Choose your region and language



Power transformer repairs

Few transformers fail due to old age per se, but rather as a consequence of external faults, short circuit faults, insulation failure (dielectric failure), local overheating (causing gassing), or accessory failure (e.g., bushings, tap changers, coolers, surge arresters).

Repairing a transformer instead of replacing can substantially reduce investment costs and provide a faster turnaround than buying a new transformer. In repairing old transformers where the manufacturer may no longer be in existence and/or the design is obsolete and a like-for-like new replacement cannot be obtained, there may be significant savings in infrastructure costs and civil works in using the existing tank and design.


Scope of work

Upon receipt of the transformer in the factory, a visual inspection and electrical control will be performed to provide a root cause of the failure or what rehabilitation actions will be taken, as well as to provide a delivery date. Pending the root cause and agreed actions taken, the core and coil or active part will be untanked, inspected and partial or full manufacturing of coils will be initiated.

Following the upgrade/service of noble parts, accessories, and other auxiliary equipment, the active part is dried and replaced in the tank, which is refilled with fresh oil, and a high-voltage test is performed. After the factory acceptance test, the newly revitalized transformer is ready to be delivered back to its owner. If requested, Hitachi Energy can of course cater for the transport of the unit back and forth from the site.

Distribution transformer repairs

Distribution transformers ranging from 315 kVA to 5 MVA are readily distributed across the distribution networks, forming an integral part of the overall distribution network.

On-site repairs

Thanks to our TrafoSiteRepair offering we can refurbish, repair or upgrade your transformer directly at site avoiding transportation risk and time thus bringing your unit back on-line in weeks or even months faster than a workshop repair or a new transformer delivery.


Repairing a transformer instead of replacing it can substantially reduce investment costs and provide a faster turnaround than buying a new transformer.

Get to know more

Transformer service

Aging assets, rising energy demand and the critical need to avoid unplanned outages are challenging utilities and industrials around the world. Hitachi Energy is the largest transformer service organization, Global expertise close to our customers.
Hitachi Energy Power Transformers


Hitachi Energy offers distribution and power transformers, Dry-type and EconiQ™ Transformers as well as services, for industrial and commercial applications.

Transformer Insulation and Components

The world's broadest and most reliable portfolio of transformers components and insulation

Contact us

Submit your enquiry and we will contact you