The SEL-351A Protection System has built-in Ethernet and IEEE C37.118 synchrophasors, and is the economical solution for overcurrent protection. Easy-to-use feeder protection and innovative features like SEL's Best Choice Ground Directional Element® logic and SELogic® control equations provide superior protection on utility and industrial power systems.

IEC 61850 Communications Protocol
Combine IEC 61850 technology, Ethernet network, and the SEL-351A Protection System for the fastest overall performance of IEC 61850 relays for substation automation and control. Streamline configuration of IEC 61850 enabled relays with acSELerator Architect^® SEL-5032 Software.
Built-In Web Server
Access basic relay information on a standard Ethernet network with the built-in web server. View relay status, Sequential Events Recorder (SER), metering information, and settings for easy access within a local network. Web server access requires relay password and is limited to read-only viewing of information.
Simple Network Time Protocol
Simplify wiring and installation by receiving a time signal over existing Ethernet networks. SNTP makes a good backup to more accurate IRIG-B time synchronization. The 5 ms accuracy is ideal for basic time synchronization throughout a substation.
Substation-Hardened Ethernet
An Ethernet port is included on every SEL-351A Relay. Multiple Ethernet options simplify integration into new or existing Ethernet networks. Enhance reliability and availability by incorporating dual-port Ethernet SEL-351A Relays in a self-healing ring structure or in a dual-redundant configuration.
Built-In IEEE C37.118 Synchrophasors
Monitor distribution and transmission networks 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. The SEL-351A-1 is also available as a dedicated phasor measurement unit (PMU).
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 provides directional stability during phase faults. Best Choice Ground Directional Element system logic provides secure ground directional element operation for all types of system grounding practices under varying system conditions.
Modbus^®, DNP3, and ASCII Protocols
The SEL-351A easily integrates into new or existing networks with these popular protocols. SCADA links, local HMI, and dial-in modems can access important relay data.
Dependable Overcurrent Protection
Six levels of phase, negative-sequence, neutral, and residual overcurrent elements give coordinated protection, and phase and sequence under- and overvoltage elements maximize control scheme flexibility.
Enhanced Security
Voltage or load-encroachment control of the four phase time-overcurrent elements provide load security.
Under-/Overfrequency Protection
Up to six steps of accurate frequency elements provide multilevel under- and overfrequency trip and control.
Reclosing Control
Programmable four-shot recloser with optional synchronism check match a variety of reclosing practices.
Metering, Power Quality (PQ) Monitoring
Accurate metering eliminates the need for external meters (MW, MVAR, MWh, MVARh, PF, RMS, and instantaneous/peak demand). Harmonic metering to the 16th harmonic simplifies power quality analysis.
Input Voltage Settings
Select line-neutral (wye) or line-line (delta) input ac voltage connections using software setting.

HOTPASH

SEL-351A Protection System