we have a found a fan De bearing looseness issue recently. Been monitoring since a while. Have observed change in spectra from past few days. Herewith Iam attaching both spectra of SAME DIRECTION.Any suggestions???
Are the bearings sleeve-type with a compression bolt on top of bearing housing? If yes, then try tightening it to recommended torque value while monitoring vibration spectrum. If bearings are ball/roller-type, then check tightness of bearing housing and base bolts. Are there any indications of vibration increase in axial/thrust direction? What is fan HP? What is maintenance history? Plan for bearing repairs to prevent consequential damage to bearing housing and shaft.
Happy to hear from you
It is a 225KW motor driven, consists of roller bearing with adapter sleeve. Axial readings were mostly constant with 4.0 mm/s vibration. Bearing replacement was done 2 years back and 6 months ago lock nut tightness verified. Nothing was done apart from this.