Keeping an “EYE” on Your Motor: Part 2 Synchronous Motor

With the release of the PdMAEYE® permanently installed electric motor test system we look forward to sharing success stories from the field as our customers add this new technology to the MCEMAX® for an optimal electric motor reliability program.

This week the second success story comes from the Cement Industry. In 2023, an estimated 93 million metric tons of cement was produced in the United States with 4.1 billion metric tons worldwide. To put that in perspective of growth, 20 years ago the worldwide cement production was closer to 1 billion metric tons. The critical equipment necessary to support this level of growth requires a lot of maintenance and testing to deliver equipment reliability and peak production. The problem is that a 400% increase in production does not mean a 400% increase in manpower to keep up with the required maintenance and reliability. The reality is with a shrinking workforce and a shrinking knowledge base, industry has to adapt to doing more with less.

While reviewing an automated event alert on a critical finishing mill from the comfort of an air-conditioned office the motor analyst noticed that the In-Rush/Start-Up characteristics changed significantly. A review of the MCEGold Historian (time-series plot) further confirmed the anomaly with a reduction in the Start-Up Current and an increase in the Start-Up Duration from previous start-ups. Synchronous motors start like an induction motor but use amortisseur windings in place of rotor bars. Amortisseur windings are basically solid bars running through the outer face of the field poles with a shorting ring at either end of the bars. Once the motor is up to speed the DC field poles are energized and the rotor synchronizes with the rotating magnetic field of the stator. Any defect in the amortisseur winding reflects greatly on the stator windings during the motor start and the In-Rush/Start-Up test offers the best opportunity to see any degradation in the amortisseur windings. A deeper data review of the voltage and load during the extended start-up cleared the possibility of a reduced voltage on start-up but did show a higher load compared with the normal start. The result was an elevated severity resulting in a priority visit status to perform a visual inspection and perform offline MCE® motor test during the next outage. Automated early remote recognition of the anomaly allowed for a more efficient use of scheduled field time as well as analyst screen time to focus on the problem areas rather than the healthy assets.

To learn more about the new PdMAEYE® permanently installed technology view the Product page.

To hear more about synchronous motor testing considerations listen to Considerations for Testing Synchronous Motors, a webinar by Noah Bethel, VP of Product Development at PdMA Corporation, hosted by CBM Connect®.