air conditioner no workie

[Warren Lake]

week or so ago put the air on and al was well day or two later wasnt sure but heard it running. Now realize that it wasnt running just the fan and the reason the fan was running was the thermostat was below the temp and had turned the fan on likely when it triggered the air cond to turn on

I turned the main power off opened the bodx outside bit furry in there so blew it out with my newly working compressor and dont get this on and off stuff. I that supposed to pull ouit and fuses in there or? I had past read that start capacitors are number one fail on air cond. Have to figure out how to get the cover stuff off but first is there a fuse or anything to this thing with the handle or is it just a tie in from wiring inside to the unit.
thanks
503886503887

[Brian Elfert]

You pull the handle out to disconnect power. You have the option of reinserting the handle flipped over so off is on top. I would just leave the handle out so you don't accidentally put it in the wrong way and have power connected when you want it off.

There are recommendations to use your right hand to pull out the disconnect while keeping your left arm behind your back. This is supposed to make it less likely for an electric shock to go through your heart.

[Warren Lake]

thanks so its only a disconnect not fuses and different than the paddle handle disconnects on the machines. Guess im going in to hunt for a capacitor next

[Tom M King]

Plenty of youtube videos:

https://www.youtube.com/watch?v=bWH38Rg1iMI

[Warren Lake]

yeah realize that plenty of woodworking you tubes as well. I dont even have a fan running so unless the capacitor can cause that there is some other issue.

[Bill George]

yeah realize that plenty of woodworking you tubes as well. I dont even have a fan running so unless the capacitor can cause that there is some other issue.

Did you check the circuit breaker for the outside power? Is the thermostat set on Cool and set cold enough to run, furnace or blower fan running.? Simple but needed checks.

No fuses in that outside box.

I wonder if this post of mine will be deleted? Others have been.

[Warren Lake]

set on cool for numbers say 70 inside turn to 65 furnace fan runs as its triggered by the Honeywill digital thermostat, stays on all the time since its set lower than ambient temp. Think the batteries are fine. Is there an actual fuse in that box I showed there? Also just reading says they have a red reset button you hold for 30 seconds. 81 at the desk now. Will go see if there is a button. Im not clear on the caps the you tube I saw the unit was running but not colling this I have no fan at all.

put the power back on and after 20 seconds furnace did a pause noise it always did when it wouild start the air only unit did not start. Put a voltage thing on the two lines on the air cond side of that disconnect box so its getting power.

can a capacitor at this point stop the whole unit from starting I think there is a side cover, ill turn the power off. I guess capacitors store energy or maybe not if not working. Remember a story from a friend who worked at a place I wont mention. He said one employee had a capacitor or capacitors on his power box at home and cut his monthly bill down dramatic said he got a knock on the door caused when they saw his bill drop so much. guy that told me that had no reason to mislead me that was long ago in high school.

[Warren Lake]

I see a contactor in there same as a woodworking machine start switch with the spring loaded part. Can I put the power back on and push that in? capacitor does not seem swollen not sure how you discharge it or measure it but can just buy a new one unit has been there for many years


503889

[Bill Dufour]

Yes that looks like the so called definite purpose contactor. It is just a relay with no overloads. The coil can be 24, 120, or 240 volts. One difficulty in trouble shooting ac is when they get an "on" signal they wait a minute or two before energizing the compressor. This is so the pump never tries to start under pressure.
I doubt there are fuses in that disconnect. Just pull it out and look at the back side of what you pulled out. Any fuses will be obvious and as big as your thumb.
Total guess that the two yellow wires on the left side of the relay are the coil supply wires. I will also guess the red and black on the right side are switched power in and out of the relay.
Bill D

[Warren Lake]

I pushed the contactor i n and it started and ran and sounds like its doing the air thing. if I can get my 92 year old neighbour to stand out here and hold the stick for a few hours home should be fine. Not sure about musquitoes though

I actually had her do that once on one machine so I could finish a few more passes. Is the capacitor a thing that triggers that coil to snap in and stay there or? Im pretty sure its working right and could mcgiver a thing up to put pressure on it but wont. starting to smarten up a bit more as i get older. Are there other gizmos in there that could cause this or cap likelyi culprit I think you can measure ohms though not sure I have a meter but maybe its on one of them

