Fan bearing and MCM anomaly in sensorless predictive maintenance
The identification of anomaly in fan bearing and MCM, in predictive maintenance without sensors is the case treated in this article.
The MCM Monitoring System
MCM is a technology of analysis of electric motors recent, that works based on Artificial Intelligence that compares the real engine, to be monitored, with a mathematical model of the engine, running up to 600 different load conditions. This mathematical model is obtained from a learning period lasting a few days.
The MCM Monitoring and Diagnostic System is also designed to detect electrical failures in motors., in response to the limitations of measuring vibrations com without sensors is the case treated in this article. In addition to the electrical failure modes, also detects mechanical failure modes the engine or driven machinery. without sensors is the case treated in this article vibration analysis.
Fan bearing and MCM anomaly – Working principle
To perform the analysis of electric motors MCM monitor uses a combination of dynamic waveforms for voltage and current, along with learned models, to detect faults in the motor or the driven equipment. Learning is supported by an additional database, if the monitor has been installed in an already faulty engine. The monitor detects differences between the observed current characteristics and the characteristics learned and relates these differences failed.
Engine fault detection is based on an engine model, learned by the monitor, physics-based, wherein the constants in the model are calculated from data in real time and compared to values previously learned.
Mechanical failure detection is based on spectral power density amplitudes. (PSD) in specific frequency bands, in relation to the learned values. This information is automatically combined with specialized knowledge in diagnosis. Because of this spectral band approach, mechanical fault detection provides guidance for a class of possible failures. Sensitivity to some flaws (for example, bearing failures of the rolling elements) decrease with distance from the component fails pathways. On the other hand, failures that increase engine load are independent of distance from the engine.
Fan bearing and MCM anomaly – The report
The report is issued automatically by the system, without the need for interpretation of an expert.
case study – Fan bearing and MCM anomaly
This case took place in a stained glass fan.
In 17 of july 2015, an increase in the equipment bearing parameter was observed and the MCM gave the alarm ‘Examine 1’ after a set period of time.
This was clear from the management view..
It was also obvious in the trend evolution..
The maintenance team detected a noise in the bearing and the failure was confirmed.
In 3 August 2015, spare equipment was commissioned during the scheduled maintenance activity.
When the anomaly was corrected the values returned to normal.
