I would be grateful for any advice anyone can give me about this persistant problem. I installed a 30,000BTU air condition unit some time ago. It is on a 220V circuit. The technician told me that he was putting two 30amp breakers. One right near the aircondtion unit and one on the main panel box for the house. The problem is that anytime I put on the a/c unit it trips one of these breakers. The catch is though that after I reset the breaker and put back on the unit it works fine. I take off the unit again and put it on and it still works fine. However after about a day has passed without the unit bein on, the unit trips a breaker again. It only trips the breaker on the first time I put on the unit for the day. Wierd huh?. Grateful for your advice.

You might want to take a look at the fan on the unit it may be sticking after sitting for a while cases the unit to trip the breaker had the same problem a while ago and that's what it turned out to be. Many units are supposed to be service each year and the fan motor may have an oil inlet in it if it drys out this sort of thing happens.

Does the same one trip each time?

should of said causes not cases sorry

try washing the outside coil. it may look clean but you'll probably be surprized .
inside coil should be washed also. the pressures can cause high amp draw and trip the breaker. be sure to cover exposed wires and openings to the compressor and fan motor.