The circuit braker on aircondition keeps turning off. When I turn on the aircondition it works a while but when it stops automatically it doesen't turn back on and the braker is shut off. What mis the possible problem on this case?

Check air conditioner electric tag for minium breaker size. Quite possible that breaker is under sized.

The circuit braker on aircondition keeps turning off. when I turn on the aircondition it works a while but when it stops automatically it doesen't turn back on and the braker is shut off. What mis the possible problem on this case?

The circuit breaker might also be weak from use at its limit or from tripping and being reset. It is also a possibility that a run or start capacitor or associated relay is going bad causing the unit to draw too much current/amps. Make sure that the wires are tight in the circuit breaker especially if they are aluminum and if they are aluminum you need to be sure the proper DE/OX paste is used to prevent corrosion.