Abstract: A three-phase non-linear transformer is cooled by first (30) and second fans (40). The first fan (30) is attached to the first core clamps (12) of the transformer using a first mounting structure (15). The second fan (40) is attached to the second core clamps (24) of the transformer using a second mounting structure (17). The first fan is positioned first so that air is directed toward a central passage of the core. The second fan is positioned so that air is drawn through the central passage of the core. The first fan circulates air through a central passage in the transformer core and channels that exist between adjacent coil assemblies. The second fan draws air through the central passage and channels and further expels the air into the surrounding environment. The first and second fans are controlled by a control panel through which they are run automatically or manually.