The safety and operational reliability of Substations (Terminal, Zone, Kiosk, etc.) are critically influenced by many factors including the composition of the ground Surface Layer utilised in their construction, particularly for enabling high-resistivity applications for safety and minimisation of voltage hazards.
This presentation examines the properties, selection, specification, and testing processes for aggregates with a focus on safety performance. Key considerations include electrical resistivity, mechanical strength, durability under varying environmental conditions with a focus of delivering a cost effective, technically compliant solution.
Industry standards and regulatory requirements such as ENA EG-0, ENA EG-1, IEEE80, IEEE81 and AS2067 are reviewed to guide the development of effective specifications.
Laboratory and field-testing methodologies and results are outlined, emphasizing procedures for measuring resistivity, moisture retention, and contaminant levels observed across a sample of varying aggregates. The findings support the use of high-resistivity, low-moisture products available to reduce step and touch voltage hazards.
This presentation concludes with best practice recommendations for sourcing the ideal aggregates and quality assurance to ensure long-term safety and compliance for Power Network Operators and Substation owners.