Filtration and maintenance is important for transformer oil since it not only enhances performance but also ensure safety and ease of operation for the transformer maintenance team. Transformer oil is also known as insulating oil owing its name to excellent insulating attributes and stability at high temperatures. It stops arcing and corona discharge besides reducing heat of the transformer and thereby acting as a coolant. The transformer oil protects the core and winding of the apparatus and prevents oxidation of the cellulose paper insulation
Entities including breakdown voltage, moisture content, neutralization value, interfacial tension, color, test for oxidation stability, flash point, pour point, viscosity, sludge test and dissolved gas analysis (DGA) helps in ascertaining qualities of insulating oil. The temperature of transformer oil increases as the load increases and results in expansion of oil volume which in turn pushes air outside the tank. When the load decreases oil volume decreases resulting in vacuum formation in the top part of the transformer oil tank. Such vacuum encourages exterior air to enter the transformer tank which brings moisture and dust along with it. At this point, silica gel comes to the rescue of the transformer and dries down air to a dew point below minus 40 degrees celsius and employs an oil seal cup to remove dust particles.