Custom mini substations for Zambian copper mine

Electrical Power & Protection

May 2026 Electrical Power & Protection

Trafo Power Solution’s reputation for providing tailored electrical solutions in demanding settings is further proven by a recent order to supply seventeen specially designed mini substations for an underground copper mine in Zambia.

According to David Claassen, managing director of Trafo Power Solutions, the orders include 800 kVA units and 1000 kVA units. The project called for precise engineering to address space limitations and operational demands, ensuring the equipment could be transported, installed and operated reliably within a confined area underground.

Each mini substation, which includes medium and low voltage switchgear as well as a transformer, plays a critical role in distributing power underground to a range of mining equipment and infrastructure.

“The first important consideration was the size of the shaft cage used to transport equipment and material underground,” Claassen says. “We understood what the limitations were and carefully designed a solution that would allow easy loading and transportation in the cage to the levels where the units would be deployed.”

The reduction in unit size posed a significant challenge regarding transformer cooling. It was essential in these designs to maintain adequate airflow to ensure proper transformer thermal management. As equipment dimensions decrease, airflow tends to become increasingly constrained.

“Trafo Power Solutions has many years of experience in technical design, ensuring the optimal performance of enclosed dry-type transformers under a wide range of environmental conditions,” he continues. “We made sure to fully understand the ambient conditions, and then adjusted the airflow to meet the specific needs of the transformer.”

This required accounting for transformer energy and heat losses that can be managed under expected conditions. Dry-type units are often chosen in underground mines for fire safety, since they contain no flammable materials like oil. He notes that the mini substations also had be moved from one underground location to another, required by the advancing of the mining face. With their convenient dimensions, the mini substations can be readily loaded onto rail cars and relocated. “Dry-type transformers offers a reliable and sturdy solution for demanding operational environments, with no risk of oil leaking due to damage to the unit,” Claassen says.

The mini substations were fully manufactured in South Africa to a tight production timeframe, and factory acceptance tests were conducted to all stakeholders’ satisfaction before shipping. In line with Trafo Power Solutions commitment to reliability and quality aftersales service, the customer will also have access to in-country support for these units.

“Our local partner in Zambia plays a vital role in supporting our customers there,” Claassen says. “We work closely together in projects like this one, both from a supply and aftersales support perspective.”

For more information contact Trafo Power Solutions, +27 11 325 4007, [email protected], www.trafo.co.za

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Electrical Power & Protection

Custom mini substations for Zambian copper mine

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