Introduction to Electrical Fault Diagnosis English Electrical ProblemsElectrical ProblemsStator Eccentricity Shorted Laminations and Loose Iron Typical Spectrum Stator problems generate high vibration

, and 5th harmonics. If the rotor is rubbing against the stator, it will produce high vibration at 1x running speed with sidebands at the running speed harmonic frequencies. It is important to note that rotor problems can also cause stator problems, as the uneven air gap caused by a damaged rotor can lead to stator eccentricity.

Bearing Problems

Typical Spectrum

Bearing problems can be detected by high frequency vibration at frequencies above 2 kHz. The most common bearing problem is damage to the rolling elements, which can generate sidebands at the bearing fault frequency (BFF) and harmonics of the BFF. Other bearing problems include misalignment, lubrication issues, and bearing looseness, which can all generate high frequency vibration.

Conclusion

Electrical faults in motors can have a significant impact on motor performance and can lead to costly downtime. By monitoring vibration spectra, technicians can identify the root cause of electrical faults and take corrective action before a failure occurs. Understanding the typical spectra associated with different types of electrical faults is essential for effective fault diagnosis