Understanding common vibratory forces helps electrical technicians diagnose, correct motor vibration problems
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Thanks for the detail discussed but one more vibration problem that is not discussed by the author is Beat Vibration in Vertical Pumps of same size running side by side. This was experienced in two Distiller Brine Re-circulation Pumps (Vertical) of 2 MW capacity each, running adjacently at 743 rpm. The vibration at the motor non-drive end was fluctuating from 5 mm/s to 21 mm/s periodically, when both the pumps were running but vibration was around 7 mm/s steady when one of the pumps were running. As the plant needs both the pump to run for 100% load, how this phenomena can be taken care off ?
Is there a bump test standard or procedure that describes how to set-up and test a large vertical motor for its reed frequency. I have been looking for a procedure which provides accurate results. I could find no industry standards or what is an acceptable tolerance between calculated and tested values. Your help would be appreciated. We do have a B&K pulse analyzer and hammer. I believe a massive foundation is required but am not sure the motor must be bolted or could be clamped to the floor. Does the number of clamps used to hol the motor to the floor make a difference?






