Di masa sekarang energi listrik sudah menjadi salah satu kebutuhan pokok bagi kehidupan manusia. Dalam penyaluran energi listrik kepada pelanggan, transformator memegang peranan penting di dalam sistem tenaga listrik. Transformator distribusi merupakan penyuplai langsung kepada pelanggan. Transformator harus dalam keadaan optimal dalam beroperasi. Transformator mengalami penurunan kualitas sejalan dengan umurnya. Semakin tinggi pembebanan, semakin sedikit sisa umur transformator. Semakin menurun pula keandalan transformator dalam beroperasi. Dengan hal ini, transformator harus segera diganti, demi memenuhi kebutuhan pelanggan. Berdasarkan hasil perhitungan transformator pada gardu KL 60 diperkirakan sisa waktu pakainya - 0,63 Tahun yang seharusnya sudah diganti. Dan pada gardu D 58N sisa umurnya 0,66 Tahun atau sekitar 7,92 Bulan

In the present, electrical energy has become one of the basic needs for human life. In channeling electrical energy to customers, transformers play an important role in the electric power system. Distribution transformers are direct suppliers to customers. The transformer must be in an optimal state of operation. The quality of the transformer decreases with age. The higher the load, the less the remaining life of the transformer. The reliability of the transformer in operation also decreases. With this, the transformer must be replaced immediately, to meet customer needs. Based on the results of the transformer calculation at the KL 60 substation it is estimated that the remaining usage time is -0.63 years which should have been replaced. And at the D 58N substation the remaining age is 0.66 Years or around 7.92 Months