Vibration sensors and temperature sensors (RTD's or Thermocouples) are sometimes used to monitor bearing conditions.

Water cooled bearings should be pressure tested for leaks before installation.  Special attention should be paid to casting plug leaks, cracks in the housing and improperly welded housing repairs. Water that leaks into lubrication systems will float the oil; the bearing will then be running in water.

Bearings too lightly loaded experience oil whip which is seen as violent shaft vibration. This is aggravated by cold oil temperature or oil that is too heavy. This problem can be eliminated by reducing bearing area and using oil at the proper temperature and viscosity.

In general, heavy oils are used for heavy loading and lighter oils are used for faster speeds.

For slinger ring type lubrication, peripheral speed and oil viscosity must be correct.

Misalignment of the shaft and bearing should be under .0003 inch per inch of bearing length.

Brinell Hardness of the shaft should be at least 100 points harder than the bearing material for good compatibility.

Usually if there is lack of bond between the Babbitt and housing it can be seen at the horizontal joint of the bearing.

Electrical conduction across the bearing can destroy the Babbitt by electrolysis.

Babbitt bearings should be inspected whenever an opportunity presents itself and always in outages

When in doubt, ask American Power Service to inspect and ultrasonically test the bearing for integrity.