This circuit demonstrates how 3-phase power works on a 480/277V Wye connected system. The Voltmeters are connected line-to-line to show how 480V is derived from two 277V sources. The line connected to the Amperemeter is the neutral line. The three resistors represent an arbitrary load for each phase. Try changing the value of one of the resistors. Notice how this creates an unbalanced load and current begins to flow in the neutral line. (NOTE: In reality, 480V or 277V are RMS values, which means the peak voltages are higher than shown here. RMS values are used for easier comprehension.)
