32
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Moving average times
•
If there is a lot of variation, simply create a moving average in the file and process the average.
In the case of a moving average time of 2 (4 times), calculate it per the figure below.
• Check that the measurement results succeeding the moving average are stable enough.
If the results are not stable, increase the moving average times.
(Increasing the moving average times will increase the effect of old values apart from values measured at the current time.
E.g. In the case of a comprehensive current diagnosis, a sampling time of 5 seconds and a moving average times of 5 (32
times) means that data from 160 seconds earlier will be effective.)
Moving average times
During actual operation, determine moving average times with more stable numbers while utilizing the data in the
CSV file. Note that setting the moving average will result in a delay in the timing in which the critical state is detect
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ed. Set it while taking into consideration the balance between the severity of the variation and timing in which the
critical state is detected.
Changing the inverter carrier frequency settings
For the K6CM-CI2M, it is possible to reduce variation by setting the inverter carrier frequency to 5 kHz or more. Try
changing this setting if it is possible to change the equipment’s functional settings.
(4) Determine the threshold levels before and after comparison.
Before maintenance, if a skilled maintenance engineer deems it necessary to perform emergency maintenance, set
the state before maintenance as a Critical threshold level. If it is deemed necessary to perform maintenance soon, set
the state before maintenance as a Warning threshold level.
This also applies to old equipment and if a critical state is reproduced.
Quantification of skilled knowledge
It is possible to quantify skilled knowledge by considering measurements of a motor deemed Critical by a skilled
maintenance engineer as K6CM measurements. Set the threshold levels to coincide with the Critical level sensed
by a skilled engineer.
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Degradation
Time (min.)
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Degradation
Time (min.)
E.g. An average value of 50 means the warning threshold values is 47
Critical (old equipment) data
Normal (new equipment) data
In the case of 4 times,
go to the fourth cell down
