High Vibration Analysis of Eddy Current Drum Coupled Motor to a Vertical Centrifugal Pump : Solution Based on EMA, ODS and FEA

Abstract

The 35-year old pump station moves up to 43 MGD of raw wastewater to the city’s treatment facility via two 1,500-hp high-capacity pumps for wet weather flows. After the motors were refurbished in 2011, excessive motor vibration occurred at certain pump speeds, thereby restricting the pumping system’s ability to handle various flow ranges. After multiple field balances to the motors and coupling drums, the City of Tampa set out to fix the vibration issue, instead of putting on a “Band-Aid” (field balancing) every time the vibration levels exceeded their limits. Prior to any finite element analysis (FEA), cladding and extra bracing were added to supporting I-beam structure to reduce vibration. This only made matters worse. The goal became to use FEA to identify and implement a practical fix that worked over the pump operating speed range.