# SEL (Schweitzer Engineering Laboratories)

> Schweitzer Engineering Laboratories (SEL) is the premier global manufacturer of digital protection relays, bay controllers, and substation automation systems with an industry-leading 10-year warranty.

> Headquarters: Pullman, Washington, USA - Warranty: 10 years - Sample models below: 7 (total catalog models: 7)

**Canonical:** https://voltformer.com/brand/sel-schweitzer - markdown: https://voltformer.com/brand/sel-schweitzer.md

## Overview

Schweitzer Engineering Laboratories (SEL) is the premier global manufacturer of digital protection relays, bay controllers, and substation automation systems with an industry-leading 10-year warranty. Request a formal factory quotation through Voltformer. Verify applicable standards, guaranteed ratings and declarations of conformity against the exact offered-model documentation and project jurisdiction. The IEC/EN 50708 series and EU Regulations 548/2014 and 2019/1783 apply only where the transformer and market fall within their legal scope.

## Official sources

- https://selinc.com/

- **Last reviewed:** 2026-09-13

## Sample Models

- [sel-487e - SEL-487E Transformer Protection Relay](https://voltformer.com/product/sel-487e-transformer-protection-relay.md)
- [sel-787 - SEL-787 Transformer Protection Relay](https://voltformer.com/product/sel-787-transformer-protection-relay.md)
- [sel-751 - SEL-751 Feeder Protection Relay](https://voltformer.com/product/sel-751-feeder-protection-relay.md)
- [sel-451 - SEL-451 Protection, Automation, and Bay Control System](https://voltformer.com/product/sel-451-protection-automation-bay-control-system.md)
- [sel-387 - SEL-387 Current Differential & Overcurrent Relay](https://voltformer.com/product/sel-387-current-differential-overcurrent-relay.md)
- [sel-411l - SEL-411L Advanced Line Differential & Automation System](https://voltformer.com/product/sel-411l-advanced-line-differential-distance-automation-system.md)
- [sel-2440 - SEL-2440 Axion Discrete Programmable Automation Controller](https://voltformer.com/product/sel-2440-axion-discrete-programmable-automation-controller.md)

## RFQ

Use the family-specific search/get tools in [the tool reference](https://voltformer.com/tool-reference.md) to choose an exact SKU or ID. RFQ submission requires authentication, a complete draft and explicit user confirmation; unknown project inputs must not be invented.