50Hz VS 60Hz

[jonr]

Resistive devices shouldn't care but inductive devices can draw more current (ie, perhaps overheat) when run at at a lower frequency.

A variable frequency drive is a good idea - it will control both the frequency and voltage to keep the motor cool.

[powerabout]

yep

Used on many megayacht air con compressors to alter capacity and to prevent any dip in the lights at start up. ( soft start)
( not cheap though )