This Standard covers the electrical performance of rotating electrical machines forming part of the equipment of electrically-propelled road and rail vehicles, including those for use in mines. Such machines are designated "traction machines". The vehicles may obtain power either from an external supply or from an internal source. It does not apply to d.c. electric motors forming part of the equipment of battery-operated road vehicles, industrial trucks and tractors. It is not intended that it should apply to small machines of a minor character, such as fractional horsepower motors, that may be used on a traction vehicle.