In a specialised application on a coal mine, Trafo Power Solutions recently supplied a dry-type transformer mounted on a mobile skid.

“The harsh environment of a coal mine required us to specially design a fit-for-purpose solution,” David Claassen, managing director at Trafo Power Solutions, says.

“The cast-resin dry-type transformer is ideal for the mobile arrangement as it is cooled without oil,” he explains. The absence of oil makes it a safer option in terms of fire hazards, especially on a coal mine.

It is also more environmentally-friendly, as there is no chance of an oil spill. The 1250 kVA dual-MV configuration supplied to this mine allows the unit to be linked up to either 11 kV or 6,6 kV supply.

“The unit was designed for a compact enclosure, while still allowing for sufficient air movement for cooling,” Claassen says. “We provided a unique solution of a cast-resin transformer with Class H insulation rating for both the medium voltage and the low voltage windings.”

This insulation standard ensures that the transformer can withstand temperatures of up to 180°C. He notes that the enclosure design had to accommodate these heat factors while also preventing the ingress of dust or water.

Special engineering was also applied to building a high level of mechanical rigidity into the transformer itself, as demanded by the regular relocation of the mobile skid. This movement means considering that vibration and other forces must be borne by the equipment without affecting its performance.

Claassen emphasises that Trafo Power Solutions is experienced in providing dry-type transformers in a range of enclosed formats to suit customers’ needs. The inherent safety of these transformers also allows them to be installed in underground mining locations.

“We can provide various dry-type transformer enclosed solutions with a mobile skid, which is a versatile format for a range of mining applications,” he says.

Trafo Power Solution’s solid track record in cast-resin transformers is based on its local expertise and design capacity, combined with the high quality manufacture of the units by Italy-based TMC Transformers.