تم تشخيص ارتخاء الجزء الثابت بواسطة أداة اختبار المحرك الكهربائي

Preliminary results

A 6.6 kV motor used for cooling gas after gas-phase polymerization at a petrochemical plant was exhibiting abnormal symptoms. A technician performed a vibration test and observed abnormal vibration. A further test was conducted without load, and the abnormal vibration persisted. The root cause of the vibration remains undetermined. A team from Instrument Resource Co. in Bangkok, Thailand, was contacted to conduct further investigation of the motor to try to identify the cause of the abnormal vibration.

Motor Circuit Analysis™ (MCA™) was performed using ALL-TEST PRO 7 PROFESSIONAL™. Through a series of tests, the AT7™ identified the problem after performing a DYN test function. This special test is designed to verify the integrity and correctness of the stator and rotor. This test requires rotating the motor shaft. ALL TEST Pro’s patented Dynamic Stator and Rotor Signature Test found a defect in the dynamic stator signature.

Dynamic signature analysis

The green line is the stator signature and represents the deviation of average values ​​during rotation for each stage. The two black dotted lines represent the rotor signature and include an upper and lower signature.

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

After the motor was repaired and reassembled, another set of tests was performed using the AT7™. Subsequent testing showed that there was no longer any imbalance in the dynamic stator signature, indicating that the stator was in good working order.

About ALL-TEST Pro, LLC.

ALL-TEST Pro delivers on its promise of genuine engine maintenance and troubleshooting, with innovative diagnostic tools, software, and support that keep your business running smoothly. We guarantee engine reliability in the field and help boost the productivity of maintenance teams everywhere, backing every ALL-TEST Pro product with unparalleled engine testing expertise.