that setting the jumpers to 1100, BMS will also report cell voltage and some other info, that on FW96.1
I have FW110.1 and kind of reluctant to try undocumented settings, at least in this learning curve period.
There is a document for Dyness battery in Victron installations, though the mentioned values were a bit high.
I am also surprised that Dyness do not offer comm software/firmware, at least for this battery. Might be only for trained technicians.
This morning, around 6.40, AC Out has been cut for few seconds, with Low Battery Alarm. No idea if is grid related but if appropriate I can create a new topic.
Battery SoC 33%, AC Load 150-200W.
Having a look at the logs, a High DC Ripple Warning has been recorded, graphs show nothing worrying.
This is the 3rd time, in two weeks, for such AC Out glitch.
I am thinking to try HomeAssistant and log with higher granularity in hope for catching the moment. ST188_log_20250511-0000_to_20250511-2359.csv (24.9 KB)
