we were experience high vibration and eccentricity during normal running condition sometimes as per previous record. but now from last few months it is continuously running beyond limiting value. only generator front and rear vibration remains high while all other points shows normal trend. can anybody ans. the reason of this.

 

The possible reasons for the only generator Vibrations are,

1) Check the oil flow to the individual bearings,

2) Check the bearing temp if increased along with vibration

3) Normally there are 4 probes of vibration ( 2 on each side of the bearings), check whether all the four are showing high vibrations other wise check the correctness of the probes by inter changing

4) Only generator vibrations can go high if there is rotor winding interturn short circuiting.

Regards,
Rangacharya