3 Phase inverters Grid Compatibility

Hi guyz,

Do you have any idea/s why almost all 3 phase inverters has 3P4W or in Wye configuration or should i say not compatible on Delta Grid systems ?


  • BB.BB. Super Moderators, Administrators Posts: 31,680 admin
    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.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Sign In or Register to comment.