Hi Konrad, I guess this forum is extremely non-responsive ... never seen a forum with so low level of response on technical questions. to your question : I have installed a TL-WPA4225 KIT on my 3-phase electrical circuit (3x400V with Common ground and Neutral). This is a basic kit (cheap) an I finally tried it following the promotion on 'coolblue' where it was mentioned that this particular kit could handle 3-phase net. And it does OK . Wired performance reported by TP-LINK is about 350 - 370 MBPS. Except in my garage where it drops below 50MBPS ! So I'm thinking to install a phase-coupler as these are not so expensive anymore ... but I cannot find any decent info whether that should improve or not functionalities.