PPI were engaged by Glencore to audit and report on the integrity and compliance of the earthing and lightning protection at the P49 and L72 Winders.

The specific scope of work included in this earthing inspection and test program follows the test regime outlined in AS 2067 and comprised the following:

1. Fall of potential test using an off-frequency, constant-current injection method;
2. Using the above measurement data, plot earth potential rise (EPR) and surface voltage contours away from the substation earth grid, under “scaled-up” earth fault conditions;
3. Measure Touch voltages around all relevant HV equipment and structures, and record any defects as required.
4. Conduct electrical continuity tests from a central site earth bar to all relevant HV equipment and structures, and record any defects as required.
5. Conduct electrical soil resistivity tests to confirm accuracy of previous site soil models.
6. Conduct visual inspections on earth grid connections, and compare with provided drawings for accuracy.
7. Provide a summary report documenting the results of the earth system testing, including a pass/fail assessment of the installed earth grid system

This project was conducted in partnership with Grant Croghan, Liberty Consulting.