Was the pump originally for 100V at 50 Hz?
Is so you are OK running it at 120 V at 60Hz.
That is really pretty common.
I assume it is a synchronous induction motor and not rectified to DC, etc.
If all of this is true then you will see a performance increase from running the pump on US power. The motor will be fine -the current is limited by inductance and your Volts / Hz ratio is fairly constant -so you are not really over voltaging the motor.
The synchronous RPM of the motor will be faster. (More Volume and Pressure) If it is a mag drive then there is some point where the pump will decouple from the motor and "slip" , but I suspect that that point is well beyond where you will be running. Again many designers assume that 100V / 50Hz motors will be run at 120V / 60 Hz.
If the pump wasn't originally designed for 100V / 50 Hz please disregard this post.
