Air Handler Unit Vibration Issue
The vibration readings on the fan free end of the Air Handler AH-15050 have been significantly higher than the baseline during the last 20 days. RMS Acceleration has increased by 100%
Raised noise floor in acceleration spectrum for Fan Free End. The spectrum peaks indicates a VFD speed change from 26Hz to 30Hz(gradually). Due to this change we are observing an increase in Accel RMS vibration. Currently the speed of the Motor is 28Hz.
In the velocity spectrum on the Fan Free End there are sub synchronous peaks present which were not significant before the increase in vibration trend.
We are seeing 1x harmonics on the fan drive end
Any advise on what could be the problem....