Défaut de barre de rotor Problème de maintenance : Alerte au capteur de vibrations

A 398 kW MV motor powering a fan in a cement plant exhibited unusual behavior. Vibration monitoring equipment indicated vibration amplitudes that became chronic over time. The maintenance team, unaware of the problem, ran the motor until the bearings needed replacing. This occurred repeatedly, with no remedy or cause found to explain the bearing failures. On a few occasions, the motor stalled upon startup. Aside from the symptoms, there was no known explanation for the repeated failures of this motor. The motor was used daily between bearing replacements.

The plant’s condition monitoring team called upon Prescon to assess the engine’s condition. Prescon used ESA (Electrical Signature Analysis) to evaluate the engine’s condition. Within minutes, the test revealed that the engine had cracks in the rotor bars and end rings.

Electrical signature analysis (ASE) is a live-voltage testing method where voltage and current waveforms are captured while the motor system is operating, in order to assess the health of the motor system. Live-voltage testing provides valuable information for induction and DC motors, generators, wound-rotor motors, synchronous motors, machine tool motors, and more.

The engine was then stopped and opened. A crack was found in one of the end rings, as shown below.

ESA technology allows users to test motors under load. ALL-TEST Pro’s ESA technology is two instruments in one: a complete motor analyzer (ESA) and a power quality analyzer (PQ). Under-load testing (ESA mode) provides valuable information on the condition of induction and DC motors, generators, wound-rotor motors, synchronous motors, machine tool motors, and more. In PQ mode, it can be used for energy data logging, harmonic analysis, voltage and current graphing, waveform visualization, peak and trough waveform capture, transient capture, and event capture.