1S8: Case Study: Induction Motors Condition Monitoring: Vibration Analysis Technique-a Practical Experience

Mikhail Tsypkin, Field Service Engineer, VSC


Vibration analysis is one of the most successful techniques used for condition monitoring of rotating machines.  The aim of this presentation is to show that vibration analysis is a very efficient and convenient tool for diagnosing mechanical and electromagnetic problems in induction motors, especially for applications using adjustable speed drives (ASD).  Case histories covering assorted modern industries represent typical mechanical and electromagnetic problems found in the induction motors by using vibration analysis techniques. Among them are: structural resonance, bearing failure, torsional vibration. Presented case studies also show different motor vibration problems related with electromagnetic anomalies in the machinery, in the power lines and in the ASD. Induction motor operating under voltage/current distortion usually shows significant vibration of an electromagnetic nature. Vibration of an electromagnetic nature may also be a result of internal faults in the machinery. Accuracy of the machinery diagnosis made using vibration analysis depends on the ability to correctly analyze vibration data. One of the goals of this presentation is to clarify the origin of the induction motor vibration of electromagnetic nature at line frequency, twice line frequency, harmonics of line frequency and at twice slip frequency.


Mr. Mikhail Tsypkin graduated from St. Petersburg Electrical Engineering University in 1976 and St. Petersburg State University in 1994, both in Russia. He is a certified member of Vibration Institute (Category III) and a member of IEEE. Mr. Tsypkin has been a Field Service Engineer for Vibration Specialty Corporation (VSC) in Philadelphia since 2001. Prior to joining VSC, he worked as a vibration analyst for Central Ship Electrical Engineering & Technology Research Institute and for VibroAcustical Systems and Technologies, Inc. (VAST), both in Saint Petersburg, Russia. He has 40 years of the experience in machinery diagnostics and vibration analysis of electric machinery.