After the power has been cut to the outdoor unit, (1992 model Tempstar), can I discharge the capacitor, using an insulated screwdriver across the terminals, do I go across both fan and C, and herm/C? Can it be accomplished with the wires still attached? The top isn't swelled up, so could it STILL be fried? What next?

I've been ALL OVER THE WEB, and just can't find anyone that can give me any information about how I might find any homeowner's literature for the unit. Anyone here that knows how to get an owner's or repair manual for a 1992 outdoor unit model NPADE29AB03? This has turned into a huge headache.

The thing will fail to start up when the thermostat tells it to. This happens several times a week. All I do is flip the breaker off and back on, then the unit will start. The breaker isn't tripped, it's just that the unit fails to start.

Help, please. My wife suffers from breathing disorders, and as oppressive as it gets where we live, if this A/C quits, I will be taking her to the hospital within hours.

 

What's happening in the no start condition?
Is anything running, indoors or outside?
More detailed info will allow us to help you troubleshoot the unit.

 

It sounds a lot like you need a contactor.
Do you have 240 volts AC on the unit side of the contactor when it fails to start?

Does your meter measure volts and have a clamp head to measure amperage?
If you grab the wire on herm with a clamp meter to measure amperage then measure voltage between Com and Herm on the run cap you can calculate capacitance.
(Amps/volts)* 2652= capacitance.

 

@Houston204: Forgive me. I am so sorry to have taken so long to reply to you. I have had numerous computer problems, and consequently, no way to get on the Internet.

I do not know which is the "unit" side of the contactor, but, if known, I can measure the voltage, I think. I'm SURE that I must be EXTREMELY CAREFUL, because the power must be applied to the unit, correct?

My meter is of the VERY CHEAP kind, and does not have an amperage clamp. Is there any other method to measure capacitance with this cheapo meter? I can only try to gain access to an amp meter, but my chances, I must say, are slim. I can't afford to buy one, that much is certain.

I found a replacement capacitor, (35 / 4mfd), 370 volts...at least, I'm pretty sure it replaces mine...online, for about 8 bucks, but at the very least, 10 bucks shipping, and that means it'll take a week or better to get here. I haven't found a parts dealer within 25 miles of me, (I live in the sticks), period...much less one that will have the cap I need for a 1992 model Tempstar.

I had a lot more written here, but the session timed out on the site, so I'll try to be more succinct, and tell you some of what I was asking.

Will cutting the power to the unit, discharging the cap, (should the wires be disconnected from the cap before I discharge?) and, (can I do this by going across the terminals w/ an insulated handled screwdriver?), be able to tell me anything without the amp meter or a meter w/ a clamp?

Someone told me to take a long stick, and the next time the unit stops and fails to start up again, push the fan blade(s) w/ the stick, and if it starts up, the cap is bad. True or not?

Should I, when the unit stops, be able to hear any sound of any kind, i.e., humming, etc.?

I should probably test voltage on the unit side of the contactor first, though, as per your instructions, right? I guess I need to know which is the unit side, BE EXTRA CAREFUL, since the power needs to be applied, right? and if there is not 240V AC, then I need the contactor, right?

Tell me, please, should I just disregard the cap for now, and just test to see if you are correct, and I need the contactor?

Thanks very much for your reply, and advice, any more that you can give me, and I want to again apologize for not being able to get back to you sooner. I appreciate everything.

 

@tomf63: I want to apologize, first of all, for not replying sooner. I've had Internet and computer problems.

In answer to your question(s), no, when the unit is stopped, and the temp has risen in the house, and the thermostat is calling for the A/C, nothing is running, inside or out, but, to my knowledge, and because of my ignorance, do I know if there is any audible sounds coming from the unit. I do need to go to the unit when it malfunctions and stops, and listen to hear if there is any sound. Nothing is "running", but there may be a humming of some sort, I do not know...yet. I WILL get back to you with that info, and any other thing(s) I discover between now and then.

