Run Capacitor Question

[Ryan C]

Air conditioner not working, circuit board and run capacitor are out. Called AC Company and the price for installing circuit board was unreasonable and customer service was unsatisfatory. Company said they could get unit working by replacing capacitor and routing around circuit board straight to fan motor but fan motor would run 24/7. I told them I was ok with that and repairs were made.

1 1/2 months went by and both units and everything in attic went out, breaker continued to reset. Called electrician and diagnosed as a ground in ac unit that was previously worked on. Called new AC company and was told that a 12.5 msd capacitor was installed instead of a 10.0, burned up my fan motor and the ground caused the electrical problems. New AC company installed new Capacitor, circuit board and fan motor.

Called old company to tell them about installing incorrect capacitor, was told that I was wrong, sent them proof and was told it was not their error as the wrong size capacitor had nothing to do with fan burning up instead it was the fan running 24/7 that did it.

New company said circuit board had nothing to do with fan motor going out and that if anything it helped the life of the fan motor as there was no stopping or starting of the fan motor for 1.5 months.

I am confused......what is the correct answer?

[Diceman]

Not sure exactly what is going on there but you can change a 10mfd run cap with a 12.5 one, there is a margin of error you can use and I think thats close enough.
Is this a heat pump?

[beshvac]

The correct answer is you should have had it fixed RIGHT in the FIRST PLACE and not be here trying to figure out if CASCADING problems caused you issue.

Sorry if this is a rant, but I HATE going to jobs that some cheapscate has cobbled together "to get it running" and never returns to FIX IT CORRECTLY!

[Special-K]

The capacitor didn't cause the problem. The motor probably just gave it up, and when it burnt up it likely caused the ground.

The first service company was unwise to rig it. You were also unwise by not taking their first suggestion of fixing it right. The first "repair" might not have had anything to do with the motor failing; but if so, you're as responsible as they are.

Lick your wounds and learn from it. Always use a pro, and always fix it right.

[Ryan C]

The capacitor didn't cause the problem. The motor probably just gave it up, and when it burnt up it likely caused the ground.

The first service company was unwise to rig it. You were also unwise by not taking their first suggestion of fixing it right. The first "repair" might not have had anything to do with the motor failing; but if so, you're as responsible as they are.

Lick your wounds and learn from it. Always use a pro, and always fix it right.

Thank you very much, that is exactly what I needed to hear.

Lesson Learned and thank you for your honest opinion and willingness to help.

[texasappliance]

It still amazes me that people will agree to a service company doing a half ass repair as a way to get them buy because they don't have the money to fix right, knowing that something like that will not last, and then get pissed with the service company when it does not last.

edit... after seeing your last post I'm glad to see you accepting the truth and not being all but-hurt about it like most.

[timebuilder]

Air conditioner not working, circuit board and run capacitor are out. Called AC Company and the price for installing circuit board was unreasonable and customer service was unsatisfatory. Company said they could get unit working by replacing capacitor and routing around circuit board straight to fan motor but fan motor would run 24/7. I told them I was ok with that and repairs were made.

1 1/2 months went by and both units and everything in attic went out, breaker continued to reset. Called electrician and diagnosed as a ground in ac unit that was previously worked on. Called new AC company and was told that a 12.5 msd capacitor was installed instead of a 10.0, burned up my fan motor and the ground caused the electrical problems. New AC company installed new Capacitor, circuit board and fan motor.

Called old company to tell them about installing incorrect capacitor, was told that I was wrong, sent them proof and was told it was not their error as the wrong size capacitor had nothing to do with fan burning up instead it was the fan running 24/7 that did it.

New company said circuit board had nothing to do with fan motor going out and that if anything it helped the life of the fan motor as there was no stopping or starting of the fan motor for 1.5 months.

I am confused......what is the correct answer?

Are you able to sift through all this? Let's review.

The capacitor was not a fundamental issue. Motors are very tolerant of a 10% difference in rating. You had an old motor.

Never ask for a partial repair. Always get the right repair.

Always use the right company. They won't do a half-a**ed repair.

Find the right company:

ask several friends which company they have used that did a satisfactory repair. Long standing relationships in that knowledge pool is best, by far. Use one of the recommended contractors, and say "(insert friend's name here) told me you do a great job."

Have that company make the right, permanent repair, with a warranty of some sort.

Shorts to ground are common problems in failing electrical components. This does not represent poor workmanship or a bad manufacturer. It is simply a failure. They happen.

Questions?

[Wendo]

Probably nothing wrong with using the capacitor temporarily until you can get the right one but I wouldn't advise leaving it in. I don't believe it's easier on a condensing fan motor to let it run 24/7 than to let it start and stop with the unit. The fan motors don't use start switches. I agree you should have fixed it right the first time!!

[Beaver Bob]

The correct answer is you should have had it fixed RIGHT in the FIRST PLACE and not be here trying to figure out if CASCADING problems caused you issue.

Sorry if this is a rant, but I HATE going to jobs that some cheapscate has cobbled together "to get it running" and never returns to FIX IT CORRECTLY!

What, I love when that happens, then we get to charge more because the number of other things that went wrong because the costumer wanted to be cheap.

[Stamas]

Thank you very much, that is exactly what I needed to hear.

Lesson Learned and thank you for your honest opinion and willingness to help.

