## 5 Research Methodology
### Experimental Setup  
Figure 4 offers a visual illustration of the assembled validation test rig at the Energy Efficiency and Sustainability Technology Laboratory, Faculty of Technology and Education, Suez University. The setup included two mechanically coupled IMs of identical size, each rated at 1.1 kW, 220 V/400 V \(\Delta\)/Y, and 1410 RPM. The motor under investigation was subjected to various fault conditions, while the second motor was connected to a variable frequency (V/F) drive, serving as a mechanical load to ensure controlled operating conditions and accurate fault replication.  
Table 1 provides a comprehensive summary of the faults introduced to the motor during the experimental tests, detailing the specific fault types, severity levels, and corresponding operating conditions to ensure a thorough analysis of the diagnostic methodology. As clearly seen from Table 1, the study focuses primarily on bearing faults, given their prevalence in induction motors [11; 24; 27], and includes a single-phase loss fault to examine electrical imbalance effects [48; 49]. These selections ensure relevance to industrial applications, where bearing degradation and phase loss are common failure modes affecting reliability and operational efficiency.  
The NI-9247 c-series current input module, the NI-9242 c-series voltage input module, and the NI-9263 analog output module were all connected through the chassis of the NI-cRIO 9056 controller (Austin, TX, USA). This setup utilized the Xilinx Artix-7 75T FPGA processor (Xilinx, Inc., San Jose, CA, USA), which managed the data acquisition and control tasks at a 5 kHz sampling rate. The extracted features were then delivered instantaneously to a real-time floating-point processor, an Intel Atom E3805, which handled communication with the centralized server. The captured three-phase RMS values of the voltage and current phasors are illustrated in Figure 5.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Operating** & **Description** & **Scenario** & **Operating** & **Description** & **Scenario** \\
**Scenario** & & **Duration** & **Scenario** & **Duration** \\ \hline No-load & \begin{tabular}{c} Motor running under \\ no-load condition. \\ \end{tabular} & & \begin{tabular}{c} Rear Defect \\ (5 mm) \\ \end{tabular} & \begin{tabular}{c} Motor at full load with a 5 mm \\ defect in the outer race of the \\ near bearing. \\ \end{tabular} \\ \hline Full-load & \begin{tabular}{c} Motor running at full \\ load, drawing a current \\ of 2.73 A. \\ \end{tabular} & \begin{tabular}{c} Front and Rear \\ Defect \\ (2 mm) \\ \end{tabular} & \begin{tabular}{c} Motor at full load with a 2 mm \\ defect in the outer races of both \\ the front and rear bearings. \\ \end{tabular} \\ \hline Front Defect (2 mm) & \begin{tabular}{c} Motor at full load with a \\ face of the front bearing. \\ \end{tabular} & \begin{tabular}{c} Front and Rear \\ Defect \\ (5 mm) \\ \end{tabular} & \begin{tabular}{c} Motor at full load with a 5 mm \\ defect in the outer races of both \\ the front and rear bearings. \\ \end{tabular} \\ \hline Rear Defect (2 mm) & \
\begin{tabular}{c} Motor at full load with a \\ face of the rear bearing. \\ \end{tabular} &
\begin{tabular}{c} Motor operating with a \\ single-phase open fault, where \\ one phase is disconnected \\ during operation. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}
Table 1: Summary of operating scenarios, fault types, and experimental conditions.  
Figure 4: Overview of the experimental setup used for validating the proposed method for fault diagnosis of IMs.  
Figure 5: Three-phase RMS values of voltage and current phasors.