The New SEL-851 Feeder Protection Relay

Protect Feeders With Overcurrent Elements

The SEL-851 offers a variety of phase, negative-sequence, residual, and neutral overcurrent elements.

Prevent Equipment Damage With Voltage Protection

The voltage input option provides voltage, frequency, directional power, loss-of-potential, and power factor elements.

Increase Safety With Arc-Flash Detection

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.

Streamline Integration

Serial, USB-C, and Ethernet ports as well as DNP3, Modbus, and IEC 61850 protocols provide communications options for improved system integration.

Simplify Inventory

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.

Reduce Commissioning Time

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.

Improve Messaging Speeds

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.

Gain Greater System Visibility

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.