Extensive maintenance of Power Transformers at various substations done to guarantee long-term life expectancy

George Municipality’s Power Transformers at various substations recently underwent extensive maintenance and refurbishment to guarantee long-term life expectancy.

Ald Leon van Wyk, Executive Mayor of George, (in red jersey) with from left, Cuan Edick (Senior Superintendent: Substations Electrotechnical Services), Jacques Lawrence (Senior Manager: Substations Electrotechnical Services) and Letsema Ndlovo (Specialised Electrician: High Voltage Electrotechnical Services) at the Heather Park substation that was newly refurbished against corrosion.

Mayor Leon van Wyk said: “This work illustrates the importance of preventative measures and making sure that key infrastructure is well maintained. We’ve started with the critical infrastructure to ensure we do whatever we can to prevent power failures. Our citizens might have noted major equipment failures taking place in other cities around the country; the maintenance done was precisely to make sure we not only prevent such occurrences in George but also prolong the working lives of our major equipment.

Mayor Leon van Wyk (with red jersey) at the Glenwood substation that had a breather and transformer maintenance with Bongani Mandla, Director of Electrotechnical Services (back left) and Cllr Nosicelo Mbete (Portfolio Councillor for Electrotechnical Services) and in front from left are Johan van der Berg (Specialised Electrician High Voltage Electrotechnical Services) and Jacques Lawrence (Senior Manager: Substations Electrotechnical Services).

Bongani Mandla, Director of Electrotechnical Services requested additional funding in the adjustment budget earlier this year to undertake and finish these preventative measures. Mandla said it is a key objective that we ensure that our infrastructure is kept at a well-maintained standard to ensure we don’t inconvenience our citizens. Mayor Van Wyk congratulated the teams on a job well done and is very impressed with the enthusiasm and dedication of the teams who maintain and deal with ongoing repairs, especially during recent winds and rain storms.

Power transformers are manufactured on request and delivery time for new units or critical spares may at times exceed 12 months, therefore unintended failures result in sustained power outages to community’s and suburbs. The average Distribution Power Transformers costs approximately R7 – 12 million rand, excluding consequential damages to commercial or residential consumers.  It is therefore of high importance that all high value, long lead-time assets are properly maintained, as well as ensuring future operational and capital costs are budgeted for the total life of the asset.

A conditioned-based assessment was performed to determine the useful life of all Power Transformers, through a contractor appointed by George Municipality. The condition-based assessments consisted of five phases:

  • Phase 1 during April 2021, a non-intrusive assessment consisting of oil sampling and visual inspections was performed.
  • Phase 2, May-July 2021, an intrusive inspection consisting of an insulation test, Low Voltage and High Voltage testing by IEC standards and procedures was done.
  • Phase 3, followed in August 2021 where verification and quality assurance by an independent specialist company in Germany was done and signed-off.
  • Phase 4 during November 2021 consisted of a stakeholder engagement between the contractor and George Municipality officials. The report findings were presented to engineering personnel and units prioritised by a risk-based approach and approximate costs for future operational and capital expenditure projections for the next 10 to 15 years. 
  • Phase 5, started February 2022, after adjustment budget, all high-risk transformers were scheduled for maintenance and all defects repaired including tap changer maintenance, anti-corrosion treatment, oil filtration and the installation of maintenance-free rejuvenating air purification units fitted.

All high priority works were completed by June 2022 costing approximately R 2.5 million. The remaining medium and low-risk units are scheduled for refurbishment for the rest of 2022 – 2024 financial years respectively.

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