Jenish-

The power from the Power Plant would be a reason for that. Might want to do some Online MCA of Power Quality Analysis if you have that ability.

Also as far as the bearing I was talking about he DE Fan bearing from one side of it to the other as shown by the green circles.

And I couldn't insert the data into my version of SKF. It's older. Sorry. But you do have a possible reason with the power.

Good luck!