Anyone with Solar Combiner which is fed by 4 single phase inverters and at the output,it gives us 3 phase load?
All solar combiners that I have seen combine DC, not AC.
To synthesize 3-phase power from single-phase sources, one in theory could combine 3 single-phase sources (not 4), but they would have to be synchronized so that each produces the same frequency and each is phased 120 electrical degrees apart from the others. It would be easier to combine one or more DC circuits (as many as you want) to drive a DC bus from which an inverter synthesizes three-phase power.
SUN 250 Grid Tie Inverter testing with Solar Panels