120/208-volt, 3Ph, 4W, wye System
A distribution system generated with three individual sine waves separated by 120 electrical degrees that are identified as phases A, B, and C. One leg of each of the three phase coils is electrically connected to the others at a common point, forming a wye, which when grounded, becomes the fourth wire (or neutral) in the system. This allows for each of the three individual phase voltages to supply 120 volts to the ground point, while the lone voltage across each of the phases produces 208 volts. The line-to -line voltages can supply both 208-volt, 3-phase and 208-volt single phase. Because the three individual phases each can supply 120 volts, this system is commonly used in commercial office applications where 120 volts is desired because the 120-volt loads can be balanced across each of the three phases.