A/C condensor fan erratic

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  #1  
Old 06-26-16, 07:58 AM
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A/C condensor fan erratic

I have a Tempstar AC that has been an "Old Faithful" for a long time and survived mouse nests on relay wires and always came back and worked the summer.

I have never replaced the capacitor or other parts of the condenser until this summer. The fan would work normally, then stall on start up. With the stalling It would start with a light tap with a hand on the top of the motor. From everything I have read it would likely be the capacitor so I replaced it by an application search at a parts house. There wasn't a tag on the capacitor itself. It's a dual run. Everything inside the house works fine.

It still does the same thing. About 75% of the time it starts and runs normally and the other 25% it stalls on startup. The compressor always comes on and works fine. It has a little humming noise that has been there since new.

I have seen some hard start add ons, if those would help. But do those only help with the compressor and not the fan? I'm also wondering if maybe there is something in the relay or motor wiring that needs looked at.

Any help appreciated.
 
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Old 06-26-16, 08:13 AM
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You're correct, a hard-start kit only works with the compressor, not the fan. After the fan has been running awhile (20-30 minutes), feel the fan motor housing. Is it hot? If it is, your motor may be going bad and needs to be replaced.
 
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Old 06-26-16, 08:16 AM
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If I were you, the 1st thing I would do is get a meter that does capacitance and check your new capacitor. New doesn't mean it's working as it's rated.

As for the hard start, I haven't seen one that helps the fan, but I'm not in the business either. I'm just a homeowner.

BTW, I'm not sure if one should do this, but I've seen posts online where people have put in slightly larger caps because they couldn't find the exact match. The people that answered these question about using a larger cap all say it's ok because the OEM uses the cheapest cost part to do the job. I'm not sure I buy that answer because caps seem to be all about the same cost. Regardless, these people have put in 7mF cap in place of a 5mF or a 45MF cap in place of a 40.
 
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Old 06-26-16, 08:20 AM
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My Tempstar condenser has a 2 speed relay that controls the outdoor fan motor.

Heat pumps have a defrost control that interrupts a wire to the fan motor.

A model number might allow us to look up your diagram.

Has the motor ever been replaced?
The required capacitor for the fan motor is printed on the side of my Tempstar motor.
 
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Old 06-26-16, 08:33 AM
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Thanks for all the replies. My model # is CA5036VKB1, Serial # L912673134. Motor never replaced, just the capacitor about a day ago.

Looks like I'll look into this thing again today so I'll check the side of the motor for a capacitor #. It never felt hot before when I checked the bearings and shaft play. Everything seems normal there. I'm pretty sure there's not a 2 speed relay on this one. It goes back a few years.

The odd thing is just having to tap the top of the fan shroud and it takes right off. Then works fine for a few cycles, then back to stalling.
 
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Old 06-26-16, 09:15 AM
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If you just replaced the cap a day ago and it's doing the same thing.... replace the motor.
It doesn't take much to keep them from starting properly.
 
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Old 06-26-16, 09:41 AM
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I agree with PJ. I had to replace the fan motor in my 2004 Tempstar a few weeks ago.
 
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Old 06-26-16, 11:09 AM
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Thanks a lot for everything. A question on the capacitor. The one they gave me by application was 40 + 5 440volt/370 and the chart I found inside the shroud said capacitor 5/370. Is that workable?
 
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Old 06-26-16, 11:15 AM
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They gave you a dual cap and the condensor motor is telling you 5/370.
Not sure what you're asking. You could just use the 5uf section of the dual cap.

When I change a condensor fan motor..... I connect a single cap to that motor only. I don't connect a new motor to a dual cap.
 
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Old 06-26-16, 11:21 AM
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It's the 40 + 5 vs the "5" I saw somewhere you could go up 5 or 45 + 5 = 5/370 and be OK. But in this case I have a 40+5 = 45. So I'm 5 below the 5 on the 5/370

When you have a "run" is it active in the motor spinning, as in it helps to drive or regulate the motor with the "start" capacitor only active in starting it?
 
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Old 06-26-16, 11:32 AM
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A 40+5 is a three connector dual capacitor. You don't add the two values together.

The run cap shifts the phase to the second motor winding for more efficiency.
 
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Old 06-26-16, 11:45 AM
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I see. Thanks PJ. The part I got says 40 +5 volt 440/370 Does that translate into a 5/370 for a capacitor like it has on the shroud or is all that different in what it does? The part I took out is a three connector start/run dual.

Will what I got work for what the condenser label says I need?
 
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Old 06-26-16, 11:57 AM
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A dual capacitor.....

Name:  cap.jpg
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Yes to the 5/370.
 
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Old 06-26-16, 12:01 PM
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40 +5 volt 440/370 is dual cap. 40 for the compressor and 5 for the fan. It's like having 2 capacitors in the same package.

As for the 440/370. If your fan motor calls for 370, a 370 or 440 is fine. The cap is just saying you can use it with either.
 
