Feature-Rich Protection at a Competitive Price
The SEL-851 offers a variety of phase, negative-sequence, residual, and neutral overcurrent elements.
The voltage input option provides voltage, frequency, directional power, loss-of-potential, and power factor elements.
The SEL-851 combines light-sensing technology and high-speed overcurrent protection to detect arc-flash events as quickly as within 1 ms, reducing equipment damage and increasing personnel safety.
Serial, USB-C, and Ethernet ports as well as DNP3, Modbus, and IEC 61850 protocols provide communications options for improved system integration.
The relay’s universal power supply (24–250 Vdc, 110–240 Vac), setting-selectable universal current inputs (1 A/5 A), and software-selectable contact inputs (24–250 Vac/Vdc) allow for reduced inventory and maintenance expenses.
The easy-to-use SEL Grid Configurator software features a spreadsheet-style editor, powerful protection visualization, comprehensive reporting, custom filters, and multiple device settings management.
Deterministic timing and ease of programming along with the flexibility and multidevice communications of fixed GOOSE messaging guarantees outgoing messages are processed every 4 ms.
High-resolution currents and voltages (sampled at 10 kHz) help quickly identify problems such as harmonics produced by switching or damaged cables before they cause a significant interruption.