Thanks for the information everyone. That's very interesting - I've always wondered how 220V (or 230V) was brought into the home (in places other than North America). From what everyone is saying, it looks like the center of the wye is grounded and the standard residential voltage is taken from one of the lines to the center of the wye (neutral). I imply this because of the voltages specified in Juile's diagram and the comments made by others. In a wye configuration, the voltage from line to neutral is the line-to-line voltage divided by the square root of three (about 1.732). So as in Rollie's example, 230V for small appliances and 400V for the range (230 is 400/1.732).

This would also imply that one side of the circuit for standard distribution around the house is connected to ground. Again, using Rollie's example, one side of the 230V would be connected to ground, while both sides of the 400V circuit are at 230V to ground.

If anyone has any corrections to this, please post. Thank you all again for your input.

Mike