AIUI, out in the road there are three live wires and one neutral. The phase s of the lives are 120 degrees out of phase with one another. The potential difference between any two live wires is 440V. The potential difference be tween any live and neutral is 230V. Domestic supplies only tap one live and the neutral to give you a single phase supply, so if you want a 3 phase su pply for a workshop or whatever, you have to get the leccy blokes in to dig up the road and tap you into one of the other live wires. Do I have that r ight?