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Old 06-26-16, 01:03 PM
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I get it now. From reading about it I thought the dual was start/run. I have it in the machine now. Hopefully I can get a few more miles out of it.
Thanks a lot to everyone for the help.
 

Last edited by marbobj; 06-26-16 at 01:48 PM.
  #16  
Old 06-26-16, 04:35 PM
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the cap

Well in some situations, you would be correct. A dual cap CAN be a compressor only combination run/start cap when a compressor has a potential relay. The 40 would only be in for a second or so, and would also have a bleed resister across it. In most all the ones I've seen, the start cap is separate and plastic. And start caps usually start at about 88mfd. The run cap is metal to dissipate heat because its in the circuit during the entire operation.. on the typical dual cap, you would have a power feed to C, for common, a brown wire to F for fan, this would be the phased side that goes to the fans start winding. A typically yellow wire on the compressor start terminal to the H (herm) connection of the capacitor or phased side for the compressor (start winding). All that being said, check for a loose wire connection. If banging on it makes it run, it likely isn't getting full voltage. Does the shaft spin freely and coast easily? When you grab the shaft does it have ANY handshaking what so ever? If you have a clamp on ammeter, clamp over the common wire of the fan motor. This should never go over the amp rating designated on the side of the motor housing. OHM out the motor windings with the meter. secure the blade not to move or the readings will go all over the place. If it has a good cap and full voltage, replace the motor.
 
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Old 06-26-16, 07:50 PM
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Appreciate the information hvac01453. I checked all the terminals, unplugged and hooked them back up. The shaft is tight to play, but not dragging. I have had a mouse in there that chewed on a relay wire. I replaced that and plugged the opening with steel wool.

I'll keep the motor replacement in mind and look for one. The system is pretty old, but trying to get a few more miles out of it.

Thanks to all for all the help, much appreciated.
 
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Old 06-27-16, 10:52 AM
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Well, working on this thing and resigning myself to a motor replacement. Last resort since everything works fine except for needing a little tap on the head to get it started. The goofy thing I noticed it would start by itself all day long, then it sat during the nite for probably four hours idle and wouldn't start by itself this morning. The compressor kicked on, but not the fan. Figuring it will only get worse and I need it to be reliable so.... new motor.

Found one on the great shopping place, Ebay that fits the specs on mine. 1/3 HP and 1075 rpms and the voltage. Probably a good brand, I just can't pronounce it. They include a capacitor which is a two post oval shape job. What i Have is a three post like PJ pictured above.

Can I work this into what I have, using the three post dual for the compressor and the oval two post from the seller for the fan and jumper the common from the two capacitors or something like that?
 
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Old 06-27-16, 11:17 AM
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Yes, you should be able to use this motor/capacitor in your system. As you noted, you just won't use the fan side of the existing dual capacitor. Of course, if it turns out that the new motor uses the same capacitance as the old motor, you could continue to use the dual capacitor you recently bought and not use the capacitor that ships with the new motor.
 
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Old 06-27-16, 11:27 AM
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OK. Thanks Bob. Looks like the replacement is a 7.5mfd/370. Mine is 40 +5/370. Theirs is a single and mine a dual. Is that an odd duck on the replacement motor?

I'll get things a little farther along and post back. Help is much appreciated.
 
  #21  
Old 06-27-16, 11:44 AM
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You'll have to use the cap that comes with the motor, since they're different values. It would have been dumb luck had they been the same. Good luck, hopefully the new motor will take care of the problem.
 
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Old 06-27-16, 11:52 AM
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Hope so. Thanks again, Bob
 
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Old 06-28-16, 04:17 PM
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Really???

I hope you checked a lot more than just cap voltage and rpm.. The shaft diameter and length of frame size?, does this motor even rotate in the right direction...does the replacement have an amp draw equal to or greater than the original? Does it have the ability to mount he same? Very difficult to return any electrical component especially if it was connected... When your done you must test the amp draw to insure it is at or below the nameplate rating
 
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Old 06-30-16, 03:30 PM
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All the physical characteristics of it fit fine. The motor is reversible and the shaft can be cut to length. The diameter is the same as the old. Amps are the same too. I got it put in though and have nothing but a hum out of it. It won't start or run with a push. The old one is pretty much done - it had a spot on the upper bearing I found when I took it out.l

The new motor is a five wire hook up and the old was three. It was pretty self explanatory on the wiring and both motors called for a 5/370 so I used the old dual capacitor. I orignally found a motor that took a 7.5/370 capacitor, but this one showed up and Bob pointed out the advantage of the matching capacitors so I bought the second one. Just have to get it to run.

I've seen where a new motor has to have a new capacitor to work. Could that be the problem?

Thanks for the help.
 

