Recent Experiences with MCSA and Flux Condition Monitoring of Mechanical Faults in 6kV Induction Motors for Water Pumping Applications

In the last years, the flux monitoring techniques have become popular amongst diagnostic engineering researchers. However the Motor Current Signature Analysis (MCSA) gains more and more ground in industrial applications. A critical comparison of the two methods in the field is then mandatory to identify the possible pros and cons, the limitations, as well as the information that can be extracted from their application. For this purpose, the authors have monitored 4 large 6kV induction motors operating for water pumping applications in the Hydro-electric power plant of “Pigai Aoos” in Greece with both techniques. It has been shown that, pump side issues might cause different harmonic index in the stator current and stray magnetic flux. The analysis of the results leads to the conclusion that the two methods need to work complementary.