Allentamento dello statore diagnosticato dallo strumento di prova per motori elettrici

Initial results

A 6.6 kV motor used to cool gas after the gas-phase polymerization process in a petrochemical plant exhibited abnormal symptoms. A technician performed a vibration test and noted abnormal vibration. Another test was conducted without load, and the abnormal vibration persisted. The cause of the vibrations has not yet been determined. A team from Instrument Resource Co. of Bangkok, Thailand, was contacted to further investigate the motor and attempt to determine the cause of the abnormal vibration.

Motor Circuit Analysis (MCA™) was performed with ALL-TEST PRO 7 PROFESSIONAL™. By running a series of tests, the AT7™ identified the problem after running the DYN test function. This specific test is designed to verify the integrity and health of the stator and rotor. This test requires rotating the motor shaft. ALL-TEST Pro’s patented Dynamic Signature test of the stator and rotor detected an imbalance in the stator’s Dynamic Signature.

Dynamic signature analysis

The green line is the stator signature and represents the deviation of the mean values ​​during rotation for each phase. The two dashed black lines represent the rotor signature and include an upper and a lower signature.

The engine was disassembled. Loose stator slot wedges were found. These loose stator slots were causing vibration and excessive imbalance in the stator dynamic signature.

After repairing and reassembling the motor, another series of tests was performed with the AT7™. The next test showed that there was no longer an imbalance in the stator dynamic signature and that the stator was in good condition.

About ALL-TEST Pro, LLC.

ALL-TEST Pro delivers on the promise of true engine maintenance and troubleshooting, with innovative diagnostic tools, software, and support that keep your business running. We ensure engine reliability in the field and help maximize maintenance team productivity everywhere by backing every ALL-TEST Pro product with an unparalleled engine testing experience.