PROTOTYPE OF AN IOT-BASED PLC CONTROL AND MONITORING SYSTEM FOR POWER SUPPLY (GENERATOR SET) AND ELECTRICITY EFFICIENCY MONITORING AS ELECTRICAL ENGINEERING LEARNING MEDIA

Abstract

Electrical equipment may be damaged or become unavailable when the supplied power exceeds system capacity or when the main electricity supply experiences a blackout. Generator sets are commonly used as backup power sources, but their limited capacity requires appropriate load prioritization. This study developed a prototype integrating a programmable logic controller (PLC), PZEM-004T electrical sensor, ESP32 microcontroller, relay modules, and a web-based monitoring interface to control priority and non-priority loads. A prototype-based experimental method was employed through whole-system functional testing, no-load testing, measurements under 5 W, 6 W, and 19 W load conditions, website data acquisition, and overload-control testing. Ten website measurements were recorded at two-second intervals for each load. The mean website power readings were 4.80 W, 5.74 W, and 18.50 W, corresponding to relative deviations of 4.00%, 4.33%, and 2.63% from the nominal load ratings. Comparison between the reference voltage measurements and website readings produced an average relative difference of 0.29%. The website displayed voltage, current, and power data consistently, while the PLC and relay system performed the intended load-control function. However, end-to-end communication latency and repeated overload-detection accuracy were not separately quantified. The prototype provides a practical platform for learning electrical measurement, PLC programming, load management, embedded systems, and IoT-based monitoring. Further research should use calibrated reference instruments, repeated overload trials, network-latency measurements, and long-term reliability testing.