Many extra miles, in fact! Ian Gray, manager of WearCheck’s transformer services division, and Des Rodel manager of the Cape Town Branch, recently travelled to Khobab and Loeriesfontein wind farms, in the Northern Cape - 450km from Cape Town - to run a transformer oil sample course for the maintenance team.

Each wind turbine is connected to a step-up (padmount) transformer which boosts the generating output of the wind turbine generator from 690 V to 33 kV. These transformers are located at the base of the wind turbine. From there, all the power is then interconnected to a collector step-up transformer located in a substation where it is transported to the electricity grid.

The reliability, or lack thereof, of step-up (padmount) transformers has led to the investigation of the total cost of ownership in trying to balance the low cost of step-up padmount transformers versus the cost of premature failures.

The insulating oil testing is typically a critical first step in this investigation that requires sampling performed by an experienced person, who has received adequate training, in accordance with IEC 60475.

Above: The Loriesfontein Windfarm maintenance team attended a transformer oil sample course run on-site by Ian Gray, head of WearCheck’s transformer services division (fourth from left with grey trousers)

Top: Ian Gray, head of WearCheck’s transformer services division, at Loriesfontein Windfarm.