Schweitzer Engineering Laboratories has delivered solutions for over 25 years that make electric power safer, more reliable, and more economical. SEL invented the world’s first digital distance relay in 1984, revolutionizing fault location, event analysis, and protection.

SEL revolutionized the protection industry by building the first microprocessor-based protective relays. These relays integrated, economized, and simplified the art of transmission line protection while introducing two powerful tools: fault locating and event reporting.

Recloser controls are the front line of the distribution power system, often located in distribution substations or on feeders, recloser controls supply the intelligence to allow reconfiguration of distribution systems and maintain reliable service to as many people as possible in the event of a fault.

Feeder products protect the distribution systems for utility, industrial, and commercial power systems world wide. The versatile and easy to use protection these products offer make them ideal for other applications such as overcurrent backup protection, automation, and control of advanced protection schemes.

SEL has set the standard in generator protection. Apply SEL generator protection products and avoid expensive equipment damage and failure while maintaining system performance and increasing availability.

Apply the flexible SEL-547 at the transfer switch site (interconnection point between the utility and the customer) and at each individual generator site. When the SEL-547 at the transfer switch site detects utility supply problems, it separates the customer system from the utility supply.

SEL understands how critical it is to provide continuous reliable motor protection. That is why SEL offers an industry-leading product with the most extensive warranty. SEL motor protection relays give customers a custom fit motor protection system with easy installation, for both retrofit and new application.

The high importance and cost of transformers make it crucial to maintain these assets. SEL has developed a wide variety of advanced transformer protection relays for all your transformer applications, providing top-of-the-line protection and control. Choose the relay that best suits your transformer needs.

SEL offers superior protection performance combined with integrated station automation for all your bus protection needs.

Precise Timing-Clocks

The need for substation time synchronization has evolved from time-stamping basic Sequence of Events and disturbance recording information to more mission-critical needs, such as synchrophasor measurement (IEEE C37.118), sampled measured values (IEC 61850 9-2), and traveling wave fault location. These new applications demand the same reliability, security, and dependability for precise timing-clocks as other […]