Managing the Risk of Isolator Failure

ElectraNet has identified the need for targeted replacement or removal of around 70 isolators and components across the South Australian electricity transmission network over the next four years as the most efficient solution to maintain the overall fleet of isolators across the network.

Most of the removed isolators are planned to be refurbished and disassembled to create a suitable spares inventory to allow for emergency maintenance of defective isolators.

The isolators that are being replaced or removed are located in the following substations:

• Metropolitan substations – Dorrien, LeFevre, Magill, Torrens Island A, Torrens Island B; and
• Rural substations – Port Lincoln, Yadnarie, Middleback, Cultana, Robertstown, Berri, Monash, Tailem Bend, Penola West, Snuggery, Mount Gambier, Davenport

On 4 July 2019 ElectraNet published a Project Specification Consultation Report (PSCR) under the Regulatory Investment Test for Transmission (RIT-T), as required by the National Electricity Rules clause 5.16. The report outlined that there was only one technically and economically feasible option which is to replace or remove identified isolators, and or parts of isolators, and refurbish and store isolators/isolator components as spares.

On 13 November 2019 ElectraNet published a Project Assessment Conclusions Report (PACR) that confirms the preferred option is to replace or remove identified isolators, parts of isolators, and refurbish and store isolators/isolator components as spares to meet the identified need of managing the risk of isolator failure.