Electrical Fault Spectrum Examination - Rotor Bar Problem / Loose Rotor Bars
High temperature was diagnosed in a 4-pole, 1480 RPM motor, but no vibration warning was observed. A high ‘G’ value was detected in the Motor - Front Bearing Housing, indicating a potential rotor bar problem.
Electrical Fault Spectrum Examination (Rotor Bar Problem / Loose Rotor Bars):
- 4 Pole 1480 Rpm ( 1X = 24.66 Hz / Stop - Start Motor) During the vibration measurement made in the electric motor, high temperature was diagnosed, but no warning was observed in vibration values (Speed RMS).
- As a result of the detailed measurement taken, a high 'G' value was observed in the Motor - Front Bearing Housing and when evaluated according to the Acceleration Severity Chart, it was determined that the 'G' value was at a dangerous level.
- In the spectrum data presented in the appendix; The peak (RBF), which is at the 58th order and gives 2X Line Frequency sidebands, is approximately 6 'G'. ( RBF = can be between at 40-60 Orders )
- After the diagnosis, the possibility of high amperage draw and heating due to coupling misalignment was taken into consideration, but during the checks, it was observed that the coupling was within the misalignment tolerances.
- After the checks, it was thought that the situation could be a Rotor Bar Problem and a motor-current analysis was requested for detailed examination.
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