What is the procedure for filtering power transformer oil?

The procedure for filtering power transformer oil involves several key steps. First, the transformer is isolated and the oil is drained into a filtration system. The oil is then heated to reduce viscosity, allowing contaminants to be more easily removed. Filtration units, often equipped with activated carbon or other media, are used to remove particulate matter and moisture. Finally, the filtered oil is tested for quality before being returned to the transformer.