If you try and run a 30 amp rated device from a 20 amp plug you will have problems. Your compressor has a 20 amp plug. It does not draw 20 amps, there is a safety margin built into the plug size and wire size. Also the plug configuration excludes you plugging that 20 amp plug into a 30 amp receptacle. The circuit breaker is there to protect the wire, not the device at the end of the wire.