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-300G Relay for comprehensive primary and backup generator protection.

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.

Apply an SEL-352 Breaker Failure Relay per circuit breaker to detect breaker failure conditions for single-pole and three-pole tripping applications with any bus/breaker arrangement.

Protect and control any two-, three-, or four-winding power transformer with the SEL-387, which provides thermal and through-fault monitoring, and with SELogic Control Equations, can detect breaker failure.

Apply the SEL-387A to protect any two-winding power transformer and perform predictive maintenance based on accumulated through-fault duty (as compared to transformer capability as defined in ANSI Standard C57.109).

Protect power transformers with up to three windings, as well as reactors, generators, large motors, and other multi-terminal power apparatus.

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.

Provide low-impedance bus differential protection, dynamic zone configuration, circuit breaker failure protection, backup overcurrent protection, check zones and voltage inputs for increased security.

Simplify relay settings and reduce inventory with one relay for all your capacitor bank needs. The versatile SEL-487V protects and controls both grounded and ungrounded, single- and double-wye capacitor bank applications.

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

Apply low-cost, compact package with essential protection and control elements for distributed generation.

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.

Apply economical differential protection for two-winding transformers or any two-terminal apparatus.

Provide single-zone high-impedance bus differential protection, backup overcurrent protection, and breaker failure protection for any number of terminals in a bus. Use the simple settings and dedicated same-ratio CTs to create a cost-effective and easily expandable bus protection solution.

The SEL-700G is the right solution for utility and industrial generator protection, with an autosynchronizer, flexible I/O, and advanced communications. Apply the SEL-700G for comprehensive primary and backup generator protection.

Monitor and Control Critical Substation Apparatus With One Powerful Package

The SEL-710 Motor Protection Relay dynamically calculates slip. This premiere motor protection scheme allows maximum start times. Thermal motor protection models give the SEL-710 advanced protection beyond industry standards.

The SEL-710-5 provides synchronous motor protection, starting control, broken rotor bar detection, and now arc-flash protection.

Use the SEL-749M to protect and control all types of three-phase motors, including two-speed and reduced-voltage start motors.

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-787 Relay is a versatile, two-winding current differential relay that protects industrial transformers. Monitor transformer health with cumulative through-fault current recording, and for the first time in the industry, automatically check and generate differential compensation settings with the Commissioning Assistant Software.

Provide complete current differential and overcurrent protection for three- and four-winding transformers. Select the SEL-787-3E or SEL-787-3S for current- and voltage-based protection on three-terminal transformers, and choose the SEL-787-4X for current differential and overcurrent-based protection on four-winding transformers.

The SEL-849 provides current, voltage, and thermal-based protection, arc-flash detection, and power metering for motor protection applications.

The SEL-2414 Transformer Monitor provides an exceptional combination of monitoring, control, and communications in a compact package.

Measure and transmit data from up to 12 RTDs and a single contact status located in transformers, breakers, motors, generators, or other system apparatus.

Add the SEL-2664 Field Ground Module to the SEL-300G or SEL-700G to protect all the critical components in your generator with one comprehensive relay. Or, add the SEL-2664 to the SEL-2664S to complete ground fault protection on both the rotor and stator.

Protect high-impedance grounded generators from ground faults at standstill, during startup, and while running with the multisine frequency injection and neutral overvoltage-based protection in the SEL-2664S.

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.