Online condition monitoring of AHU Motors is key to ensuring critical machinery such as this one in our Global customer’s plant in Singapore, are carefully maintained. In the global pharmaceutical industry, where precision and efficiency are crucial, there is a recognized emphasis on its demanding standards to optimize operations and minimize downtime. For these reasons, at the beginning of 2019 the Eastway Safeguard® System was installed in a pharmaceutical company in Singapore to ensure 24/7 monitoring of both critical and non-critical equipment. Along with this, advanced machine learning models have been developed for these machines, based on the history and type of failures, guiding the company into a new era of predictive maintenance and data-driven insights.

Case description

In January 2023, the Eastway Safeguard® System recorded a moderate rise in acceleration levels for the AHU motor. Acting on this, Eastway recommended to continuously monitor the vibration trend levels of the AHU motor. By March 2023 values continued to increase again and they were detected above warning levels as shown in Figure 1. Additionally, there was a noticeable rise in velocity values. Alerts were sent to key personnel and the Eastway team.

Figure 1. AHU motor non-drive end acceleration trend from Oct 2022 to April 2023

Recommended Action

Upon examining the FFT spectrum of the AHU motor, significant differences were identified when comparing the recent data from January and March 2023 to the baseline data from October 2022. The FFT spectrum from March showed elevated amplitude levels at high frequencies related to the motor bearings, indicating the early stages of bearing deterioration as shown in Figure 2. Based on this analysis, it was recommended to plan the motor bearings replacement at the next downtime

Figure 2. FFT acceleration spectra (g’ RMS) recorded in March 2023

Action taken

As recommended by Eastway, the maintenance team in Singapore replaced both AHU motor bearings during the scheduled downtime in June 2023, resulting in a significant reduction in vibration values, as shown in Figure 3. Upon inspection of the old bearings, several defects were identified, underscoring the accuracy of the previous analysis. The client’s feedback regarding the bearings indicated an inner ball defect, noticeable scoring marks on both bearing balls, and corrosion on the outer races of both drive and non-drive end bearings, see Figure 4. This feedback confirmed the importance of the timely intervention, emphasizing the efficacy of the Eastway Safeguard® System monitoring of AHU motor, in preventing potential extensive damages and unplanned downtimes.

Figure 3. AHU motor non-drive end velocity trend showing a high decrease in values after motor bearings replacement.

Figure 4. Defects on the balls of the motor non-drive end bearing


By proactively identifying the AHU motor bearing deterioration, Eastway Safeguard® System facilitated timely intervention and ensured that the necessary components and tools were promptly arranged. Thus, in addition to identifying problems and dramatically reducing downtime, the detection also significantly reduced the man hours to replace the components and carry out maintenance work.

Table 1 highlights the importance of online monitoring of AHU motors. In this case, early detection of motor bearings was detected by the Eastway Safeguard® system, allowing timely corrective action.

Table 1. Estimated cost savings

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