SEL-311L Line Current Differential Protection and Automation System

Use the SEL-311L Line Current Differential Relay with integral four zone distance backup for easy-to-apply, high-speed line protection.

Apply subcycle current differential protection with included four zone distance and directional overcurrent backup. Use single or dual differential channels for reliability. Apply the SEL-311L on two- or three-terminal lines. Unique measuring elements provide coordination with tapped loads. Reduce total project construction and operation costs through integration of the included four-shot recloser and relay logic operators into your automation system.

Improve protection system reliability with continuous checks of communications quality, breaker wear, battery voltage, and relay health. Use the included LCD display in place of traditional panel meters.

Functional Overview

Front- and Rear-Panel Diagrams

Front		Rear

Protect

Apply single-pole or three-pole subcycle current differential protection. Reduce protection system costs by using built-in distance and/or overcurrent backup functions.

Simplify

Innovative operating characteristic makes settings easy. No fault studies are required for most differential applications.

Optimize

Use single or dual channels for reliability. Apply on two- or three-terminal lines with or without tapped lines.

Monitor

Incorporate synchrophasor measurements into wide-area protection and control systems. Use high-accuracy time correlation to improve event report analysis.

Automate

Reduce total project construction and operation costs by integrating four-shot recloser and relay logic operators into your automation system.

Integrate

Improve station integration with serial and Ethernet communications. Use IEC 61850 communications for interoperability between relays with a select-before-operate function for added operational security. Increase communications dependability with dual failover Ethernet.