SEL-751
Feeder Protection Relay
The SEL-751 is the right solution for industrial and utility feeder protection, with conventional/low-energy analog (LEA) current and voltage input support, flexible I/O options, easy mounting, and fast settings.The SEL-751 provides complete protection for radial and looped distribution circuits. It offers arc-flash mitigation, fault location, high-impedance fault detection, intermittent ground fault (IGF) detection, broken conductor detection, event analysis, and more. You can quickly integrate the relay into serial- or Ethernet-based communications with IEC 61850 Edition 2.1, IEC 60870-5-103, the IEC 62439 Parallel Redundancy Protocol (PRP), High-Availability Seamless Redundancy (HSR), EtherNet/IP, the Rapid Spanning Tree Protocol (RSTP), the IEEE 1588 Precision Time Protocol (PTP), Modbus, DNP3, and other protocols.
Starting at
$1,380
Feeder Protection
Protect radial and looped distribution circuits with comprehensive protection capabilities, including time-overcurrent, directional overcurrent, autoreclosing, over-/undervoltage, frequency, second- and fifth-harmonic blocking, optional LEA voltage inputs, IEC cable/line thermal element, islanding detection, and much more.
LEA Sensor Inputs
Apply the SEL-751 in medium- and low-voltage applications that use low-energy current/voltage sensors. LEA sensors for measurement of primary voltages and currents are gaining popularity owing to their excellent linearity and wide dynamic range characteristics, reduced size, reduced weight, and enhancement of personnel safety. The LEA current/voltage input card supports three current channels, Rogowski coil or low-power current inputs, three LEA voltage sensor inputs, and one 200 mA neutral input. The LEA current and voltage channels accept an RJ45 connector input, and the 200 mA neutral channel accepts a terminal block input.
Ground Fault Detection and Directional Control
Protect ungrounded, high-impedance grounded, resonant-grounded, and Petersen coil-grounded systems with your choice of several options. Use the optional 200 mA neutral input for SEF protection with the relay directional element or for nondirectional protection. IGF detection and a zero-sequence phi element identify ground faults and their direction, sending a trip command when the fault count exceeds the threshold you set.
Arc-Flash Mitigation
Improve safety for personnel with optional arc-flash detection capabilities. The SEL-751 offers combined light and high-speed overcurrent detection for arc-flash events. This combination provides the ideal solution for speed and security.
High-Impedance Fault Detection
Detect downed conductors, even on poorly conducting surfaces, with Arc Sense technology (AST). AST algorithms detect arcing produced by some high-impedance faults and will alarm or trip the breaker. This technology provides an added level of protection over conventional feeder protection methods.
Reliable Protection in Harsh Environments
The SEL-751 operates in extreme conditions, with an operating temperature of –40° to +85°C (–40° to +185°F), and it is designed and tested to exceed applicable standards, including vibration, electromagnetic compatibility, and adverse environmental conditions. In addition, the SEL-751 is ATEX-certified and Underwriters Laboratories (UL) Class I, Division 2-certified for use in hazardous and potentially explosive environments.
Automation and Control
Apply the SEL-751 on feeders and provide protection, automation, and control capabilities all in one package. Choose from a wide array of field-upgradeable I/O cards for the back of the relay. Provide ample capacity for automation and control applications by ordering up to four extended I/O modules; each module provides either 21 programmable inputs or 12 contact outputs.
Event Analysis
Conduct post-event analysis more efficiently with the detailed event records that are available in the SEL-751. Combine oscillographic and digital information to find root cause. Add a satellite-synchronized time source, like the SEL-2401, SEL-2407, or SEL-2488 Satellite-Synchronized Clocks, for convenient alignment of event information from multiple devices.
SEL-751 Features
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- Large 2 × 16 character LCD
- Default messages or up to 32 customizable display labels notify personnel of power system events or the relay status
- Programmable front-panel tricolor LEDs
- Customizable pushbuttons and labels
- User-configurable label kit
- Two programmable tricolor LEDs per pushbutton
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- The 5-inch, 800 × 480 display offers direct navigation via a capacitive touchscreen.
- Folders and applications provide quick access to bay screens, metering and monitoring data, reports, settings, and more.
- The home pushbutton allows you to easily return to the default home screen.
- Programmable front-panel LEDs with user-configurable labels alert operators to faulted phases and element operation.
- Programmable operator pushbuttons with user-configurable labels allow front-panel customization.
- Add up to four optional extended I/O modules.
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- The optional output module provides 12 contact outputs.
- The optional input module provides 21 programmable inputs.
- Power supply options include 110–250 Vdc/110–240 Vac or 24–48 Vdc.
- A variety of communications protocols and media provide flexibility to communicate with other devices and control systems.
- The integrated web server enables direct relay access for metering and monitoring data.
- The optional fiber-optic serial port provides quick and easy engineering access.
- The card slots include positions for optional I/O or an arc-flash detection/Vsync/Vbat card.
- Phase current and optional phase voltage inputs are on one card, freeing up space for additional SELect I/O card options.
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- Power supply options include 110–250 Vdc/110–240 Vac or 24–48 Vdc
- A variety of communications protocols and media provide flexibility to communicate with other devices and control systems
- Integrated web server enables direct relay access for metering and monitoring data
- The optional fiber-optic serial port provides quick and easy engineering access
- Card slots include positions for optional I/O or an arc-flash detection/Vsync/Vbat card
- Low-energy analog current and voltage sensor inputs (compliant with IEC 61869-6,-13 standards)
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- Bay Screens and Bay ControlSelect from predefined bay screens, or configure as many as five custom bay screens using the acSELerator® Bay Screen Builder SEL-5036 Software and acSELerator QuickSet® SEL-5030 Software. You can control one breaker, eight two-position disconnects, and two three-position disconnects and can view analog and digital data in a contextual display. To control a breaker or disconnect, simply tap the Bay Screens application on the home screen and then the breaker or disconnect you want to control.
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- AuthenticationEnter your Level 2 password and tap Submit. The onscreen keyboard allows you to quickly and easily enter passwords, search for Relay Word bits, and enter settings.
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- Breaker ControlTap Trip or Close to control the breaker. When asked to confirm the action before the operation is completed, choose Yes or No.
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- Meter FundamentalsView the real, reactive, and apparent power of each phase in your system, and monitor the power factor information to determine if the phase current leads or lags the phase voltage.
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- Meter PhasorsView a graphical and textual representation of the real-time voltages and currents in a power system during balanced and unbalanced conditions. By analyzing the phasors, you can determine power system conditions.
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- Meter EnergyDisplay the real, reactive, and apparent energy metering quantities imported and exported by your system. You can reset the energy values via the display and record the time and date of reset. Whether your system is a net energy producer or consumer, metered quantities accurately account for the power system energy flow.
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- Sequential Events RecorderEasily review the time-stamped Sequential Events Recorder (SER) data, including whether or not the Relay Word bit asserted or deasserted, during root cause analysis of an event.