Medium voltage surge arrester are electrical devices designed to protect electrical equipment from surges or transients that occur on medium-voltage power systems. These systems typically operate at voltages between 1kV and 36kV, and they are commonly found in various industries, such as manufacturing, oil and gas, and utilities.

Medium voltage surge arresters work by detecting and diverting excess voltage away from the equipment and toward the ground. They are typically composed of metal oxide varistors (MOV) or zener diodes, which provide a low resistance path to the ground during transient events. When a surge or transient occurs, the surge arrester conducts the excess energy to the ground, protecting the equipment from damage.