Key Features and Benefits:-


The SEL-851 Feeder Protection Relay provides an exceptional combination of protection, monitoring, and control in a compact and simple package.

Powerful and Simple Protection. Offers fast start up time and protection that is enabled within 2 seconds. The simplest feeder relay to set up and use.

Fastest Arc-Flash Protection. Increase the safety of your personnel and equipment, and significantly reduce incident energy by sending a trip signal to a breaker in as fast as 1 ms.

Better Visibility of the System. Gain better visibility of your system with high-resolution currents and voltages sampled at 10 kHz.

Intuitive and Efficient Software. SEL Grid Configurator is a user-friendly interface that reduces engineering and commissioning time. Improve setup efficiency by sending settings to all of your networked relays at once.

Reduce Downtime. High-reliability hardware, programmable digital inputs, a universal power supply, and settingselectable current inputs.

Dual Ethernet Capability With IEC 61850, DNP3, and Modbus Protocols.



Currents and Voltages. The relay includes four current inputs and three optional voltage inputs for comprehensive current, voltage, and frequency protection.

Feeder Protection and Control Features. Protect low- and medium-voltage three-phase feeders with breaker/ contactor failure, phase, negative-sequence, and neutral instantaneous/time-overcurrent elements. Additionally, the relay also supports recloser control.

Digitally Signed Firmware. Relay firmware can be securely downloaded to your relay via the Ethernet port. The firmware is digitally signed to prevent malicious modification.

Optional Protection Features. Use the SEL-851 relay with the voltage input option to provide over- and undervoltage, over- and underfrequency, directional power, loss-of-potential, and power factor elements.

Operator Controls. Increase operator safety using Local/Remote control on the front panel along with the ability to perform breaker control. Use the eight programmable LEDs on the front panel to reflect the operating conditions of the system.

Integrated Web Server. Log in to the built-in web server to view metering and monitoring data, download events and Sequential Events Recorder (SER) reports, view or edit settings, and upgrade firmware.

Intuitive and Efficient Software. SEL Grid Configurator is a user-friendly interface that reduces engineering costs for relay settings and logic programming.

Metering and Monitoring. Use built-in metering function to eliminate separately mounted metering devices. Analyze Sequential Events Recorder (SER) reports and oscillographic event reports for rapid commissioning, testing, and post-fault diagnostics. Additional monitoring functions include signal profile monitoring and demand metering.

Direct Connect Voltage Inputs. Optional voltage inputs allow for wye-connected, open delta-connected, or single-voltage inputs to the relay.

Control Inputs and Outputs. Four or ten (optional) internally wetted, programmable control inputs or four or ten (optional) externally wetted, programmable control inputs (24–240 Vac/Vdc) and two hybrid contact outputs (Form A) and three electromechanical contact outputs (one Form C and two Form A) for control and status indication.

Communications Ports.

➢ Port 1 is an EIA-232/EIA-485 (RJ45) rear-panel port with IRIG-B time code input

➢ Port 2 is a single or dual (optional) 10/100BASE-T Ethernet port(s)

➢ Front-panel USB-C port

Time Synchronization. Synchronize events and expedite analysis by connecting the standard IRIG-B input to a synchronized time source or using Simple Network Time Protocol (SNTP).

➤ Communications Protocols.

➢ Modbus RTU, Modbus TCP/IP

➢ IEC 61850 Edition 2 (optional)

➢ SNTP ➢ DNP3 Serial and LAN/WAN (optional)

➢ Secure File Transfer Protocol (FTP)

➢ Secure Telnet Protocol

➢ SEL protocols for metering and event data


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