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How to detect a defective tank stirrer or a broken belt on e.g. a compressor using the Condition-Monitoring-Sensor Multi Physics Box MPB10?

How to detect a defective tank stirrer or a broken belt on e.g. a compressor using the Condition-Monitoring-Sensor Multi Physics Box MPB10?
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In general, the Condition-Monitoring-Sensor Multi Physics Box MPB10 is made to detect if a vibration, shock or temperature value is above the adjusted threshold.
In this application we have to detect if the clutch -or the stirrer itself- of a tank stirrer is defective and the tank content isn't stirred correctly anymore.
The same behavior you can face if you try to detect if the belt of a belt driven machine e.g. compressor is broken.
In both cases we receive higher vibration values in the good condition than in the failure state, which should be detected, so vice versa than in the MPB10 standard use case.

What we need:

To solve this task, we need:

  • a MPB10 Part no.: 1123926
  • a SIG200 to realize the logic (if available, a PLC can do the job too)
  • a SLT060-0B010J700 Part no.: 6075938 to visualize the good condition by a green light and the failure state by red lighting state
  • a fan with 2 speed stages to simulate the good and the bad condition of the stirrer

MPB10 set up:

First, we connect the MPB10 via the Silink2Master to SOPAS ET and open the MPB10 device window.
Then we go to the "General Device Settings" tab and set the:

  • "Alert delay time" to 1000 ms to prevent short alert impulses shorter than 1000 ms
  • "Automatic alert reset time" to 2000 ms to reset the alert automatically after 2000 ms if the corresponding alert condition is no longer fulfilled



If the vibration is strong enough we can go to the "Vibration", "Settings" tab and enable the "Activity detection", for our small office fan example that's not needed:


Than we switch the Fan to the fast speed and have a look on the "Vibration", "Time Domain" tab.
There we click the "reset min./max. values since last reset" button. 
By mouse over on the V-RMS Magnitude graph we can see the live, min and max values:



After a few minutes at the fans high speed we choose a suitable "Max. limit" value that is below the "Min since last reset" value. In our example we choose 2 mm/s.
The "Pre-Max. limit" we set slightly over the value that is showed if the fan is switched off. In our example to 0.4 mm/s.
With these settings we should have no alert when the fan is off and only the "V-RMS  Pre-Max. limit" alert at the slow fan speed which demonstrates our bad = failure condition:


At the fast fan speed which demonstrates our good condition the "V-RMS - Pre-Max. limit" and the "V-RMS - Max. limit" alert should be active:
If you switch the graph on the bottom to v-RMS you can see those values over time.



In the real application you now have to check if the chosen thresholds fit to the different machine states like filling levels and if the detection of the stillstand, good and bad state is always correct and to correct the values, if necessary.

In the "Home" tab you can see the current state of both diagnostic alerts in the process data,
V-RMS PreMax = diagnostic alert 1
V-RMS Max = diagnostic alert 2
and an alert list on the right-hand site:


Smart Light Tower SLT setup:

We open the SLT device window in SOPAS ET and go to the "configuration" and "color" tab.
There we switch the SLT "operating mode" to "Signal lamp mode" and
create 2 groups with each 10 LED's,
group 1 constant green lighting = good condition and
group 2 red flashing = failure state:


SIG200 setup:

To realize the logic with the SIG200 we connect the
MPB10 to port 1 
the Smart light tower SLT to port 2.



Than we upload the IODD files of both devices and assign it to the correct port:



Now we need a logic that works like the following table:
(the second line cannot occur therefore strikethrough)

Pre-Max alert Max alert good state
green light
failure state
red light
0 0 0 0
0 1 1 0
1 0 0 1
1 1 1 0

And here you can see the same logic in the SIGs logic editor:


S3DO4 and S4DO4 are only to visualize both MPB10 alerts directly on the SIG200 digital output Port 3 and 4.

Final test

Finally we can test our setup at the different fan speed stages:

  • Fan off = no light
  • Fan speed stage 1 slow = failure condition = red light flashing
  • Fan speed stage 2 fast = good condition = green light
broken belt detection, Condition-Monitoring-Sensor, defective tank stirrer detection