html{display:none} SEL-351A Protection System | Schweitzer Engineering Laboratories


Protection System

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.

Starting At


Request a Follow-Up



Request a Follow-Up

Comprehensive Protection—Provide primary or backup overcurrent protection on distribution feeders with sensitive phase, negative-sequence, residual, and neutral overcurrent protection elements.

Relay Access Convenience—Access basic relay information on a standard Ethernet network with the built-in web server. Securely update firmware and view relay status, settings, and other read-only information within a local network.

Protection Scheme Security—Set the bus overcurrent backup relay close to maximum bus load current levels by using load-encroachment logic to increase security in the system.

Fault Location—Estimate fault locations accurately and reduce total costs by eliminating the need for expensive communications channels, special instrument transformers, prefault information, or line crews to travel the distance of the line for visual fault inspection.

Optimized Asset Utilization—Validate system load flow and fault models by using instantaneous voltage angles from IEEE C37.118 synchrophasors. Use system-state measurements to increase stable system loading through reduced margin requirements.

  • Integrate and automate substation equipment, even devices from multiple vendors, with IEC 61850 communications protocol.
  • Provide primary or backup overcurrent protection on distribution systems with sensitive phase, negative-sequence, residual, and neutral overcurrent protection elements.
  • Use wire-alike terminal configurations to take advantage of advancing technology, improving system protection performance and reducing total costs. This is the wire-alike upgrade for the popular SEL-251 Relay.
  • Set the sensitive phase and ground directional elements for accurate and secure fault detection.
  • Enhance sensitivity with two independent residual ground time-overcurrent elements.
  • Measure and record in nonvolatile memory MW, MVAR, MWh, MVARh, PF, instantaneous and/or peak demand, eliminating the need for external meters.
  • Provide multistep load-shedding schemes using under-/overfrequency elements.
  • Use acSELerator QuickSet SEL-5030 Software to manage your relay settings.
  • Use acSELerator Team SEL-5045 Software to automatically gather relay event reports on your PC and manage them with a database.
  • Use synchroWAVe Event Software


    1. 1

      USB port simplifies local connections and speeds up relay communications

    2. 2

      Front-panel LEDs alert operators in the substation to faulted phases, the relay’s status, and element operation

    3. 3

      Default displays or programmable custom messages notify personnel of power system events or relay status

    4. 4

      Optional SafeLock® trip/close pushbuttons and bright indicating LEDs allow breaker control independent of the relay

    1. 1

      High-current interrupting output contacts increase contact robustness and reliability

    2. 2

      SafeLock® trip/close pushbuttons on the front panel are wired directly to these terminals to allow breaker control independent of the relay; this is an optional feature.

    3. 3

      Harmonic metering to the 16th harmonic enhances power quality analysis

    4. 4

      Sensitive earth fault (SEF) protection accurately detects ground faults with low current values; this is an optional feature. 

    5. 5

      Built-in phasor measurement unit allows wide-area power system monitoring

    6. 6

      Dual copper Ethernet port allows communication between devices and provides redundancy

    7. 7

      Standard multisession Modbus® TCP, Modbus RTU, DNP3, and IEC 61850 provide communications flexibility; this is an optional feature.

    8. 8

      EIA-485 port provides quick and easy engineering access



  • SELogic control equations
  • Event reports
  • Sequential Events Recorder (SER)
  • Breaker wear monitor
  • DNP3 Level 2 Outstation
  • Modbus RTU and TCP
  • High-accuracy metering
  • Remote and local control switches
  • Wye or delta voltage connection
  • Synchrophasor measurements
  • Fault locator
  • Fast SER protocol
  • acSELerator QuickSet Compatible
  • Conformal coating
  • SafeLock independent trip/close pushbuttons
  • Dual copper, single or dual fiber-optic Ethernet ports
  • Panel-mount or rack-mount hardware package
  • EIA-485 serial port

Minimum Software Version

Latest Firmware Versions

There are no firmware versions available for this product.

Product Revision Firmware ID Date Available Serial Number
SEL-351A R518-V1 SEL-351A-R518-V1-Z107106-D20210917 9/28/21 ~1212710001 or ~3212710001
SEL-351A-1 R518-V1 SEL-351A-1-R518-V1-Z107106-D20210917 9/28/21 ~1212710001 or ~3212710001

The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.

Minimum Software Version

Sales Resource Central access is required to view the content in this tab.

Sales Resource Central

3xx Software Tab

Configuration Software

acSELerator QuickSet SEL-5030 Software

QuickSet is a tool for engineers and technicians to quickly and easily configure, commission, and manage power system devices. QuickSet includes a Graphical Logic Editor and a device template tool to reduce configuration time and streamline deployment.

Learn more and download on the QuickSet software page.

acSELerator Architect SEL-5032 Software

Architect allows users to configure and document IEC 61850 systems that include GOOSE, Sampled Values (SV), or Manufacturing Message Specification (MMS) communications. Architect automatically compares SCL files with IEC 61850 requirements to ensure standard compliance.

Learn more and download on the Architect software page.

Automated Data Collection

SEL Data Management and Automation (DMA) Application Suite

Available on the Blueframe platform, DMA applications automatically collect, store, and manage device-specific information like oscillography, Sequence of Events (SOE) data, device settings, and property information. They also provide automated password rotation and streamlined device audits.

Learn more on the DMA software page.

Visualization and Analysis

SEL-5601-2 synchroWAVe Event Software

synchroWAVe Event helps engineers diagnose a protective relay’s behavior during a power system fault. It is a powerful and easy-to-use solution for displaying and analyzing SEL relay event reports and COMTRADE files.

Learn more and download on the synchroWAVe Event software page.

Product Certifications