Those of us in the maintenance and reliability industry should be aware of the importance of a quality condition-based monitoring program to maintain the reliability of any given operation. We should also know what key tools are necessary for our program. Vibration, oil analysis, infrared, electric motor testing, motor circuit analysis, non-destructive testing, and ultra sound to name a few. But, how do we get the most from each testing method?
That, friends, is the million dollar question!
Rotating machines reside in the realm of vibration but often times lack of available man-power limits how many assets can be covered with quality results. Oil analysis can cover all of the equipment that utilizes lubrication, depending on sampling frequency and procedures. Motor circuit analysis and electric motor testing monitors the electrical health of the motors. How many can be monitored? Well, that depends on which tests are to be performed and availability of the equipment. NDT is a world all of its own, with a few aspects that can be used to isolate and identify structural issues in equipment frames and bases. Ultra-Sound has heavy application in leak detection with applications in electrical (airborne mode) and thru contact, has applications with lubrication. This is how we use these technologies, but how can one help the other to provide a higher level of reliability? IR can monitor motors faster than any of the other methods but is not able to diagnose what fault is in progress. The ability to monitor motors that are not in the Vibration, MCE-EMT, or Ultrasonic lubrication routes, once an anomaly is detected (a motor that is operating hotter than normal), can direct another method to diagnose the problem and have it repaired. The same methodology can be used on slow speed bearings. For a CBM program to be effective the ability to monitor as many assets as possible is very important.
Let’s look at a typical industrial location. Say there are total of 3000 motors at this location. Vibration can cover about 50% of those motors with available man-power and equipment. Of that 50% MCE-EMT covers about 50% (25% of the total) due to the same factors. Ultrasonic lubrication has a total of 70% of the 3000 the remaining 30% are sealed bearings, but takes the crew 3months to complete one pass. Do we just let the other motors go unmonitored? Do we increase staff and purchase more vibration equipment, and more motor testing equipment. Or we can use the IR camera to monitor the other motors not covered by vibration or MCE-EMT, and direct efforts to increase the overall reliability. I am not saying that IR is the first line of defense or the best tool for monitoring motors, but it can definitely help the efforts of the CBM program.