Monitoring Kecepatan Motor Tiga Fasa Menggunakan Encoder Berbasis PLC Mitsubishi FX5U

Three-phase induction motors are widely used in industrial environments because they have high efficiency, large torque, and can operate continuously; therefore, a monitoring system is required to maintain safe and optimal motor operating conditions. This study aims to design and develop a three-phase motor monitoring system based on a Mitsubishi FX5U Programmable Logic Controller (PLC) that can monitor motor speed and electrical data in real time. The method includes the use of a rotary encoder as a speed sensor, a Frequency to Voltage Converter module to convert frequency signals into analog signals, and a PZEM-004T sensor to measure current and electrical power. Speed data are processed by the PLC and displayed through a laptop-based Human Machine Interface (HMI), while current
and power data are processed using an Arduino Uno and displayed on an LCD. The test results show that the system can display monitoring parameters properly. Motor speed measurement shows errors of 5.40% and 5.34% compared with a
tachometer. The rotary encoder produces frequencies of 17.92 kHz and 17.94 kHz, while the Frequency to Voltage Converter produces an output voltage of 8.61 V with errors of 3.90% to 4.01%. Load testing shows that current increases from 2.15
A to 2.22 A and power from 161.6 W to 182.3 W as the load increases. Based on these results, the designed monitoring system functions according to the research objectives and can be used as a monitoring tool for three-phase motors in industrial applications.