I have NEVER seen a capacitor cause a BREAKER to trip. Possibly to happen, but extremely remote. If you want a quick test to determine if the wiring from the breaker to the AC control is shorted. Take the 120 wires loose at the control box and stick the Black and white into a 12 gauge extension cord and run on FAN ONLY. Since you state it trips on fan only also, if the fan runs and the wall plug for the extension cord does not trip the breaker you have your answer. Since you state it does it on fan only also, it seems that the fan motor is the shorted part. You do NOT have to do the extension cord test if the breaker trips ONLY after turning the AC fan to on only if it trips all the time. Doug