[Bill Dufour]

Capacitor has nothing to do with the relay. It is just a motor run or start capacitor. The motor is sealed inside a can with no capacitors just freon and a pump. This makes it easier to change caps when needed.
I would disconnect power and exercise the relay a few times. Blow out any dust/dirt/bugs. use a dry paintbrush as well. If that does not solve it put a strip of brown paper bag between one set of contacts and lightly push the relay closed and drag the paper through the contacts to clean them. Do this few times for both contact sets and see if that works. Do not use sandpaper. Too abrasive and many finer grits can be electrically conductive. Any grit not cleaned out can cause wear and jamming latter.
If not replace the relay with one of the same coil voltage and enough amps to carry the load. if you are lucky the mount screws will line up the same.
Bill D

[William Lessenberry]

You may take the cover off of the contactor and find the contacts full of dead bugs. That happened to my A/C Friday afternoon. Bought a contactor and capicitor, plugged them in and the condenser fan came on, but the compressor is still DIA. Guess a call to my A/C guy is in order.
BillL

[Warren Lake]

okay ill try to blow it out rather than take it apart. I guess I cant really tell if the compressor is on or not but the fan is running for sure. If push the contactor in is there a pause of a minute or two for the compressor to kick in maybe ill try it again as not sure

[Bill Dufour]

link to amazon for a 2 pole, 24 volt ac coil contactor. Not too expensive for 40 amps. not an exact fit. The coil connections look to be spade connectors like yours
Bill D.
https://www.amazon.com/Contactor-Generic-Conditioner-Condenser-Compressor/dp/B09KGB7B6G/ref=asc_df_B09KGB7B6G/?tag=hyprod-20&linkCode=df0&hvadid=563791382339&hvpos=&hvnetw=g&hvrand=6468654092715786381&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1014019&hvtargid=pla-1594532994709&psc=1

[Bill Dufour]

If push the contactor in is there a pause of a minute or two for the compressor to kick in maybe ill try it again as not sure[/QUOTE]
That sounds like "delay on" feature is working. You should hear and feel a low hum as the compressor comes on. A helper can see the power company meter jump as the compressor comes on
The return line will get cold after few minutes of compressor run time. The high pressure line out of the compressor will quickly get hot as the pump runs.
Bill D

[Warren Lake]

do I need that, is it not that the capacitor is gone and that is why the contactor is not getting power? sorry I dont understand more wish you were close by id hire you to look at one machine I need running right away and it was after i had taken some start buttons apart past.

[Warren Lake]

just adding to my post that doesnt show I had taken the two start buttons apart and got both working fine machine left for a while then Murphy must have settled in need to look at it in case im missing something.

[Brice Rogers]

I've been nursing two AC units for over 25 years. The failures that I have incurred include:
1. AC capacitor (probably 3 replacements - - major failure item). They typically get "puffy" when they fail. They cost about $20 or less. You can check them with an ohm meter do determine if they are "open", or "shorted" (unlikely failure mode). Let me know if you want to know how to determine if they have capacitance - - or just spend $20 and replace it.
2. Cartridge fuse (they are only good for a certain number of cycles, so they can fail). They are located inside the disconnect. It is easy to ohm them to determine if they have opened.
3. Contactor contacts had a fried bug in them. 800 grit sand paper fixed it. People told me that I shortened it's life (10 or 15 years ago).

[Tom M King]

If that capacitor is blown, nothing will run, or as they say around here: "she won't say nuthin' "

I learned how to work on them myself, and have all ours running great, but I didn't figure it out in my head without some studying.

There is a long list of possible problems, but it's so easy to check the cap that's usually the first place the troubleshooting stream starts.

[Rod Sheridan]

Hi Warren, with the thermostat calling for cooling, measure the contactor coil voltage, it should be 24 volts AC. There probably isn’t any due to a safety interlock

My suspicion is that the low pressure switch has opened due to a leak, or the high pressure switch has opened. The high pressures switch may have a reset button, if so press it once.

Probably time for an HVAC tech, in Ontario you need a license to work on the refrigerant circuit.

