Bay Control for Two Breakers
Complete two-breaker control and breaker failure complement the versatility of the SEL-451 programmable logic to meet your bay control needs. Easily control motor-operated switches, capacitor banks, and field I/O from the front panel or remotely. Configurable labels make it easy to customize relay controls to match your application.

Transformer Inrush Harmonic Monitoring
Apply the second-, fourth-, and fifth-harmonic elements with individual threshold settings to detect transformer energization and overexcitation conditions. The output from these harmonic detection elements can be used for a variety of functions, including modification of relay settings to improve security and event reporting to make identification of transformer energization events fast and simple.

Maximize the Capability of Substation Equipment
Fully load equipment by monitoring power, including thermal or rolling interval demand as well as peak demand on positive-, negative-, and zero-sequence current. Use the full capacity of the equipment while maintaining SEL quality protection.

Advanced Visualization Tools
The SEL-451 offers a configurable HMI for easy integration into your application or operating standards. HMI tools include custom metering and status displays, direct pushbutton access, critical information alarms in chronological order, a rotating display, and time-stamped SER reports. You can reduce errors by automatically scrolling between one-line bay diagrams, custom metering displays, and alarms

Improve Operation With IEEE Synchrophasor Data
Give operators critical system information via serial or Ethernet communications. With the SEL-451, you get the required substation protection, monitoring, and control in addition to a built-in phasor measurement unit at each substation. The relay makes control decisions based on voltage, current, or frequency data from other relays. The synchrophasor real-time control (RTC) capability makes this information available for local or system-wide control and automation.

Digital Fault Recording (DFR)
Combine relaying reliability with true DFR functionality. The SEL-451 Relay’s high-speed sampling (8 kHz) and COMTRADE output provide advanced oscillography. The acSELerator QuickSet SEL-5030 Software graphical user interface makes it easy to view harmonic analysis and events.

High-Accuracy Timestamping
Time-tag binary COMTRADE event reports with real-time accuracy of better than 10 µs. You can view system state information at the time of faults, or with timed triggers, across the entire system. This system state information helps validate system models and improve transfer limits and system stability.

Integrate Many Substation Devices Into One Powerful System Using the SEL-451
Control cooling fans, motor-operated switches, or other equipment using the processing and I/O of the SEL-451. Hardware options let you expand I/O up to 103 inputs or 68 outputs.

Expanded SELogic Control Equations
Use math and logic combinations of analog and digital values for customized applications, adapt system control based on prefault conditions, and scale analog values and latch momentary inputs for SCADA retrieval.

Voltage Sag, Swell, and Interruption (VSSI) Report
Capture power quality data related to voltage disturbances over a long period of time.

Built-In Web Server
Access basic relay information on a standard Ethernet network with the built-in web server. You can view relay status, Sequential Events Recorder (SER) information, metering information, and settings with easy access within a local network. The web server access requires a relay password and is limited to read-only viewing of information.

SEL TiDL-Based Solutions
Apply a TiDL-based process bus solution, where SEL-TMU devices are placed in the yard close to the primary equipment to digitize discrete I/O signals and analog data. SEL-TMU units exchange these data with an SEL-451-6 TiDL relay in the control house. Each SEL-TMU can share data with as many as four TiDL relays, providing protection design flexibility.

TiDL combines the proven protection of the SEL-400 series relays with the purpose-built SEL-TMU, simplifying deployment, reducing training requirements, and increasing availability. TiDL technology uses point-to-point connections and a non-Ethernet protocol. TiDL also provides built-in data synchronization and synchronous sampling, ensuring protection is available in the relay regardless of whether an external time signal is available.

SEL SV-Based Solution
Based on the IEC 61850 standard, SV-based solutions maximize flexibility and interoperability. The SEL-401 Protection, Automation, and Control Merging Unit and the SEL-421-7 Protection, Automation, and Control System Merging Unit digitize analog signals from primary equipment and send them using the Sampled Values protocol to an SEL-451-6 SV relay in the control house. Because all SEL SV devices are compliant with IEC 61850-9-2 and the UCA 61850-9-2LE guideline, the SEL-451-6 SV relay can be used with other manufacturers’ IEC 61850-compliant units.

Flexible Ethernet Communications
The two-, four-, and five-port Ethernet communications card options enable you to communicate using a variety of protocols, including FTP, HTTP, DNP3, PTPv2, PRP, Telnet, synchrophasors, and IEC 61850 Edition 2.

The TiDL and SV relays can be configured with a five-port Ethernet card supporting PRP or failover functionality to increase system availability, as well as the Precision Time Protocol Version 2 (PTPv2) on process bus or station bus ports for time synchronization. Use network monitoring features in the relay to further improve system availability by actively monitoring each redundant path to detect communications network failures.

The five-port card also features dedicated ports and IP addresses for station bus and engineering access networks to provide selective access control. All ports support SFP transceivers. Single- and multimode communications options provide increased flexibility. All ports support 100 Mbps SFP transceivers, and process bus ports also support 1 Gbps SFP transceivers.

Serial Communications
All four independent EIA-232 serial ports support SEL Fast Message, ASCII, Compressed ASCII, Extended Fast Meter, Fast Operate, Fast SER, SEL Mirrored Bits communications, Ymodem, and DNP3 Level 2 Outstation as well as dial-out, Virtual Terminal, and communications with SEL-2600 series RTD modules.

Simplified Settings Management
Use acSELerator QuickSet SEL-5030 Software to develop relay settings offline and program SELogic control equations. Configure the TiDL and SV relays using SEL Grid Configurator, a software tool that increases efficiency and improves settings insights. It features a spreadsheet-style editor, protection visualization, comprehensive reporting, custom filters, and multiple-device settings