The introduction of advanced transformer diagnostics allows performing a reliable assessment of technical condition and presentation of the expertise with recommendations for further operation of the unit.

The lifetime of the transformer is determined by the technical condition of its insulating system, in particular the solid cellulose-based insulation. It is well-known that the lifetime of the transformer is expressed by lifetime of paper, used for its insulation. Natural process of thermal degradation of the cellulose, taking place during the operation, mainly leading to the reduction of its fibers length, causes deterioration of insulation mechanical properties, and only in a small extent the decrease in electrical strength of oil impregnated paper.

See more: Comprehensive diagnostics of the transformers technical condition

Degraded power transformer insulation
a), b) – sludge on the active part, c) – degraded cellulose, d) – deformed windings

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ENERGO-COMPLEX runs the on-load tap changers service, produced by Machninenfabrik Reinhausen. We specialize in various types of OLTC repairs and replacement on-site of a transformer operation. We provide high level of service.

Our offer of repairs and modernization services include:

  • inspections and repairs of transformers at the installation site
  • internal inspections of transformers
  • transformer oil treatment
  • transformer oil regeneration
  • transformer sealing
  • modernization of cooling systems
  • Installation of valves and gate valves
  • accessories replacemenT
  • transformers cleaning and painting
  • anticorrosion maintenance

ENERGO-COMPLEX offers service and repairs of on-load tap changers

Service include:

  • oil replacement in diverter switch compartment
  • cleaning of diverter switch and sleeve
  • condition control of contacts and springs
  • checking tap number conformity of head drive
  • checking and maintenance of angle transmission gears
  • checking and maintenance of OLTC drive control box
  • measuring and recording of times
  • recording of power continuity

If it is necessary to replace subsystems, we offer wide range of spare parts produced by our company. We can also supply reconditioned OLTC head of any type, to minimize switching off period of transformer. We provide necessary amount of oil to refill OLTC and all specialized tools used during technical inspection. The maintenance procedure is followed by measurements and recording of OLTC times and their divergences, conducted by digital diagnostic device.

General repairs include:

  • demounting and cleaning of tap changer in workshop conditions
  • replacement of springs
  • replacement of moving and fixed contacts
  • assembly and pre-regulation
  • regulation of switching times and subsystems interaction
  • mounting of tap changer in a transformer

We also offer repairs of the whole tap changers, including tap selector switching cage.