Emerson AMS Wireless Vibration Monitor, User Manual, Page: 62 / 86

Figure 5-8: Motor - OH after the bearing is replaced (PeakVue)
5.3 Temperature
The levels at which to set temperature alerts depend on a number of factors including the
specific process, the operating environment, and the characteristics of the equipment
being monitored. This section provides some generic guidelines, given some knowledge
of the variables involved, for setting the thresholds for your specific AMS Wireless
Vibration Monitor installation. However, the generic methodologies described here are no
substitute for first-hand knowledge of your plant. If, for example, you know that you have
problems when a temperature exceeds a particular value, then set your thresholds
accordingly rather than following these generic guidelines.
In general, the best way to detect a developing fault related to temperature is to look for
an increase in temperature, relative to ambient, over time. This implies that, for reliable
alerting, the thresholds should change as ambient temperature changes. In practice, this
can be difficult to do because it requires the operator to constantly monitor the ambient
temperature and adjust the alert levels accordingly. It is customary, therefore, to pick an
"average" ambient temperature (that is generally seasonal for outdoor installations) and
choose fixed thresholds based on this average. Also, there are issues with this
methodology (such that it does not work well) in areas with large variations in ambient
temperature.
You can select thresholds based on some absolute temperature limit. In practice, this is
much easier to maintain but is not as effective at detecting early failures as relative
monitoring.
Overall Velocity, PeakVue, and temperature User Guide
August 2020 MHM-97927-PBF
62 MHM-97927-PBF, Rev 1