Trafo Power Solutions has said four of its dry-type transformers have been an instrumental part of a mobile process plant at a Sierra Leone mine since last year.

The dry-type transformers have been so successful in powering the process plant that the customer has ordered six more for its recent phase two upgrade.

Trafo Power Solutions Managing Director, David Claassen, said: “The mine required a solution that would withstand the demanding conditions of a mobile process plant needing to be moved frequently over rugged mining terrain – as often as once a month. They could not risk using a conventional oil-cooled transformer as they needed to avoid any risk of fire or oil leaks. They also needed a product that would require little to no maintenance.”

The second contract was a repeat of the initial order and is comprised of two 800 kVA units, one 1,600 kVA unit and one 2,000 kVA unit as well as two more transformers – 1,600 kVA and 800 kVA – which will replace two existing oil filled transformers.

The company said: “Demonstrating its flexibility in meeting specific customer requirements, Trafo Power Solutions designed the solution to cater for the mine’s unusual voltage levels of 13.2 kV/480 V at 60 Hz.”

The transformers are installed in a 6 m long E-house on the mobile process plant, which is moved around the site on skids as required by the mining plan.

“We were able to customise the design of the transformers for the customer’s specific application,” Claassen said.

“This required a special reinforced frame to accommodate the constant vibration of the working plant, as well as the bumping motion when the skid-mounted plant is dragged to a new location. The design also included anti-vibration damping on the transformer feet, to further mitigate the impact of the vibration.”

Source: International Mining