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Discussion Starter · #1 ·
Hi,

I'm in Texas and today's tempreture is over 103. The AC condensor fax outside stops working :( We would appreciate it if someone could help.

The label on condensor motor show "GE thermally protected, 5KCP39FF, N859BS". I Google it, it seems either condensor fan motor or capacitor or both need to be replaced. How can we be sure the problem is on capacitor or motor?

I go outside to check the condensor after turning on the AC. I feel heat comes out from the top of the condensor box even though the fan doesn't spin. The fan motor makes some noise that sounds like a giant bee. If I pull out fuse on the wall, then the fan motor stops making noise.

Two questions:

- based on the descriptions above, is the problem on capacitor or fan motor?
- where is capacitor located?

Thanks,
bj
 

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Don't run your system without fan work.

You can try to move the blades using a stick.
 

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If the fan motor is buzzzing, chances are it is seized up. With the power OFF try to move the blades with a long screwdriver or 12" wooden ruler or such. The blades should turn freely. If you can't move them, it's seized up. Check to see if you have oil cups or ports on each end of the motor.

D
 

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Discussion Starter · #5 ·
Thanks for your help, all of you.

Here is more details I found:

Wait a coule of hours to let the unit cool down. Turn on AC to try what you suggested (keep the AC on for very short period of time. Don't want the condensor to be over heated). A few seconds later after AC is on, I can feel heat come out from the top of the unit outside. This is probably a sign that condensor is working okay (right? because it takes heat from inside of home). I use a stick to move the blades. The blades can move to either direction freely.

The buzz sound seems come from the condensor, not the fan motor.

Based on this information, can we say it's capacitor's problem or fan motor's?

If I open the unit, can I visually check the condition of the capacitor?

Thanks & regards,
bj
 

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If you have a multimeter you can check both fan and capacitor
 

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Discussion Starter · #7 · (Edited)
If you have a multimeter you can check both fan and capacitor
If only motor run capacitor is broken but fan motor is okay, then after I move the blades with a stick, the fan motor should be able to start spining by itself. Do I understand right, or necessarily?

Thanks & regards,
bj
 

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If only capacitor is broken, then after I move the blades with a stick, the fan motor should be able to start spining by itself. Do I understand right, or necessarily?

Thanks & regards,
bj
Yes, if the fan start spinning after you manually move the blades. The fan motor is ok
 

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Discussion Starter · #9 ·
Yes, if the fan start spinning after you manually move the blades. The fan motor is ok
Yes, it's understandable that if the fan starts spining then the motor is ok.

What I was trying to understand is where the problem is, motor run capacitor or fan motor. Suppose capacitor is bad but motor is good, after I manually move the blades, should motor start spining? In other words, if fan motor does not spin after I manually move the blades, does it mean the motor is bad?

Thanks & regards,
bj
 

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Yes, also any mechanical problem could cause the motor spin slowly or make noise.
 

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You should have a meter to check the various voltages at the unit.

Always replace the capacitor when replacing the fan motor.
 

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The fan motor may have a high temperature cutoff switch inside it to protect against oveheating.

You could get by temporarily by putting a large portable fan against the AC unit to blow air through in the same direction as the built in fan did.
 

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The fan motor may have a high temperature cutoff switch inside it to protect against oveheating.

You could get by temporarily by putting a large portable fan against the AC unit to blow air through in the same direction as the built in fan did.
Spraying water on it will also keep it on line.
 

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Discussion Starter · #14 ·
Hi,

Thank you all so much for your help.

I manually move the blades one more time. This time I move it a lot with a stick, and this time the blades start spining iteself after I manually move it. We have cool air now. Yea :thumbup:

Can we say for sure now the problem is the motor run capacitor? Also, could someone please tell me where I can buy a motor run capacitor in Austin, Texas? I can order one from eBay but we have to wait for many days for it to arrive.

Thanks & regards,
bj
 

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The vast majority of times in situations like this it is the capcitor.It is also the least expensive of the two possibilities.Capacitors come in various sizes to match the motor they are working on.The new one must match the need exactly.There is also a voltage after the UF number and if yours is 370.you can use a 440 but not the other way around.
You may also have a dual capacitor uin which the fan is on one side and the compressor is on the other side.If you get a new one,the same advice is true you must match the UF factor exactly but you can go up to 440 on the voltage.
Do not run the a/c until you have fixed the problem.Only bad things can happen if you do.
 

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Hi,

Thank you all so much for your help.

I manually move the blades one more time. This time I move it a lot with a stick, and this time the blades start spining iteself after I manually move it. We have cool air now. Yea :thumbup:

Can we say for sure now the problem is the motor run capacitor? Also, could someone please tell me where I can buy a motor run capacitor in Austin, Texas? I can order one from eBay but we have to wait for many days for it to arrive.

Thanks & regards,
bj
I'm in Austin. What is the capacitor value?
 

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Discussion Starter · #17 ·
The vast majority of times in situations like this it is the capcitor.It is also the least expensive of the two possibilities.Capacitors come in various sizes to match the motor they are working on.The new one must match the need exactly.There is also a voltage after the UF number and if yours is 370.you can use a 440 but not the other way around.
You may also have a dual capacitor uin which the fan is on one side and the compressor is on the other side.If you get a new one,the same advice is true you must match the UF factor exactly but you can go up to 440 on the voltage.
Do not run the a/c until you have fixed the problem.Only bad things can happen if you do.
Thanks for your advices. I have turned off the AC.

The only question I have now is where I can possibly buy a motor run capacitor in Ausitn, Texas. I google it but fail to find useful information :(

Thanks & regards,
bj
 

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Discussion Starter · #19 ·
I'm in Austin. What is the capacitor value?
Ok, finaly got it.

There are 2 seperate capacitors inside the unit:

(1) 135-162 MFD, 330 VAC. This one looks fine visually.

(2) This is a dual capacitors in one unit with three terminals: "C", "FAN" and "HERM". One end (the one with terminals) of the capacitor is swelled that is a sign for bad capacitor. The value is: 5 MFD + 25 MFD, 440 VAC.
 

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Discussion Starter · #20 ·
Ok, finaly got it.

There are 2 seperate capacitors inside the unit:

(1) 135-162 MFD, 330 VAC. This one looks fine visually.

(2) This is a dual capacitors in one unit with three terminals: "C", "FAN" and "HERM". One end (the one with terminals) of the capacitor is swelled that is a sign for bad capacitor. The value is: 5 MFD + 25 MFD, 440 VAC.
Two things I don't understand are:

Q1: Why I have 3 capacitors (1 indivisual capacitor and 1 dual-capacitors in one) in the unit? If I understand right, most AC boxes outside only need 2 capacitors. One for fan and one for condensor.

Q2: My understanding is terminal "C" is common, "FAN is for fan motor and "HERM" is for condensor. Since the dual-capacitor unit looks bad (swelled). Why fan doesn't work but condensor is still working okay?

Thanks & regards,
bj
 
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