Application of linear alkyl benzene as a liquid dielectric

Petroleum based mineral insulating liquid has being used for a long long time as transformer oil. As there are limited reserves of precious petroleum, the search is on for an alternate suitable synthetic liquid. An effort has been made to evaluate LAB (linear alkyl benzene) as per relevant standard specification (IS: 335-1993) for a new transformer oil. It is observed that it also conforms to the requirements of equivalent international standards e.g., LEC 296, BS 148, ASTM D 3487. This is also compatible with different construction materials of transformer as well as mineral insulating oil in service. Significant improvement in pour point and ageing characteristics of indigenous paraffinic transformer oil is observed due to blending of LAB. The lower gassing tendency of LAB makes it a good substitute as a capacitor impregnant. There is a need to conduct long term ageing studies and field trials to ensure its reliability as a liquid dielectric.