©2023 Bentley Systems | EasyPower, 15862 SW 72nd Ave, Suite 100, Portland, OR 97224, USA | Tel. 503-655-5059 | www.EasyPower. com 1 – Grounding System Performance Fluctuates It may not be apparent, but local site modifcations such as new breakers, transformers, and general layout changes as simple as fence-line modifcations could result in touch voltage hazards in previously compliant sites. Additionally, ofsite utility system changes may afect the performance of a grounding system. The addition of a new switchyard, transmis- sion lines, or generation may increase the power system fault current availability and corresponding touch and step voltage hazards. Additionally, soil resistivity may vary signifcantl y based on the seasonal and climatic changes at a sit e, which signifcantly afects the grounding system performance. Figure 1 shows most of a system is within permissible limits, in green, but as ambient temperatures decrease, the native soil resistivity increases resulting in exceeding permissible touch voltage limits throughout the site, shown in Figure 2. Figure 1. Summer Grounding System Performance 10 Common Misconceptions for Grounding Analysis INTRODUCTION An important aspect of a grounding system design is personnel and public safety. It is important to reduce the misconceptions regarding grounding system design, as personnel are dependent on these buried systems and typically unable to di- rectly evaluate their condi- tion while on-site. Ground- ing system performance is afected by multiple […]