The workbook doesn’t care what the spindle voltage is. It only needs the spindle’s rated power, current, and speed. But the VFD needs to know the spindle voltage necessary to drive the spindle to achieve those values, as well as what the values are.
“Off cut topic - is there a chance to calculate a ramping or plunge load with options to change speeds and degree? Plunge milling is on the list of fun things to try”
I’ll think about that one.