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kutra · Aug 24, 2009, 07:36 AM

My A/C circuit breaker tripped two nights ago (after a huge rain shower in the evening), and each time I reset it, it tripped within 3 seconds. I then, shut OFF the Main, reset the A/C circuit breaker, and then turned ON the Main. The A/C has been working fine ever since. What do you think was the problem?

My A/C circuit breaker had tripped once last year, but I reset it and the problem went away; I did not have to turn OFF and ON the Main at that time.

Regards,
K

tkrussell · Aug 24, 2009, 07:45 AM

Problem can be any one of several reasons, such as a defective breaker, or loose connections at the breaker causing heat that is being conducted into the breaker and causing the tripping, or a short in the wiring that is intermittent, or a device in the AC unit that is failing.

Without doing a visual check and checking the wiring and devices,ie: compressor or fan motors, all can be done is speculate.

Even after inspecting, there still may be no conclusive reason found, and the problem may need to be allowed to get worse to be able to find the cause.

I will copy this over at the HVAC forum, see if any of the resident HVAC experts can offer any additional advice.

kutra · Aug 24, 2009, 07:59 AM

Originally Posted by tkrussell

Problem can be any one of several reasons, such as a defective breaker, or loose connections at the breaker casuing heat that is being conducted into the breaker and causing the tripping, or a short in the wiring that is intermittent, or a device in the AC unit that is failing.

Without doing a visual check and checking the wiring and devices,ie: compressor or fan motors, all can be done is speculate.

Even after inspecting, there still may be no conclusive reason found, and the problem may need to be allowed to get worse to be able to find the cause.

I will copy this over at the HVAC forum, see if any of the resident HVAC experts can offer any additional advice.

Thanks tkrussel! I shall save you the trouble and post it myself.

Q: I do have an annual HVAC contract. Would the HVAC company be able to find the problem during their inspection or does it have to be a service call?

Regards,
K

kutra · Aug 24, 2009, 08:00 AM

My A/C circuit breaker tripped two nights ago (after a huge rain shower in the evening), and each time I reset it, it tripped within 3 seconds. I then, shut OFF the Main, reset the A/C circuit breaker, and then turned ON the Main. The A/C has been working fine ever since. What do you think was the problem?

My A/C circuit breaker had tripped once last year, but I reset it and the problem went away; I did not have to turn OFF and ON the Main at that time.

Regards,
K

tkrussell · Aug 24, 2009, 08:08 AM

This,

Originally Posted by kutra

Q: I do have an annual HVAC contract. Would the HVAC company be able to find the problem during their inspection or does it have to be a service call?

Regards,
K

Will depend on how the contract is written. An annual inspection most likely is just that, one visit per year to clean and inspect the unit.

Any problems found during the inspection may or may not be included. Most likely not be included, and any repairs will be extra.

This problem, unless checked out during the inspection, and if you can bring them in now, most likely will need a service call.

Even if done during the time of inspecting, I believe this would fall under extra work, and be billable over and above the inspection.

Read your contract.

kutra · Aug 24, 2009, 08:24 AM

Tkrussel:

I really appreciate your prompt response. Will read the contract this evening when I get home. I have Home Warranty Service, so hopefully they should be able to cover this.

Regards,
K

hvac1000 · Aug 24, 2009, 10:59 AM

What do you think was the problem

You might have answered your own question.

My A/C circuit breaker tripped two nights ago (after a huge rain shower in the evening),

It might just be that simple so check over all the wiring in the outdoor disconnect and unit for starters.

BTW on problems such as these you really need to be ON SITE to figure them out.

kutra · Aug 24, 2009, 12:17 PM

Originally Posted by hvac1000

What do you think was the problem

You might have answered your own question.

My A/C circuit breaker tripped two nights ago (after a huge rain shower in the evening),

It might just be that simple so check over all the wiring in the outdoor disconnect and unit for starters.

BTW on problems such as these you really need to be ON SITE to figure them out.

Thanks for your reply.

kutra · Aug 31, 2009, 01:26 PM

Originally Posted by hvac1000

What do you think was the problem

You might have answered your own question.

My A/C circuit breaker tripped two nights ago (after a huge rain shower in the evening),

It might just be that simple so check over all the wiring in the outdoor disconnect and unit for starters.

BTW on problems such as these you really need to be ON SITE to figure them out.

Here's an update. The A/C's circuit breaker tripped again last night, and this was without any rain at all. I shut off the Main, reset the A/C circuit breaker, and then turned ON the Main. The A/C circuit breaker tripped again. So, one more time, I shut off the Main, reset the A/C circuit breaker, BUT this time waited for 30 seconds and then turned ON the Main. A/C's working fine since then.

Eager to troubleshoot with my subpar electrical skills, I decided to replace the A/C circuit breaker today because if that was the problem, it would save the $100 trade call fee on my Home Warranty service. The circuit breaker was 20 yrs old. When I removed the old A/C circuit breaker, I noticed that there was a thick grey liquid where the A/C's two wires were connected to the screws... seemed like something had overheated and melted. I checked the wires and screws of all the other circuit breakers and they all seemed fine. So, I wiped the end of A/C's wires, and replaced the A/C circuit breaker. The A/C's working fine... it's been only 1 hr so far since the replacement.

