Main level system for home found no power at outdoor unit. 40 amp breaker in home was tripped. Technician reset breaker and after approximately 10 minutes of operation the breaker tripped again. 40 amp breaker in panel was warm to the touch. Technician verified tight connections. Tested all capacitors and connections in out door unit. Capacitors and connections are good. Recommend replacement of 40 amp breaker in panel. Both systems the main level and upstairs are 30 years old and because of age and lack of efficiency replacement is recommended. Office will schedule appointment with customer and our comfort specialist to discuss various options.