Addressing Misconceptions to Reduce Touch and Step Voltage Hazards at Power Systems

In the event of a fault, hazardous touch and step voltages may develop that can injure personnel or the public. A grounding analysis is performed by engineers to design a substation, generation, or industrial site's grounding system to reduce hazard associated with touch and step voltages. Several misconceptions have led to the inaccurate design of new and existing grounding systems. These misconceptions also result in existing grounding systems exceeding their design parameters as power systems fault duties increase, protection schemes change, and infrastructure ages. This paper provides a reference for identifying data and other factors that affect the accuracy of grounding system analysis and design, with reference to IEEE Std 80. Common errors and misconceptions are discussed, and case studies presented to highlight hazardous scenarios. Additional guidance is provided for determining when existing systems may require evaluation to maintain industry recommended best practices for personnel and public safety.