The tap changer is located in HV winding in Resiglas dry type transformers. Setting the tap involves simply changing the order of connections between particular taps, identically on all HV windings. Lower values on LV terminals means that lower values on HV terminals as well, thus the tap changer must be set for lowering the HV, for instance from value 21000V to 20475V. Similarly, excessive values of LV terminals voltage means that excessive voltage values on HV terminals. Therefore the tap changer must be set for higher HV, for instance from value 21000V to 21525V. Individual settings (connecting order of the taps) of the tap changer are presented on a diagram, placed in a form of a sticker on the yoke beam of the transformer.
