Total Cost of Ownership (TCO)

Why is TCO an important consideration in the selection of your next industrial and substation automation and computing system? TCO quantifies the direct and indirect cost of the device across its entire lifecycle, providing a more accurate depiction of the true cost than a simple consideration of only the initial capital expenditure .

SEL Total Cost of Ownership Calculator

Reliability, Availability, and Serviceability (RAS)


Fans that dissipate heat are one of the most common points of failure in computers. The unique thermal design of SEL automation controllers allows them to dissipate heat quickly and eliminate problems associated with moving parts such as fans, spinning drives, or vents. The power supplies are fanless and have a high mean time between failures (MTBF). SEL automation controllers are also designed to be easily enhanced or upgraded, even in the field.

SEL automation controllers withstand harsh environments of –40° to +85°C (–40° to +185°F) and are built with the highest quality components available.

Design, quality components, system testing, memory, storage capacity, and the ability to upgrade as needs change make SEL automation controllers the reliable choice for your demanding computing applications.  


Design features, such as no moving parts, error-correcting code (ECC) RAM, and modular components, increase the availability of SEL automation controllers. The no-moving-parts design eliminates problems that are associated with normal wear and tear, and ECC memory protects against bit flips to prevent digital logic errors. Dual power supplies ensure continuous power, with the typical configuration of one power supply connected to a battery bank and the other connected to line power. And, with a RAID configuration, you can remotely rebuild a failed drive onto a spare. Designed for maximum availability, SEL automation controllers won’t break down even if there is a problem.


With modular designs and hot-swappable drives and power supplies, SEL automation controllers let you replace components in the field while your system is up and running. The modular design also allows you to perform memory upgrades in the field. SEL automation controller processors feature Intel Active Management Technology, which allows you to view logs for evaluation and service even when the unit is powered off. You can reboot into another OS for diagnostics or to batch install software and then bring the system back online, all remotely. SEL system monitor (SysMon) software creates runtime event logs within the OS to aid in quick recovery. Additionally, KVM-over-IP capabilities allow a remote expert to help with troubleshooting as needed for upgrades or commissioning.

System Reliability, Availability, and Serviceability

SEL Automation Controllers

Typical Computers

Operating Temperature Range

SEL automation controllers feature a wide temperature range of –40° to +85°C (–40° to +185°F) and have up to 95 percent relative humidity resistance for operation in outdoor, industrial, manufacturing, and utility environments.

Typical PCs are designed for use in commercial or light industrial environments—typically +10˚ to +35˚C (+50˚ to +95˚F).

Environmental Operation Conditions

  • SEL automation controllers are designed to operate in the presence of vibration, seismic, and shock (15 g) events due to nearby equipment or rough handling. They correctly operate during 15 kV electrostatic discharge (ESD) events as well as during electrical surges caused by lightning and other events.

  • Conformal coating on the internal components provides additional protection in corrosive environments.
  • Vibration and shock damage are the result of unsecured components, connectors, or boards common in office or typical industrial computers. ESD and electrical surges often cause typical PCs to reboot or misoperate.
  • Corrosion leads to early failures.

System Reliability and Availability

  • SEL automation controllers have a proven reliability ten times greater than that of traditional industrial computers (>300-year typical MTBF).
  • SEL power supply reliability is greater than 1,000 years MTBF, and each supply can operate on ac or dc inputs. An optional redundant, hot-swappable power supply is available.
  • The advanced thermal design eliminates fans and vents, so no dust or dirt is pulled into the device and there are no moving parts to wear out.
  • The SEL-3355 Automation Controller offers up to four drives with RAID 0, 1, 5, or 10 for worry-free storage and easy replacement (hot-swappable). The SEL-3360 Automation Controller SSDs support RAID 0 and 1 and are hot-swappable. The SEL-3350 and SEL-3360 Automation Controllers include up to two drives and support higher data densities with multilevel cell (MLC) and industrial-grade MLC (iMLC) SSD options.
  • ECC RAM continuously checks for bit errors and immediately corrects them, preventing system crashes.
  • Critical system functions and the status are monitored and logged using SEL SysMon Software. A programmable watchdog controller and an alarm contact output can alert you to potential problems.
  • SEL automation controllers include an optimized version of the SEL backup and recovery tool (BaRT), which can back up or restore an OS image in just a few minutes.
  • Intel vPro technology in the Intel Xeon processor enables remote and local monitoring, remediation, and repair, even if the device is shut down or if the OS is not functional.
  • The reliability of typical industrial computer systems is 50,000 hours, or a 5.7-year MTBF.
  • Power supplies, fans, and rotating disk drives are the three highest failure points.
  • Fans contaminate system components with dust. When the fan bearings wear out, high-power components overheat and fail.
  • Rotating hard disk bearings fail over time, and wear is accelerated by any shock or vibration. While available as an option on SEL computers, MLC SSDs have much lower program/erase cycle endurance, which reduces usable life, and are more likely to corrupt data in hot environments. SEL recommends the use of single-level cell (SLC) and iMLC drives.
  • Standard RAM experiences frequent random bit errors that can result in unexplained OS and application crashes.
  • Basic monitoring and watchdog capability limits health monitoring to “operational” or “nonoperational.” Typical PCs have no alarm output contacts.
  • Third-party recovery tools are available and can be expensive, hard to use, and time-consuming.
  • Remote monitoring may be available on PCs that include Intel vPro technology.


SEL provides a comprehensive worldwide, ten-year warranty, so you can be confident in the automation controller’s long-term performance and reliability. In practice, we support our automation controllers beyond ten years.

Typical industrial computers come with a two- or three-year limited warranty. You can purchase extended warranties for an additional fee (typically to extend the warranty to five years). Depending on the manufacturer, support for products beyond the warranty period may not be available.


SEL-3355 Design and Testing

Introducing SEL-3355

SEL-3355 Thermal Management

SEL Automation Controllers Defy Brazil’s Heat