Regards, Rod

[Bill George]

Having been in the HVAC business for 30 years or so I may add a little advice. If the outside contactor is not pulling in its because it does not have the 24 volts or it does and the coil is burnt out. The bugs have been mentioned and that is certainly is possible turn off the 230 volts and check. I had one that routinely bugs would chose to get smashed.

The compressor starts and runs you proved that by pushing in the contactor which rules out the compressor capacitor and the bugs.... maybe. If its a higher dollar unit it might have a high or low pressure limit switch that tripped.

You need a voltmeter to check for 24 volts AC on the coil, if you have it, then the contactor needs replaced. No 24 volts, either a wiring issue, limit switch or the thermostat Y wire.

When troubleshooting you always start with the thermostat, turned to Cool does the blower or furnace motor start? Did the outside unit fan start, you have just proved you have power to the blower motor and the thermostat works. Outside fan on, you have proved you have 230 volts, not cooling start from there.

[Warren Lake]

in the house when I turn the thermostat down after some seconds there is a clic. That would be normal and from inside id hear the unit start. This time after the clic the unit does not start. So I hear that signal from the thermostat clic and the furnace makes that pause for a split second, past id always here the unit turn on its close enough just outside. Had an AC guy a block away he moved. have to pick up materials so it wont get more attention right away.

[Rich Engelhardt]

A/C no workie = call a guy and get ready for the really bad news.
Bad news is you need a new A/C.
Really bad news is you need a new furnace too.

Really terrible news is while they are replacing the furnace, they tell you the water heater is on it's last leg.

Been there - had all of it happen. A/C and new furnace multiple times.

[Tom M King]

Here is one of my favorite HVAC youtube channels:

https://www.youtube.com/watch?v=5UU2c5e2ork

[Tom M King]

This is the other in the top two channels:

https://www.youtube.com/watch?v=1nQ7k_X2aXA&t=556s

[Warren Lake]

see what the coil thing is, notice the wires that go to the contactor are really long pull them out notice the slip on connectors are loose on both and the tangs whatever they called are sort of dull corroded. would make sense to clean them with some fine sandpaper first id say. Not sure why such long wire length but guess it doesn't matter maybe not the contacts but worth looking at

So that wire from my thermostat should show 24 volts? there are two so same on a battery there is a positive and a negative or one is the ground. Am I concerned with that or just hook the mulitmeter up to either then reverse if not reading to be sure im not back wards?

thanks

[Michael Weber]

Warren, it doesn’t matter which meter lead goes to which wire on the contactor.

[Bill George]

see what the coil thing is, notice the wires that go to the contactor are really long pull them out notice the slip on connectors are loose on both and the tangs whatever they called are sort of dull corroded. would make sense to clean them with some fine sandpaper first id say. Not sure why such long wire length but guess it doesn't matter maybe not the contacts but worth looking at

So that wire from my thermostat should show 24 volts? there are two so same on a battery there is a positive and a negative or one is the ground. Am I concerned with that or just hook the mulitmeter up to either then reverse if not reading to be sure im not back wards?

thanks

Its AC alternating current has no polarity. And remember the KISS rule and start with simple.

[Warren Lake]

thanks ill try and clean and measure before I go pick up materials if not will be when back apprciate the info Yes its time for new stuff but at the moment prefer to get this running if possible. Takes me a bit of time to do research on stuff with most things. Furnace a 90,000 Keeprite super high effic and know its time so both get done same time could use a few more months to keep focused on other stuff.

[Warren Lake]

I got sort of different readings wish the meter had clip on ends, will get some. The readings I got were mostly 2-3 volts. Did at one point see 10 but for the most sort of 2-3 and that is pressing the wires hard on the meter ends. Is the multimeter set correctly think so this is where id read a car battery and see about 13 volts approx. realize the 24 you are saying is more than the 20 setting on the meter. when I got 2 3 it was almost if I waited or that it came up a few times to six or the one time for 10 but for the most part just low as shown or bit more these are the wires right at the AC unit that come from the thermostat in the home

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[Bill George]

