The SEL-351S Protection System offers comprehensive feeder and overcurrent protection perfect for industrial and utility feeder applications. Enhance your quality of service with lower costs and innovative features, like Mirrored Bits communications, IEEE C37.118 synchrophasors, expanded operator controls, and SEL's Best Choice Ground Directional Element logic.
Complete Distribution System Protection—Apply a comprehensive mix of overcurrent functions for sensitive protection from phase-to-phase and phase-to-ground faults, and achieve fast operation for three-phase faults.
Reclosing Control—Program the relay four-shot autoreclosing function with synchronism and voltage check logic to mimic a variety of reclosing practices. Sequence coordination logic coordinates with downstream reclosers for a complete protection scheme.
Fast Substation Restoration—Commission automatic substation restoration schemes using programmable user interface controls and Mirrored Bits communications in conjunction with the SEL-2100 Logic Processor.
Reliable Breaker Control—Open or close the circuit breaker manually with the optional SafeLock trip/close pushbuttons, which provide direct control of the breaker independent of the relay.
USB port simplifies local connections and speeds up relay communications
Default displays or programmable custom messages notify personnel of power system events or relay status
Programmable operator pushbuttons and optional user-configurable labels allow for ease of operation
Front-panel LEDs can be programmed to indicate custom alarms
Optional SafeLock® trip/close pushbuttons and bright indicating LEDs allow breaker control independent of the relay
High-current interrupting output contacts increase contact robustness and reliability
Harmonic metering to the 16th harmonic enhances power quality analysis
Dual copper Ethernet port allows communication between devices and provides redundancy. Single or dual fiber-optic ports are also available.
Standard multisession Modbus® TCP, Modbus RTU, DNP3, and IEC 61850 provide communications flexibility
Mirrored Bits® communications provides fast and reliable relay-to-relay communication
EIA-485 port provides quick and easy engineering access
SafeLock® trip/close pushbuttons on the front panel are wired directly to these terminals to allow breaker control independent of the relay
Expanded I/O allows for flexible applications
Sensitive earth fault (SEF) protection accurately detects ground faults with low current values
Built-in phasor measurement unit allows wide-area power system monitoring