A service man installed a delay to prevent the air conditioner from coming on while the compressor pressure is still high. That didn't fix the C/B trip problem. When I check the house in the morning the circuit breaker for the Lennox HS23 411 1P air conditioner is always tripped. I reset it and check again in the evening and it is never tripped and the house is at the set temperature.

Is should also have mentioned that before I called the service man, I cleaned the condenser by vacuuming and hosing the radiator.

That's really strange. Must be something happening at night that doesn't happen during day. Do you have a lawn sprinkler system that comes on during night that might be wetting the A/C disconnect box?

You don't have any kind of "supposedly energy saving device" put on by the power company to cut back on power during periods of high demand do you?

Yes I have s Saver Switch controlled by the power company. I will try to find out the history of their usage and how likely they are to cut back at night.

Suspect that is the problem. Don't know why they would cut back during early morning hours unless programed incorrectly.

Don't know how devices work but do know that power company cannot control amperage, only voltage. If voltage is cut back, amperage goes up. Increased amperage would cause breaker to trip.

My wife wanted to join that program, thinking it would be a savings. I said no for reasons just like this.

Thanks for your help. I talked to the power company this morning and they controlled power in the Twin City area only once in the recent past - on July 18 from 3:00PM to 6:00PM. When they are controlling power, they don't lower the voltage, they interrupt it - 20 minutes on and 20 minutes off throughout the control period which, on the 18th, was three hours. As a result It doesn't look like the Saver Switch is the cause.

I have some more information to add. Yesterday, Sunday evening, I found the C/B tripped at 20:05 hours. After rechecking my notes, I discovered that on July 21 I had found the breaker tripped at 14:15 hours and that after resetting the breaker the A/C ran for one minute and tripped again. After resetting it the second time, I didn't find it tripped until the next morning at 08:30 hours. So my statement "never throughout the day" is incorrect. A more accurate statement would have been C/B found tripped 7 times in the morning and twice during the day. I apologize for the misinformation.

If an A/C is low on freon, would that cause a C/B to trip? I'm also beginning to wonder if I have a marginal circuit breaker.

More information. The C/B was found tripped at 14:45 hours. The score is now 7 to 3. That run of morning trips is beginning to look like chance.

Agree, beginning to look like weak breaker. Check A/C unit outside, should give minimum breaker size. Given an 30 or 40 amp double breaker cost about $15, I'd replace it just on general principle. If the minimum size breaker is greater than what is currently installed tell us what the listed minimum size is and what the size of the A/C wire size is. There are some special rules that allow you to install a larger breaker on an A/C circuit than you can on other circuits.

I am back from the lake and replaced the C/B with another 30 amp double pole breaker. The breaker is still tripping.

Hk, Per your suggestion, I found that the line to the A/C is #8 THW copper wire. This has an ampacity of 50 amperes and the maximum overcurrent protection allowed by the code is the ampacity (50 amps). The Lennox specification reccomends a 35 amp circuit breaker for the HS23-411, so I plan to replace the 30 amp C/B with a 35 amp one. Thanks again for your help.

A 35 amp breaker should solve problem. We haven't discussed as whether this is a new problem you haven't had in previous summers. Could be related to the extreme heat wave we are currently having over most of the country. Power companies are having a hard time keeping up and probably have cut back on voltage to everyone to prevent brown outs.

If 35 amp breaker doesn't solve problem, you may have to have air condition tech put on what he will probably call a "hard start" capacitor. That, to me, is just a larger capacitor to help the compressor get started.

Just for fun have you checked the voltage you presently have at the panel?

It is not a new problem, but it is more severe than it has been in the past. For example recently it has been tripped virtually every morning as opposed to running 3 or 4 days without a trip in the past. I think it is resolved now. I installed a new 2-pole 35 amp breaker and haven't had a trip for over 41 hours. The longest stretch withouit a trip for the past month was 26 hours. When I installed the breaker, I also measured the line voltage at the service panel. It was 242 volts.

Hopefully it will run until winter time.