Because of savings in the controller, the cost of adding a motor on a 480 Volt system is less than if it were added on a 208 Volt system. The 200 Volt motor is likely to be more costly as well. The graph shown below compares the cost per horsepower for squirrel-cage induction motors for different sizes and voltages. It is also important to consider the size of the plant load and the range of sizes of the motors which will be used throughout.
Definite savings are indicated by choosing the 480 Volt system over either 208 Volts or 240 Volts. That is why 480 Volts is rapidly becoming the preferred voltage for low voltage systems in moderate sized industrial plants and in larger commercial buildings. As a result, equipment manufacturers are standardizing more and more on 480 Volts.
