Distance Protection

SEL provides reliable and secure distance protection that can be applied with or without communications and can function as a backup for communications-dependent line current differential protection.

Distance protection solutions include: 

  • Quadrilateral and mho distance elements—SEL transmission relays allow you to choose either or both.
  • Optimized system loading—Built-in load encroachment logic allows you to securely apply distance protection elements on heavily loaded transmission lines.
  • Improved system stability—The SEL zero-setting out-of-step (OOS) blocking function improves security during power swings without requiring time-consuming and expensive system stability studies.
  • Communications-assisted tripping—SEL transmission protection relays accommodate many of the common pilot protection schemes, so you can configure protection without any need for external coordination devices.

Communications-Assisted Protection

Implement communications-assisted tripping and remedial action schemes (RASs) with SEL networking and control products.

Engineering Services

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.

Products and Service You Can Rely On

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.

Questions? Contact Us!

If you have any questions about SEL products, services, solutions, or support, please contact us. Our service and support professionals are ready to provide the answers you need.

Unbeatable Support

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.

More about SEL warranty and support