Circuit breakers breaking the circuit are not just there to be a hassle, the breaker is trying to protect you from yourself. Continuous breaker tripping is weakening your wiring inside your walls which can lead to a fire. This breaker is doing everything in its power to tell you that you have a dangerous situation, everytime you reset it you are basically ignoring its warnings. Get an electrician out to see what the problem is. Circuit breakers rarely are the problem, I say rarely, most likely you have an issue with the unit itself or the wiring. The circuit may not be high enough amps to handle the a/c. 50 amps is pretty common for a central a/c unit.