html{display:none} SEL-401 Protection, Automation, and Control Merging Unit | Schweitzer Engineering Laboratories


Protection, Automation, and Control Merging Unit

Apply the SEL-401 for substations with IEC 61850-9-2 Sampled Values (SV) systems. Sample analog data, such as currents and voltages, then publish that data to a fiber network for use in other IEDs such as the SEL-421-7. The SEL-401 publishes sampled values to the process bus network and also provides local protection. Use the built-in phase-overcurrent and breaker failure protection to provide backup in case of communications system failures.


Starting At

5,000 USD

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IEC 61850-9-2 Sampled Values (SV) Implementation—Place the SEL-401 Protection, Automation, and Control Merging Unit out in the yard right next to primary equipment. The SEL-401 digitizes analog signals from primary equipment and then transmits them to the control house via an Ethernet network. Publish as many as seven outgoing data streams of IEC 61850-9-2 SV data to any relays that subscribe to SV. The data can be synchronized using the IEEE 1588 Precision Time Protocol Version 2 (PTPv2) or an IRIG-B time input.

Integrated Protection—Provide local breaker failure and phase overcurrent protection during a loss of the precise time signal or communication to a main substation relay. The SEL-401 uses high-speed (5/8-cycle) open-pole detection logic to reduce coordination times for critical breaker failure applications.

Dual-Breaker Schemes—Accommodate two sets of three phase currents and two sets of three-phase voltages to support substations with dual-breaker schemes. Combine currents within the relay from two sets of current transformers (CTs) for protection functions, but keep them separately available for monitoring and station integration applications.

Oscillography—Record voltages, currents, and internal logic points at up to an 8 kHz sampling rate. Phasor and harmonic analysis features allow the investigation of relay and system performance.

Sequential Events Recorder (SER)—Record the last 1,000 entries, including setting changes, power-ups, and selectable logic elements.



SEL SV Technology—Implementing the Merging Unit with Local Protection

The SEL SV merging unit and relay are fully compliant with IEC 61850-9-2 and the UCA 61850-9-2LE guideline as well as capable of interoperating with other IEC 61850-9-2–compliant devices.