Surge Protection Devices (SPD) are used to protect the system or application from over-voltage.
A surge protection device (SPD) is designed to limit transitory overvoltage and divert current waves to the earth in order to limit the amplitude of this overvoltage to a value that is less dangerous towards the electrical installations and switch gears.
It commonly installed in power distribution panels, process control systems, communication systems, and other heavy-duty industrial systems to protect against the surge of electrical current that may include the caused by lightning.
