The cooling fan of dry-type transformer can be installed in two ways: left (a) and right (b). The left side should be installed as far as possible, the right side should be installed as far as possible, and the fully sealed fan should always face out. Check whether the screw of dry-type transformer is loose and damaged before installation. Whether the blades collide or move with the air duct or not, if not, they shall be adjusted properly. After the installation of the fan, the test run shall be carried out, and the on-line use shall be carried out after the fan runs normally.