Dual Breaker Bay Control—Meet your bay control needs with complete two-breaker control and high-speed breaker failure detection. Easily control motor-operated switches, capacitor banks, and field I/O from the front panel or remotely. Use configurable labels to customize relay controls to match your application.
Rapid Bay Control Commissioning—Choose among different bus configurations, including single- and dual-busbar, transfer bus, tie-breaker, breaker-and-a-half, ring-bus, double-bus/ double-breaker, and source-transfer configurations. These bus arrangements allow easy status and control of as many as ten disconnect switches and two breakers.
High-Impedance Fault Detection—Detect high-impedance faults with Arc Sense technology (AST). High-impedance faults are a common result of a downed conductor on surfaces with poor conductivity. With AST, alarm or trip for faults that produce low fault current and are undetectable with conventional overcurrent relays.
Complete Overcurrent Protection—Customize distribution protection with multiple instantaneous and time-overcurrent elements combined with SELogic control equations. Best Choice Ground Directional Element logic optimizes directional element performance and eliminates the need for many directional settings.
Pad-Mounted Switchgear Protection—Protect pad-mounted switchgear with the SEL-451 with low-energy analog (LEA) voltage inputs; this helps to save in overall system cost by eliminating the need for amplification electronics between the line sensor and the relay. Having fewer devices also leads to a simpler system, a reduction in labor costs, and elimination of a possible point of failure.
Breaker Wear Monitoring—Compare published data of the breaker’s manufacturer to the actual interrupted current and number of operations for two breakers, and create alarms accordingly. Monitor mechanical and electrical interruption time per pole, comparing average and last trip times for maintenance scheduling.
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.
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) 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.
Simple Network Time Protocol (SNTP)
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 good for basic time synchronization throughout a substation.
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 human-machine interface (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 timestamped SER reports. Reduce errors by automatically scrolling between one-line bay diagrams, custom metering displays, and alarms.
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. Use configurable labels to customize relay controls to match your application.
Improve Operation With IEEE Synchrophasor Data
Give operators critical system information via serial or Ethernet communications. Install required substation protection, monitoring, and control using the SEL-451, and get a built-in phasor measurement unit at each substation. Make 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.
Time-tag binary COMTRADE event reports with real-time accuracy of better than 10 µs. View system state information at the time of faults, or with timed triggers, across the entire system. Use system state information to validate system models and improve transfer limits and system stability.
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. Use the acSELerator QuickSet SEL-5030 Software graphical user interface for harmonic analysis and easy event viewing.
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 to 55 inputs and 24 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. Scale analog values and latch momentary inputs for SCADA retrieval.
acSELerator QuickSet Software
Help speed up relay applications by developing relay settings offline, programming SELogic control equations, and analyzing post-fault event reports.
Voltage Sag, Swell, and Interruption (VSSI) Report
Capture power quality data related to voltage disturbances over a long period of time.