I appreciate very much, your quick reply, would be very grateful for anything else you might advise me to try, and I again want to express my sincere apologies for not being able to post sooner. Thanks again.

 

Previously, I started a thread here about our 1992 Tempstar. It's model number is NPADE29AB03, and finding out about it, via phone AND EVEN Internet, is worse than the needle in a haystack deal.

After the temperature inside has been satisfied, it shuts off per normal. On average, 2 or 3 times a day, when temperature calls for the unit to start back up, it fails to do it. I can go to the panel box, (have already switched to a new breaker) the breaker is NEVER tripped, flip it off, on again, and the unit will start.

When the unit has stopped due to this malfunction, there is nothing audible outside or inside. There is no hesitation on startup, nor any abnormal sounds. I've measured capacitance, voltage and amperage on the larger of 2 capacitors that I have located, (this one being mounted on an inside wall near the compressor), and the readings appear to add up, ( blue wire, "herm", 4.16A, 2 red wires, "C", 11.0A and 8.8A, brown wire, "fan", .4A ). The voltage across "herm" and "C" is approx. 340VAC. Using the formula "amps / volts *2652, I get 32mfd. This coincides with the "35 / 4mfd" manufacturer's specs. I think this one is the dual run capacitor, and I don't think there is anything wrong with this cap. There is no residue running down the side of it, and the top isn't swelled. The other is a smaller, (lengthwise) cap, mounted on top of a blower at the opposite side of the unit. It is really rusted, and its' labeled specs are gone. There are only 2 wires, and 2 terminals, but I don't know what it is for, nor its' specific purpose or name. The top is also not swelled, no oily residue. Just badly rusted. Once I find out it's values, (VAC & mfd), and proper name, I am replacing this one.

All of this notwithstanding, I'm thinking that I might just need a contactor. Although I get 240 & 120VAC respectively, there is what appears to be a small, single set of contacts, basically in the center and the usual top / bottom wire terminals. I've given this contactor a pretty good look see, and I can only spot the single, small set of contacts, and they are definitely burnt. I guess it doesn't matter if there ARE ANY OTHER SETS of contacts, on it I have found at least one set fried, so I will replace the contactor, and then perhaps my problem will be solved. Maybe.

What is this "other, smaller" 2 terminal capacitor called? Have I gone over the logical "first steps" to pinpoint my real problem? Is it possible that there is more than one component to blame; one that I haven't gotten to yet? Am I seeing only one contactor pair, (burnt) because I didn't look well enough, or is the one set all there is? (If need be, recall make and model number at the beginning of the post)

Could someone please tell me if they might know any possible way for me to obtain an owner's or repair manual for this A/C?

I apologize for the long post. If ANYONE can provide some assistance, advice, and / or any website that is helpful, I, ( and my better half ), would be very grateful. She has acute breathing problems. So far, we've been lucky when I've had to restart the air conditioner. Without it, and WITH a hot, very humid day, like we have here constantly, I'll be rushing her to the hospital within hours.

I'd very much appreciate any replies from anyone that knows more than I do, about A /C. Thanks again.
Tommy aka kleinscmidt

 

Tommy.... I moved your new post into this thread. A lot of ground was already covered here and by starting a new thread it just takes longer as many of the old questions get re-asked.

Houston and I will address this thread soon.

 

Where do you see 120 volts? You should get 240 or 0 volts on the high voltage terminals unless you are measuring to ground which doesn't help.

Still sounds like you need a contactor but the real proof would be measuring 240 volts between L1 and L2 but 0 Volts between T1 and T2 when 24 volts is present at the 2 smaller terminals that supply control voltage to the contactor coil.

 

@Houston204: I took another reading with the meter, (the unit was not running at the time) on the contactor. BTW, there is no labeling, or any other markings that indicate L1 and L2, nor T1 and T2. I measured, though, between the two top terminals, and read 240VAC, and zero between the two terminals at the bottom, but zero volts between the low voltage wires.

