Hubbell Power Systems - Metal Oxide Varistor

Hubbell Power Systems has been manufacturing high voltage surge arresters for over 70 years. Surge arresters protect power utility equipment from damage by high voltage sources such as lightning strikes. The component critical for the arrester to work is the M-O-V —the heart of the surge arrester. The MOV or Metal Oxide Varistor is a disk or block of crystalline semiconductor material made from zinc oxide. A varistor can instantly change its resistance to voltage from high resistance, during everyday operation, to low resistance if a lightning strike threatens nearby. An MOV can survive lightning strikes over and over so that power grid equipment is never affected. To manufacture an MOV requires state-of-the-art technology to incorporate additives into a crystal matrix that gives an MOV special electrical properties.