29-06-2017, 03:46 PM
Few transformers fail due to old age per se, but rather as a result of external faults, short circuit faults, insulation faults (dielectric failure), local overheating (causing gases) or failure of accessories (eg bushings, tap changers , Dischargers).
Repairing a transformer instead of replacing it can substantially reduce investment costs and provide a faster change than buying a new transformer. In repairing old transformers where the manufacturer can no longer exist and / or the design is obsolete and a similar one can not be obtained for the new replacement, there may be significant savings in infrastructure costs and civil works in the use of the tank and The existing design.
Scope of work
Upon receipt of the transformer at the factory, a visual inspection and electrical control will be performed to provide a root cause of failure or what rehabilitation measures will be taken, as well as to provide a delivery date. Pending the root cause and the agreed actions, the core and the coil or the active part will be decompressed, inspected and the partial or total production of coils will begin.
After upgrading / servicing of noble parts, accessories and other auxiliary equipment, the active part is dried and replaced in the tank, which is filled with new oil and a high voltage test is performed. After the factory acceptance test, the newly revitalized transformer is ready to be returned to its owner. If requested, ABB can of course handle the transport of the unit from one side to another of the site.
It can be understood in the following video: