Hi guys,
I have a Motor-Pump assembly showing high 1x peak.. The vibration levels were as high as 18mm/s. The equipment is aligned recently. 3596RPM Motor. Highest vibration levels are at Motor side.

Can anybody give some help on these phase readings?

Motor NDE

H-V 179degree

Motor DE

H-V 10degree

Motor DE-NDE

H-H 4degree

V-V 162degree

Across the coupling 111degree

Have a nice day!

This could be resonance. Determine if this is the case.

Jenish,

If I read your post correctly, the drive end of the motor is in phase while the non drive end is out of phase. This is only true in the vertical direction, while in the horizontal direction both ends of the motor are in phase.

More and more manufacturer's are producing motors that operate above the first critical, but if this motor is more than 10 years old it's probably not designed this way.

Typically on a horizontal pump / motor assembly, the stiffest axis is in the true vertical direction. If in the past you normally see the majority of the vibration in the horizontal direction, this would suggest you have a typical horizontal pump / motor.

Assuming that the rotor is not in the second mode shape (highly doubt this) and motor was balanced before installation (this doesn't look like imbalance) what would cause the vibration at one end to be 180 out of phase from the other in only the vertical direction.? To me, the first thing that I would check would be looseness of the bearing, bearing support and structure, particularly at the non drive end of the motor.

Hope this helps,

Zack

quote:

Motor NDE

H-V 179degree

Motor DE

H-V 10degree

Motor DE-NDE

H-H 4degree

V-V 162degree

Across the coupling 111degree

What are the amplitudes at the points and does this drawing sort of ressemble what you are saying?

Hi guys,

May be this will help...

Have a nice day!!