Signalling its recognised and specialist expertise in dry-type transformers, Trafo Power Solutions will this year design and deliver almost 50 mini substations to a growing copper mine in the Democratic Republic of Congo (DRC).

“This significant order is testament to Trafo Power Solutions’ experience and capability, and the value that we have created for customers over the years,” says the company’s managing director David Claassen.  

The customer’s specifications for the mini substations vary between 630 kVA and 1,600 kVA, and will be supplied in both 11 kV and 33 kV formats – with multiple configurations of low voltage output from 400 V and 690 V, including dual secondary in some cases. The design specifications will allow the units to be applied in a combination of surface and underground applications, which required compact designs and innovative approaches to cooling.

Among the benefits of dry-type transformers in underground mines are their safety features, notes Claassen. Due to the absence of oil as a cooling agent, dry-type transformers are a very low fire risk – and there is also no environmental risk of oil leakage or spillage. Maintenance is also minimised by the use of air for cooling instead of oil; this obviates the need for regular oil testing and replacement.

“Our experience and track record with dry-type transformers have given us a good understanding of the rigours of deploying electrical equipment like this in a demanding mining environment,” he says. “As an African company we have worked all over the continent and understand the conditions; this has developed our ability to design and manufacture mini substations for various applications.”

Trafo has supplied dry-type transformers around Africa including South Africa, Zambia, DRC, Mozambique, Sierra Leone and Zimbabwe. The units will be delivered to the DRC mine in batches over the course of 2023.