I am encountering a strange issue with my Infini 3KW plus inverter. Whenever grid goes down, AC output drops to around 8% load. So if load was 50% when grid was available, when grid goes down, only about 8-10% load keeps running despite the fact that enough PV is available and batteries are also close to 100% charged. Some appliances are turning off while others remain on. Some lights, ceiling fans keep working but bigger loads like refrigerator switch off. As soon as grid comes back online, all the loads that were disconnected are now re-powered through PV.

Inverter is running in Grid Tie with backup mode II.

Load supply source (PV available) is 1st PV, 2nd Grid, 3rd Battery.

Load supply source (PV unavailable) is 1st Grid, 2nd Battery.

See the image below with an explanation of what is happening. Does anyone have an idea what is going on?

The issue has been solved. It turned out to be a wiring problem with the load neutrals. Most of the load neutrals were connected to the main neutral bus bar instead of being connected directly to Infini output neutral. The issue was resolved when I moved all load neutrals from main neutral busbar and connected them to Infini output neutral in the distribution box.