New GEMI Analysis Software improves and simplifies protective power system design

Free downloadable program draws on extensive research to properly evaluate effective ground-fault current paths and EMI in electrical raceway systems

GLENVIEW, Ill. (February 10, 2021) — For 25 years, electrical contractors have relied on the free grounding and electromagnetic interference (GEMI) software designed by the Steel Tube Institute to analyze effective ground-fault current paths and electromagnetic interference (EMI) in power systems. Now, the GEMI Analysis Software has been completely overhauled to offer improved detail and a more intuitive and customizable user experience.

The Steel Tube Institute re-created the original physical tests and mathematical modeling that were used to develop the original GEMI design by using improved testing equipment and additional variables and sample types to further refine the software’s efficacy. Research conducted by Advanced Power Concepts in conjunction with the Steel Tube Institute helped provide definitive evidence of a circuit’s utility as an effective ground-fault current path and potential for EMI mitigation.

In addition to functional improvements, the user interface was also enhanced to offer a wider range of variables and visualizations, including:

  • Detailed displays
    Conduit fill factor, circuit cross-sections with field displays, effects of non-concentric arrangements
  • Customizable variables
    Editable conduit and material libraries, field and permeability visualization paths
  • User-specific inputs
    English or metric units, default settings based on NEC® Article 250

Without proper protection, data integrity and security are at risk of irreparable damage from electrical faults and EMI. GEMI Analysis Software ensures compliance and safe installation by helping contractors evaluate and identify an effective ground-fault current path according to NEC 250.4. In addition to evaluating the ground-fault path for steel raceways, GEMI can also facilitate this evaluation for copper and aluminum wires or a combination of raceway and wire.

“Steel conduit continues to offer the greatest protection for closed power systems, but without proper design, there’s still the potential for safety concerns and equipment damage,” Steel Tube Institute Director of Steel Conduit Dale Crawford said. “With the latest version of GEMI, it has never been easier for electrical contractors to prioritize and optimize protection during system design.”

The desktop version of GEMI Analysis Software is currently available for Windows, and it can be downloaded for free at

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