I got sort of different readings wish the meter had clip on ends, will get some. The readings I got were mostly 2-3 volts. Did at one point see 10 but for the most sort of 2-3 and that is pressing the wires hard on the meter ends. Is the multimeter set correctly think so this is where id read a car battery and see about 13 volts approx. realize the 24 you are saying is more than the 20 setting on the meter. when I got 2 3 it was almost if I waited or that it came up a few times to six or the one time for 10 but for the most part just low as shown or bit more these are the wires right at the AC unit that come from the thermostat in the home

503892 Looks like your meter is on DC - +, should be on AC to the right of the OFF location.

[Warren Lake]

its set how I always use it on car batteries and its read perfectly. Is it not the same setting. Plants watered and have to leave now thanks for all the help ill try a bit more later. one question when I take the two wires from the furnace thermostat before the unit should they read 24 volts there? that is what I measured. Or is it the 24 volts after that little round coil thing where the wires are the two yellow on the contactor?

[Bill George]

its set how I always use it on car batteries and its read perfectly. Is it not the same setting. Plants watered and have to leave now thanks for all the help ill try a bit more later. one question when I take the two wires from the furnace thermostat before the unit should they read 24 volts there? that is what I measured. Or is it the 24 volts after that little round coil thing where the wires are the two yellow on the contactor?

Don't get confused, but its not DC (I can not see where the arrow or knob on your meter pointing at?) but put your meter as I said on AC and stay where your at troubleshooting for now. That little round thing in your picture looks to have some rust on the connections and perhaps its a time delay, but don't have any idea unless you can safely pull it out and read the label or brand name?

[Bill Dufour]

That little round thing in your picture
Do you mean in the little box in lower right corner with all the yellow wires? Looks to me like a thermal switch or overload switch. He did say the delay on timer is working when he pushes in the contactor.
Bill D

[Bill George]

That little round thing in your picture
Do you mean in the little box in lower right corner with all the yellow wires? Looks to me like a thermal switch or overload switch. He did say the delay on timer is working when he pushes in the contactor.
Bill D

I can not find those numbers online but F55 usually means a temperature something and it could be some low ambient lockout that keeps the outside unit from running when its below 55 degrees. But without more information its just a guess. A time delay is always in the control circuit and in this case it would be 24 volts. When you hold the contactor in there is no control circuit involved.

When you enlarge that picture it shows the contacts as being pretty burnt. But the issue is, the contactor is not pulling in.

[Bill George]

These are the only ones I have ever used. https://www.grainger.com/product/SUPCO-Single-Function-Encapsulated-407L15

[Derek Meyer]

Is this an electric furnace or a gas furnace? I had a problem with my gas furnace a few years ago where the thermostat would call for heat and the unit would click and try to turn on, but fail. It turned out that there were a bunch of wasp's nests in the exhaust pipe that had plugged it, and the furnace could not breathe. Once that pipe was cleared, everything worked normally. I'm pretty sure it would have done the same thing if trying to cool.

[Warren Lake]

asked a neighbour who is some type of industrial electrician. Said it likely needs freon if never charged and he wont work on it as not in the trade. Asked him about a saw I have an issue and even though hes been a supervisor for many years figured i out instantly. asked for just two seconds on the air cond and had a seat there and all open as i left it. I asked him to measure the thermostat wires and as he did they pulled out from the wall and been chewed through by a mouse. So need some wire to hook that up and see. Glad I asked him to look even after he said no.

will report back. happy the saw is running and one switch the one had repaired he said is bad. I spent time on that little thing bending and tested it 100 times then murphy showed up before I went to use it next time. 81 in here now, half a day in the car picking up materials in the over populated city where they bring in 300k more people every year to keep their buddies in business with endless work.

[Bill George]

Sounds like you found the problem, just get some TStat wire and splice it in, with the 24 volts turned off of course. Think about replacing that contactor as the contacts are pretty burnt. NO you do not need to add refrigerant, it does not wear:) out its suppose to be a sealed system. If the older ones leak, its usually in the evaporator coil and its corrosion, just replace the system if its over 15 - 20 years old.

