This paper describes the importance of study the overvoltages in medium voltage network. Based on that, an overview of a prototype to register overvoltages in networks of 11.4 kV is carried out. This prototype can register some parameters of this phenomenon without performing any operation on the system. In the first section a summary of the most important concepts of overvoltages is presented, and then the different stages of the prototype are presented, including the sensor, acquisition and processing of the recorded data.
