The SEL-851 provides comprehensive feeder protection, monitoring, and control for utility and industrial applications in a compact device. Its arc-flash protection capabilities significantly reduce incident energy by sending a trip signal to a breaker in as fast as 1 ms. With 10 kHz sampling of currents and voltages, the SEL-851 allows you to gain better visibility of your system. The relay is configured with SEL Grid Configurator software, enabling the quick creation, management, and deployment of device settings.

Protect Feeders and Equipment—The SEL-851 includes four current inputs and three optional voltage inputs for comprehensive current, voltage, and frequency protection. Protect low- and medium-voltage three-phase feeders with current unbalance, over/underfrequency, breaker/contactor failure, phase, negative-sequence, and neutral instantaneous/time-overcurrent elements along with autoreclosing functionality. The voltage input option provides voltage, directional power, loss-of-potential, and power factor elements.

Increase Safety With Arc-Flash Mitigation—Improve safety and prevent equipment damage with the relay’s four optional arc-flash detection (AFD) inputs. The SEL-851 combines light-sensing technology and high-speed overcurrent protection to detect arc-flash events in as fast as 1 ms.

Improve System Visibility—With 10 kHz sampling of currents and voltages, the SEL-851 allows you to gain better visibility of your system. Identify problems, such as harmonics produced by switching or damaged cables, before they cause a significant interruption.

Increase System Reliability—Improve your system reliability by coordinating the SEL-851 and its reclosing control functionality with downstream reclosers for a complete restoration scheme.

Reduce Commissioning Time—Configure SEL-851 settings using SEL Grid Configurator software, which is a new tool that increases efficiency and improves settings insights. It features a spreadsheet-style editor, powerful protection visualization, comprehensive reporting, custom filters, and multiple-device settings management.

Streamline Integration—The SEL-851 relay's Ethernet, serial, and USB-C ports and its various communications protocols, including Mirrored Bits communications and IEC 61850 Edition 2, make integrating it into your existing systems easy. Pick multiple sessions of Modbus TCP, Modbus serial, DNP3 LAN/WAN, or DNP3 serial for custom configuration of your applications.

HOTPASH

SEL-851 Feeder Protection Relay