Dry-type transformers traditionally have been used indoors because of their intrinsic safety. However, with purpose-designed IP-rated enclosures they can also be used in demanding outdoor applications where there are high levels of dust and moisture. Trafo Power Solutions can design enclosures that, for example, keep out fine coal dust and still ensure the transformer is effectively cooled.
Local transformer specialist Trafo Power Solutions can design and supply dry-type transformers in enclosures that have an IP65 rating.
“The absence of oil in dry-type transformers makes them safe and suitable for many indoor applications,” says David Claassen, Managing Director of Trafo Power Solutions. “However, we are now installing them increasingly in outdoor environments with demanding conditions, due to their safety, reliability and low maintenance cost.”
Although dry-type transformers are air-cooled, Claassen explains that the enclosures are carefully designed to facilitate adequate cooling. The temperature rise of each transformer needs to be considered in the enclosure design, together with the available footprint on the customer’s site – so that the dimensions of the enclosure are suitable.
“Transformers must of course be protected from water, as well as from dust which can inhibit heat losses and potentially lead to short circuits,” he says. “Our IP-rated designs ensure that we meet the demands of the prevailing outdoor conditions on a given site and the cooling needs of the transformer so that it operates optimally and safely.”
Ingress protection or IP rating is a ranking of the level of protection against ingress of dust and moisture that an enclosure can provide. In an IP rating of 65, for example, the first digit refers to the level of solid particles being excluded – and the second digit refers to the moisture level. Trafo Power Solutions regularly designs transformer enclosures for IP ratings as high as IP65 or IP66.
“This means we can provide a level 6 protection against dust, which is essentially dust tight,” he says. “The level 5 or 6 moisture protection confirms that the enclosure will protect the transformer against jets of water and water from heavy seas.”
Claassen notes that most enclosures are designed to disperse heat by the natural flow of air. However, he says, there are various levels of temperature rise associated with a transformer’s specific insulation class, so other technologies can also be applied. Certain applications will require a forced air system, operating in a closed loop to ensure sufficient insulation from outside conditions.
“If more cooling is needed, there are also technologies which use water as a medium to remove heat from an enclosure effectively,” he adds. “And we can address other challenges too, such as the risk of condensation where outdoor temperatures are very cold.”
Trafo Power Solutions collaborates closely with its Italy-based technology partner, TMC Transformers, to design the enclosure at the same time as the transformer – in order to deliver optimal results for the customer.
For more information visit: https://www.trafo.co.za
