2x 5kW Sunsynk inverters reboot during loadshedding when usage is above 7kW

System installed: 2x 5.5kW Sunsynk inverters connected in parallel, 20x 455W JA solar panels and 4x Pylontec UP3000C batteries.

During loadshedding my 2 Sunsynk inverters reboot if the consumption of the house is above 7kW. This happened today during the day while the solar input was around 7kW, the house was consuming around 4.2kW (geyser heating and basic house items switched on) and then a kettle (of about 3kW) came on. Once the system reboots i get 2 errors on the app i.e. "F41: Parallel system stop" and "F34: AC overload fault". 

I am aware that the Pylontec batteries are rated 0.5C but in the above case, there was no usage from the batteries so i do not suspect that as an issue. This only happens during loadshedding and i have seen the inverters handling above 10kW usage from the house previously when there is no loadshedding.

I have checked the settings and the power for each timeslot for the inverter is set to 5000W. The installer has also made sure that the cables from the batteries to the inverters as well as the cables from the main DB to the inverters are equal in length.

What else could be the issue?

Edited January 15, 20232 yr by D_Naidoo