Design and Development of a Portable Device for Monitoring and Fault Diagnosis of Industrial Electric Motors

Abstract

Industrial three-phase electric motors are widely used in production systems, and their reliability directly affects operational continuity, maintenance cost, and equipment safety. Abnormal conditions such as overcurrent, undervoltage, overvoltage, overheating, excessive vibration, and phase unbalance may reduce motor performance if they are not detected early. This study presents the design and development of a portable monitoring and fault indication device for three-phase electric motors. The proposed system integrates an ESP32-S3 microcontroller, three PZEM-004T modules for phase voltage and current measurement, a DS18B20 temperature sensor, an ADXL345 accelerometer, a 7-inch DWIN HMI display, a buzzer, and IoT based data transmission using Wi-Fi and MQTT communication. The measured parameters are processed to obtain average voltage, average current, voltage unbalance, current unbalance, temperature, and vibration indication. A threshold-based method is used to identify abnormal conditions and display alarm information. The test results show that the voltage measurement differences between the developed device and the reference multimeter ranged from 0.7 V to 1.2 V, while the current measurement differences between the developed device and the clamp meter ranged from 0.20 A to 0.57 A. The integrated three-phase motor operation test under normal condition showed average voltage and current unbalance values of approximately 1.76%, stable temperature between 33.00°C and 33.25°C, and vibration indication between 0.36 mm/s and 0.85 mm/s. During controlled abnormal motor operation, the system displayed FAULT status and alarm information for low voltage, overcurrent, and high vibration conditions. These results indicate that the developed device can support practical on-site monitoring and early fault indication for three-phase electric motors.