AC Breaker Trip

[Flashdman11]

Ok so I searched the forum and can’t find the same set of variables so I will explain situation.
Hooked up to 50 amp. Main AC trips 20a breaker but seems to be worse when the sun is on it and temps are over 85. No issue during night. I checked the capacitor’s and they are fine. Does not trip while on FAN only. Condenser coils are clean, filters are clean. No loose wires at AC nor at breaker. Nothing else plugged in to pull amps. Compressor has no blockage in lines nor is it froze. Breaker is not hot to touch.
What else can I check?

[Nature Ist]

Does it trip very shortly after compressor tries to start up again?

[Flashdman11]

Originally Posted by Nature Ist

Does it trip very shortly after compressor tries to start up again?

No. It blows cold air and what is expected coming out of vents. Right now, it’s 73 outside and cloudy and is running fine with thermostat setting. I did a temp check at the breaker and it is rising about 7 degrees when running. But if sun comes out or gets hotter outside (like yesterday) it trips. What if it was shortly after compressor start, what is your suggestion?

[Nature Ist]

If it only happened as the compressor re-starts, it could be too much back pressure on the compressor putting too much load on the motor. There's a delay cycle preventing re-starting too soon in the unit control. That doesn't seem to be your problem.
My AC had to be replaced under warranty immediately after I took delivery. I was informed by the RV tech that there are very few components that can be replaced other than the capacitor and motor. That yours has trouble when the ambient temperatures are higher indicates to me that the refrigerant pressure is increasing with the heat. I'm not sure that is realistic.
There is a slight possibility that particular circuit breaker is faulty. You could try replacing it with a new one, or swap it with the breaker for your second AC unit to see it the problem persists.
You may need an AC tech with all the diagnostic stuff we don't have.

[garywilson]

Just for grins...
My main panel at my house.
Started out that on a hot day either A/C or main would trip, on a cool day no problem. Neither breaker seemed to be getting hot. It didn't make sense to me that it would trip either one and not be consistent.
Replaced A/C breaker, then on a hot day main would trip.
Replaced main breaker, no more issues.
I guess it was just tired.

[craigav]

Did you check the voltage yet? If it is low, that could be the issue and cause the symptoms you are having. ~CA

[Marcm157]

How did you check the capacitor? Visual inspection or did you discharge it and verify MF's with a meter?

[Flashdman11]

Originally Posted by garywilson

Just for grins...
My main panel at my house.
Started out that on a hot day either A/C or main would trip, on a cool day no problem. Neither breaker seemed to be getting hot. It didn't make sense to me that it would trip either one and not be consistent.
Replaced A/C breaker, then on a hot day main would trip.
Replaced main breaker, no more issues.
I guess it was just tired.

Probably going to do this next and cross my fingers.

Originally Posted by craigav

Did you check the voltage yet? If it is low, that could be the issue and cause the symptoms you are having. ~CA

I'm checking this tonight before I replace breaker.

Originally Posted by Marcm157

How did you check the capacitor? Visual inspection or did you discharge it and verify MF's with a meter?

Removed, discharged and verified MF's within +- 5% per rating

[pconroy]

Originally Posted by Flashdman11

What else can I check?

Probably not the issue, but I'll toss it out there: is there an extension cord in the middle? I was having some probs on my 20A circuit, until I spent the money for a high quality 10g cord.

[Jagiven]

Lots of good comments above. Sounds like you might have some electrical knowledge.

Breakers to go bad. Your AC breaker may just be weak. Weak breakers do not have to get hot to trip. When both the compressor and fan are both on, it may just be overloading a weak breaker and trips prematurely.

Do you have a multimeter with an amp clamp? I would check your voltage. Then clamp the hot wire and monitor it. Pending on the clamp, you can see the average amps, and/or the peak amps.

X2 to CA's comment. As voltage decreases, the amps must increase to overcome the lower voltage for the same power rating. Hence causing the AC breaker to trip.

Good Luck

[Flashdman11]

Originally Posted by Jagiven

Lots of good comments above. Sounds like you might have some electrical knowledge.

