Effect of Motor Voltage Unbalance on Motor Vibration: Test and Evaluation

There have been many discussions on the importance of balanced power supply for both best performance and for lower vibration during operation of industrial motors in petrochemical duty and related installations. Results of tests that were conducted on several low-voltage IEEE 841 motors to observe the effect on vibration due to unbalanced power supply will be presented. Various increments of voltage imbalance from 1% up to 10% were tested and monitored on several pole speeds. This paper will present actual test data collected, along with a discussion on how these results relate and impact the various vibration testing and operational conditions provided within industry standards.