Temperature - WEG Motor Scan Manual General De Instalación Y Operación

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Example 3 – The graph of Figure 5.10 shows the importance of assessing the trend of the motor vibration levels.
In May and June, the measurements were around 2 mm/s in addition to a motor stoppage. As of July there was
a change in the vibration levels, showing a rising trend in the vibration amplitudes. Such rise may be due to some
kind of failure or variation in the motor operating condition (increased mechanical rotation, load, etc.).
Figure 5.10 – Chart of the RMS values on the X radial over time
(*) ISO 10816-3 - "Mechanical vibration – Evaluation of machine vibration by measurements on non-rotating
parts – Part 3: Industrial machines with nominal power above 15 kW and nominal speeds between 120 r/min
and 15000 r/min when measured in situ".
(**) ISO 13373-1 - "Condition monitoring and diagnostics of machines – vibration condition monitoring.

5.2.2 Temperature

The WEG Motor Scan measures the motor surface temperature in the area where it is installed. In addition, the
WEG Motor Scan measures the ambient temperature around the sensor. Using that information, it is possible to
monitor the thermal behavior of the motor, even analyzing the machine temperature rise based on the difference
between motor and environment temperatures.
It should be noted that measurements are individual and do not represent the temperature of the winding or other
specific areas of the motor, such as the bearings.
The "alert" and "critical" alarm limits are factory set at 60 °C and 75 °C respectively, but they can be manually
changed by the user as needed. If the user chooses to change the factory limits, it is recommended to adjust
them when the motor is operating in normal duty so as to avoid unwanted alarms during the monitoring. If the user
cannot identify the operating duty, it is recommended to determine the alarms after assessing the measurements
for a period of the motor operation long enough to enable you to identify properly the patterns of the application
behavior. Figure 5.11 shows an example of monitoring where alarms can be viewed and measurements can be
made by the WEG Motor Scan. Figure 5.11 also shows an example of an "alert" alarm changed from 60 °C to 50
°C after the identification of the motor behavior pattern.
Figure 5.11 - Temperature monitoring with change in the "alert" level
42 Manual of Electric Motors