There are many problems that can arise from harmonic currents flowing in a power system. Some are easy to detect. Other problems may exist and persist because harmonics are not suspected as the cause. Harmonic currents cause higher RMS current and voltage in the system. This can result in any of the problems listed below:

• Failed Power Factor Correction Capacitors


• Blown Fuses (no apparent fault)


• Tripped Circuit Breakers


• Overheated Transformers


• Overheated Conductors


• Worn Conductor Insulation


• Misfiring of AC and DC Drives

One of the larger problems is overheating transformers. In fact, a 10°C rise in operating temperature of transformers, motors or capacitors can cut equipment life by 50%. The harmonic currents are higher frequencies and tend to travel along the outside (skin effect) of the conductors, which results in insulation breakdown.