Odd's are what you have is a 240V/1 phase 60hz
compressor, specially if it came from
Florida. The
generator is close enough spec wise in voltage and hert that it runs the
freezer fine. The 220V 50hz
inverter would cause the
compressor windings to run rather hot.
IF there isn't a setting for 60hz on your
inverter, you can find a 1kw 240v 60hz inverter for not a lot of
money, you could use that to run just the
freezer.