Last edited by marbobj; 06-30-16 at 04:54 PM.
  #25  
Old 06-30-16, 05:55 PM
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Does the wiring diagram show how to wire it in a 3-wire configuration? Most fan motors are 4 wires and can be configured in either a 3 or 4-wire configuration (3-wire with dual capacitor, 4-wire with separate capacitor). Since it's a new motor with a new capacitor, it should run properly. I would suggest that you double check your wiring to make sure you haven't overlooked something. If you have a single 5mfd capacitor you could try it configured with a separate capacitor and see if that works any better.
 
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Old 06-30-16, 06:07 PM
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This is a different motor than I was going to get. It shows a 5/370 cap or a 7.5 for 208 volts. I'm sure I have 230 here. This motor didn't have a capacitor with it and since my old one was a dual that worked for the old motor (5/370) I used it.

The wiring is to use a five wire motor on a three wire hook up. Two of the wires are tied off together (brown/yellow) or (purple/yellow) depending the direction of rotation. I need the ccW or the brown/yellow together. From there the black goes to the contactor/motor. The orange goes to capacitor on one side and the purple to capacitor on the other side. The purple T s off to the other pole of the contactor. What they are calling a brown wire is more of rose colored wire. The others are more accurate. Maybe there is a mixup with the color coding?

I have the compressor off the capacitor right now so I can tell what the fan is doing. All I get is a hum out of the fan motor. Is there a reason an old capacitor may not work on a new motor even though it was working on the old one? Is it some type of matched set.

I'll pickup single capacitor tomorrow and try your suggestion. Appreciate the help.
 
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Old 06-30-16, 06:18 PM
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A capacitor is a capacitor. All that matters is that it's the right capacitance (mfd value) and has a sufficient voltage rating. I'm assuming that you're using the new dual capacitor that you purchased (mentioned in original message) and not the "old" capacitor. I can't see your wiring diagram. Are you sure that you don't have the orange and purple wires reversed? I'm not saying that you do, just that it's worth double checking. Also, as wired, is the Orange going to the F terminal on the cap and the Purple to the C terminal?
 
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Old 06-30-16, 07:02 PM
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appreciate the suggestions. I have the Purple to C, Orange to F.
 
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Old 06-30-16, 07:27 PM
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.This is what I was using to wire it. Hope this is clear enough

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Old 07-01-16, 04:11 AM
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Thanks for sending the image of the wiring diagram. The way I read the diagram, for a 3-wire connection (which you have), you should reverse the orange and purple wires. Orange should go to the C terminal on the cap, and the purple to the F terminal.
 
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Old 07-01-16, 08:06 AM
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I'll try that Bob. Will post back. Thanks.
 
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Old 07-01-16, 08:21 AM
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Still get the same thing. Just a buzz. The compressor kicks on fine, but nothing with the fan motor. I'll try changing the capacitor on this thing. I can always put a new bearing in the old one to get by, but I have all the wiring done on the new one, if I can get it going, would really help.
 
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Old 07-01-16, 10:28 AM
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Well, ran my "motor" into a shop and had them test the motor = bad. Probably why it wasn't working. Thanks a lot for the help.
 
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Old 07-01-16, 10:54 AM
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I wonder if having the wires reversed damaged the motor?
 
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Old 07-01-16, 11:38 AM
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Yes.... keeping 240v on the start winding will burn the winding pretty quickly.
 
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Old 07-01-16, 11:50 AM
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Thanks Pete. I thought that might be the case.
 
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Old 07-01-16, 05:49 PM
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The smoke

I heard it once said, the OEM puts a small amount of smoke in the motor, and if you somehow, let this smoke out of the motor, it's kaput!
🤑
 
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Old 07-02-16, 05:16 AM
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I don't know for sure why it wasn't working. The reversed wires on the cap may well have been a problem, but the old motor was ran the same way for a short time, looking for possibilities. It continued to run.

When I tried the new motor It wasn't switched on and left for any time. I have the open relay contacts with the center push bar. I had disconnected the compressor from the relay and tapped on the relay with my plastic scraper. It wasn't held in the on position for any time.

The new motor wasn't a high dollar, job, but the OEM wasn't either. The latter was an Emerson and the new one was a Pro-Tech. Both are made in China and I saw where Dayton has outsourced theirs to China as well. Apparently, they all use the same drawing board, so when I took both motors apart, they interchanged pretty well. I drilled out the dimple case ends that hold in the end caps/bearings/armature on the old motor to take it apart. The Pro-Tech had the thru bolts.

In the new case windings I didn't notice any scorching or any electrical burn smells, but I didn't look too hard for anything like that.

Everything seems to be working, fingers crossed. It's an old system. A few more miles would be great, but it hasn't been a money pit either way.

Thanks Pete and Bob for all your help. Now back to my refrigerator.
 
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Old 07-02-16, 06:15 AM
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Glad to hear that everything is working now. It sounds like you took parts from both motors (old & new) to make one working motor. Pretty ingenious. It's a good thing both motors were so similar to allow you to "mix & match".
 
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Old 07-02-16, 08:53 AM
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Pretty ingenious
Bob - could you put that in a message to my wife. I don't get that very often.
 
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