What is the composition of electrical transformer oil?

The composition of electrical transformer oil primarily consists of refined mineral oils, which are derived from petroleum. These oils are treated to remove impurities and enhance their dielectric properties. Additionally, transformer oil may contain additives such as antioxidants, corrosion inhibitors, and pour point depressants to improve performance and stability. The specific formulation can vary by manufacturer, but the core components remain consistent to ensure effective insulation and cooling in power transformers.