Daftar Isi:
  • A power transformer has a system of testing - testing transformer which aims to determine whether the transformer is feasible to operate. One of transformer testing is testing the insulation resistance. This testing is done directly between windings to ground by using a megger. So, from this test can be calculated that the value of polarization index test results for 10-minute insulation resistance compared with the results of testing insulation resistance 1 minute. This study aims to determine how much influence the polarization index values that the results will determine whether the transformer is safe to operate. Based on the results of the discussion about the value of polarization index of 18 MVA power transformer in the substation Keramasan PT PLN (Persero) Power Sector Keramasan, shows that the average value of polarization index - average in 2013 was 1.4 shows that the transformer is in good condition. Polarization Index and the value of the average - average in 2015 was 1.88 in good shape. Ie transformer windings increases of 0.48. The increasing age of the transformer if it is not done then the maintenance of the transformer Polarization Index value will decline.