Transformer taps help


Batteries Not Included
United States
34.5kv system. Secondary bus voltage is going to be kept continuously around 105% or 36225 volts via on board tap changer to compensate for voltage drop at the far end. Primary voltages vary +-5% steady state of 115000 volts hence the LTC on the secondary.

Do I set my primary taps to 109250 volts (position 5) so that I have 36225 volts when the secondary LTC is in the neutral position or do I leave the primary tap at 115,000 (position 3) and let the LTC do all the boosting to 36225 volts? Or do I simply spec a 115000/36000 transformer ratio from the factory? How is this normally done?