- Jun 21, 2020
Assuming an hour is statistically long enough to show up the issue, then focus changes to SSC.RCinFLA,
Inverter has been running without PV input for about an hour. AC output voltage under various loads is a constant 119v. Plus/minus 0.3 volts.
You can check PV input voltage when you see AC voltage fluctuation to see if you also see fluctuation in PV voltage. What are your typical Voc, Vmp, and Imp currents from PV when seeing AC output voltage fluctuation?
If you run PV panels Vmp too high in voltage, there may not be enough headroom to the 250 vdc max input limit to do a proper MPPT search. With Vmp typically between 0.81 to 0.85 x Voc and Voc max limit of 250vdc, Vmp max input limit is 200-212 vdc. The inverter spec of Vmp max of 245v is not possible with silicon PV panels and still keep maximum Voc less than 250vdc.
If you have too small a battery AH size or too small battery cabling gauge, the SSC power can pull the inverter AC output voltage. The unit should automatically back down PV power output to prevent this. Check inverter DC input voltage when you see the AC output voltage fluctuation.