SEL line current differential protection provides robust, configurable high-speed protection for transmission line systems where distance protection may be inadequate.
The advanced technology in SEL relays—with subcycle single- or three-pole protection, flexible communications, and backup distance protection—helps solve your most difficult and complex protection challenges, such as parallel line protection and maintaining primary line protection when connecting wind farms to the grid.
Complete protection and control of any transmission line in a single relay. The SEL-411L offers line current differential protection plus all the distance protection features of the SEL-421 Protection, Automation, and Bay Control System. Deploy the SEL-411L with the SEL ICON or other communications platforms.
Subcycle current differential protection with four-zone distance and directional overcurrent backup. Apply the SEL-311L on two- or three-terminal lines.
A wide-area networking multiplexer optimized for utility applications. The ICON is configurable for SONET or Ethernet transport. It is also ideal for migrating legacy network technologies to a converged network solution.
Receive Global Navigation Satellite System (GNSS) time signals, and distribute precise time via multiple output protocols, including IRIG-B and the Network Time Protocol (NTP).
Let us partner with you to create an SEL solution for your system. From engineering studies and system design through commissioning and training, SEL engineers bring inventiveness and a deep understanding of the fundamental principles of electric power systems to every project. No matter how complex or sophisticated the system, we can help you protect, simplify, and control it.
SEL products are designed and manufactured for the world’s most challenging environments, exceeding all industry standards for temperature, shock, and electric stress. An optional conformal coating for circuit boards adds an extra level of protection against contaminants in extreme environments.
Every SEL product comes with a ten-year warranty—the best in the industry. If any product fails under warranty, we’ll repair or replace it for free.
We’re happy to answer all your questions and help develop the best solution for your needs.
SEL support teams are stationed in regional offices around the world and staffed with application engineers who are experts in our products and in power system applications.
Technical support for SEL-manufactured devices is always free. No matter how often you need to call or how long your SEL products have been in service, you’ll reach an SEL expert who can provide the service and support you need.
Our cybersecurity team is always ready with the information and resources needed to keep your OT networks and critical systems secure and working effectively. Cyber services support contracts can include incident response, audits, system hardening, and more, depending on your anticipated needs.