Use SEL-387L Line Current Differential Relays for economical, easy-to-apply line protection.
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.
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.
Connect single-mode optical fiber, 1300 and 1550 nm, for distances up to 120 km without a repeater. No additional transceivers are required.
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.
Develop relay settings off-line, program SELogic control equations, and analyze postfault event reports.
The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.
QuickSet is a tool for engineers and technicians to quickly and easily configure, commission, and manage power system devices. QuickSet includes a Graphical Logic Editor and a device template tool to reduce configuration time and streamline deployment.
Learn more and download on the QuickSet software page.
Available on the Blueframe platform, DMA applications automatically collect, store, and manage device-specific information like oscillography, Sequence of Events (SOE) data, device settings, and property information. They also provide automated password rotation and streamlined device audits.
Learn more on the DMA software page.
synchroWAVe Event helps engineers diagnose a protective relay’s behavior during a power system fault. It is a powerful and easy-to-use solution for displaying and analyzing SEL relay event reports and COMTRADE files.
Learn more and download on the synchroWAVe Event software page.