I am looking at the datasheet for a motor. This is an AC induction motor designed for use in electric vehicles. It includes the statement [my emphasis]:
The motors are designed for installation in electrically driven vehicles. and are characterized by their high power density, ruggedness, long lifetime, and overall reliability. The variable-speed three-phase motors are operated from a frequency converter. The direct connection to the three-phase line supply is not permissible.
The AC specifications are never listed (I assume the inverter uses some frequency other than 50/60Hz, and you'd have to calculate the appropriate AC voltage/current requirements based on the DC requirements) so is that the only reason this wouldn't be allowed? Is this statement based on physical limitations, or is this just business?