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TGrayson 05-18-2012 03:06 PM

Lennox 10ACC−036 compressor fan won't start on its own
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I have a Lennox 10ACC−036−230 A/C unit and the compressor fan won't start on its own, but if you spin it a few time it will.

This unit which is about 8-9 years old initially had a dual capacitor, but a few years ago a technician replaced it with two separate run capacitors (I think because he did not have a dual w/him). Last year I noticed that the fan motor would run for about 20 mins and cut off, so after getting advice from kok328, I replaced it's capacitor (7.5mfd 440vac) and it worked fine for almost 1 year to the day.

The other day, I noticed that the compressor would kick on the but the fan motor would just hum while the fan would seem to struggle to move. If I helped the fan motor out by spinning it in the proper direction after a few times it would run on its own. So I replaced the capacitor again, it worked great for 24 hrs. It started up fine on its own during the day and night, but now the fan motor won't start again on its own, but the compressor kicks on. Now about 48hrs since I replaced the fan motor run capacitor it will turn on only if I help it, like a jump start spin.

I have attached a picture of the 2 capacitor if that helps. The capacitor on the left is for the compressor (50mfd) & the capacitor on the right is for the fan (7.5mfd 440vac). It may be hard to see but the white wire connects the two.

Should I replace the two run capacitors with a new dual capacitor? The capacitor for the compressor is 3 years old now. Or do you think it need a new fan motor?

To see previous post with kok328 please use the following link:

Thanks in advance for your assistance.

kok328 05-18-2012 05:51 PM

Do the fan blades spin freely by hand?
You may be looking a new fan motor. You sometimes can buy a little time by applying some light weight oil to the shaft bearings. Although these are sealed bearings, they sometimes will repsond favorably to oiling.
If the bearings are going bad it will add resistance to the motor and it may be cutting out on overload.
You can check the capacitor if you have a volt/ohm meter with a capacitor setting.
You can do a visual inspection on the capacitor by looking or corrosion, swelling and/or leakage.

kok328 05-19-2012 07:50 AM

Just like last time, the capacitor is you cheapest option to replace and see if it corrects your problem.
Usually the motor will spin with less resistance once it's "broke in" but, you might even replace the capacitor with a slightly stronger one this time.
A $9 capacitor is cheaper than a volt/ohm meter to test the cap and also cheaper than a service call and/or a new motor.
If you end up having to replace the motor, it will come with a new cap.

TGrayson 05-19-2012 01:26 PM

Thanks for the quick replies. You were 100% correct, it's the fan motor. When I replace the capacitor the other day I just happened to spray the shaft with a little WD40 so that would explain why it worked for 24hrs. Today, I took the fan blades off and really got a good amount of WD40 down the shaft. It spins a little more freely now, whereas before it did not spin quite as free. Is there a better oil to use than WD40 & is there a way to take apart the casing to get more oil in and clean out the dirt? I really could use it to last another few weeks before I purchase a new motor.

This is the motor I am looking at from Grainger: DAYTON Fan Motor, PSC, 1/3 HP, 1075, 208-230v, 48YZ
Would you mind taking a look and telling me if you think it's a good replacement?

Thanks again for your help!!

kok328 05-20-2012 08:03 AM

Yes, use a light weight oil. WD-40 is not a lubricant. It was designed by the military as a Water Displacement (WD) agent. WD-40 will dry up and/or evaporate quicker than you need it to last. A good product would be Zoom Oil. Zoom comes in a 6-8oz. bottle and has a long dispenser tube to allow you to get into tight/awkward places without having to dismantle the components. I believe you can get it at the big box store and/or your local hardware store. Short of that, you could apply some typical household white oil. I can't recall the product name but, it comes in a small red&white can. The casing can be taken apart but, it will yeild little advantage as these are permanently sealed bearings so you won't be able to clean them. There is a bearing at each end of the shaft so if you remove the motor and turn it upside down (shaft pointing down) you may be able to get some oil in the other end of the shaft. There may be a metal cap covering that end of the shaft. Sometimes you can drill a small hole in the cap and nurse some oil into the hole to buy some time. Dayton is a good motor. You will need to pay attention to shaft diameter, RPM, voltage, frame size, etc. It should come with a capacitor. You can always cut the shaft to the proper length so that's not too big an issue. Your best bet is to take the old motor to Graingers and let them crossmatch it for you. Good Luck.

TGrayson 05-20-2012 12:28 PM

Thanks again for the advise. Later today I will try to find the Zoom Oil or something similar and apply it as you suggested. I will let you know how it works out.

I really appreciate all of your assistance!

kok328 05-20-2012 04:56 PM

Your welcome. Just some FYI, when changing the fan blade, it may be rusted to the shaft of the old motor. If you bend the yoke of the fan blade, it will put it out of balance and could even change the pitch of the blade(s). I have had good results by cutting the shaft close to the fan yoke, remove the set screw, apply a little penetrating oil, open a bench vise just enough to allow the shaft to pass through and the tap it out with a drift punch & hammer. Before you do any of this, pay attention to how deep the fan is in the condensor unit and which side of the fan is up and which on is down (don't ask me how I know this ;))

TGrayson 05-25-2012 04:33 PM

Thanks again. I was concerned that that might be an issue, but to my surprise the fan blade came off just fine. I did what you suggested regarding get oil down the shaft. I could not find Zoom oil any place close to me here in Charlotte but I did buy a 3 in 1 oil (SAE 20) that said it was good for fans & motors and it even said that it was a "special blend for 1/4 hp motors or larger". I turned it over like you said, took the fan blade off and let the oil really soak while spinning the shaft. It is A LOT better now. After putting the fan blade back on a gust of wind almost got it to turn a little. I put it back together and it worked great! Started up right away.

Now I still need to take care of the leak in the evaporator coil. I had 2lbs of R22 put in last year and it seems to be ok this year so far. R22 is so expensive this year I was thinking of getting my EPA 608 certification so I could do it myself, but eventually we will have to get a whole new system anyway.

Hope you have a great Memorial Day weekend. Thanks again!

kok328 05-25-2012 04:49 PM

Excellent!! and just in time for the coming heat wave. Hope you have a great Memorial Day weekend too.

TGrayson 07-05-2012 01:55 PM

Hey kok328,
I recently posted a question about the fins on the outdoor unit of my A/C:

I was wondering if you could take a look & tell me what you think. You have been a great help to me in the past. I really respect your opinion & would appreciate your advice. I have updated the above mentioned posting with a picture. Thanks to your previous advice, the system is working great & I would like to keep the compressor & fan/motor working properly. So any help would be greatly appreciated.

Thanks again!

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