Following setup : 3 x Multiplus 48/5000 II, 1x MPPT 250/100 , 1x Fronius Symo 12.5 and 2 x BYD 15.4
AC1 out and AC2 out are separated.
AC1 loads sum up to 10kW and AC2 loads sum up to 10kW max
We have been observing 2 problems :
1. Approximately every 7 or 10 days we encounter this problem. During daylight, while Fronius is producing 2-3 kW, and system is working with reasonably low loads under ESS batterylife, suddenly one of the phases gives overload alarm and system shuts down. We ask the household, they say nothing of high power was being drawn that moment.
2. During ESS, now and then AC2 output is disabled, although there is grid on the mains.
Following my observations :
This overload situation or AC2 output disabling never happens when system is in passthru mode.
Overload situation seems to happen while Fronius is producing, could it be that due to sudden clouds, the pv production makes a dip and then the multiplus try to invert that missing power ? which is then too sudden and causes overload ?
AC2 disabling : could it be that during ESS AC1 and AC2 are being regarded as one output and as soon as the total load of AC1 + AC2 goes higher than 15kVA AC2 is being dropped ?
What are your suggestions to debug these problems ?