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we made laser alignment last year. 208 hz was occur after bearing unit changed ( 2 months ago ).
Last week total RMS app 7 mm/s , after system stop for cleaning than start RMS app 10 mm/sn V direction. than we make rigid support some area under base frame. This fan on the spring. And 1x 2985 rpm onthe other hand I see W/M shape in TWF. 2 pole motor.
doyou say how can we improve vibration vzlue? and what is the 208 hz? Also 208 hz reduce when we add rigit suppurt under base frame.

best regards


The replacement bearing may not be exactly what you thought, so the default frequency calculations are incorrect. If the calculated fault frequency is slightly higher than your problem frequency at 208 Hz, then the bearing may be spinning on shaft or inside housing and changing fault frequency. You indicate that the bearings were replaced, so the most likely cause of the vibration is looseness within the bearing housing or bearing fit on shaft. The vibration levels are low now, so there should be no need for immediate action prior to a scheduled outage.


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