Electricity + Control

Installed last year, four dry-type transformers from Trafo Power Solutions are proving their worth on a mobile process plant at a mine in Sierra Leone – such that the customer has ordered six more for a second phase upgrade.

Trafo substation on site Sierra Leone

Dry-type transformers supplied by Trafo Power Solutions are proving their worth on a mobile process plant at a mine in Sierra Leone.

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

The second contract was a repeat of the initial order and comprises two 800 kVA units, one 1 600 kVA unit and one 2 000 kVA unit, plus a further two transformers, 1 600 kVA and 800 kVA, which will replace two existing oil-filled transformers. 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 six metre long E-house on the mobile process plant, which is moved around the site on skids to be located as required by the mining plan.

“We were able to customise the design of the transformers to this specific application,” says Claassen. “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.”

The entry of Trafo Power Solutions dry-type transformers to the African market coincides with growth in the use of modularised substations. As dry-type transformers do not use oil as a coolant, they are suitable for installation in confined spaces without any of the conventional infrastructure usually necessary to protect the environment from possible oil spillage.

“Modular and mobile substations are growing in popularity for applications all around Africa, as they can be fully prepared under workshop conditions, reducing the work required on site,” says Claassen. “With regard to the installation of the transformer, for instance, we ensure that the temperature control relays are fully programmed and tested in South Africa, along with the fan system – making it ready for action on site.”

In the unlikely event of any further attention being necessary, Trafo Power Solutions can mobilise service support to any of the sites it supplies.

For more information contact Trafo Power Solutions, T. +27 (011) 325 4007, or email: david@trafo.co.za