If the unit was installed according to specifications, the breaker should be rated high enough to tolerate even a hard starting compressor. Sounds to me like the run winding or start winding is grounded to the case, ie: compressor burnout. I would look on the unit to see if the installing company put a sticker on it somewhere, becasue the compressor should have at least a five year warranty, and many manufacturers now offer ten or more year warranties. I would make the call first thing in the AM
HandymanTrainer