Is it bearing information, number of poles, frame size, number of gears, impellers, blades, horse power, operating voltage, motor type, manufacturer, number of belts, sheave size, or tooth count? Nope! None of the above.

All of the above information is great to have when analyzing vibration data, but the single most important item that is always required is the running speed of the equipment.

Not knowing the true running speed makes vibration analysis impossible for determining the proper defect to be reported. For example, if the speed was recorded at 1,780 RPM, but the true speed was 3,560 RPM and a high peak at 3,560 RPM is present; it could lead the analyst to believe that the 2× turning peak is related to another issue. Having the proper running speed of the equipment will assist the analyst in making the correct diagnoses for the equipment.

Once the correct turning speed has been identified the spectrum can be broken into three types of energy: sub-synchronous, synchronous, and non-synchronous.

Having this information available can assist the analyst when analyzing the vibration data.

by Yolanda Lopez