Often, large commercial and office buildings are supplied by a three-phase utility source. However, internally the voltage distribution and the load are primarily single phase, between one of the three line voltages and the neutral, as shown in a simplified manner in Fig. 5-28. An attempt is made to load all three phases equally. In case of linear loads, if all three phases are identically loaded, then the neural current i, will be zero. In the following section, we will discuss the impact of nonlinear loads on the neutral current.