We understand, defend, and serve ICS and OT networks.

Cybersecurity is not one thing. It is never finished. Our mission is to provide services and solutions that defend and maintain the availability of industrial control system (ICS) and operational technology (OT) power systems.

Our Approach

We simplify cybersecurity with layered defenses that apply the right technologies in each layer. 
Learn why we're different 

Our Solutions

Cyber systems and solutions designed for critical infrastructure.
See how we solve the problem 

Our Services

Strengthen your defenses and streamline maintenance and compliance.
Partner with us to get it done 

Our Support

We strive to be not just a vendor, but a partner you can rely on.
See how we support our partners 

Our Approach

We believe in establishing a strong understanding of the system you are defending and that simpler products and systems are easier to defend. The layered defense model is most effective when the right technologies are applied at the appropriate layers and incorporated to support the specific purpose of each part of the system.    

Zero Trust for ICS and OT Cybersecurity 

The concept of zero trust for securing information networks is gaining in popularity. This is underscored by the executive order of May 12, 2021, to improve the nation’s cybersecurity, highlighting zero trust as a key component.

A zero-trust architecture is a powerful tool that helps security professionals determine optimal ways to design security controls for their networks. However, ICS and critical infrastructure networks have important differences from IT networks and require a modified approach—particularly regarding the decision of where to encrypt traffic and at what point end-to-end encryption hurts the availability of protection and control devices.

Furthermore, the notion that trust can be excluded from the calculus of network security is misguided. Trust underpins all security; therefore, when applying zero trust to a network, security professionals should continually evaluate these questions:

  • What do I trust?
  • Why do I trust it?
  • When should I no longer trust it?

From our knowledge base 

Our Solutions

Cybersecurity, and the protection of critical infrastructure, is a mission we serve every day and have done since the beginning of our company. We design cybersecure systems and solutions for all industries based on an in-depth understanding of OT performance requirements, customer needs, and critical infrastructure demands.

Layered Cybersecurity

SEL solutions incorporate layered cyber defenses to help keep your system secure.  

These defenses incorporate security features that support the specific purpose of each part of the system, such as: 

  • OT software-defined networking (SDN).
  • Role-based access controls.
  • Integration with multifactor authentication systems and one-time-password (OTP) solutions.
  • Encrypted external communications via VPN with IPsec. 
  • Hardened engineering access and HMI systems.

SEL networking solutions and automation controllers can also be integrated into security information and event management (SIEM) and intrusion detection systems (IDSs), which help detect and counter cyber attacks before they disrupt operations.

We thoroughly review and test every line of code in our products, which provides greater control over their quality, security, and functionality. 

We also follow secure supply chain management best practices and help our customers comply with applicable supply chain and cybersecurity standards (for instance, NERC CIP-013 for certain North American utilities). 


Our Services

From system assessment and baselining to cyber-defense solution development and ongoing system management, our full suite of security services can help strengthen your defenses and streamline the demands of maintenance and compliance.

SEL cybersecurity professionals will work with you directly to develop a secure solution that is tailored to your priorities and objectives.

We help with:

  • Services and solutions that ensure compliance with NERC CIP requirements.
  • Assessment services and risk remediation plans based on National Institute of Standards and Technology (NIST), NERC CIP, and IEC 62443 cybersecurity frameworks.
  • Design and implementation of secure communications networks, access management, and remote access solutions.
  • OT system baselining.
  • Threat management solutions, including logging and monitoring, visualization, reporting and alerting, incident response plans, and data backup and recovery.
  • Making a cybersecure transition from serial communications to Ethernet—and streamlining the maintenance and compliance requirements that follow.

SEL practices a defense-in-depth philosophy of cybersecurity. We design secure systems starting with the device closest to the critical asset and working out to the user, ensuring that authentication, authorization, and accountability are intact at each stage. We also ensure that security features don’t compromise the performance of critical protection and control systems.

Our Support

We believe you should never have to worry about whether your protection and control systems will be working when you need them most. That’s why every device we manufacture comes with a 10-year warranty and free technical support.

It’s been this way at SEL since the company was founded nearly 40 years ago—a major reason why we’re North America’s most trusted provider of protective relays and ranked #1 by international utilities in price, service, and support.

The Industry’s Best Warranty

SEL devices are designed for a working life of at least 20 years, and every SEL-manufactured device comes with a 10-year warranty—the best in the electric power industry. If it fails under warranty, repair and replacement are free.

We always do all that we can to repair any returned product, whether it meets our warranty or not.

Proven Reliability 

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.

Our products have a mean time between returns for repair (MTBR) of more than 250 years, based on observed field performance. This means that if you have 250 SEL products installed in your systems, you can expect to have less than one unscheduled removal from service per year for any reason, whether it’s a defect or an external factor such as overvoltage, overcurrent, wildlife damage, or environmental exposure.

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