The unit came back on while I was still there, and then I got the same readings as the above on the high voltage, ( 0 at the bottom two terminals, also zero between top / bottom on either side ) and then read 24VAC across the contactor coil wires.

The 120VAC I spoke about in the previous post undoubtedly must have been a mistaken placement of the meter leads, or other circumstance, because this time, I found no 120V at any point(s).

As I said in the previous post, the readings are on target for voltage, amperage, and capacitance on the larger run cap. I am, for the time being, discounting it as the cause of the problem. The smaller cap mounted on the blower is badly rusted. Although I can't see ANY labeled values at all on it, I will still need to determine them somehow, because I am definitely replacing it.

So, and again as I said earlier, the contactor points are burned badly. This more or less proves, to me at least, that I should replace it, too. I DID take the contactor loose from its' mounting point, and found a label that reads Honeywell, with some numbers that I wrote down. I am now going to try and use those numbers to locate the correct contactor, which, as you know, I have been unable to find at this point. I am hoping this will change now.

Thanks for your reply. I apologize for the time lapse between your post and mine. I thought that I would get an e-mail each time someone replies to a post. I'm going to look the site over again to see if there is a setting for that, and activate it if there is.

I'll be back at 'cha later on, Houston204, (I don't know your real first name). I REALLY APPRECIATE your correspondence, and am hoping that, between us, we'll finally get this aggravating issue solved, once and for all.

 

Thanks for the help, and the heads up, PJ. As you can see, I've posted a reply to Houston204. With any luck, this may very well be the necessary action(s) that will finally solve my A / C woes. BUT, if you, or anyone else, has any thoughts or ideas AT ALL, please do not hesitate to post them. I would be very grateful. There's no way they could hurt. Besides, any further info might be used as future reference. Thanks again.

Tommy AKA kleinscmidt

 

I have attached a photo of the voltage test points on a contactor. L1 and L2 are power coming into the unit. Each wire has 120V on it. To test the voltage you place one lead of your multimeter on L1 and one lead on L2. You should get a reading of approximately 240V across the two wires. T1 and T2 are the terminals that provide power out to the compressor and fan. To test these you do the same test as you did on L1 and L2. To get a reading on T1 and T2 the contactor the plunger on it must be pulled in when there are 24V on the two smaller wires on the side of the contactor. These two smaller wires on the side of the contactor are the 24V control voltage wires. When the thermostat calls for cooling to come on 24V are sent to these two wires. Do the same test as before on these two wires. When you do the test you should have approximately 24V. If you get the 24V across these two wires the contactor should pull in the contactor plunger to complete the path from L1 and L2 to T1 and T2 to power the various components. If the contactor does not pull in when there are 24V present on the two wires the contactor needs to be replaced.

 

Everything firedawgsatx said is correct. I just wanted to add that even if the contactor is pulling in when the 24V is applied across the coil, it's still possible that the contactor is bad. If the contacts are burned or badly pitted, it's possible that they may not be making good electrical contact, in which case the contactor should be replaced.

 

Here is a photo of my Honeywell A/C contactor. The unit itself is a 1992 model Tempstar, so I do not know if the contactor was installed by Tempstar at manufacture, or if someone had already replaced the original equipment.
As seen, L1, L2 and T1, T2 are plainly visible, but not labeled in any way. At the far left, the two terminals seen with yellow wires would be the 24V control wires. And also plainly visible, are the single set of contacts, burned very badly. This alone, tells me that the contactor needs to be replaced.

The voltages are all correct while the unit is either off OR running, including the low voltage control terminals. So, as you can plainly see, the contactor plunger is badly burned. This fact alone tells me that the contactor needs replacing.

I can only hope that this FINALLY puts this headache to rest. More to come. Thanks for the reply.

 

Definitely needs a new contactor. Good work!

