Utilities around the world choose SEL for leading technologies and superior products, services, and solutions. SEL commits to our quality with a worldwide, ten-year, no-questions-asked warranty and unmatched, free technical support and customer service.
SEL has served utilities since 1984, when we introduced the world’s first digital protective relay to the electric power industry. The first SEL digital relay, the SEL-21, revolutionized the power protection industry by providing fault locating and real fault data at a much lower cost to the customer than traditional electromechanical relays.
Today, SEL partners with customers around the world to ensure the safe, reliable, and economical delivery of electric power. SEL leads in the protection, monitoring, and control of electrical transmission and distribution lines, apparatus, and substations. We offer a full line of protective relays, substation automation systems, communications solutions, cybersecurity devices, automation controllers, and networking equipment that work together to provide protection, SCADA, automation, monitoring, and asset management.
One of SEL’s latest innovations includes time-domain protection technology that delivers a dramatic reduction in transmission relay tripping times. The SEL-T400L Time-Domain Line Protection securely trips in 1 to 4 milliseconds. Faster tripping means more megawatts transmitted, better stability, improved safety, less damage to equipment, and a reduced fire risk.
Life-saving protection at the speed of light
Increasing energy efficiency
SEL is the electric power industry's leader in fault indicator technology, producing the widest variety of fault indicator products
Industry-leading accuracy, time distribution, and dependability
SEL Protection and Automation Services improve power system performance.
Synchronized phasors (synchrophasors) provide a real-time measurement of electrical quantities from across the power system.