The treatment method for external cracks in dry-type transformers is as follows:

Inspection: Inspect the extent of damage to the transformer to determine the location, size, shape, and other details of the cracks.

Material preparation: Prepare materials such as epoxy resin polishing area repair putty, power epoxy repair putty, polyester paint, or PRTV anti-pollution flashover paint.

Repair: Remove the epoxy resin in the cracked area to form a grinding area; use electrical epoxy putty to repair the grinding area and form a repaired area; after the power epoxy putty is cured, grind the repaired area to make the entire winding surface smooth and flat; spray the entire paint on the winding surface.

Precautions: During the processing, it is necessary to adhere to relevant operational specifications and safe operating methods to ensure the safety and reliability of the process. Furthermore, after the repair and after a period of use, the dry-type transformer needs to be re-inspected to ensure that the repair meets the expected results.

The above methods are for reference only. If you need more accurate information, it is recommended to consult a professional.