[jankeymeulen]

3 phase typically has 400V between the phases and neutral in Europe, the phases don't gain you anything, but the voltage does.

[phs2501]

Pretty sure residential 3-phase in Europe is 400V phase-to-phase, it's 220V phase-to-neutral.

[dotancohen]

It's 220/240 volt RMS to neutral, which is about 312 volt maximum to neutral at the top of the phase.

[qayxc]

make that 230V (min.) or rather 240V (nominal).

[ajsnigrutin]

230V nominal in EU

[qayxc]

You're right, though tolerances allow for up 253V since 2009. I usually measure between 235V and 242V from the wall.

[ajsnigrutin]

3 phases give you three times amount the power as 1-phase with only 4 wires (instead of 2 in a single phase, or 3x the thickness).

[bluGill]

Voltage is solely a matter of how the transformer is wound. In the US you get a choice when you contact the power company, 208, 240, 440, and 480 are all voltages I've personally seen in the US, depending on the area (not all utilities will provide all voltages, so there are some I haven't seen)