This question is very hard to answer because you have not provided enough information, list all the pertinent information from the nameplate of the motor such as FLA, volts, Power Factor, H.P. ( I assume from 45Kw its a 60 HP motor). Than provide more information the type of physical load this motor will be powering. Also you must describe the circuit, Is it connected to an MCC, does it have a V.F.D (Variable Frequency Drive), is the a disconnect right before the motor? What is the cable sizing between each D/C?
After you've provided this information I will definitely be better able to give you an opinion.