Surge suppressor units are a kind of protective device used to ensure that electrical equipment is not damaged by a sudden voltage spike. This can be caused by a lightning strike or simply an electrical fault. Surge suppressors are often built into devices such as power strips, but they are also available as standalone units.
Surge suppressor units protect devices by blocking or diverting the excess voltage to the ground. They are triggered when the voltage exceeds a pre-determined threshold. They are often used as part of power distribution units, and sometimes come with a warning light to indicate pre-failure.
Surge suppressor units can vary in a number of ways, including the mounting method they require, their maximum surge current, and the type of electrical equipment they are to be used with. For example: