wires to capacitor on YORK AC unit are burned and melted

[Keith Reding]

I thought I would get my York central AC unit repaired well before summer hits. The unit is about 9 years old. Last year, the unit stopped cooling but the fan still ran fine. The repair guy look at it and the wires going from the compressor area to the capicator had melted and stopped working. The repair guy replaced the wires and the capicator. A few months later it happened again. A different repair from another company installed a heavy duty wiring kit and the unit worked again for a few months then stopped when the wires melted again.

Obviously the unit is pushing too much current through these wires. A friend said that it might have a starter relay on top of the compression that is not shutting off after the compresser is started. I have not taken it apart to look.

Does this sound correct? I don't understand why the repair guys wouldn't know this? Any other suggestions on the cause of the problem?

Thanks,

Keith

[TURTLE]

This is Turtle.

First here, If the wires [ like the whole length is melting ] is melted. You have these things wrong with it. You have too big of a breaker to your condenser unit or have to reset the breaker every hour or so, The wire kit he put on it is too small, and You have a shorted out compressor somewhat. If everything is installed correctly. You can't melt the wires.

Now secondly here. If the end only that tie on to the compressor are melting about 1 to 3 inches back up the wire from the compressor. You have rusted or defective terminal on your compressor and not letting the spades connect correctly. I see this a lot on older equipment and you need a screw on clamp wire kit. It will have a screw on clamp to tie on to each terminal of the compressor. You buy them in sets and they will stop the burning of the terminal off like you have. Now you have only about 3 to 6 burns off before you burn the terminal off the compressor and then you will buy a new compressor because you will have nothing to put the clamp on wire kit to hold the wire on it.

Now Have the breaker / wire sized for the condenser and put a you a clamp on wire kit on it and forget about it.

TURTLE

[Stormin Mormon]

Dear Tony, I've been posting to home repair for a couple years. I've read Turtle's posts for several years, and he's been a real wealth of information. He's solved problems for myself, and many others. I'm not quite so sure about you, though. However, it is very possible that I'm mistaken. Lets see if maybe I'm mistaken. How about you answer a couple questions for me. I'm a rather new heating and AC tech, so here's a great chance for me to learn.

1) You say that each of the three compressor terminals represents its own winding. I know of two windings, but you say there are three. What are the names of the three windings, and what do they each do?

2) What are the names of the electrical terminals on a typical compressor? What does each terminal do?

3) In terms of temperature, what happens when a terminal is corroded, and trying to carry current? And in terms of the electrical flow, what happens when a terminal is corroded?

4) What is the electrical current path through a compressor? For example, which terminal is hot, and which is neutral?

I will likely be working on condensing units this summer, and perhaps some of your answers will help me to be a better technician.

[CBhvac]

You are a hack, nothing but a halfassed locksmith that claims to be a tech....

If you dont know, you are over your head already.

It sits there and sings dixie every once in a while..

Ok...you can stop with the jokes now...Mr hvac tech..

There ISNT a neutral in a compressor on a home central system moron.

No...4 years of tech school might.

[Tony Berlin]

"TURTLE" wrote in message news:c0cn8t$1569a5$ [e-mail]...

There is no such thing as a shorted out compressor, somewhat. It's either shorted out or it is not. Keith the correct answer to your question, or at least as correct as any observation can be using the information available and considering this is as I always say the internet. Each of the three wires on your compressor represents it's own respective winding in the compressor. Each, when excessive current draw is present, indicate to a competent (dare I say that word here), technician the correct path to follow with respect to troubleshooting. So in order to even begin to remotely guess at the problem one would need the information specific to which wire is carring excessive current. Even though they all may indicate excessive current, simply due to the proximity of one to the other, there is one that is the actual carring the excessive current. With that being said, the first thing a service tech would do is use an Amprobe to determine the actual draw in each conductor, I further suspect that your friends assesment is incorrect, if what he indicated to you were true, you would get zero run time out of the compressor, it would quickly overheat and cut out on an embedded thermal overload-quickly, not a few days, few weeks or few months. There would also be other indicative attributes that you have not mentioned.Since from what I read the most educated observation that can be concluded is that the problem is associated with the run winding, assuming the capacitor that your are referring to is in fact the run capacitor and not the start capacitor. There are a multitude of factors that can contribute to issues with the run winding in the compressor. To begin with the run cap itself can be defective, has anyone tested or replaced it? A dirty condenser coil will increase the current draw on both the run and common windings in the compressor, has the coil been cleaned thorughly since the issues originally occured. For the same reason that a dirty coil can cause it, so to can a condenser fan that is not performing to design requirements, if enough heat is not being rejected at the condenser because of dirt or a bad or faulty fan it will be indicated in the compressor current draw. Oversizing wires, if that is in fact what the latter contractor did, is not only bad practice and stupid it is also dangerous. The wiring within the equipment is the size (AWG), that it is for a reason. And finally, even though it would be premature, provided the equipment is properly maintained, the fault may in fact be a defective compressor, it certainly would not be unheard of. I would contact a competent service company that uses meters to determine cause.

[CBhvac]

obviously...no. You have not given the model number or serial number to the unit. Depending on the model and serial, you may have a couple of items, and if you will get that and either post it, or send it this way, we can pull up the unit, and tell you what is the most likely problem.

Nope...not always.

See the reply above. Once I know what model and run line of unit you have, then its a simple matter of pulling it up on cd and badda bing...there you go.

The reason I need that, is that some of those had issues, that looked one way, and were another.

[Keith Reding]

The unit is a York Model H2DAQ42SQ6A. The Serial Number is ELBM396211.

Here are the links to some photos showing the burned wires. I thought the burned wires were connected to the capacitor but they are not. See the photos for a better explanation.

Thanks for your help.

Keith

[TURTLE]

This is Turtle.

Hummmmmm , You must not have checked too many compressor lately have you. The test to check for a shorted or internal short from one pole to the other is to use a OHM meter and see if you have a path to gound first and then read each of the terminal to the other to see if you have the correct ohm's throught each. You read from R to S and get the ohm reading and then read from R to C and S to C and add the two together and you should get the ohm reading you got by reading R to S. If they don't match you have one winding touching the other some where in side the motor it'self. They can still run with a bleed over. Now for a simple explained condition of this is when you hear a tech say That compressor is just high amping too much or just pulling too many amps. This is what he is telling you here. A short out compressor does not have to be to ground and can be a short from one winding to the other and when I say somewhat. This is what I'm speaking of. There is a reply below here too.

You are saying here that the problem may lie with the run winding because the run capasitor or maybe the start capasitor maybe defective. I maybe catching or reading you wrong here by you saying the run capasitor or the start capasitor is in the run winding circuit in some way. I can't remember here , is the run capasitor in the run winding ? Clear this up for me.

Your saying the amps will go up on the Run winding and the Common winding. I have never heard of a common winding on single phase compressors in my 40 something years in the business. They have a Common winding on 3 phase stuff but not on single phase stuff. Clear this up for me.

If the condenser fan motor is too slow / wrong blade / wrong R.P.M. / or just not moving enough air throught the condenser and causing the compressor to over amp. You will see a 90 to 100 psi suction and a 400 to 500 psi head pressure on the freon system. Then you say the amp will go up to enough to burn the wires off the compressor. If the amperage goes above the rated limit of the compressor more than 5 minutes. The compressor will cut out on high temp or high amps. If the amperage goes up enough to melt the wires to the compressor the service breaker or the internal overload will trip and cut it off. I just can't see the amperage staying above 60 to 90 amps for very long at all with out something cutting it off. One other thing here. If the amperage goes above the rating limit of the compressor more than 5 minutes it will turn off for 2 to 4 hour while it cools off. Clear this up for me.

You say by using a larger compressor wire kit is Stupid and is also Dangerous. You also said the wire to the compressor is designed to be a exact size [AWG] and you should not go up on it. I just don't see any danger in upping the wire size kit to the compressor unless your using the wires as a fuse and will burn off at a high amp rate. I alway just put a breaker on the whole condenser and use it and not the compressor wires as a fuse link. Clear this up for me.

And finally, even though it would be

Now this I agree with finally.

TURTLE

[TURTLE]

This is Turtle.

I wouldn't either if i didn't know how to.

TURTLE

[Keith Reding]

I have not taken any measurements on the unit, neither did any of the technicians who worked on it. One tech said that he would be glad to keep charging me $100 for each visit to replace the wires. Otherwise, I should buy a new unit. I will do that if I have to but not sure I need a new unit to fix the problem.

I bought the house 4 years ago and the unit was about 5 years old when I bought the house. I don't know that is has ever been flushed. Neither tech suggested that to me.

Keith

in

[PJx]

Tony, you are dumber than a stump.

[TURTLE]

This is Turtle.

OH My GOD , You give me a hard one here. Look Son i don't have all day to explain to you the wire design of compressors but will shorted it to this. If you call a start winding a common winding , you say too big of wire on a compressor is dangerous, you say the capasitor is in the run winding circuit, you don't know what a bleed circuit is inside a compressor is or shorted winding & still run, and you say a condenser motor running too slow can burn the wires off a compressor. I will tell you one thing. I have some Green Tech working for me that would get a laugh out of your replys. If you want to clear up your reply and the question i ask you , do so. Please do , I would be interested in hearing them. Now when a poster starts asking question in the place where there should be a answer. I take it he / she does not know the answer and just side stepping the question ask of them by changing the subject by asking a question.

Now until you answer my question , i will take it that you are a wantabe hvac Tech in the making.

Now if you would like to ask any question about hvac or Refrigeration. Ask away and I don't give Bullshit answers like you do.

TURTLE

[TURTLE]

This is Turtle.

You can stop right here for i'm looking at the effect of a loose connection wire burn out. I see them all the time when the connection of the wire is not tight and it will just burn off. Replace the contractors and run new wire to the compressor to the contactor and you will never hear from it again , but tighten the connection real good and don't use the male spades if all possible , also.

TURTLE

[TURTLE]

This is Turtle.

If the Tech / service company can't tighten up the connection enough to keep them from burning off. Two thing is taking place here. 1) He is wanting to sell you a new condener by leaving the connection loose and let them burn off. 2) The tech just does not know how to tighten up the connection correctly.

Run their ass off before the mess something up here and you may really have to buy a condenser.

TURTLE

[RB]

You really are impressed with yourself. Perhaps because no one else is.

RB

T> I will simply answer your question by replying to the first part, since you

[Tony Berlin]

[Tony Berlin]

[Tony Berlin]

[Al]

I fully agree with Turtle that the contactor (relay) is bad.

I'm not a HVAC technician, but I am an electrical engineer with 15 years of experience testing contactors and relays. The photos show that the terminals are corrode; chances are, the contacts of the contactor are as well. Fungus, corrosion, and normal usage can cause an increase of resistance on electrical contacts. An increase of resistance will cause a voltage drop to appear across the contacts of the contactor thus making the contacts dissipate more power (heat). From what I see, the wires are burned near the relay. I have seen this condition many times in relays that were under test. The contacts get hot enough to melt the insulation on the wires near the relay but not hot enough to melt the relay. Replace the relay and the wires and that should solve your problem.

Turtle is a smart cookie.

[Keith Reding]

Sounds reasonable. The first time the wires burned through it was at the capacitor. The second time it was at the relay. The third and current time is at the relay but the wires going to the capacitor looks fine. I will replace the relay and wires and hopefully that will make a difference. Each time I have had burned or melted wires they have been at the connectors so hopefully this will fix the problem.

Thanks to everyone for their assistance.

Keith