Un outil d’essai de moteur électrique permet de diagnostiquer le relâchement du stator

First results

A 6.6 kV motor used to cool gas temperature after it has undergone a gas-phase polymerization process at a petrochemical plant exhibited abnormal symptoms. A technician performed a vibration test and noticed an unusual vibration. Another test was conducted with no load, and the abnormal vibration persisted. The root cause of the vibration has not yet been determined. A team from Instrument Resource Co. in Bangkok, Thailand, has been contacted to examine the motor more thoroughly and attempt to determine the cause of the abnormal vibration.

The Motor Circuit Analysis™ (MCA™ ) was performed using ALL-TEST PRO 7 PROFESSIONAL™ software. After running a series of tests, the AT7™ identified the problem following the execution of the DYN test function. This particular test is designed to verify the integrity and health of the stator and rotor. It requires the motor shaft to rotate. The patented ALL-TEST Pro test of the stator and rotor dynamic signature revealed an imbalance in the stator’s dynamic signature.

Dynamic signature analysis

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

The motor was disassembled. Loose stator slot shims were found. These loose stator slots were the cause of the excessive vibration and imbalance in the stator’s dynamic signature.

Once the motor was repaired and reassembled, another series of tests was performed with the AT7™. The following test showed that there was no longer any imbalance in the dynamic signature of the stator, indicating that the stator is in good condition.

About ALL-TEST Pro, LLC.

ALL-TEST Pro delivers on its 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 the productivity of maintenance teams worldwide, backing every ALL-TEST Pro product with unparalleled engine testing expertise.