Easy Application
Protect two-terminal transmission lines 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 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. 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.