AC Repair Help (Rheem)

[battmain]

I was about to spend 4k on replacing an original Central AC unit, and I decided to poke around. The symptom is that the AC wasn't cooling. It was cooling fine the last time I used it. I discovered that the fan for the compressor isn't running. The fan turns freely by hand, and I hear a hum assuming the compressor is running.

Label on the compressor unit attached. The other device in attachment AC_part.jpg. Is it a switch or a relay? It seems to have some corroded contacts and does click when power is applied, but appears the corroded contacts could be the issue.

Is my diagnosis correct?
What is this thing? A switch or relay? Is available anymore? Seems to have the name Essex on it.

 

[DOUGD]

First do a search and learn how to shut off power and saflely discharge your start/run capacitors before working on the AC unit.I am not an AC guy by trade,but yes those do fail.I call it a contactor could also be called a relay or switch. Over the years I have had those contacts stick shut not letting the fan or compressor shut off,and I have seen the contacts burnt up not letting the fan or compressor start up. Shut off power and carefully clean the contacts with a cardboard nail file this may get you running,also a thump with a block of wood may bring the contactor back to life and help you pinpoint the problem.The contactor and the start capcitor are commonly replaced wear items.If you have a multimeter it should be easy to see if fan and compressor are getting proper voltage.Be careful and hopefully it requires no more than a contactor,capacitor, or fan.

 

[rickairmedic]

Battmain you have one of 2 problems either your fan motor has taken a poop or the capacitor is bad . I would guess since you dont know what that thing in the pic is ( its a contactor ) you may want to call a pro ( I are a pro ) and have them come out . You do at least have some knowledge now as to what the problem may be . I wont say that thats all that is wrong with it as there could be more but those 2 items given your symptoms ( over the computor ) are the most likely issues.


Rick

 

[justsam]

My limited experience, (I am not a pro) says it is a start or run capacitor for the fan.

Look for a cylindrical or oval device 4 to 6 inches long and an inch in diameter. It will have two or three tabs on it. Rating is in microfarads, anywhere from 5 to 30, and it may be dual. Get close to those ratings, and at the same voltage rating and you should be good.

Capacitors are much cheaper over the net as opposed to your local HVAC dealer if you are up for it.

As stated, observe all saftey and disconnect procedures, and remember capacitors can store an electrical charge after disconnected. Short the terminals with a screwdriver, in all combinations after power is off of course.

If any of this is greek to you, call in a pro.

 

[battmain]

Thanks for the info. I had been searching on relay or switch and couldn't find much. I found lots of hits on 'contactor' and all I have to do now is match the model numbers and hope a replacement for this vintage thing exists. The capcitor is right beside it.

I'm aware of the hot lines. Got zapped with 120v as a kid and that's something you never forget. I've also melted a screwdriver or two properly discharging a CRT. I sure as heck don't want to experiment with two hot lines.

I'll update the thread when I get around to it.

 

[brewchief]

If the compressor is running then the contactor is OK, if it was bad neither the fan or compressor will run.
If the compressor is running and the fan isn't then you have either a bad fan motor or bad capacitor, nothing else to stop the fan unless you have a head pressure control on it but those will be very rare on a residential unit.

Contactor will be a standard part, look on the side for an amp rating(should be 30 or 40 amp in this case) and buy a 2 pole contactor with the same rating and a 24volt ac coil.

If you need to replace the motor always replace the capacitor at the same time, make sure the microfared rating is the same and the voltage is the same or higher on the new one.

 

[absolutelybillsmood]

I watch "Kung Fu" maintenance on youtube a lot to get advice on home repairs he has a lot of hvac videos too.
http://www.youtube.com/playlist?list=PLF7C50F974FBF878D

 

[vanessar]

Also the gas may need refilling if it is not replaced before..

 

[CNGsaves]

I'm New on this community. I deals with CoolAirUSA offers the best variety in A/C solutions and services in Miami, Fort Lauderdale and Palm Beach. With our excellent customer care we guarantee 100% satisfaction. Check this out .

Strange first post ??

Any purpose other than Advertising to revive a 2 year old thread??

I'm fairly certain that the OP has already fixed his A/C problem in 2 yrs !!! :