In Canada and the US motor voltages are always listed differently than the nominal supply voltages from generators and utilities. General purpose transformers also are rated with the nominal supply voltage while dedicated motor/drive isolation transformer are rated with the utilization voltage.
I have never heard a good reason why this difference exists. I do not agree with the idea that it has to do with voltage drop. I just take it as fact and get on with my life. (There is also another rating quirk, in that heating equipment is often rated for higher than nominal voltages)
Supply - Utilization (always 4.17% lower)
120 - 115
208 - 200
240 - 230
480 - 460
600 - 575
