Typical A/C Problem???

Reply

  #1  
Old 05-27-07, 04:11 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Angry Typical A/C Problem???

OK here it goes from a first time poster.

Currently weather 90 degrees, turned on Central A/C yesterday for the first time this season.

I have a 7 year old Rheem Split Unit. Outside Fan works, no debris blocking, inside fan works. Problem is NO COLD AIR and sounds like the compressor is not running - not getting the normal sound from it, it's actually too quiet.

The two lines running into the house (big and small copper) are neither hot nor cold, they just feel like copper pipe.

I just replaced the filter yesterday before I turned it on. Currently 82 in the house with an oscillating fan, please help!

Is this something I can fix myself or do I have to call the repair guy and rearrange my work schedule?
 
Sponsored Links
  #2  
Old 05-28-07, 06:41 AM
Member
Join Date: May 2006
Posts: 253
If you are comfortable opening up the control panel and taking a look you may see a burned wire, swollen capacitor etc. which you could fix. Depends on your experience level and respect for electricity.
 
  #3  
Old 05-28-07, 09:41 AM
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,816
kill the power

Take a peek behind the panel cover...I suspect the wires may be burnt off the compressor on either the ones that connect to the contactor or the ones that connect directly to the compressor. Plkace you hand on top of the compressor if its hot, let it cool off for several hours, then have someone apply power for you so that you can hear what it's doing while attempting to start
 
  #4  
Old 05-28-07, 04:32 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
I'm comfortable with the electicity, I can turn it off first and work on it, not totally uncomfortable with working with it turned on though.

I'm going to assume the compressor is in the unit on the outside of the house? Underneath the big spinning fan? I would definately be turning the power off to get into that.

I'm not sure what a contactor are or a capacitor (hopefully it's not a flux capacitor?, my wife would kill me if I invented time travel). I did follow the wires from what I think is the compressor (big bottle looking thing under the outside fan) and they came up out of there to a switch looking thing (I'm going to guess this is the contactor?) it's hooked up to the opposite side of the switch that turns the fan on (found that out when I had the panel open with the electric on, oops). The third wire goes to a weird looking circular thing with two other wires hooked up to it, not sure what that is though.

You guys are awesome and I appreciate your input. I had a friend suggest it could be the main circuit breaker on the outside of the house? I turned off the power and looked at it, took it out and it looked alright to me, would it make any sense replacing that just to see? He suggested it was a two pole breaker where the part to the compressor may be out? Just a thought?
 
  #5  
Old 05-28-07, 04:46 PM
Ed Imeduc's Avatar
Member
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 18,389
Wink

You need a smalll electric meter to tell just what you find inside a unit. As to what has power or dont. Or like if you have just one leg 110V and not 220V
 
  #6  
Old 05-28-07, 04:53 PM
HotxxxxxxxOKC's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jul 2006
Location: USA
Posts: 8,044
Talking

and Mike....the flux capacitor is in the A coils, not the compressor; your wife will find something else to kill you over! :-p
 
  #7  
Old 05-28-07, 04:58 PM
Member
Join Date: May 2006
Posts: 253
The third wire goes to a weird looking circular thing with two other wires hooked up to it, not sure what that is though.


That's your capacitor. If you don't see any obvious swelling or distortion of the capacitor and no burned wires anywhere you will need a volt/ohm meter to go further.
 
  #8  
Old 05-28-07, 05:00 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Back to the Future

No we're not talking about a flux capacitor nor will you need 1.21 gigawatts.
The capacitor will be either oval or cylindrical & have two or three sets of terminals on it. There may even be more than one. Trace the wires from the compressor. Usually there are three wires. Two heavy wires will go to the contactor & the third (usually a lighter wire) will go to the capacitor. It is not at all uncommon for a capacitor to go out over the winter.

To remove the cap, kill the power at the breaker & put tape over the breaker as a warning to anyone else. Use a well insulated screwdriver to short across the various terminals of the cap. Mark the cap with a marking pen to identify where each wire goes then remove the cap. Take it to an electric motor shop or HVAC supply house & they can test it. If bad get & install a new one.
 
  #9  
Old 05-28-07, 05:04 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Yup I know the capacitor now!!! It is all rusted on the terminals. I unplugged them and plugged them back in when I was in there before, nothing changed.

Does the fan and the compressor work off the same capacitor?
 
  #10  
Old 05-28-07, 05:09 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Capacitor

How many SETS of terminals on the cap? If two, the cap is dedicated to either the fan or compressor. If three, it is a dual capacitor having "common", "fan", & "herm" (or "comp") terminals. The fan & common can be good while the compressor side is bad.
 
  #11  
Old 05-28-07, 05:15 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
It has three sets going into it, it's a dual capacitor. I'll work on it tomorrow, hopefully. Would be great if that's all that's wrong, hopefully!!!! I'll let you know what I find.
 
