This is the server.
If you mean to be using the Production ("Live") site, please go to selinc.com.
This server is used for reviewing content or features before they go live. The content, data, and functionality on this site may not match the live production website.

SEL-387L

Line Current Differential Relay

Use SEL-387L Line Current Differential Relays for economical, easy-to-apply line protection.

Starting At

USD2,940

Request more information

*Required


Find Rep By Location

Line Current Differential Protection—Protect two-terminal transmission and subtransmission lines with the same ratio CTs on each end. Apply a 64 kbps digital communications channel for complete phase and ground fault protection with simple settings.

Simple Installation—Set the relay in minutes! Only label the relay and terminals, and provide a unique address for the transmit and receive communications. Connect single-mode optical fiber, 1300 nm and 1550 nm, for distances up to 120 km (74 mi) without a repeater. No additional transceivers are required.

Differential Communications—Apply the SEL-387L Line Current Differential Relay with a multiplexed communications system using single-mode fiber optics or the built-in IEEE C37.94 compliant connection. Connect to EIA-422 and G.703 multiplexers by using the SEL-3094 Interface Converter.

Three-Terminal and Tapped Lines—Protect three-terminal lines with two SEL-387L Relays and one SEL-311L Line Current Differential System. Coordinate the tapped load protection for sensitivity and speed by designating the SEL-311L as the leader to make all the protection decisions. No settings are made in the SEL-387L Relays.

Simple Backup Protection—Choose the SEL-387L as a simple solution for discrete backup protection. Coordinate with another local relay, such as an SEL-551 Overcurrent/Reclosing Relay, to provide breaker failure, autoreclose, overcurrent, and ground fault protection functions in addition to current differential protection.

Easy Application
Protect two-terminal transmission lines and subtransmission lines with the same ratio CTs on each end. Apply a 64 Kb digital communications channel for complete phase and ground fault protection with no settings.

Simple Installation
Connect single-mode optical fiber, 1300 and 1550 nm, for distances up to 120 km without a repeater. No additional transceivers are required.

Flexible Communications
Apply the SEL-387L with a multiplexed communications system using the built-in IEEE C37.94 compliant connection. Connect to EIA-422 and G.703 multiplexers using the SEL-3094 Interface Converter.

Low-Cost Replacement of Obsolete Systems
Use the SEL-387L for complete protection of two-terminal lines. Save money with low equipment costs and no settings costs. Replace error-prone pilot-wire relays with a sensitive and secure fiber-optic line current differential relay. Use the built-in communications monitoring and alarm system to improve protection quality.

acSELerator Software
Develop relay settings off-line, program SELogic control equations, and analyze postfault event reports.

  • IEEE C37.94 compliant multimode fiber-optic interface
  • 1300 nm multimode or single-mode interface
  • 1550 nm single-mode fiber-optic interface
  • Conformal Coating protects equipment from harsh environments and airborne contaminants, such as hydrogen sulfide, chlorine, salt, and moisture.

Product Certifications

UL_CSA_CE_Logos
GSA_Logo