Transformer On load Tap changer
ON Load Tap Changer There is always requirement of variation of voltage at secondary side even when load is connected then on load tap changer is used for the same. In case of on load tap changer tapping’s on the winding are brought out through a terminal board to separate oil filled compartment in which the on-load tap changer switch is housed. This tap changer is in the form of switch with motorized control. Handle is also provided in case of emergency. The essential feature of an on-load tap changing gear is the maintenance of circuit continuity throughout the tap changing operation. The circuit must not be broken otherwise there will be discontinuity of supply to load. Selector switch must not break current an additional separate oil filled compartment is used to house the diverter switch which breaks the load current by an interrupted arc. During that process carbon will be formed therefore oil in the diverter switch compartment must be prevented from mixing with oil in the main