  #12  
Old 05-28-07, 07:00 PM
Member
Join Date: May 2007
Posts: 14
Mike,
I'm new here also but I'll tell you what I learned the hard way about the capaciter. Even with the circuit breaker off, that little round metal can with wires plugged in one end can store alot of electricity. Sometime for more that a day after electric has been turned off. I thought I would fore warn you as it can deliver a nasty shock and will definatly scare the Sh-t out of you. There are several way to discharge this current if you are planning on testing that electronic piece.

Heres how it works..
http://youtube.com/watch?v=4o0ca4N8zM8&mode=related&search=

Good Luck....
 
  #13  
Old 05-28-07, 08:09 PM
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,816
I'm shocked

you guys know that much of that movie...What a scream! To short out the cap I use needle nose pliers, open them up and close them till they touch the two terminals. It makes a small spark SOMETIMES...most of the time you see nothing. Your guessing on the parts was pritty good! The compressor is sometimes called a can in the trades. Check the wire terminals under the cover of the compressor. When the outdoor fan runs, so should the compressor. I'll bet the can was hot...and going off on overload. When it tries to start youll hear a small Bink! This is the overload tripping because the compressor is seized... When the compressor has been off for several hours it will make a louder hum or noise trying to start before it tripps.... Try it from a cold start. You'll need to power it up outside yourself if within reach. I have cooled these down in the past with a bag of ice on top of the compressor to speed things along...
 
  #14  
Old 05-29-07, 04:02 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Back to the drawing board

OK, I looked at the capacitor. There is power to all three of the connections. Just for kicks I unhooked the fan, the compressor came on for about 5 seconds then clicked off. I also switched the fan to the other connections on the capacitor, it worked on all of them.

Any advice from here? I had an issue last year to, it was blowing cold but not too cold, that was just a filter problem, they checked the freon too and everything was ok then.

Any thoughts on a compressor booster? Happened to see that on the internet yesterday LOL.
 
  #15  
Old 05-29-07, 08:16 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Capacitor

To test the capacitance (thus the name capacitor) you need either a volt meter & clamp on amp meter OR a meter to test capacitance directly. If you take the cap to an electric motor shop or an HVAC supply house, they can test it for you & sell you a replacement if needed. Without the right test equipment all we can do is guess. If the cap tests good, you could have a bad compressor.
 
  #16  
Old 05-30-07, 01:34 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
When all else fails hit it with a hammer

Just to see what happens I opened up the Outside A/C unit. I couldn't really get to the wires on the compressor (short on time) but made sure they weren't loose. I then took a rubber mallet and whacked it a few times (what the heck, can't hurt, I hope).

Hooked everything back up. Actually got the compressor going for about 5 minutes, first time I tried to start it since last night, then it shut off again. It was very hot to the touch and nothing happening in the copper pipes into the house (they were both the same temp feel). After that it would just buzz for awhile and shut off.

I'm going to replacer the capacitor just for kicks ($12 at Grainger, can't hurt, I hope lol).

Any other thoughts? If the new capacitor doesn't do the trick, is it time for a repair guy? I know diagnosing over the net isn't the best way, but thanks for all the advice, it's been fun if anything. And I haven't blacked out the neighborhood.........................yet.
 
  #17  
Old 05-30-07, 01:44 PM
Ed Imeduc's Avatar
Member
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 18,389
Wink

Id say your down to Ohm out the compressor and see what you have there If its good or bad.
 
  #18  
Old 05-30-07, 06:39 PM
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,816
potential relay

There is a possibility you have a potential relay in your unit. Take a pic of the control box and post it. Check the connections to the compressor ON the compressor under the black plastic cap. The start booster (hard start) is for units with caps, and easy to connect. They are used all the time. Read the voltage on the compressor while it running across R and C terminals on the compressor. It should be about 208 volt. Check the connections for tightness on the contactor (to include the screws). I find these loose many times because techs use the stake-on connectors BUT these are held on with the screws. So check connections because it sounds like its drawing high amps. The hard start will help it get started so that the run cap can take over once started. I'd get em both while your there. Check L1 to T1 on the contactor, it should be less than 1 volt with the unit running and then check L2 to T2 on the contactor too! If it reads more than 1 volt, replace the contactor. Let er cool off before trying this...
 
  #19  
Old 05-31-07, 01:44 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Good News/Bad News

Thank you for the all the help.

I have good news!!!!!!!!!!!! The new capacitor fixed my problem and the A/C worked.

I have bad news!!!!!! Being the dope that I am, I couldn't just let it run I had to make sure the compressor was running, so like a dope I unhooked the fan from the capacitor (probably not my best move). Yup the compressor was running like a champ. Then, like the dope that I am, I went to plug the fan back into the capacitor and OOOOPPPSSSSSS fried the fan motor. DOH!!!!!!!

