By dissipating and diverting excess voltage, Wiremold Sentrex and Perma Power surge protection devices keep your critical systems functioning properly and provide maximum protection for advanced electronic equipment. Electrical surges are present in every AC power system. They can penetrate a facility via AC, telephone, and communication lines, or on any other wires that enter a building. Surges and noise are also generated inside a building by fluorescent lighting, office machines, electric motors and HVAC equipment.