The calculator will calculate the site KW and use a multiplier to work out the size of capacitor bank required.
The nominal running current will help you to size the cables needing to feed the unit using GenCalc or similar.
The Protection device must be able to handle the full load running current of the unit as well as the inrush of large correction steps being switched in.
Round this up to the nearest circuit breaker size to specify the rating of the feeder circuit breaker.