Breaker Tripping

ZimZimmer

AC unit trips breaker occasionally on restart when extremely hot out. Will run fine for hours after breaker is tripped back, but will occasionally trip again during hottest part of day when system is cycling often. I have replaced the thermostat, condenser fan motor, capacitors, contactor, breaker, and added a hard start kit. I have also cleaned the coils, cleaned inside of unit, and removed all shrubs near the unit to allow unobstructed airflow. Any suggestions? I’m thinking high head pressure or possibly upgrading to a 40 amp. breaker (assuming I have a 30 and the unit allows for a 40 – need to check on that)

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REP

I don't know where you are getting 40 from when it says as plain as day max fuse or breaker 30.
Assuming you replaced the fan motor with an exact replacement,I'd double check and make sure you have the right capacitor in there..
Throwing the breaker is a sign that something is working way too hard and drawing amps to do it.

ZimZimmer

I looked at the max breaker size after I posted the thread - I see now that is not an option. I had a licensed reputable HVAC company do all the work and he told me he was putting in OEM replacements. When he replaced the condenser fan motor and capacitor there was no improvement. When he added the hard start kit and replaced the contactor it trips less frequently, but still on really hot days when it cycles on and off frequently. My problem is I can’t predict when it is going to trip to take a reading of the amp draw. I’m running out of options. The first time they came out and checked it he couldn’t find anything wrong and just assumed it was the fan motor because it seemed to be running hot. After he replaced it, the new motor didn’t run nearly as hot, so he thought he fixed the problem. Is there any way for a DIY’er to modify the delay time to allow for the head pressure to go down? I cannot find any way to make the change on the thermostat.

JJboy

You should check the compressor with a Megger test.

__________________

**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.

ZimZimmer

Not familiar with the Megger test, but I’ll do some research. Would that have been a normal test done in the technician’s diagnostic? He assured me the compressor was fine after a myriad of tests. I thought for sure it was going to be the contactor when he showed me it was pitted on the contacts. Thanks for all replies – this has been a very frustrating (and expensive) experience.

REP

I don't know what to tell you.
If I had a customer that called me because the breaker was tripping and I dis all those things and charged you and you called me back and told me the breaker is still tripping I would (and have) feel obligated to get to the bottom of the problem on my time.
I'm guessing here understand but looking at the list of things that have been changed I would say you haven't gotten a service tech out to your problem but rather a parts changer.Possibly he gets paid on commision on the parts he sells.
I don't know about you but I would be mad as *ll for paying for a problem that has not been fixed.

JJboy

This is why you're a good technician. Totally agree with you.

__________________

**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.