Only the most common vibration trouble sources are listed here.
* The number refers to situations when the bearing itself is the primary source for excessive vibration due to poor installation or manufacturing defects. When performing periodically monitoring, bearing vibration occurs more often. However, it is usually the result of wear due to an uncorrected other vibration source, such as unbalance or misalignment. For those programs that focus mostly on detecting bearing deterioration (rather than main vibration source), this number easily reaches 50 percent or more.
Tip provided by Dennis Shreve, Support Engineer, Commtest, Inc.