Last year, electrical and digital building infrastructure specialist Legrand launched its range of products and systems for electrical installations and building infrastructure encompassing environment-friendly cast resin transformers designed for low environmental impact.
“Legrand’s energy efficient cast resin transformers, which efficiently transfer electric power between two different voltage systems, at the same frequency, are manufactured by a Legrand subsidiary, Elettromeccanica di Marnate (EdM), according to stringent quality and safety specifications,” says Legrand Southern Africa GM Luk Ivens.
These transformers do not use oil, unlike other transformers in the market, and, therefore, there are no pollutants and waste, explains Ivens.
The transformers also do not run the risk of insulating fluid losses and are a low fire hazard – even in harsh environments, such as mines and in chemical and petrochemical plants, he adds.
“Other advantages of these transformers are significant savings on electricity costs and minimal energy waste. “This compact system has also been designed for easy instal- lation and low maintenance requirements – no oil changes are necessary,” says Ivens.
He explains that the absence of flammable insulation liquids, the use of self-extinguishing materials exempt of toxic gas emissions, reduced noise levels and low electromagnetic emissions ensure enhanced environmental protection in all sectors.
The company’s standard distribution transformers have rated power between 100 kVA and 3 150 kVA, primary rated voltage of up to 36 kV and secondary rated voltage of up to 433 V. Special transformers have rated power of up to 17 000 kVA.
Unlike oil transformers, these cast-resin units, with reduced overall size dimensions, can be installed inside buildings and do not require additional building structures. This means optimum flexibility in any installation. Because no cooling fluids are necessary, maintenance costs are also reduced.
These transformers have features for enhanced efficiency and optimum safety. Rubber inserts alleviate the transmission of vibrations between core and windings, also reducing operating noise levels and absorbing thermal expansion of components. The sockets on the medium-voltage (MV) side adapt the primary voltage to the mains, which can be set with the transformer switched off, says Ivens.
Class F insulating material, at 155 °C, enables a temperature rise of 100 °C and the epoxy resin insulation means low maintenance. The carriage of these units, which enable safe movement, is pre-equipped for the mounting of ingress protection (IP) reinforced enclosures.
“Protective enclosures, available with different degrees of protection – IP21, IP31 and IP23 – protect transformers from external environmental impacts and people from the risk of direct contact,” he says.
Accessories for the transformers include thermal sensors or thermistors, electronic units for temperature control and forced ventilation systems to increase transformer power in temporary overloads or at high environment temperatures. Legrand can also supply MV terminations for plug-in connections, surge arrester kits and antivibrating supports.
EdM transformers are enhanced by the Zucchini busbar trunking system, which provides synergy for a direct connection. These busbars are available in aluminium or copper.
Ivens concludes that Legrand offers a technical advisory service specifying which transformer and busbar trunking systems provide the best solution for specific applications in the distribution of electric power, energy cogeneration, rectification and traction.