[Warren Lake]

maybe and just made another one. Pulled the wire for the thermostat through the wall and as I did saw a spark. Same time the furnace shut off. My mistake there so now that has done some damage maybe as the same time the thermostat spark happened it shut down and wont start up. I did fiddle with the thermostat a bit and it started but then shut off. 3 inches of wire casing is chewed off with teeth marks in the copper. If I rewire back out to the AC can iI use any wire or is that solid wire specific that is can i use a straded wire and mars just to get it working then maybe it wont dont even have a furnace fan now argh :)

[Bill George]

maybe and just made another one. Pulled the wire for the thermostat through the wall and as I did saw a spark. Same time the furnace shut off. My mistake there so now that has done some damage maybe as the same time the thermostat spark happened it shut down and wont start up. I did fiddle with the thermostat a bit and it started but then shut off. 3 inches of wire casing is chewed off with teeth marks in the copper. If I rewire back out to the AC can iI use any wire or is that solid wire specific that is can i use a straded wire and mars just to get it working then maybe it wont dont even have a furnace fan now argh :)

Just buy some thermostat wire. Lets hope you have a fuse at the furnace, normally a 3 amp on the low voltage side. Or perhaps you fried a transformer or circuit board, thermostat ?

[Warren Lake]

so first thanks for all your help, long day no food guy helped with the saw and good then had looked at the air. Shows up two hours later more wobbly and has a friend loves woodworking wants to meet me and and I tell him I screwed up pulled the wire through the wall and had forgotten I had turned the thermostat down so its sending a signal. Tell him the furnace guy and his employee both told me I took out a fuse when it sparked 3" of insulation gone both wires. I need to make Cayenne pepper paint for some wires. So at that point hes measuring stuff and pulling things off and this and that then says what about the panel. I said shit i did turn it off as my hands are in all this stuff and I didn get the contactor was working last night so turned back on the unit started right away and ive dropped 2 degrees temp wise and 11 now humidity massive difference./ 81 F now and 58 humidity. what a difference water is like a garden hose coming from the furnace. As hes talking he hits the thermostat with his hand it goes flying and I grab it and all the face digital stuff is gone its blank argh. Take it apart and make sure the batteries are good wait then assemble then in a bit it clicks and furnace back but air not running try a few things and I notice it says wait must have been 20 minutes then it started up fine and happy to keep going so far. Fingers crossed. It will all get replaced but this problem this happened after the first day or two of using it, the fan kept running as I had set it on run then i was thinking doesnt feel as cool second or third day. He was wrong about freon he said the pressure will be low and it wont start. I bet that AC unit is over 20 years old, its never even not worked always worked well. Keeprite and had Keepright furnaces past and done fine iwht them though know there is better all good two things got fixed to day saw I need and air now just need lunch and dinner thanks for all your help and care. Great group of knowledge here.

[Warren Lake]

Still working fine. Could still be lower in here but easing into it. 8 degrees cooler is dramatic. I had posted about an issue with the compressor not turning off and after tapping on it it was fine. Realized this guy will understand that and will ask him first that its wired right and it should be and has been forever so find out what his understanding of the high low switch is. Likely its the cause and had stuck. Still have to pressure test the valve that someone suggested and will do that just came to mind. Humidity in the main shop is down a fair bit. A cold air return picking up off floor level would make sense.

[Bill George]

Still working fine. Could still be lower in here but easing into it. 8 degrees cooler is dramatic. I had posted about an issue with the compressor not turning off and after tapping on it it was fine. Realized this guy will understand that and will ask him first that its wired right and it should be and has been forever so find out what his understanding of the high low switch is. Likely its the cause and had stuck. Still have to pressure test the valve that someone suggested and will do that just came to mind. Humidity in the main shop is down a fair bit. A cold air return picking up off floor level would make sense.

If its working now, please do not mess with anything. I don't understand compressor not turning off, why would you want it off if its cooling? If its running and cooling you do not have a pressure switch issue.

[Ron Selzer]

spark might have tripped a ciruit breaker on the transformer or destroyed the transformer which would be in the furnace.

