Hi,
i m posting my problem with spectrum,pls help at the earliest, we've Boiler feed pump ruuning at 2991 rpm , there is no vfd. last two week vibration on motor nde 4.3 mm/s . when we checked yesterday vibration increased 5.4 mm/s.the spectrum shows running harmonic freq,In DE side, vertical shows subharmonic freq 3.5mm/s .i am suspectig rubbing and motor run at noisly , we have checked operation parameters ,ther is no change and voltage maintain balancly.let me know what is this peak and this freq corresponds to bearing or not.(journal bearing on both end)
motor rpm-2991 rpm,800 kw.

bfp-3a_spectrum.xls (60 KB, 42 downloads)

Does this motor have babbitt bearings?
Looks like looseness.

Maybe a bearing has failed in the motor, since there are so many 1/2x peaks present in the spectrums.

Half harmonics indicate rub or excessive looseness. Multiple harmonics indicate excessive clearance. When was the machine overhauled last? what were the bearing data at that time? Since how long the motor is running? Anyway , you may have to strip the bearings. What about bearing oil temperature coming out of bearing? Check time waveform also.
Regards
Irshad