Can someone give me a simple diagram in autocad on how to setup a 3pole / 3phase connection?

Are you trying to do Grid Tied to a 3 phase utility power system--Then you connect 1-3x single phase inverters to your three phases based on voltage (i.e., if you are 220 phase to phase, then p1 and p2 to first inverter, p2 and p3 to second inverter, and p3 to p1 for third inverter--In the US, typical 10 kWatt maximum per inverter if less then 3 inverters). Also, in some cases, the utility may require something to turn off all 2-3 inverters if a single phase is lost.

There are two types of three phase power connections... Delta and Wye ("Y" or "Star"). Each type has different voltages (in the US, Wye is common for small business--120 from neutral (center of "star") to each hot leg, and 208 between each hot leg).

From what I have seen, most all smaller GT inverters are native single phase--Some have control inputs to detect/shut down on loss of phase. Only large inverters (50 or 100 kW and above) seem to have three phase native units.

If you are looking for off grid 3 phase power--That is difficult to justify three relatively large OG inverters (say 4-8 kW each) wired up to support three phase off grid (battery backed) power. These are very large systems (for off grid use) and not usually cost effective for smaller installations--And large installations are expensive (batteries, solar panels, inverters, wiring, backup genset, etc.).

-Bill