Surge protective device

SPD is the code and product-standard name for what stores sell as a surge protector. Leviton groups SPDs by where they install. A Type 1 SPD goes before or at the main breaker panel. A Type 2 SPD goes on the load side of the service panel. Type 3 goes at the protected equipment, such as computers and TVs.

Layering types gives more complete protection. A whole-house surge protector is a panel-level SPD. A plug-in strip is the last line of defense. See whole-house surge protector installation.