Products

With breakthrough time-domain technologies, the SEL-T400L Time-Domain Line Protection trips in as fast as 1 millisecond, records events with 1 MHz sampling, and locates faults accurately to the nearest tower with single- and double-ended traveling-wave fault locators.

Apply the SEL-311C Relay for complete protection, monitoring, and control of transmission lines.

Use the SEL-311L Relay with integral four-zone distance backup for easy-to-apply, high-speed line protection.

The SEL-321 Relay delivers outstanding EHV protection, performance, and features—at a price practical for all voltage levels and with the features you need for system integration.

Select the SEL-321-5 for 50 Hz applications requiring enhanced single-pole tripping, phase and ground distance, directional overcurrent, and negative-sequence protection.

The SEL-351 Relay has built-in Ethernet and IEEE C37.118 synchrophasors, and is ideal for directional overcurrent applications. Optional Mirrored Bits communications and power quality monitoring add flexibility to solutions. The SEL-351 is the protection standard for utility and industrial electrical systems around the world.

The SEL-351A Protection System has built-in Ethernet and IEEE C37.118 synchrophasors, and is the economical solution for overcurrent protection. Easy-to-use feeder protection and innovative features like SEL’s Best Choice Ground Directional Element logic and SELogic control equations provide superior protection on utility and industrial power systems.

The SEL-351S Relay provides wide-area system stability awareness with IEEE C37.118 synchrophasors and simplifies communications with built-in Ethernet. Large, easy-to-use operator controls and optional independent SafeLock trip/close pushbuttons enhance operation and simplify panels.

Use SEL-387L Line Current Differential Relays for economical, easy-to-apply line protection.

With comprehensive distance and differential protection the SEL-411L allows you to stock one relay for all transmission lines. The SEL-411L is also the only relay with traveling-wave fault location which pinpoints faults to the nearest tower or span.

Protect transmission lines with high-speed distance and directional functions.

Quickly integrate bay control status and control for breakers and disconnect switches with full automation and protection in one device. With advanced synchrophasor measurement, the SEL-451 provides system stability awareness. Choose between Ethernet and serial communications ports with DNP3 and IEC 61850 Edition 2 protocols.

Simplify protection in two-high switchgear with two independent sets of protection elements in one compact relay.

The SEL-551 Overcurrent/Reclosing Relay replaces the many relays, control switches, and wiring required in traditional distribution substation protection and control panels. The relay also replaces line recloser control packages at a fraction of the cost.

The SEL-551C Overcurrent/Reclosing Relay combines overcurrent protection, built-in I/O, enhanced communications features, and multiple-shot reclosing in one compact relay. Great for industrial, commercial, and utility, primary or secondary overcurrent protection.

The SEL-751 is ideal for directional overcurrent, fault location, arc-flash detection, and high-impedance fault detection applications. Flexible I/O options, easy mounting, and fast settings make the SEL-751 the right solution for industrial and utility feeder protection.

The SEL-751A offers industrial and utility feeder protection with flexible I/O options, easy retrofit, and fast setup and configuration. The SEL-751A provides complete feeder protection with overcurrent, voltage, and frequency elements. The SEL-751A remediates arc-flash hazards with arc-flash detection.

The SEL-4520 provides a convenient way to test the operation of arc-flash detection relays installed in metal-clad and metal-enclosed switchgear. The SEL-4520 is used to test the SEL-751 and SEL-751A Feeder Protection Relays and other arc-flash detection relays that use light and overcurrent for sensing an arc-flash event.