TEVKO
Workshop interior with transformers and overhead cranes.

Service

Transformer repair and rehabilitation

Major rehabilitation and repair of distribution and power transformers — including shell-type (armored) transformers — subject to workshop feasibility by weight, dimensions and process.

Workshop interior with transformers and overhead cranes.
What the photo showsWorkshop interior with transformers and overhead cranes..

Rehabilitation restores a transformer to the condition the manufacturer specified — rewinding, core repair, insulation restoration and tap-changer service — extending its life at a fraction of replacement cost and lead time.

Rehabilitation is the deepest intervention on a transformer: it addresses the active part — windings, core, solid insulation — and the accessories, restoring the mechanical and dielectric properties degraded by ageing, faults or moisture.

TEVKO repairs both core-form (column) and shell-type (armored) transformers subject to workshop feasibility by weight, dimensions and process, including tap-changer repair — a specialized process because the shell construction wraps the core around the windings and demands specialized disassembly and reassembly.

Every rehabilitation starts from a diagnosis with real electrical data and closes with an acceptance test protocol — turns ratio, power factor, insulation resistance and, where applicable, SFRA to confirm the internal geometry is correct after reassembly.

What we rehabilitate

Shell-type (armored) transformer repair

Specialized disassembly, repair and reassembly of shell-form transformers and their tap changers.

When it applies: Shell-type units that few workshops can service.

Rewinding & insulation restoration

Rewinding, core repair, controlled drying of insulation and full oil processing.

When it applies: Windings or insulation degraded by faults, ageing or moisture.

How we execute the service

Diagnosis

Condition assessment with electrical and oil tests to define scope.

Intervention

Active-part repair in plant with 60-ton cranes and drying ovens.

Drying & processing

Controlled drying of insulation and oil treatment.

Acceptance

Acceptance test protocol confirming electrical and mechanical health.

Frequently asked questions — transformer repair and rehabilitation

Do you repair shell-type (armored) transformers?

Yes. TEVKO repairs shell-type (armored) and column transformers, plus tap changers, subject to workshop feasibility by weight, dimensions and process. The scope is confirmed against handling limits and process requirements.

When is rehabilitation better than replacement?

When the asset is structurally sound and the diagnosis shows the degradation is recoverable. Rehabilitation avoids the months-long lead time and higher cost of a new transformer.

What does the rehabilitation include?

Depending on diagnosis: rewinding, core repair, insulation restoration, drying, tap-changer service and full oil processing, closing with acceptance tests.

How do you verify the result?

With an acceptance test protocol comparing before/after values against standards (IEEE, IEC, NMX), including SFRA when mechanical integrity must be confirmed.

Transformer repair and rehabilitation in images

Core-and-coil assembly lifted by crane inside the workshop bay, in black and white
Core-and-coil assembly lifted by crane inside the workshop bay, in black and white
Technicians beside the exposed core-and-coil assembly above a transformer tank.
Technicians beside the exposed core-and-coil assembly above a transformer tank.
Overhead crane lifting a transformer cover inside the workshop bay, with technicians guiding the lift from a ladder
Overhead crane lifting a transformer cover inside the workshop bay, with technicians guiding the lift from a ladder

Related services

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