Modern Mining July 2025

MINING NEWS ENERGY

Designing transformers, substations for resilience on Africa’s mines Electrical equipment at mining operations in Africa face multiple challenges, such as variable voltage supply and high ambient temperatures, demanding innovative solutions to ensure reliability and performance while not incurring excessive cost through over-designing.

David Claassen, Managing Director of Trafo Power Solutions.

T rafo Power Solutions, which designs and supplies electrical solutions including transformers and sub-stations, has wide experience in dealing with these conditions across the continent, according to Managing Director David Claassen. “In all projects, it is vital to understand that every electrical solution on a mine is affected by the broader ecosystem of infrastructure,” says Claassen. “For instance, it is not uncommon to find that a national power grid delivers an unstable voltage supply which can affect how equipment performs as well as its longevity.” The voltage fluctuations on the supply network in some countries and regions can reach 15 to 30%, he explains, so the products that are designed and installed to meet the customer’s operating specifications must also accommodate such factors that are outside of the mine’s control. “It takes considerable ingenuity to achieve the right balance – with a solution that is fit for purpose but remains economically cost effective,” he says. “This is particularly important for remote operations – many of which run continuously – where it is costly and time consuming to attend to equipment that fails due to excessive voltage fluctuations.” Even if components like surge arrestors or switchgear can be quickly replaced, voltage fluctuations still pose a serious risk

to the transformer itself if it hasn’t been specifically designed to withstand such conditions. Transformers are critical assets with long manufacturing lead times and their failure can halt production entirely — leading to severe economic consequences for the operation. “In environments like these, we collaborate closely with our customers and technology partners to develop tailored solutions that address their unique challenges,” he says. “The resilience we build into our products directly supports the operational reliability our customers depend on.” Claassen emphasises that in mining environments the reliability of electrical equipment is just as critical as its performance and must be deliberately factored in during the design phase. He notes that many African mines also contend with high ambient temperatures, often intensified by prolonged exposure to direct sunlight, which can accelerate the ageing of electrical equipment if not properly accounted for in the design and choice of materials. “To ensure our equipment operates within safe temperature limits, we explore a range of cooling options,” he explains. “Depending on the specific environment, we typically design transformer and electrical enclosures with either natural

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