Surge Protective Devices (SPD) are circuit protection components designed to help limit the impact of transient overvoltage events on electrical and electronic systems. They operate by diverting or clamping surge energy away from sensitive circuitry to reduce the likelihood of damage and disruption.

Within the broader Circuit Protection category, SPDs are used as protective elements that complement other protection functions by addressing short-duration voltage spikes and surges.

• Primary purpose: Mitigate transient overvoltage stress on circuits and connected equipment.
• Protection approach: Provide a controlled path for surge energy or constrain the voltage to a safer level.
• Common implementations: Built using dedicated surge-handling technologies and assemblies intended for electrical surge suppression.