WEG Motor Scan Manual General De Instalación Y Operación página 43

The diagnosis must be done based on the track record of the measurements, since the duration of each event
is very important for the proper interpretation of the possible problems. Below are some examples that may help
identify the probable causes based on the interpretation of the temperature records.
Example 1 – The chart of Figure 5.12 shows that between days 7 and 8 the temperature increased significantly
and remained at high levels on the following days. That event may indicate problems such as:
a) Increased motor load;
b) Damaged fan (e.g., broken blades);
c) Bearing severely damaged;
d) Problems with the motor power supply.
75
75
65
65
55
55
45
45
35
35
25
25
15
15
1 2 3 1 2 3
Figure 5.12 - Temperature monitoring with change in the measurements
Example 2 – The chart of Figure 5.13 shows that on day 7 the temperature increased significantly, but it returned
to normal levels on the following days. That event may indicate a momentary change in the motor load or motor
power supply problems. It is recommended to check if the peak represents a normal behavior for the application.
75
75
65
65
55
55
45
45
35
35
25 25
15 15
1 2 3
1 2 3
Figure 5.13 - Temperature monitoring with sudden temperature change
4 5 6 7 4 5 6 7
Day
Dia
Dia
4 5 6 7
4 5 6 7
Dia
Day Dia
8 9 10 11 8 9 10 11
8 9 10 11
8 9 10 11
Manual of Electric Motors
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Alert
Alerta
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Critical
Crítico
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