Someone listened, learned and said thanks.

Ripping them more afterwards??????

[newoldtech]

I'm amazed how many think 12.5 instead of 10 is within 10%.

Oh though I dont' think that would necessarily cause a problem. Leaving the motor to just run is not something I would want do for more than a day and only if I had no better option at the time and I explained the risks to the customer. And I wouldn't leave that capacitor in long term either. Its hard to say for sure what caused the problem but you leave yourself open to alot of criticism when you do obvious wrong things.

[timebuilder]

I'm amazed how many think 12.5 instead of 10 is within 10%.

10% of 10 is one. That makes 11 uf on the upper end.

Then, you can consider that the capacitor is built to a tolerance that is 5 to 10%. A capacitor that says 12.5 on the side may be closer to 11.8 uf.

So, while not exactly a 10% difference between to two caps, you can feel comfortable that using a 12.5 in place of a 10 will get the job done until a more precise cap can be obtained and installed. It is unlikely that using a 12.5 in place of a 10 is going to cause an imminent failure of a motor.

So, to review: motors easily tolerate a 10% difference in the cap value, and they will tolerate more of a difference from the ideal value when pressed.

[newoldtech]

10% of 10 is one. That makes 11 uf on the upper end.

Then, you can consider that the capacitor is built to a tolerance that is 5 to 10%. A capacitor that says 12.5 on the side may be closer to 11.8 uf.

So, while not exactly a 10% difference between to two caps, you can feel comfortable that using a 12.5 in place of a 10 will get the job done until a more precise cap can be obtained and installed. It is unlikely that using a 12.5 in place of a 10 is going to cause an imminent failure of a motor.

So, to review: motors easily tolerate a 10% difference in the cap value, and they will tolerate more of a difference from the ideal value when pressed.

I disagree. To me 10% means 10%.

Especially with the capacitors we've all been dealing with lately. They don't seem to have any "tolerance" even when you use the right size one. So in a fix I might use a 12.5 instead of a 10 but I would go back to change it.

[timebuilder]

I disagree. To me 10% means 10%.

Especially with the capacitors we've all been dealing with lately. They don't seem to have any "tolerance" even when you use the right size one. So in a fix I might use a 12.5 instead of a 10 but I would go back to change it.

I would also go back and change it. No reason not to.

Actually, the tolerances have grown larger for the manufacture of overseas components for electronics. 5% isn't what it used to be. If you wanted a great deal of accuracy, you would use Mil Spec. Now, if you want any accuracy at all, you need Mil Spec.

[Beaver Bob]

I would also go back and change it. No reason not to.

Actually, the tolerances have grown larger for the manufacture of overseas components for electronics. 5% isn't what it used to be. If you wanted a great deal of accuracy, you would use Mil Spec. Now, if you want any accuracy at all, you need Mil Spec.

Very true, but why even bother making the specs at all if your going to just venture out of them anyway even if just a little.

These compenants are designed for said specs blah blah blah I do not know why people insist on pushing that bar and avoid following them to the exact. Is the risk of broken equipment really with it, maybe its job security I dont know but at times it gets aggravating.

[fearlessfurnace]

I think its just one of those things.
if you had payed the big buck for the first call you would still have had the second
maybe with the right capacitor and running part time the motor would have failed next summer instead of this.
inside blower motors are happy running 24-7 why not outside?
what bothers me is the possibility of an electical supply problem that is causing all this mayham

[beenthere]

Maybe it was the motor that caused all of the problems to begin with. And the board and cap were damaged by the motor. And the tech using a 12.5 instead of a 10, had absolutely nothing to do with the motor failing completely later.

I'm sure the rest of you have put on a new cap that was the size listed by the motor. And less then a year later. The motor goes out. Because it was what caused the cap to go out.

[timebuilder]

Very true, but why even bother making the specs at all if your going to just venture out of them anyway even if just a little.

I think the answer to that is that you don't have the right cap with you, and you use the 12.5 as a temporary fix to get the customer some cooling.

[newoldtech]

Maybe it was the motor that caused all of the problems to begin with. And the board and cap were damaged by the motor. And the tech using a 12.5 instead of a 10, had absolutely nothing to do with the motor failing completely later.

I'm sure the rest of you have put on a new cap that was the size listed by the motor. And less then a year later. The motor goes out. Because it was what caused the cap to go out.

Yes, of course, we've all done things totally by "the book" and still have had failures. But my point is why leave yourself open to potential problems like the OP is talking about. The last thing I want is some HO telling me that some other company said I did something wrong and caused a problem.

I'm old School and don't do everything by "the book" but I do always try and use the right Capactior size, motor size etc. Its got to give you a better chance of success not to mention CYA.

[timebuilder]

Yes, of course, we've all done things totally by "the book" and still have had failures. But my point is why leave yourself open to potential problems like the OP is talking about. The last thing I want is some HO telling me that some other company said I did something wrong and caused a problem.

I'm old School and don't do everything by "the book" but I do always try and use the right Capactior size, motor size etc. Its got to give you a better chance of success not to mention CYA.

It occurs to me that the first company may have wanted to return to replace the temporary cap, but was prevented from doing so. They might have been told not to return because "this is all I want for a repair right now."

We have to bear in mind that we were not there to hear the tone and tenor of these conversations.