First and foremost you should treat a tripping breaker as a sign of potential trouble. Don't assume a worn out breaker replacement will solve the problem. Hire an electrician to change the breaker and to check all the wiring. Old wires fray or shed insulation causing faults; wires get exposed to moisture or water; there could be loose screw connections at the outlets, or the circuit may be overloaded with other appliances you never knew were connected. Play it safe - hire an expert to give everything a look.
Tripping Breakers
I have a musical fidelity KW500 that trips a 20 amp (dedicated curcuit/12 gauge wire/hospital receptacle) the instant the power switch is pushed. I have checked everything I can think of that could cause it (hookup is fine). Everything else about the system and circuit is unchanged and has worked for years. When it did turn on before it sounded great and played without tripping the breaker. Anybody else have this problem? If so what was it? Your help is appreciated. Chris.