[ Ref. Giorgio Farabegoli in 130318 MMDigest --
Converting from 220 volts to 110 volts is very simple -- it uses a
simple step-down transformer. The frequency, however remains at
50 Hz instead of the requested 60 Hz. The motor will run using this
transformer, but it will run at 83% of its speed.
I ran my Duo-Art and Ampico pianos on 50 Hz for many years using the
step-down transformer. To fix the speed issue I replaced the pulley on
the motor with one of a slightly larger diameter. (You need to
increase the diameter by 20%!)
I never had a motor over-heat from this; basically, you're still
driving the same load as the motor was designed to run -- the pump
is still running at the same RPM.