 

This will probably solve my electrical and running cycle issues. Now, I need to get more cold air force coming out of the registers.

It most likely needs recharging the refrigerant. That's a tricky one, for obvious reasons. (hint): certified tech. Some "repair guy" told me several years back, that my model #NPADE29AB03 Tempstar, was some kind of "sealed system", and would NEVER NEED recharging of the refrigerant. Don't know for sure about that one. It's a 1992 model. I'll have to ask around, ( here, for instance ), and other places, too, to see how accurate that statement is.

I also received, from ICP, Tempstar's parent company, an email with a pdf that was 4 pages of exploded views, components listed and named, and replacement parts model numbers. I found the contactor replacement, but still have to see if I can match it up with a parts a, (online, and otherwise). You will find that if you go to ICP's website, OR Tempstar's, there ain't no stinkin' ordering parts there. You can BARELY find a "contact us"! That's no lie! There ISN'T EVEN a "contact us" at the ICP site. It's "feedback" that you have to click there...AND THAT brings up an "inquiry" form that you must fill out, then only to wait for a 24-48 hour approval, after which THEN you may kneel and request information. SMH Not quite THAT DRASTIC, (lol), (actually, it was), but they eventually emailed the pdf file.
Thank you all for your input, suggestions, advice, and answers to my numerous questions. I'll summit this Everest yet! (seems as though ALL of my DIY projects turn into an Everest!)

BTW, going completely off topic, does anyone know how to get up a custom avatar on your profile here by browsing your PC's files for your choice? I see several here, but when I try to clear the button that allows you to do it, I get no further, so I have chosen one from DIY's list, for the time being.

IF anyone has some insight on this, please don't hesitate to PM me. I don't mind at all. I know. It's petty and trivial, but it's the principle of the thing. Thanks.

Tommy AKA kleinscmidt

 

An air conditioning system is a sealed system and should never need recharging. That part about not needing recharging is true only if no leaks develop in the system. Over time, pinhole leaks can develop in the evaporator or condenser coils, or where the lines are brazed.

 

As far as the contactor, the replacement you need is one of the most common and readily available. It does not have to match the original part number found in the manual. It needs to match the specs such as 1 pole, 24V, 25 amp. Your best bet is to turn off power to the unit and look on the contactor to get the part number from it. Some of the suitable part numbers I came up with are HQ1050699PU, 3100-15Q1191, and 1050699. There are many others, but you can plug one of those numbers in your favorite internet search engine and you will come up with a multitude of sources and at a vary reasonable price. If you have a local Grainger's or Johnstone you can walk in there and get the contactor at a reasonable price. I checked a local source and found the contactor under $15.00. If you decide to use the internet to source the part, you will find prices vary considerably so it definitely pays to search until you find the right source. Many sellers have free shipping.

 

I bought a new contactor, a Packard universal. I didn't see the "no returns on electrical parts" sign, but found this out later when I tried to do that very thing. So, either way, I'm out 27 bucks...PLUS gas and travel time, 45 minutes each way.

My unit was running when I started to install the new part, so I cut the power first. The L1 / L2 wires had forks on the ends, that would not fit in the new contactor, so I just squeezed then with pliers, and took them off, exposing just the naked wire end. This was the ONLY thing I changed.

Referring to my photo of the old contactor, I hooked up all of the wires accordingly, but had to put L1 / L2 bare ends, behind the aluminum screw-in @ the front of the contactor, turned the unit back on at the breaker, and nothing. Just MY luck.

Reading all of the voltages, (unit energized, but not running) yielded the following: L1 / L2, 0 vac; T1 /T2, 240 vac, and zero vac at the low (24v) voltage coil wires. Here is where I was left scratching my head...L1 / T1, 240v; L1 / T2, 0v. Then, L2 / T1, 240v; L2 / T2, 0v, with 0v at the 24v terminals.

