Good morning, Everyone

I will be connecting 3 x 8000kVA Single Phase Inverters in parallel. The system is totally off grid. What would be the best way to combine the 3 ac outputs into 1 supply to the main DB EL? I bought 16mm2 cable, so wiring size shouldn't be a problem.

16mm^2 is rated at around 60A, thus over 12kW, which is more than you need per inverter, 6mm^2 rated at 40A would probably be better, then run this 6mm^2 from each inverter into your DB into a 40A breaker for each inverter, I'd say, making all the cables the exact same length, then from each of the 3 40A breakers, run again 6mm^2 cable of same lengths to your main input switch which should probably be rated at around 100A or even a bit larger. As for the parallel cabling for the master and 2 slave inverters, someone who actually has done, this should chip in with some details...