I was monitoring a Induction Motor at 2994 RPM & 1700 kw. coupled to Centrifugal pump.
which present high vibration in all directions and the same spectrum, 7 mm/sec O/All.
the spectrum show one peak 1x rpm whith side band of Pole Pass sidebands.
In solo run condition the high vibration desapear.
also the periodic current variation is present ( 1 cycle / 2.66 sec) the variation of current is 5 amps aproximatly.
the motor show beating with high sound.
The pressure is steady at 200 Kg/cm2.
I would like to share this case to look up the cause.