The SEL-551C Overcurrent/Reclosing Relay provides overcurrent relay users with new flexibility in distribution system protection. The SEL-551C provides six inputs and three outputs, with up to two communications ports, for more control options. The SELogic control equations have added rising and falling edge triggers and latches for custom logic applications.
Asset Protection—Monitor and protect distribution feeders, distribution buses, transformers, capacitors, or circuit breakers.
Current Transformer (CT) Connection Versatility—Connect the separate neutral-current input to accommodate core-balance CTs, separate neutral CTs, tertiary-winding CTs, or CT ground-residual circuits.
Reclosing Control—Coordinate with downstream reclosers using sequence coordination logic to program up to four reclosing attempts.
Integration—Integrate into protection and control schemes with the Modbus RTU protocol. The optional front-panel EIA-232 port on the SEL-551C allows easy connection, even while communicating on the rear port.
Complete Overcurrent Protection
Protect lines and equipment using a sensitive and secure mix of phase, negative-sequence, and ground overcurrent elements. Provide high-speed operation, even with severe CT saturation, using the SEL Adaptive Overcurrent Element.
acSELerator QuickSet SEL-5030 Software
QuickSet helps speed up the relay application by allowing you to develop relay settings offline, program SELogic control equations, and analyze post-fault event reports.
Field-Proven Hardware With Optional Features
The six inputs and three outputs are fully programmable to meet your application needs. A wide operating temperature range (–40° to +85°C) allows for installation in a control house or outdoor enclosure.
Advanced Programmable Logic and Local/Remote Controls
Configure traditional or advanced protection and control schemes. Use edge- triggers or latches within the SELogic control equations for advanced control.