Hi, I've got the database mostly setup for our plant, but I'm not really sure how I should set up measurements for our agitators. We have a few dozen of these that have belt driven speed reducers connected to the shafts supported by two pillow block bearings. These are all around the 70-130 rpm range. I used the software's auto alarm setup for our motors, pumps, etc which seems to have worked well, but there's nothing there that really matches up with our agitator bearings.

What should I setup as an inspection for these? Velocity vs displacement, spectrum vs time waveform, or just an overall? Not really sure where I'd set alarm levels either (try to mimic the ones automatically setup for faster bearings on pumps?)

Any advice on this would be appreciated, I really haven't been able to find much on this.

Thanks,
Keith

What system are you using CSI or other.CSI does have a setup for slow speed stuff. SST so you can set the point up using these parameters it is what I use on our slow equipment.I cannot access it right now to even give you the setup as our system is down so if I can remember I will try to send you the particulars for a point like that or maybe someone else can provide it.

We're using Commtest with its Ascent software. It supposedly sets up alarm bands using the Technical Associates method. What I have entered now for these bearings is "gearbox output" for the overall alarm magnitude and "general roller bearing" for what I believe sets the specific alarm ranges based on the rpm, but I don't know if this work around is what I need. (I end up with a velocity spectrum).

Thanks,
Keith

I Keith,
I joined the analysis parameter set i uses on the output shaft of my agitator. I am using CSI so I don’t really know how you can set it up in the Commtest system. Speed is 73 rpm.
Best regard, Marcel

Periodic Analysis Parameter Set Details
***************************************

Database: Procédé.rbm
Report Date: 28/08/08 10:53:29

Set 17 - Gear, 100xTS(400/3)

Spectral Frequency Setup: Orders
Low Frequency Signal Conditioning Limit: 10.00 CPM
Upper Frequency of Spectra: 100.00 Orders
Lower Frequency of Spectra: 0.00 Orders
Number of Lines: 400
Number of Averages: 3
Spectral Averaging Mode: Normal Mode
Window Type: Hanning
Spectral Weighting: None
Perform 1/3 Octave Analysis: No
Use Analog Pre-processor: No
Filter Setting: None
Envelope Demodulator: Model-750 w/o D
Obtain Special Time Waveform: Yes
Special Time Waveform Maximum Frequency: 5000.00 CPM
Special Time Waveform Data Units: Sensor Units
Special Time Waveform Number of Points: 4096
Special Time Waveform Trigger: None

Description Parameter Type of Lower Upper
Units Type Parameter Frequency Frequency
-------------- ------------- --------------- ------------ ------------
1 PK-PK WAVEFORM Default Units P-P Waveform 0.00 0.00
2 CREST FACTOR Default Units Crest Factor 0.00 0.00
3 1xTS Default Units Order Interval 0.70 1.40
4 2xTS Default Units Order Interval 1.40 2.70
5 3xTS Default Units Order Interval 2.70 3.70
6 4-16xTS Default Units Order Interval 3.70 16.70
7 17-32xTS Default Units Order Interval 17.70 32.70
8 33-65xTS Default Units Order Interval 33.70 65.70

Periodic Analysis Parameter Set Details
***************************************

Database: Procédé.rbm
Report Date: 28/08/08 10:54:55

Set 16 - PEAKVUE (1600)

Spectral Frequency Setup: Orders
Low Frequency Signal Conditioning Limit: 0.00 CPM
Upper Frequency of Spectra: 40.50 Orders
Lower Frequency of Spectra: 0.00 Orders
Number of Lines: 1600
Number of Averages: 1
Spectral Averaging Mode: Normal Mode
Window Type: Hanning
Spectral Weighting: None
Perform 1/3 Octave Analysis: No
Use Analog Pre-processor: Yes
Filter Setting: 1000 Hz HP
Envelope Demodulator: PeakVue
Obtain Special Time Waveform: No
Special Time Waveform Maximum Frequency: 80.00 CPM
Special Time Waveform Data Units: Sensor Units
Special Time Waveform Number of Points: 1024
Special Time Waveform Trigger: None

Description Parameter Type of Lower Upper
Units Type Parameter Frequency Frequency
-------------- ------------- --------------- ------------ ------------
1 PK-PK WAVEFORM Acceleration P-P Waveform 0.00 0.00
2 DIG. OVERALL Default Units Order Interval 0.00 40.50
3 1xTS Default Units Order Interval 0.70 1.40
4 2xTS Default Units Order Interval 1.70 2.40
5 3xTS Default Units Order Interval 2.70 3.40
6 4-12xTS Default Units Order Interval 3.70 12.40

quote:

Originally posted by Crashing Keith:
We're using Commtest with its Ascent software. It supposedly sets up alarm bands using the Technical Associates method. What I have entered now for these bearings is "gearbox output" for the overall alarm magnitude and "general roller bearing" for what I believe sets the specific alarm ranges based on the rpm, but I don't know if this work around is what I need. (I end up with a velocity spectrum).

Thanks,
Keith

Sorry to chime in, but wanted to say , nice to see another Commtest user.. I'm in the same boat with you. We too have some slow turning machines. What I have done, is when using the machine builder in Ascent, is I use the actual output rpm of the point in question, and use the general rolling element case A for bearings. This creates a velocity parameter. I then go and edit the parameter to more lines, include twf, and increase the Fmax a bit. I also create a Accel parameter to take along with the velocity reading.

When you review your reading in Ascent, you can switch between velocity, displacement and accel on your original velocity reading by right clicking the spectrum and changing your left axis.