Touch Potential and Earth Leakage Study
Customer: Holcim Albion Park Quarry, Croom NSW
Project type: Electrical Engineering
Standard: AS/NZS 3000 / AS 2067
Touchstone Systems was engaged by Holcim to undertake a qualitative touch potential and earth leakage study for the electrical installation at Albion Park Quarry. The assessment reviewed and verified existing earthing, cabling, and protection arrangements across the entire site electrical network, from the high voltage point of connection through to LV switchboards, motor control centres, and final subcircuits.
The study was informed by site verification activities, data supplied by Holcim and Endeavour Energy, and a newly developed full-site PowerCAD model constructed by Touchstone’s engineering team. Findings and recommendations were classified into immediate and general categories to support prioritised remediation.
Key deliverables included:
- Development of a full-site PowerCAD model covering the complete electrical network from HV supply through to all LV distribution
- Touch potential assessment including fault current and touch voltage calculations for all circuits on site, with reference to AS/NZS 3000 Figure B4 maximum prospective touch voltage limits
- Review of earthing system configuration
- Earth leakage protection assessment reviewing RCD application, sensitivity settings, and coordination and discrimination between upstream and downstream devices across all circuits
- Immediate recommendations to ensure all circuits meet the requirements of AS/NZS 3000 Figure B4 maximum prospective touch voltage limits including earth leakage relay setting adjustments across multiple switchboards and the installation of supplementary earthing to reduce touch potential levels and improve prospective earth fault trip times.
The completed report provides Holcim with a clear picture of their electrical safety risk profile in relation to touch potential across the site.