Omron K6CM User Manual page 78

3 Measuring and monitoring System
Monitoring by Velocity
In monitoring on monitoring, you can generally monitor the load imbalance, misalignment etc.
Set the alarm threshold from the class (i.e., capacity and installation status) of the motor to be moni-
tored. Refer to the figure below and set the threshold value. (It will be set according to ISO 2372.)
Rmsvalue of
vibration velocity
0.71 mm/s
1.12 mm/s
1.80 mm/s
2.80 mm/s
4.50 mm/s
7.10 mm/s
11.20 mm/s
18.00 mm/s
The target motor class follows the table below.
Equipment class
I
II
III
IV
The default value of the alarm threshold is set as follows.
• Alarm threshold (Warning): 40 mm / s
• Alarm threshold (Critical): 45 mm / s
Velocity reacts not only to vibrations but also to things like shocks. An alarm may be output due to
unnecessary vibration or shock when mounting a vibration and temperature sensor. Therefore, the
default value of the alarm threshold is set to a higher value. In actual use, set the alarm threshold to
an appropriate value according to the monitor target.
Additional Information
If you want to monitor using only acceleration or speed
If you only want to monitor using acceleration, set the alarm threshold of speed to the maximum
value (9999) so that the speed alarm is not output. Likewise, if you only want to monitor using
speed, set the alarm threshold of acceleration to the maximum value.
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Class I Class II
A
A
B
B
C
C
D
D
Small-sized machines (typical example: motor with output less than 15 kW)
Medium-sized machine (typical example: motor with output of 15 kW to 75 kW or less
and machine with 300 kW or less)
Large-sized machines: machine installed on a heavy foundation with high rigidity.
Large-sized machines: machine installed on a foundation with soft rigidity.
K6CM Motor Condition Monitoring Device User's Manual (N219)
Class III Class IV
A
A
B
B
C
C
D
D
Definition
Judgment
Normal
Warning
Critical