I've just moved into a home with an existing Armstrong Concept 10 A/C unit that's at least 15 years old. When I left for a 2-week vacation, the unit was working great. I set the thermostat to 77 to save energy. Upon returning, I lowered the thermostat to 70 and waited, and waited and waited several hours only to find the temp. in the house was not lowering, it was actually rising! I could see the unit's fan blade was not moving so I checked the circuit box in the basement, and the A/C breaker HAD BEEN TRIPPED! I reset the circuit breaker and even turned the unit on/off from the thermostat. The fan was moving now, but the temperature was still NOT LOWERING! I went to bed hoping the problem would be resolved in the morning, but I was not. Again, the unit is running, blade moving, fan blowing, but no 70 degree air, the air is probably the 77-79 degree air the thermostat is displaying as the indoor temp. 1. What may have caused the circuit to trip? 2. What can I check outside on the unit itself to get it cooling again? 3. What damage, if any, may have occurred to the unit if it ran non-stop for 2 weeks? Thank you!