So instead of a nice $12 fix, I have to now replace the fan motor. Good news is I'm fairly confident I can install it. My only question is, the old fan wires went to this white "connector" plastic thing (a quick disconnect?) and then went to the contactor. I'm guessing I"ll need tools for that thingy? Can I reuse it or get a new one?

Thanks again

Signed Mr DOPE
 
  #20  
Old 05-31-07, 03:40 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Fan wires

You have two choices. Either get an exact replacement motor which will come with the plug OR splice the wires. Most of the time I splice the wires with heat shrinkable stake on butt connectors.
 
  #21  
Old 05-31-07, 04:13 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
I have a Grainger account through the company I work for. I found what looks to be an exact match to the motor that is in it, all the specs are the same.

Do I need to actually have that little plastic quick disconnect or can I hard wire right into the contactor?
 
  #22  
Old 05-31-07, 04:45 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Motor Wiring

If the leads are long enough (usually not) you can wire it directly to wherever the existing leads go.
 
  #23  
Old 06-01-07, 02:23 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Almost done

OK, I got the new fan motor. Got it installed, hooked everything up. According to my voltage meter, its got 233 to the fan at the contactor and 230 to the compressor. Compressor works.

The fan spins but spins slower (or so it seems) than the old fan and it's awfully quiet (probably not a bad thing). Also, it has it's own capacitor on the motor itself, should I then disconnect the old capacitor wire to for the fan? I also used the old wire connect from the fan. I kept the original wires that were from the connector to the quick connect and then took about a foot of the wire from the quick connect and sliced them onto the new fan motor wires with those butt end connector things. Could that have anything to do with the problem? Also looks like the compressor is overheating because the fan is moving slower. I shut it off for now, thunderstorm coming through.

do you think I did it right or is there something I'm missing. Any thoughts? I'm almost there I can feel it LOL
 
  #24  
Old 06-02-07, 01:17 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Fan Motor

Make sure the capacitor is the correct microfarrad & voltage for the new motor.

You should always get & install a new cap with a new motor.

Check the speed, HP, & rotation of the new motor vs the old.

Wire as per diagram on or with motor.

Splices should not matter if done correctly.
 
  #25  
Old 06-02-07, 01:38 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
I got the fan fixed. I had spliced one of the motor wire to the wrong wire. Works great now.

Only problem now is the compressor will run for 10-15 min and then shut off, the it's just the fan running.

1 - could it be a new compressor needed?

2 - could it be low on freon?

3 - is it time to call the A/C guy.
 
  #26  
Old 06-02-07, 01:44 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Make the call

I vote for option #3. Could be low on refrigerant. Could be weak cap for the compressor. Could be, could be. A good service tech can tell you just what's going on. He/she should check refrigerant charge, capacitor, & if needed, resistance between the various terminals of the compressor.

Please post back & let us know what the servicer finds.
 
  #27  
Old 06-02-07, 01:47 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Yup, I think you're right (so does my wife LOL).

I'm hoping it's not a compressor replace and just low freon.

I'll let you know what happens.
 
  #28  
Old 06-02-07, 01:54 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Other Thread

Just saw your other thread. Check that fan rotation. The fan blades should turn so that the low edge of the blades are the leading edge. Usually the hub on the fan is up. Also check how high the fan is on the shaft. If there is a tapered ring in the top of the condensing unit, general rule is the center of the fan blade should be at the lower edge of that ring.
 
  #29  
Old 06-02-07, 08:27 PM
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,816
correct rotation

I think this is a possible problem, most today are reversable...
Feeling the piping between the indoor unit and outdoor unit while running for say 5 minutes will tell part of the story...does the insulated line sweat, is it cold, and the other one warm to the touch, and not hot? If its hot you either left the panel off while doing this or the condenser coil is dirty.............if the insulated line is not cold, its likely low on charge. Don't just let him do a gas-and-go. If refrigerant is needed, locate the leak.
 
  #30  
Old 06-03-07, 12:09 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
The two copper lines are about the same temperature, bascially "room" temp. Neither of them are hot or cold. I cleaned out the condensor coil and replaced the air filter.

I'm going to hope it's low on freon, would that make the compressor kick off?

Also, the insulated pipe has a "dent" in the section from the wall unit into the house, that could be the cause of the leak?
 
  #31  
Old 06-05-07, 06:25 AM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Freon

Finally fixed!!!!!

The outside unit had 0 freon, nada, zip, nothing, kaput. We did locate a leak at the valve that looks like a tire fill valve, somehow it got loose. Filled up with freon, working great, closing the windows and enjoying the A/C.