It was VERY hot and humid, so it didn't take but a few minutes for the inside temp to rise to 80*F. I HAD TO do something, because my wife's health issues demanded it. I took a small sliver of a zip tie, and jammed it in at the plunger contacts, making the unit start, but obviously, I couldn't leave it running continuously. SO, when the temp lowered to our usual setting, I just cut the power, leaving the jury rigged contactor as is, and as of this minute, (Thursday, 9/4; 6:30am) I'm still just flipping the breaker on and off as needed to regulate the inside temperature.

With the unit running, voltage readings were: L1 / L2, 240 vac; T1 / T2, 240 vac, and again, 0 volts at the coil (24v) wires. Previously, I had read those OTHER, "criss-cross" voltages just out of curiosity, and did not check them here.

HELLLPP! What is going on with this thing?? Reading zero @ the 24v wires, both, while the unit is energized / not running, AND WHILE RUNNING, leads me to believe that, (A), this was a defective contactor at time of purchase, OR (B), when power was applied, something went awry, and perhaps blew the coil. ?????

PLEASE hurry. I IMPLORE ANYONE to reply, maybe with some answers. I'm not certain if I'm going to have to BUY ANOTHER contactor...or if there is a solution here without having to do that, (I REALLY can't afford that), but if I have to, I'll have no choice. I just need to get this figured out VERY QUICKLY...my wife, (nor I, for that matter) can't do without the A/C, and I sure as heck can't keep cutting the power off and on, while I have the contactor plunger stuck shut.

 

The 24 volts is provided by the indoor unit.
Check the fuse in the indoor unit if you didn't turn off the stat before replacement of the contactor.

Post a pic of the new install if there is any question as to the location to connect the 24 volt wires to the new contactor.

 

Sorry to hear about your problem. Looking at the photo of your bad contactor I notice the 24V wires are both on the left side of the contactor. In today's post you stated you referred to the photo of your old contactor and wired it accordingly. The replacement contactor you purchased more than likely is designed to have one of the 24V wires going one to each side not both on the left side. If you did in fact wire the 24V wires as the original contactor I would say that is your problem. If that is the case, turn power off to the condenser and move one of the wires to the opposite side. Hopefully the new contactor was not damaged. Refer to the photo I posted in post #11 to refer to the correct 24V wiring connections.

 

Hi, Houston, thanks very much for the quick reply. This is getting to the point of insanity. I exchanged the new contactor for another, and I have the exact same result. Whether the breaker is on or off, I am reading ZERO volts at L1 / L2. ONLY IF I stick the contactor plunger to the run,(pushed in)position, and MAKE the unit run, (in this case, it HAS TO run continuously), do I get a 240 volt reading across L1 / L2. On the other hand, T1 / T2 reads correctly with the breaker on, but the plunger does not have to be pushed in, and the unit running, for me to get 240v there.

I hope you can follow this OK. I'm trying my best to keep it simple. I am almost certain that the following is wrong, but with the unit running, I am also getting 240 from L1 / T1, and 240v from L2 / T1, but zero volts from L1 / T2, and zero from L2 / T2. IN ANY SCENARIO, I am getting ZERO volts at the 24v terminals, unit running or not.

I have the 2 low voltage wires, 1 connected to either side of the contactor, as they should be. I did not make the same mistake twice over, after exchanging the first for the second new one. I have also taken the thermostat off of the wall, but there is no fuse to check. It's only a circuit board, 2 AAA batteries, (which I exchanged for new ones), and read 24v coming out of the wall, between the R and Y terminals, as instructed by the thermostat manufacturer (wires there are R/yellow, and Y/white.)

There is some sort of "jumper" that looks like 2 small metal pins, joined together, that are in terminals B and O, which are the very first 2 from left to right. This configuration is also by the manufacturer, (Honeywell, programmable model # BTH2300B). It is only a few months old, and self-installed, as per the thermostat's instructions.

