Alda,
The wild leg is ONLY useful in configurations that do not require a neutral, such as 3 phase equipment, or 240 volt loads with no neutral, otherwise you burn it up.
You ONLY have a high leg in Delta systems (open or closed) because you tap mid phase of one coil (between A and C)
That's why the Wye is the popular form today, it creates no high leg and all 3 phases are useful with the neutral.
You often see 199 volt high legs, this is from 230 volt systems. Phase to ground voltage of A or C phase X 1.732 = phase to B voltage.
