Design of a Selective Load Protection System for Households Using Node-RED with Priority-Based Load Shedding Method
Keywords:
ESP32, PZEM-004T, Load Shedding, Thermal MCB Curve, Node-RED, MQTT, DFPlayer Mini, Voltage ProtectionAbstract
Overvoltage and undervoltage are electrical disturbances in household) s that
can damage electronic equipment. The use of excessive loads, especially
compressor-based devices that are vulnerable to on-off cycles due to
conventional MCB trips, can shorten equipment life. This study aims to design
and build a selective load protection system based on IoT using the
Priority-Based Load Shedding method with Node-RED integration. The
system uses ESP32, three PZEM-004T sensors, relay module, and DFPlayer
Mini for local audio alerts, with MQTT protocol via HiveMQ broker for
real-time communication. Test results show the PZEM-004T sensor has voltage
error 0.35%–0.49%, active power 3.6%, and current 6.19%. Voltage protection
successfully interrupts power flow in less than 2 seconds. The load shedding
mechanism successfully unloads non-priority loads sequentially when total
current exceeds the safe limit. The Node-RED dashboard can monitor all
electrical parameters in real time and send direct control commands to
hardware.
