Preventive maintenance in the factory of a transformer reduces the stress of aging, re-establishes short circuit strengths and improves dielectric strength. A well maintained transformer reduces operating cost and improves reliability.
Rehabilitation aims to restore key components of the transformer to a state as close to “as new” as possible by performing refurbishment and replacement actions without replacing major components such as the windings or core. To maximize the assets technical life, this refurbishment or overhaul can be an intermediate action when no failure has occurred yet but the ageing of the unit has reached a stage where the continued reliability of the transformer is unacceptable.