Abstract: A modular system applied to transformers, particularly power transformers, which comprises a structure having modules coupled between each other by fixation means, in such a manner that, the set thus formed, is positioned in the perimeter of the tank of the transformer and to which it is possible to connect several equipment and components, so that the referred components and equipment are positioned in the interior of the tank of the transformer, thus permitting the access to the referred components and equipment, when carrying out maintenance, supervision or control work, as well as to permit the optimization in the manufacture thereof, assembly, transport and installation.