compressor

I want to use the wireless temperature sensor to work with Compressor control panel of the refrigerator, I am just new in tinkering this kind of stuff any advice to make it possible will be much helpful.

I have a 250 amp, 120/240 volt, single phase panel with 100 amps dedicated to resistive load (heating) at 240 volts and 40 amps to incidental loads at 120 volts. What size 240 volt compressor can I run from this load center?