I need help guys. I have a vertical pump. Motor sits on top. Pump has a column. Installed in a pit with impeller, casing in the pit. Just to give you an idea of the pump type.
Pump RPM is 1800, did bump test, got NF at 30 Hz. Vibrations meet specification when water level in pit is low. When water level is high, vibrations exceed specification. Predominant peak is at 1X. I will add more information as we discuss this further.
Any help will be greatly appreciated.