This paper aims to construct an experimental system using the Arduino UNO microcontroller board to measure the electrical quantities and protect against surge circumstances in a single-phase power supply. The system utilized a voltage sensor and a current sensor, and data was transferred to a personal computer for graphical examination. The Root Mean Square (RMS) method was used to measure electrical values, and the system is allowed to decide whether to turn the load on or off based on the comparison of RMS voltage measurement to the lowest and maximum voltages. The Telemetry Viewer v0.5 software was used to create the monitoring interface, which monitored the system's RMS voltage, RMS current, active power, and trip signal.