The growth of data centres in South Africa has been rapid in recent years, with exacting requirements related to safety and reliability being placed on all relevant equipment. This has created special opportunities for the application of dry-type transformers. 

According to Trafo Power Solutions managing director David Claassen, there is a significant amount of data space currently being constructed in South Africa. Alongside the issue of data security, says Claassen, the top priority in these facilities is uptime – as a data centre can simply never be offline. 

“The volume of equipment in these large server rooms creates considerable heat and therefore requires extensive cooling facilities – all leading to high levels of energy demand,” says Claassen. “Transformers therefore play an important role in these operations, and they must function to the highest levels of safety and reliability.”

He notes that South Africa faces a significant additional challenge, with unreliable electricity supply from the national utility. This requires backup power facilities to be installed, so that 100% uptime can be guaranteed.

“Even aside from the power supply issues, data centres must deliver a constant service without interruption, so redundancy capacity is required should any of the system components go down,” he says. “This redundancy can effectively double the design capacity of these centres.”

In these applications, dry-type transformers are well suited in terms of safety and risk, he explains. As the units are cooled by air and not oil, there is zero risk of fire and no chance of oil leakage. These transformers have an F1 fire rating, demonstrating their resistance to flammability; they are designed to be flame-retardant, and do not generate harmful emissions. 

By not having oil as a coolant, the maintenance of dry-type transformers is also reduced substantially. Oil-cooled transformers, by contrast, experience frequent oil temperature variations as load rises and drops. This variation creates opportunities for moisture ingress, making regular oil sampling and testing vital. If this is not conducted regularly, performance becomes unreliable. 

“Dry-type transformers can be installed inside or outside of a building or substation, with no special fire protection systems needed,” he says. “As oil testing is not required, dry-type transformers need very little maintenance – adding to their cost-effectiveness.”

He explains that data centres have high levels of non-linear loading, so these transformers must be designed for a high K-factor of typically around 13. The quick pace of construction of these facilities also often favours a modular approach, to which the dry-type transformer lends itself well.

“Modular substations can be rapidly manufactured, and dry-type transformers can be readily incorporated without the need for any special fire suppression,” says Claassen. “Another important factor is efficiency, as large data centres could consume as much power as a mining operation.” 

Trafo Power Solutions designs and manufactures dry-type transformers that comply with the highest efficiency standards and lowest loss levels recognised internationally – in line with data centres’ efforts to achieve the lowest possible energy consumption. 

Because of the individual nature of mines, a one-size-fits-all solution is often unfeasible. With that in mind, leading dry-type transformer specialist Trafo Power Solutions will use Electra Mining Africa 2022 to showcase its ability to customise its solutions for mine-specific conditions. 

“Leveraging many years of experience in the mining industry, pretty much across all commodities, we have comprehended that each mine is different and has its own set of challenges,” explains David Claassen, managing director of Trafo Power Solutions. “A one-size-fits-all approach is therefore out of the question, which is why most of our products are custom designed and manufactured to specific site conditions.”

Because they use air as a medium of cooling, dry-type transformers are typically installed in indoor environments, however, Trafo Power Solutions has a wealth of experience in supplying dry type transformers for outdoor applications The design of the enclosure is therefore critical to withstand the common harsh conditions associated with high dust and moisture levels. Despite the restrictive nature of enclosures, Trafo Power Solutions’ custom design capability guarantees enough ventilation, while allowing for necessary levels of ingress protection to keep dust and moisture at bay. 

“With our in-house design capability, we are particularly able to custom engineer solutions for challenging underground applications. We are able to tailor the dimensions, weight and other factors to match the space constraints presented by using vertical shafts or decline shafts to take the transformer underground,” explains Claassen. 

Amid a renewed focus on environmental, social and governance (ESG) in the mining industry, Claassen says Electra Mining Africa presents an opportunity for the company to showcase how its solutions – dry-type transformers, modular-type and miniature substations, among others – meet the growing requirement for environmentally friendly solutions. 

“There is a common understanding that sustainability represents one of the mining industry’s most significant opportunities for long-term value creation, building trust and sustainable growth,” says Claassen. “By using air as the insulating and cooling medium instead of oil, dry-type transformers allow mines to reduce their reliance on fossil fuels.” 

Apart from sustainability, mines are continually pushing safety boundaries. In fact, one of the key drivers of dry-type transformer technology in the mining sector is the safety imperative, says Claassen. 

“Mining companies have strongly shown their commitment to continually evaluate their operating practices to work towards a workplace with Zero Harm,” says Claassen. “The absence of oil in dry-type transformers translates into reduced safety and environmental risk. It also means that there are no chances of  leakages and possible fires.”

Dry-type transformers are categorised as F1 in terms of fire resistance ratings, indicating a low level of risk. Cooling options include natural ventilation and forced ventilation, with availability of air-to-air heat exchangers and auto heat exchangers. This gives dry-type units the significant advantage of having an inherently low risk of safety and environmental impact. 

Electra Mining Africa 2022 will take place from 5 to 9 September at the Johannesburg Expo Centre. Claassen is excited that the trade show has finally come back to life after the previous event was cancelled due to Covid-19. 

“Electra Mining Africa feeds into our overall company strategy. We see the mining industry as a significant growth area for us. We are therefore looking forward to participating in-person and reconnecting with the various stakeholders, from junior and senior mining personnel to original equipment manufacturers,” concludes Claassen.