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.