I'm going to keep an eye on it for leaks though. We checked all the connections but I'm thinking there may be a bigger leak somewhere else.

Thanks for all your help guys.
 
  #32  
Old 06-05-07, 09:01 AM
Member
Join Date: Oct 2006
Posts: 78
how do you check for freon?

is this something a user can do or need the techies?
 
  #33  
Old 06-05-07, 12:10 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
You can check for a freon leak yourself. All you need is some dishsoap/water mixed in a spray bottle. Spray it on the copper lines and if you see bubbles you have a leak.

As far as checking the freon level, I would let the guys who do it for a living check it, plus they are the only ones that can recharge the freon, a do it yourselfer cannot.
 
  #34  
Old 06-05-07, 01:54 PM
hexonx's Avatar
Member
Join Date: Mar 2007
Location: 120 klicks from NYC
Posts: 91
Talking Freon LOL!! Cut it out you guys!!

Just an FYI!!

Freon was an old CFC R-12 trademark. Refrigerant used in cars, etc.
I don't know if they ever used it in CACs. Anyone? I know it's now very difficult to get because of the Ozone and CFCs.

Funny how Dupont's trademark becomes a house hold name. In reality Refrigerant is not freon unless it's the old R-12 Dupont product.

http://en.wikipedia.org/wiki/Freon

and

http://inventors.about.com/library/inventors/blfreon.htm

I also catch myself using Freon instead of refrigerant. It's a hard habit to break.
 
  #35  
Old 06-05-07, 04:38 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Yeah you're right. It was the current R-22 "refrigerant".

He also told me that in a couple years, R-22 will be discontinued and a new one will take it's place that, of course, will need a whole new entire system. Anyone else hear that?
 
  #36  
Old 06-05-07, 06:17 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Correction Re: Freon

The name Freon is a DuPont registered trademark for any of their CFC or HCFC refrigerants. Not just R-22. I buy & use "Freon 22". There are at least a dozen different refrigerants labeled as FreonŽ.

Yes, R-12 was used in air conditioning other than automotive.
 
  #37  
Old 06-06-07, 06:26 AM
hexonx's Avatar
Member
Join Date: Mar 2007
Location: 120 klicks from NYC
Posts: 91
Thumbs up R-22 good for quite a while yet.

Thanks Grady. I didn't know they also used the name Freon in R-22 etc. I read the links thinking Freon was only but you are again correct. It's good that we brought this up. I further found a list of refrigerants. Wow.

http://en.wikipedia.org/wiki/List_of_refrigerants

Amazing list. and of course, if you click on R-22:

http://en.wikipedia.org/wiki/Chlorodifluoromethane

It looks like R-22 will nolonger be manufactured starting 1-1-2010. I read on another thread here on DIY that it would be gone by a much high year date. I'm sure they will make alternative refrigerant for existing systems when that time comes.

A side note. I read that although R-22 is bad for the environment, it cools better than the new multi-refrigerants that need high operating pressure etc.
I've noticed that with R-12 and R134A in automobiles. The new R-410a is friendlier regarding health and environment but the pressure is deadly. I guess all the refrigerant pressure can be deadly, hence the EPA license.
 
  #38  
Old 06-06-07, 10:19 AM
Ed Imeduc's Avatar
Member
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 18,389
Wink

Ah yes the refrigerants . I think if you check that R 22 will be made till 2030.After that it can be pulled out cleaned and put back in. Now the bad part about R410a. It dont take much of a leak in a unit that has R410a and you have to take it all out fix the leak. Then put all new R410a in the system. Thats like say you have a very small leak in you system. After a time you dont have R410a in there any more. It is a mix of 2 refrigerants and they burn off at different temps. Another thing any time you open a R410a system they say to put in a new drier. As it bad on moisture pick up.
 
  #39  
Old 06-06-07, 05:36 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
2010 or 2030 ED?

It is my understanding no new equipment which uses R-22 can be made after 2010. R-22 itself will still be made for repair purposes until 2030.

R-410a would appear to be a more efficient refrigerant based solely upon the physical size of the equipment for a given cooling capacity & SEER. In almost every manufacturer's line of equipment the stuff using R-410a is smaller than that using R-22 with the same capacity & SEER rating.

My big beef with R-410a is pretty much the same as Ed's. The fact you must completely recharge with fresh refrigerant if the system leaks more than 1/3 of the charge & the oil being SO hydroscopic are major down points in my opinion.
 
  #40  
Old 06-07-07, 05:06 PM
Member
Thread Starter
Join Date: May 2007
Posts: 48
Smile

Hopefully by 2010 I will have invented the Flux Capacitor and I can go back in time and make sure my A/C doesn't break, LOL. (was on Cinemax last night)

Thanks for all you help guys, you guys are great!!!!!!!!!!!
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes