Walt Strong posted:
Did you clean the fan rotor before balancing it?
Did you weld weights on rotor for balancing? If yes, then was the electric welder properly grounded to the fan rotor and not to the case?
I assume the bearing was destroyed to cause the inner race to drag over the shaft and cause all of the surface gouging; correct?
Did you use any other means of bearing fault detection; such as high frequency acceleration or demodulation?
Were the bearing housing grease seals in good condition and keeping contamination from the lubricant (grease or oil)?
Considering the trend of the spectra with no bearing fault frequencies present, it looks like the bearing damage occurred as a result of the balance job!
thanks for your attention
yes the welding machine was properly grounded and the procedure of balancing and welding was correct.
i used peakvue technique yes i always use peakvue using CSI 2140
the bearing seal was replaced two days before balancing as it was damaged.
the balance job damage the bearing ??!!! i doubt.