My Outside AC , which is a pretty old unit( 15+) recently started tripping the circuit breaker. If I go and turn the circuit breaker back on the unit will run for about five minutes then trip the circuit breaker again.

Is it time to replace the unit? My AC repair guy did tell us last summer that the unit is on its last leg, but when he checked it a few weeks go it was working after getting some Freon added to it.