Schweitzer Engineering SEL-851 overview
Schweitzer Engineering SEL-851 Feeder Protection Relay The SEL-851 provides comprehensive feeder protection, monitoring, and control for utility and industrial ...
Manufactured bySchweitzer Engineering
Part number or familySEL-851
Product groupFeeder Protection Relay
Product details
Manufactured bySchweitzer Engineering
Product groupFeeder Protection Relay
DescriptionSchweitzer Engineering SEL-851 Feeder Protection Relay
OverviewThe 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.
Features & BenefitsProtection, monitoring, and control in a simple, compact package Apply comprehensive current, voltage, and frequency elements to protect low- and medium-voltage feeders. Increase safety and reduce incident energy with arc-flash protection that sends a trip signal to a breaker in as fast as 1 ms. Quickly create, manage, and deploy relay settings using SEL Grid Configurator. Simplify relay selection due to the universal power supply, universal current inputs, and software-settable binary inputs. Easily integrate the relay into your system using dual Ethernet ports that support IEC 61850, DNP3, and Modbus protocols.
Key FeaturesProtect Feeders and EquipmentThe 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, breaker/contactor failure, phase, negative-sequence, neutral instantaneous, and time-overcurrent elements along with auto reclosing functionality. The voltage input option provides voltage, frequency, directional power, loss-of potential, and power factor elements. Increase Safety With Arc-Flash MitigationImprove safety and prevent equipment damage with the relay’s four optional arc-flash detections (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. Streamline IntegrationChoose from Ethernet or serial communications ports and several protocols, including Mirrored Bits communications and IEC 61850 Edition 2. Pick multiple sessions of Modbus TCP, Modbus serial, DNP3 LAN/WAN, or DNP3 serial for custom configuration of your applications. Simplify InventoryThe SEL-851 is built with high-reliability hardware and comes with a universal power supply, setting-selectable universal current inputs (1 A/5 A), and optional software-selectable binary inputs (24–250 Vac/Vdc). Its simplified design helps reduce maintenance expenses. Reduce Commissioning TimeQuickly create, manage, and deploy device settings and reduce engineering and commissioning time using the new SEL Grid Configurator software. It features a spreadsheet-style editor, powerful protection visualization, comprehensive reporting, custom filters, and multiple-device settings management. Achieve Fast, Deterministic Relay-to-Relay CommunicationsFixed GOOSE provides ease of programming and offers the flexibility of multidevice communication of digital and analog quantities at a fixed 4 ms rate. Gain Greater System VisibilityWith high-resolution currents and voltages sampled at 10 kHz, system visibility is improved. This allows you to identify problems, such as harmonics produced by switching or damaged cables, before they cause a significant interruption.
Front Panel FeaturesLarge LCD display for navigation, relay control, and diagnostics Function keys USB-C engineering access port Two fixed and eight programmable tricolor LEDs Trip and Close breaker control pushbuttons Local/Remote and Target Reset control pushbuttons
Back Panel Features4 digital inputs 5 digital outputs (1 Form C, 2 Form A Standard, 2 Form A Hybrid) Universal power supply (24–250 Vdc, 110–240 Vac) EIA-232/EIA-485 serial port with IRIG-B Single or dual 10/100BASE-T Ethernet port(s) (optional) 6 additional digital inputs (optional) 4 current inputs 3 ac voltage inputs (300 Vac) (optional) 4 arc-flash inputs (optional)
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Feeder Protection Relay
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