A Surge Protective Device (SPD) is a component designed to protect electrical and electronic equipment from transient overvoltages, such as those caused by lightning strikes or power grid switching. It works by limiting the voltage supplied to a device and diverting excessive current to the ground, thereby preventing damage to connected equipment. SPDs are commonly installed in power distribution panels, communication systems, and data networks. They are classified into three types: Type 1 (for high-exposure outdoor lines), Type 2 (for sub-distribution boards), and Type 3 (for point-of-use protection). Using SPDs improves system reliability and reduces downtime caused by surge-related failures.
