One typical way that technicians determine whether the replacement motor has sufficient power output is to compare the nameplate amps of the original motor with that of the replacement model. If the replacement motor's amp rating is at least as high as the original, you can consider the replacement suitable. In many cases, this comparison simply confirms what other factors, such as nameplate horsepower and rated voltage, tell us. This practice is most satisfactory when there is little or no variation in the efficiency from the original motor to the replacement. This method works well, for example, with most three-phase motors.