Design of a Sag and Surge Detector For Residential Voltage

An inexpensive protection device capable of disconnecting a load upon detecting a voltage sag or surge is presented. Said device is aimed towards the residential voltage of Venezuela’s electrical system. The device is based on the Arduino platform, and uses an ATmega 328P. It detects the presence of a voltage sag or surge by sampling the residential voltage used to feed the load, and continuously measuring the RMS $\frac{1}{2}$ voltage. It disconnects the load after 3 semi-cycles where the residential voltage is outside the boundaries established by Venezuela’s national electrical code, and therefore there is the presence of a voltage sag or surge. The device is capable of transmitting the data of the sampled signal, for making further analysis.