Unique relationship between interfacial tension test (IFT) and neutral number test (Acidity) of transformer insulation oil in PLN P3B JB - Jakarta and Banten Regional

Transformers are one of some important equipment on electricity network. Each utility, in this case PLN P3B Jawa-Bali, has to assure their reliability in order to maintain electrical power system stability by assessing transformer conditions. Insulation system, which consists of liquid and solid insulation, is the most important part of transformer system. The performance of transformer will depend on its insulation system. Solid insulation has a function to provide mechanical strength, dielectric strength and dielectric spacing. Liquid insulation has a function to provide dielectric strength, cooling and protect the active material. To assess the quality of liquid insulation in this term is insulation oil there are several test that can be done i.e. water content, breakdown voltage, acidity, interfacial test, sediment, flash point and color. These tests will give information whether the insulation is in normal ageing condition or in accelerating ageing condition due to oxidation. This paper will explain the typical of Interfacial tension test (IFT), neutral number test (acidity) during degradation process due to oxidation in PLN P3B JB - Jakarta and Banten regional and the unique relationship between interfacial tension test and neutral number test (acidity) itself. The data shown that an increasing of neutral number (acidity) value always followed by a characteristic drop in IFT. Our analysis that we´ve done refer to oil quality test in PLN P3B JB Jakarta & Banten regional at 2008 which consist of 250 transformers.