Breakers to go bad. Your AC breaker may just be weak. Weak breakers do not have to get hot to trip. When both the compressor and fan are both on, it may just be overloading a weak breaker and trips prematurely.

Do you have a multimeter with an amp clamp? I would check your voltage. Then clamp the hot wire and monitor it. Pending on the clamp, you can see the average amps, and/or the peak amps.

X2 to CA's comment. As voltage decreases, the amps must increase to overcome the lower voltage for the same power rating. Hence causing the AC breaker to trip.

Good Luck

My Brother-in-law is an Electrician so he has guided me in the past. I did check the voltage with a meter clamp and it is good.
I did just notice there is a delay with the thermostat. I can lower it several degrees and it takes a few minutes before kicking on.
Wish something would just break so I know what to fix lol

[RedHorse1]

There’s 2 big users of electricity on the AC side of the A/C, compressor and fan motor and the breaker is also a suspect. IMHO it’s likely one of those 3 culprits. The easiest to check is the breaker, swap with the other AC if they are the same amp rating. If the breaker still trips then use the clamp-on to see if the other culprits are being piggy. If these all check ok maybe a loose connection somewhere between (ground?). It also sounds like the breaker doesn’t trip on startup but after its been running a bit (and it’s hot).

[Flashdman11]

Originally Posted by RedHorse1

There’s 2 big users of electricity on the AC side of the A/C, compressor and fan motor and the breaker is also a suspect. IMHO it’s likely one of those 3 culprits. The easiest to check is the breaker, swap with the other AC if they are the same amp rating. If the breaker still trips then use the clamp-on to see if the other culprits are being piggy. If these all check ok maybe a loose connection somewhere between (ground?). It also sounds like the breaker doesn’t trip on startup but after its been running a bit (and it’s hot).

Actually, now paying more attention to it, it will run for hours as long as it doesn’t turn off. Once it meets thermostat temp and starts to cycle, it will pop a few time into the cycle. I checked the caps again and they are right on target range. Maybe I should just replace them since it’s a cheap fix?
I’m going to do a deep clean of the evap and condenser coils tomorrow.

[craigav]

Originally Posted by Flashdman11

My Brother-in-law is an Electrician so he has guided me in the past. I did check the voltage with a meter clamp and it is good.
I did just notice there is a delay with the thermostat. I can lower it several degrees and it takes a few minutes before kicking on.
Wish something would just break so I know what to fix lol

The only way to know if the A/C is the problem (vs the breaker for example) is to determine what the startup and running amperage actually is along with the specific voltage prior to and after starting the A/C and if possible, also at the time the breaker trips (leave the clamp on amp meter in place perhaps with logging enabled if it has it).

When you checked the voltage, what voltage did you get prior to and then after the A/C was running and at what amp draw? Knowing these answers would allow for some specific answers as to what you are encountering.

Perhaps your BIL can help you if you are not familiar with how to measure the volts and current draw at the compressor (or the entire a/c), and if you are not familiar with working with electricity, I would leave it to an electrician or A/C service person (BIL or hire someone to check it out) as the voltage and current inside the A/C (along with the cables going to it) is high enough to cause death if someone was to become accidently electrocuted (not that it will cause death, just that it could). Be safe for sure. ~CA

[Dhardy193]

You could install either a start capacitor or an easy start kit. Either of these would help if your problem is related to current draw at start up. Outdoor temps definitely play a role in how much current your A/C will draw. Cleaning your condenser is a good first step as the cleaner your condenser is the more efficiently the a/c will operate. You really need to measure your current with a meter that will log peak amp draw. 30 yr HVAC tech here.

[Flashdman11]

BIL did all the volt checking and said was all good, not an electrical issue. I went as far and switched caps from other AC and still tripped, so no way a faulty cap. I changed the breaker with a new one also.

[Flashdman11]

Update: I think it may have been a loose connection at the post. I secured it a bit better and haven’t had a trip since. Crossing my fingers anyway cuz it’s 102 today