---
title: "What Is Surge protective device? Electrical Glossary"
description: "A surge protective device (SPD) is the formal name for a surge protector. It diverts extra voltage away from connected equipment."
url: https://danielelectric.multisites.ai/glossary/surge-protective-device
publisher: Daniel Electric
phone: +1-817-481-8606
quote: https://danielelectric.multisites.ai/contact
---

Safety devices

# Surge protective device

A surge protective device (SPD) is the formal name for a surge protector. It diverts extra voltage away from connected equipment.

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](https://danielelectric.multisites.ai/glossary/type-1-spd) goes before or at the main breaker panel. A [Type 2 SPD](https://danielelectric.multisites.ai/glossary/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](https://danielelectric.multisites.ai/glossary/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](https://danielelectric.multisites.ai/whole-house-surge-protector).

[Daniel Electric can helpWhole-house surge protector installation](https://danielelectric.multisites.ai/whole-house-surge-protector)

## Related terms

-   [Type 1 SPD](https://danielelectric.multisites.ai/glossary/type-1-spd)
-   [Type 2 SPD](https://danielelectric.multisites.ai/glossary/type-2-spd)
-   [Whole-house surge protector](https://danielelectric.multisites.ai/glossary/whole-house-surge-protector)
-   [Point-of-use surge protector](https://danielelectric.multisites.ai/glossary/point-of-use-surge-protector)

## Sources

1.  [Leviton: Surge Protective Devices (SPDs) brochure](https://leviton.com/content/dam/leviton/commercial-industrial/product_documents/brochure/Surge%20Brochure%20Condensed%20Q-1186H%20(1)%20(2).pdf)
2.  [Leviton: Surge Protective Devices (SPDs) brochure](https://leviton.com/content/dam/leviton/commercial-industrial/product_documents/brochure/Surge%20Brochure%20Condensed%20Q-1186H%20(1)%20(2).pdf)

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## Need an electrician in Southlake?

Call and tell us what is going on. A photo of the panel label or the problem helps us come prepared. Quotes on new installations are free.

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