Vibration technician

Figure 10-2 A vibration technician taking readings on a cooling water pump.

Focusing repair efforts to the source of the machine problems via vibration diagnoses so that repairs are effective and efficient. One service request for the vibration technicians involved a 200-H.P. motor-driven, induced-draft fan. An area maintenance crew considered sending the large motor to a repair shop because they were unable to get the system to operate smoothly. The vibration technician diagnosed the problem as a simple imbalance in the fan, which was corrected easily with balance weights. 

After the initial programming of the state-of-the-art data collector units, a display window on the modnle provides a description of each piece of eqnipment on the surveillance route in seqnence. The vibration technician inspector, prompted by the instalment readont, walks np to the operating eqnipment described on the display and thrasts a probe on the indicated bearing or other data point. When the analyst presses a button, the modnle captnres the vibration level and any required analysis data. The data collector antomatically identifies tronbled sets based upon preset alarm values and collects spectmm data. Once the data collection is completed on an equipment point, the program automatically advances to prompt data collection at the next point [10]. 

For example, many include a low-level alert that automatically alerts the technician when acquired vibration levels are below a pre-selected limit. If these limits are properly set, the alert should be sufficient to detect this form of bad data. 

With the combined power of the data collector and system software, data acquisition has been reduced to simple measurement routes that require limited operator input. The technician s role is to temporarily mount a transducer at the proper measurement point and push a button. The microprocessor automatically acquires conditions, evaluates, and stores the vibration data. 

Three well-trained, full-time, energetic analysts comprise the surveillance crew of the PPG Industries Vibration Group. The technicians develop their skills through self-study, peer support, periodic out-of-plant training, years of experience and participation in the Vibration Institute. The program has three fundamental components Surveillance, Analysis, and Correction. 

Technicians require minimal effort to generate surveillance and summary reports, once the vibration data is collected. The vibration signals from the operating equipment is computer classified using proprietary computer programs into three levels of operation (1) Smooth, (2) Marginal, and (3) Rough. 

One example illustrates a simple solution. When heating and cooling technicians create a section of a duct for handling conditioned air, it is common to place an X crease on the large panel sections. The crease stiffens the flat side of a large duct and prevents vibration from occurring. 

Figure 12.3 A technician gathering vibration readings from a refrigeration compressor to help ensure reliabiUty.

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