[Warren Lake]

it did some type of temp damage would not run at all now its run perfectly for 12 or 14 hours whatever it is, Not so with the compressor just used it and did not shut off so will be looking at replacing the high low likely, ill see if I can get the same guy to look at it. Can use it that way not in the same room and it got to new levels and the safety didnt kick out. Did manually set it off after its likelyi sticky from never being used in 36 years Need the thing working and now. ill take photos of the parts tonight if can get at it, nice to have air and will bump it down tonight.

[Bill George]

I do not have a clue of what your talking about Warren. What is a High Low? The only thing I suggested is replacing the contactor as the contacts look pretty burnt. Ok so your talking about your air conditioner and now its the Air Compressor.

[Warren Lake]

that was the shop compressor that is not turning off. Hope to get a chance to move it out tonight and see a make and model number on it.

[Mel Fulks]

Warren , I would just try to get the kid who runs the place ,to use less oxygen. Maybe just run old Churchill speeches. “ If the Canadian
People last for a thousand years ….men will still say “ this was a cooler place than the Equator” .

[Bill George]

that was the shop compressor that is not turning off. Hope to get a chance to move it out tonight and see a make and model number on it.

Most air compressors use a off the shelf common air pressure switch, all you need is the pipe size and is it a 2 pole or not.

[Warren Lake]

thanks Bill

Had to move stuff then move the compressor its under a stair case and moving was a pain. Got photos of the pressure switch and the contactor. I didnt understand the contactor it seemed pulled in all the time but it was hard to tell I didnt have the travel others have which seems to be 3/16 of an inch or a 1/4. I did run it and it didnt shut off had to run to the power box. Ill post what it is on the original post. I think someone said it could also be the contactor stuck in the on position. Ive never heard of that happening and not on any other machines here past.

[Jerome Stanek]

Had a air compressor the would run and not shut off as the contacts were weld shut.

[Warren Lake]

thanks l one of a number responded on the pressure and in stock maybe this truly is stuck and thats why I cant feel any movement or very minimal. since it did work properly a day ago shut off on its own and the stop button worked I wonder how that could be if it is stuck in. Hope to ask the electrician later but thanks to both for saying that is a second possibility. I did a post on the shop area. For this post air still working perfectly.

[Lee DeRaud]

okay ill try to blow it out rather than take it apart. I guess I cant really tell if the compressor is on or not but the fan is running for sure. If push the contactor in is there a pause of a minute or two for the compressor to kick in maybe ill try it again as not sure
On the ones I've owned, the fan and compressor come on together. (Furnace fan will run for 30 seconds or so after the compressor shuts off, presumably to keep the evaporator from freezing up.) There is typically a 10-minute delay after that before the compressor can turn back on.

[Lee DeRaud]

I think someone said it could also be the contactor stuck in the on position. Ive never heard of that happening and not on any other machines here past.
The AC unit that came with the house did that once a year or so, just from cruft building up in the moving bits. Didn't help that it was under a tree (since removed). A quick hit from a screwdriver handle usually freed it up.

For some reason, all three of the ACs I've owned use open-frame contactors, no cover. I guess that means that dead bugs building up under the cover can't happen, and it certainly makes diagnosis easier. In any case, they're cheap and at least as easy to swap out as the capacitor. The service manuals for most compressor units are available online and will provide the part number for the replacement capacitor and contactor. I keep a spares for both on hand, maybe $30 total...Murphy's Law guarantees I'll never need them.

[Warren Lake]

still working perfect I guess that time delay when I shorted the thermostat caused some temp issues and when the guy knocked the thermastat and it went blank it likely was 10 minutes approx then happy to carry on happy to have it the shop humidity is not down alot but feels way better old places need cold air returns at the floor for the summer pick up the cold air fro the coldest place, most older places ive had no cold pickup in the basement only main floor.

[Lee DeRaud]

If the posts I responded to were talking about air compressors and not A/C compressors...never mind. :)
(I'm familiar with the concept of "thread drift", but that sounds more like the thread jumped off the roof and face-planted.)

[Warren Lake]

my brain skips around a fair bit five things at once now pressure up on stuff more skipping as more to do. Whats insane is my friends understand me. :)

[Terry Wawro]

Here is one of my favorite HVAC youtube channels:



https://www.youtube.com/watch?v=5UU2c5e2ork

Amazingly detailed and simple video.