A/C tripping breaker during afternoons

[Johnnyma45]

I'm having an issue with my upstairs condenser unit tripping the breaker. It is a ~12 yr old York HLRA048S06D 4-ton 10 seer (?) unit. A quick history of this summer's A/C woes:

1) A couple months ago, the condenser unit stopped working at random intervals (condenser fan and compressor off, internal fan on, no breakers tripped). Compressor sometimes made squealing sound with the fan not turning. A/C tech couldn't diagnose at first, but then was able to determine that the capacitator was bad, which he replaced. A/C started to work normal, until...

2) A week after, the A/C started failing in the afternoons, 3-6pm at the hottest periods of the day. Internal fan runs as before, condenser fan continues to run but compressor shuts down for a couple hours, before turning back on and cooling normally. This continues for a few weeks, I didn't bother to call another tech as this seemed liveable.

3) Yesterday, the condenser unit started to trip the breaker. After resetting, it happened two more times, and started to run normal after 8pm.

It may seem obvious, but does this mean I'm having a compressor issue, or an electrical? I have already replaced the compressor in my downstairs unit this summer, and it seems to still follow in the path of afternoon shutoffs, so I'm thinking the compressor was weakened by the fan issues earlier, and now is failing. Anything I should point the tech to when they come out?

Thanks!

In case you're interested, previous threads:
Initial issue:
http://hvac-talk.com/vbb/showthread....s-off-randomly
Second issue (Afternoon cooling)
http://hvac-talk.com/vbb/showthread....ght=johnnyma45

[Toddbrewster]

Has the condensor been cleaned lately?

[Johnnyma45]

I rinsed out the condenser coils a couple weeks ago, no noticeable effect, otherwise no.

[jtrammel]

Might need a good cleaning by a tech. Have them come out in the afternoon and check head pressure and amp draw

[jtrammel]

Might need a good cleaning by a tech. Have them come out in the afternoon and check head pressure and amp draw

It may save you a costly repair of compressor

[Johnnyma45]

It may save you a costly repair of compressor

Thanks, will look into that...I have a tech coming out tomorrow through my home warranty. At this point, I almost want to replace the compressor, lest it continue to fail. Last night it failed overnight for the first time, rather than just during the hottest parts of the afternoon...terrible night's sleep.

[vstech]

are you certain the tech installed the correct capacitor?
did they verify charge/subcool/superheat?
you stated it was not cleaned, this alone could cause the tripping.

[Johnnyma45]

are you certain the tech installed the correct capacitor?
did they verify charge/subcool/superheat?
you stated it was not cleaned, this alone could cause the tripping.

No to the above...not sure how to verify charge. And not sure if the tech installed correct capacitor...I will have him check tomorrow.

[jtrammel]

Home warranty companies generally use cheap unskilled hvac techs.

[Johnnyma45]

Home warranty companies generally use cheap unskilled hvac techs.

...that sucks. I figured if they were licensed that they were competent and could diagnose issues.

[motoguy128]

...that sucks. I figured if they were licensed that they were competent and could diagnose issues.

No such requirement. Their goal is to band-aide the problem and spend as little as possible to get you to the end of the warranty period then cut your loose. IF their repair is substandard and costs you twice as much to fix two years after the warranty expries.... that's not their problem. Remember, this is a product/service where it's primary pruchse is to provide a seller with a piece of paper that instills confidence on a buyer, and the buyer gets a piece of paper that suposedly worth something at closing.

Personally, I would rather get a credit from a buyer equal to the home warranty price, have the buyer simply fix any known problems and buy a property "as-is" and accept it as part of the price of home ownership.

Your experience is all too common and tends to be hte norm rather than an exception.

[Johnnyma45]

No such requirement. Their goal is to band-aide the problem and spend as little as possible to get you to the end of the warranty period then cut your loose. IF their repair is substandard and costs you twice as much to fix two years after the warranty expries.... that's not their problem. Remember, this is a product/service where it's primary pruchse is to provide a seller with a piece of paper that instills confidence on a buyer, and the buyer gets a piece of paper that suposedly worth something at closing.

Personally, I would rather get a credit from a buyer equal to the home warranty price, have the buyer simply fix any known problems and buy a property "as-is" and accept it as part of the price of home ownership.

Your experience is all too common and tends to be hte norm rather than an exception.

Thanks for the insight. We essentially had the previous owner last year fix anything we could find, and the warranty was provided "free" aka built into the sale price. We were able to get the downstairs A/C compressor replaced with the bulk of it covered by the home warranty, so we figured it was a decent investment. Gives me some food for thought though.

Regarding the capacitor, I had figured that since it restored the fan operation it was ok. Making a list to address with the tech tomorrow.

[vstech]

Thanks for the insight.

Regarding the capacitor, I had figured that since it restored the fan operation it was ok. Making a list to address with the tech tomorrow.

not a valid assumption. two different values, between the fan and the compressor. and the fan is pretty much a standard, the compressor has to be exact.

[Johnnyma45]

not a valid assumption. two different values, between the fan and the compressor. and the fan is pretty much a standard, the compressor has to be exact.

I'll make sure to have the tech check the capacitor. Thanks for the help all

[Johnnyma45]

Update - the tech found that the compressor was overamped, and recommended replacing the compressor. Couple hours after he left, the breaker tripped again and won't reset. So, w/o A/C upstairs for now, waiting to contact home warranty to see how much this will cost.

[jpsmith1cm]

Update - the tech found that the compressor was overamped, and recommended replacing the compressor. Couple hours after he left, the breaker tripped again and won't reset. So, w/o A/C upstairs for now, waiting to contact home warranty to see how much this will cost.

That doesn't sound like a valid diagnosis to me.

To say that a compressor is 'overamped' without identifying a cause for that is not making a complete diagnosis.

Now, that the breaker will not reset is bad news, IMO.

[jtrammel]

That doesn't sound like a valid diagnosis to me.

To say that a compressor is 'overamped' without identifying a cause for that is not making a complete diagnosis.

Now, that the breaker will not reset is bad news, IMO.

X2

[Johnnyma45]

So, taking the fact that, if it is overamped, what typically could cause that? I attributed it to the age of the unit (and the fact that I replaced the downstairs unit's compressor earlier this year), but I am not an expert.

I tried the breaker again tonight after a few hours off, and it seems to be working right now...but it probably won't last. I probably shouldn't touch it anymore.

[jtrammel]

Dirty cond coil, weak or stopping condenser fan

[jpsmith1cm]

Dirty cond coil, weak or stopping condenser fan

I just found almost this exact condition on a large rooftop unit.

Condenser was very dirty causing high amperage and blowing 80 amp fuses.

Got those coils cleaned and it has been running like a champ all summer long.

The fact that your unit is running right now and providing cold air means that there is nothing wrong with the compressor. Don't pay or a perfectly good compressor to be replaced.