- Transformer Installation and Maintenance

Power transformers demand a high degree of care during installation. The large capital investment for the transformer and their importance to the power system demonstrate the need for careful field preparation for service. This chapter will highlight recommendations for the proper receipt, inspection, field assembly, oil processing, acceptance testing, and maintenance of large liquid-immersed power transformers rated 10 MVA or greater or with primary voltage rating of 69 kV and above. Basic transformer field installation and maintenance processes will be reviewed to include receiving inspections, assembly of transformer, field dry out techniques, determination of insulation moisture concentration, provision for cold ambient temperature processing, vacuum filling processes, acceptance testing, maintenance schedules, components maintenance, and oil reconditioning and reclamation. The processes and recommendations introduced may not cover all possible contingencies based upon design, construction, and application of the transformers; therefore, the original equipment manufacturer’s (OEM) instructions may differ from standard industry practice. The manufacturer’s guidelines 22