3 Phase inverters Grid Compatibility

It depends on what is common for local 3 phase power in your area... For example, even though in the US 120/240 VAC split phase power is common and standard... In California, the default power for small (office park) 3 phase power is 120/208 VAC (Wye).

From what I understand, it is because in the US 120 VAC (which is our default consumer power) is easily taken from a 120/240 VAC Wye system. And, in many cases, devices rated for 240 VAC can take 208 VAC directly, or be rewired cheaply (in a case I had, a small+cheap auto transformer was used when 240 VAC device was ordered for our 120/208 VAC office park).

If you look at Delta wiring--You can only (easily) pull 120 VAC from one of the center tapped transformers to give you 120/240 VAC (in US we have grounded center taps). It is not "easy" to balance 120 VAC 3 phase loads in that configuration.

For 480 VAC 3 phase systems, a Wye connected set of transformers gives us 277 VAC between the center tap and any hot leg--A very common voltage for industrial lighting.

-Bill