A power quality motor winding failure can result from several causes. This includes transient voltage, harmonic distortion, and voltage imbalance. Transient voltages can come from a variety of internal and external sources. Transient voltages are simply voltages that vary in frequency and amplitude. They can cause power quality problems including insulation breakdown and erosion. Harmonic distortion refers to unwanted sources of currents or AC voltages that deliver power to the motor windings. A voltage imbalance refers to an imbalance in load distribution or impedance in all three phases of a distribution system that creates stress on the system.