Substation-Hardened Ethernet
An Ethernet port is included on every SEL-351S Relay. Multiple Ethernet options simplify integration into new or existing Ethernet networks. Enhance reliability and availability by incorporating dual-port Ethernet SEL-351S Relays in a self-healing ring structure or in a dual-redundant configuration.
Built-In IEEE C37.118 Synchrophasors
Monitor distribution and transmission networks to detect potential cascading voltage collapse before it happens. IEEE C37.118 synchrophasors, at up to 60 messages per second, allow access to system values for wide-area monitoring and control. The IEEE C37.118 standard simplifies communication and data coordination between synchrophasor measurement units.
SafeLock™Trip/Close Pushbuttons
Optional independent trip/close pushbuttons and high-visibility indication provide direct breaker control. Simplify installation and panel wiring with built-in control switches. The SafeLock system keeps pushbuttons secure when not in use and accommodates tag-out procedures.
Innovative Directional Element Polarization
Positive-sequence voltage-polarized phase directional element with memory for directional stability during phase faults. Best Choice Ground Directional Element™ system logic for secure ground directional element operation for all types of system grounding practices under varying system conditions.
- Large Operator Controls
Large front-panel keyboard with local display panel and programmable operator control interface pushbuttons to replace unnecessary control switches and wiring at the breaker control panel. Under- / Overfrequency Protection
Six levels of frequency elements, plus under- / overvoltage protection for advanced load shedding.
Mirrored Bits® Communications Technology Provides fast and reliable relay-to-relay communication for advanced communications-assisted protection, network reconfiguration, pilot protection, and restoration schemes. Learn more.
Reclosing Control
Four-shot recloser with sequence coordination, synchronism check, and voltage check.
Modbus, DNP3, and ASCII protocols
Easily integrate into new or existing networks with these popular protocols. SCADA links, local HMI, and dial-in modems can access important relay data.
- Recloser Time-Overcurrent Curves
Use any of the 38 traditional recloser curves in the SEL-351S Relay to time-coordinate with downstream circuit reclosers. Sequence coordination keeps the SEL-351S in step with downstream reclosers and prevents tripping by overreaching overcurrent elements for faults beyond reclosers. Five-each standard US and IEC time-overcurrent curves provide coordination with other time-overcurrent relays. - Fault Locator
Impedance-based fault locator for accurate distance to fault measurements. - Metering, PQ Monitoring
Accurate metering eliminates the need for external meters (MW, MVAR, MWh, MVARh, PF, instantaneous/peak demand). Optional power quality monitoring records voltage sags, swells, and interruptions. Input Voltage Settings
Select line-neutral (wye) or line-line (delta) input ac voltage connections using software setting.
acSELerator® Software
Helps speed relay application by allowing you to develop relay settings offline, program SELogic® control equations, and analyze post-fault event reports.