But my question is that now that we know about the thick grey liquid as a result of possible melting, was the A/C circuit breaker the root of the problem? Or does this overheating/melting indicate a serious problem and requires a HVAC specialist to check it out?

Please advise.

Thanks,
K

kutra · Aug 31, 2009, 01:27 PM

Here's an update. The A/C's circuit breaker tripped again last night, and this was without any rain at all. I shut off the Main, reset the A/C circuit breaker, and then turned ON the Main. The A/C circuit breaker tripped again. So, one more time, I shut off the Main, reset the A/C circuit breaker, BUT this time waited for 30 seconds and then turned ON the Main. A/C's working fine since then.

Eager to troubleshoot with my subpar electrical skills, I decided to replace the A/C circuit breaker today because if that was the problem, it would save the $100 trade call fee on my Home Warranty service. The circuit breaker was 20 yrs old. When I removed the old A/C circuit breaker, I noticed that there was a thick grey liquid where the A/C's two wires were connected to the screws... seemed like something had overheated and melted. I checked the wires and screws of all the other circuit breakers and they all seemed fine. So, I wiped the end of A/C's wires, and replaced the A/C circuit breaker. The A/C's working fine... it's been only 1 hr so far since the replacement.

But my question is that now that we know about the thick grey liquid as a result of possible melting, was the A/C circuit breaker the root of the problem? Or does this overheating/melting indicate a serious problem and requires a HVAC specialist to check it out?

Please advise.

Thanks,
K

hkstroud · Aug 31, 2009, 02:08 PM

Is the A/C wiring aluminum?

kutra · Aug 31, 2009, 02:36 PM

Originally Posted by hkstroud

Is the A/C wiring aluminum?

I am almost certain it is aluminum, but how do I confirm it for you?

Regards,
K

hvac1000 · Aug 31, 2009, 02:45 PM

That thick liquid as you call it was probably DeOx compound. It is usually used on aluminum wire to prevent corrosion. I will post back a bit later the dinner bell just went off. LOL

Stratmando · Aug 31, 2009, 02:54 PM

If the wires are loose on breaker, or a burn buss(what breaker plugs onto), it can trip breaker.
Inside breaker for Air Handler stays on, but circuit to outside disconnect is what's tripping?
If so and no short, could be compressor or fan,
An Amprobe can show where the high current is going.

tkrussell · Aug 31, 2009, 02:55 PM

This is why a fee is needed, for a professional with all the expertise needed to do this trade.

Good thing your getting advice here.

The generic name of the gray liquid is an anti-oxidant compound, it prevents aluminum from oxidizing from water and moisture in the air. Aluminum oxide is less of a conductor than bare aluminum, and can create a heated connection, and where there is heat, well you get the point.

The gray compound needs to be replaced.

kutra · Aug 31, 2009, 03:06 PM

Thanks for all the replies. However, I'm a little confused now.

Did I royally screw up by removing the old A/C circuit breaker, wiping off the deoxy liquid from the wires and putting in the new circuit breaker without ant deoxy on the wires?

Should the next step be to call the HVAC guy even if the A/C circuit breaker is no longer tripping?

medic-dan · Aug 31, 2009, 03:15 PM

Good job on investigating this.

Was it an actual liquid or more of a paste? Were the wires aluminum?

They put an antioxidant on aluminum wires to help prevent the connection from oxidizing and overheating.

kutra · Aug 31, 2009, 03:26 PM

Originally Posted by medic-dan

Good job on investigating this.

Was it an actual liquid or more of a paste? Were the wires aluminum?

They put an antioxidant on aluminum wires to help prevent the connection from oxidizing and overheating.

They were silver so I am guessing they were aluminum. It was more of a grey sticky paste. Actually, I just confirmed from my Home Inspection report from last year that this anti-oxidant paste was applied to this exact circuit breaker (from the pictures that I have).

So basically, I am nowhere close to troubleshooting the A/C circuit breaker tripping problem! I just replaced the circuit breaker for no reason and (even worse) removed the anti-oxidant paste that was put in place for protection!! :(

Please guide me on the next course.

1. Should I reapply the paste? I guess I should, eh? Would Home Depot have this?
2. Do I call HVAC only when the A/C circuit breaker trips the next time, or should I do that right away since my circuit breaker has tripped twice in the last 2 weeks?

Thanks,
K

medic-dan · Aug 31, 2009, 03:47 PM

Hi,

It still could have been a bad breaker so give that a try. They do wear out.

Yes, HD should have the paste. Just clean and put it on the terminals. You should be all set.

Do you have an outside disconnect? Can you check that for water/damage? With the power off course.

If the new breaker trips, I'd call the A/C guy. Unless you have reason to suspect the wiring is at fault.

kutra · Aug 31, 2009, 04:09 PM

Originally Posted by medic-dan

Hi,

It still could have been a bad breaker so give that a try. They do wear out.

Yes, HD should have the paste. Just clean and put it on the terminals. You should be all set.

Do you have an outside disconnect? Can you check that for water/damage? With the power off of course.

If the new breaker trips, I'd call the A/C guy. Unless you have reason to suspect the wiring is at fault.

Should the paste be applied only on the exposed part of the wire or even on that part of the wire which is under the screw?

Regards,
K