I'm not sure if I've left anything out, but, in a nutshell, I HAVE TO MANUALLY PUSH THE CONTACTOR PLUNGER IN, AND MAKE IT STAY THERE with a small piece of plastic zip-tie, in order for the unit to run. UNDER NO OTHER CIRCUMSTANCES will it run, AND UNDER NO CIRCUMSTANCES WHATSOEVER, do I get anything other than a ZERO volt reading across the 24v terminals, BUT GET 24V AT THE THERMOSTAT.

Geeez, man, I am really sorry to lay all of this on you, but I don't have any more hair to pull out!!
Whatever, if anything, you may have for anything that resembles a solution, PLEASE let me know. Thank you very, very much for reading this "rant", and I'm grateful for anything you can tell me.

Tommy aka kleinscmidt

 

@ firedawgsatx:
Thanks very much for the quick reply. This is getting to the point of insanity. I exchanged the new contactor for another, and I have the exact same result. Whether the breaker is on or off, I am reading ZERO volts at L1 / L2. ONLY IF I stick the contactor plunger to the run,(pushed in)position, and MAKE the unit run, (in this case, it HAS TO run continuously), do I get a 240 volt reading across L1 / L2. On the other hand, T1 / T2 reads correctly with the breaker on, but the plunger does not have to be pushed in, and the unit running, for me to get 240v there.

I hope you can follow this OK. I'm trying my best to keep it simple. I am almost certain that the following is wrong, but with the unit running, I am also getting 240 from L1 / T1, and 240v from L2 / T1, but zero volts from L1 / T2, and zero from L2 / T2. IN ANY SCENARIO, I am getting ZERO volts at the 24v terminals, unit running or not.

I have the 2 low voltage wires, 1 connected to either side of the contactor, as they should be. I did not make the same mistake twice over, after exchanging the first for the second new one. I have also taken the thermostat off of the wall, but there is no fuse to check. It's only a circuit board, 2 AAA batteries, (which I exchanged for new ones), and read 24v coming out of the wall, between the R and Y terminals, as instructed by the thermostat manufacturer (wires there are R/yellow, and Y/white.)

There is some sort of "jumper" that looks like 2 small metal pins, joined together, that are in terminals B and O, which are the very first 2 from left to right. This configuration is also by the manufacturer, (Honeywell, programmable model # BTH2300B). It is only a few months old, and self-installed, as per the thermostat's instructions.

I'm not sure if I've left anything out, but, in a nutshell, I HAVE TO MANUALLY PUSH THE CONTACTOR PLUNGER IN, AND MAKE IT STAY THERE with a small piece of plastic zip-tie, in order for the unit to run. UNDER NO OTHER CIRCUMSTANCES will it run, AND UNDER NO CIRCUMSTANCES WHATSOEVER, do I get anything other than a ZERO volt reading across the 24v terminals, BUT GET 24V AT THE THERMOSTAT.

Geeez, man, I am really sorry to lay all of this on you, but I don't have any more hair to pull out!!
Whatever, if anything, you may have for anything that resembles a solution, PLEASE let me know. Thank you very, very much for reading this "rant", and I'm grateful for anything you can tell me.

Tommy aka kleinscmidt

 

The fuse that Houston204 is referring to would be inside the air handler. The fact that you have 24V at the thermostat would indicate the fuse is not blown. If one is installed it should look like an automotive fuse. If you have a control board it will be located on there. The fuse is sometimes just wired in line on the low voltage wire coming out of the 24V side of the transformer. If there is no fuse installed there is a great possibility the transformer may be "fried". I would start there. Look in the area where the blower motor is and find the transformer. If there is a fuse it will be in that area. I have attached some photos of what to look for. Turn off power to the indoor unit before touching anything!!

Also, did you connect the two wires coming from the disconnect to L1 and L2 terminals and not T1 and T2? They need to be connected to L1 and L2.

Since you say you have 24V at the thermostat you need to trace the 24V signal all the way from the thermostat to the outside wires going into the condenser to see where it is being lost.