Hlpmepls,
In any case it will not run on US 60 Hz and is not designed for it and there would be no warranty in an incorrect country and/or voltage/Hz change speed and loading would be different, see:
50Hz motor running on 60Hz:
- The core loss will increase and cause over heating of core.
- As the core loss will increase, the Power Factor of motor will reduce.
- The motor speed will be higher, so shaft load will increase. Motor will be overloaded at rated load.
- Motor will produce magnetic humming sound.
- Motor Bearing life will be reduced (marginal) for more speed and more load.
- Dielectric Stress on insulation will increase due to higher frequency, causes marginal reduction of life of motor insulation.
But, it is practically seen, there is not much difference in service of a 50Hz, 2HP/3HP, motors when operated at 60Hz.
We know synchronous speed of motor is directly proportional to frequency so for 50 Hz machine when operated in 60 Hz it speed will increase and motor would try to catch up that speed for which more current will be drawn. And also motor needs to maintain constant V/Hz ratio which has got limitation of increasing voltage and frequency above which the flux will be saturated leading to more iron losses which will generate noise increase eddy current loss and force in the winding also gets increased which may lead to serious damage and also due to increase in voltage level insulation may get failure. In summary I would like to say initial operation wouldn't be dangerous but increasing its duty may lead to heating of motor and finally decrease its life due to losses.
Stephen