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Discussion Starter #1 (Edited)
So my compressor stopped starting(Kicks breaker) 2 weeks ago and I have been diagnosing it off and on. I do not mind not fixing it, but I can't give up till I know whats wrong with it....

I do not know what this part is...Its clipped to the left side in picture 4. The first pic is its little housing clip.

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The Motor does not test or even look burned out it never smoked. It spins freely.
The start Cap tested bad , run Cap tested good...I replaced both they both test good...but no help. Points seem clean( I touched them up with 2000 grit paper for a few seconds) and the whole inside is not very dirty...considering its 22 years old. The centripetal switch moves well. manually moving doesn't help to kick it into run.

The one curious thing is the caps never seem to have a charge....which would cause the start issue if I could find out why...No wires are burned or off.
 

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The red ID plate looks like it's from the original manufacturer. What's the model # Sears used for the Craftsman compressor? That will help us find the correct parts diagram.
 

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Discussion Starter #3 (Edited)
The red ID plate looks like it's from the original manufacturer. What's the model # Sears used for the Craftsman compressor? That will help us find the correct parts diagram.
I'll go look for it Rod...It just occurred to me to look for the original manual...

Edit: That is great Rod I found the manual with the number I can use to search for parts Model No. 919.165220

and off the GE motor tag...

IMG_20191004_182924.jpg
 

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Possibly a thermal overload switch?
 

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Discussion Starter #5
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Sears only lists the motor as a complete assembly. They don't sell the individual motor parts. Can you post the actual GE motor model number (or a better pic of it)?
 
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Discussion Starter #8 (Edited)
sears only lists the motor as a complete assembly. They don't sell the individual motor parts. Can you post the actual ge motor model number (or a better pic of it)?
5kcr49tn2235x

I'll test that relay this weekend and replace it if bad.
 
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Clean the starter contacts. They apply the starter capacitor and when the motor spins on start they open up, disconnecting the starter capacitor.
 

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That does looks like a thermal OL to me also but ....I don't think it would cause the circuit breaker to trip unless it allowed the smoke out of the motor before it opened.
I'd look at the starting circuit, centrifugal switch, start cap or it may have an electronic start switch if you can't see the centrifugal switch at the back end of the motor.
Screen Shot 2019-10-05 at 10.43.47 AM.png

One thing you maybe able to do is take the load off the motor, spin it by hand then see if it will pick up and run.
Just a thought.
 

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Discussion Starter #11 (Edited)
Clean the starter contacts. They apply the starter capacitor and when the motor spins on start they open up, disconnecting the starter capacitor.
Thanks , per OP I did that...:cheers:

One thing you maybe able to do is take the load off the motor, spin it by hand then see if it will pick up and run.
Just a thought.
Thanks Dave , also per OP been trying that...At this point I am going back and going thru everything possible again.

I have a backup compressor but having this one down has really thrown a monkey wrench into my schedule...

The Thermal overload tests good. I removed it from the circuit and it kills everything...So it has not failed. Tested it for resistance across its terminals and its open as it should be if it is working.
 
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Thanks , per OP I did that...:cheers:

Thanks Dave , also per OP been trying that...At this point I am going back and going thru everything possible again.

I have a backup compressor but having this one down has really thrown a monkey wrench into my schedule...

The Thermal overload tests good. I removed it from the circuit and it kills everything...So it has not failed. Tested it for resistance across its terminals and its open as it should be if it is working.
While I would exercise caution in my advice as I am not there to see everything, I believe the thermal overload should be "normally closed" when it is below the determined change state temperature.
Thus jumping this switch would be the valid test.
 

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Discussion Starter #13 (Edited)
While I would exercise caution in my advice as I am not there to see everything, I believe the thermal overload should be "normally closed" when it is below the determined change state temperature.
Thus jumping this switch would be the valid test.
Let me ask this Jeff, I am thinking that when this reaches its temp or gets worn out and fails (As we are shooting for) wouldn't it prevent the unit from starting at all? As it is, if its the issue, the unit is still trying to start, it just cant...

The thermal overload is open across all three of its terminals two were soldered and one is a spade...Its out of the unit. So no resistance on the mutli meter...If that indicates its bad I'll replace it. I was thinking it would break the circuit when it heated up?

I tried jumping it....which leads me to below...


I ordered another Start Capacitor, on the off chance the new one I bought is also bad...I don't have a capacitor tester, the new one just tests good with a mutlmeter(So I assumed its reaching the required micro fahrads or volts). Since the old one definitely tests bad and the new one didn't fix the problem , I have been thinking I had two problems, but maybe its still the start capacitor.:unknown:
 
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Let me ask this Jeff, I am thinking that when this reaches its temp or gets worn out and fails (As we are shooting for) wouldn't it prevent the unit from starting at all? As it is, if its the issue, the unit is still trying to start, it just cant...Normally, yes, I agree that it should prevent a restart.

The thermal overload is open across all three of its terminals two were soldered and one is a spade...Its out of the unit. So no resistance on the mutli meter...If that indicates its bad I'll replace it. I was thinking it would break the circuit when it heated up?No resistance meaning extremely low Ohm's? Or meaning extremely high resistance as in open circuit?

I tried jumping it....which leads me to below...


I ordered another Start Capacitor, on the off chance the new one I bought is also bad...I don't have a capacitor tester, the new one just tests good with a mutlmeter(So I assumed its reaching the required micro fahrads or volts). Since the old one definitely tests bad and the new one didn't fix the problem , I have been thinking I had two problems, but maybe its still the start capacitor.:unknown:
It is hard sorting out the motors internal circuit because they often only give you enough of a schematic to safely hook it up.
I would wonder if the thermal overload was capable of interrupting both legs of power if you had it wired for 240 single phase.
If it were possible in the case of 240 then one leg may be failed open and you are getting a low voltage application through the higher voltage windings.

Don't know sir...I don't blame you for trying new caps, normally the symptoms you are encountering would certainly suggest them.
I am also lacking a cap tester in my collection of electrical test gear, I have to use a stopwatch while my current, old Fluke meter discharges it.
 

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The circuit breaker is tripping because of what we called LRA in the trade, Locked rotor current. I’ve fixed a ton of these. Find the centrifugal switch and clean the contacts. That starting capacitor causes a phase shift to start the motor and once started cuts the phase shift capacitor out of the circuit. Without that happening, the rotor stands fast and it’s the equivalent of a short circuit with no back EMF on the armature. That motor in the pic is not complicated. You have connections to the armature and windings along with the centrifugal switch. Really light sand paper, no emery and spray it with a real good electrical contact spray. Unless there’s something I don’t know about, that should fire you up
 
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Discussion Starter #16 (Edited)
The circuit breaker is tripping because of what we called LRA in the trade, Locked rotor current. I’ve fixed a ton of these. Find the centrifugal switch and clean the contacts. That starting capacitor causes a phase shift to start the motor and once started cuts the phase shift capacitor out of the circuit. Without that happening, the rotor stands fast and it’s the equivalent of a short circuit with no back EMF on the armature. That motor in the pic is not complicated. You have connections to the armature and windings along with the centrifugal switch. Really light sand paper, no emery and spray it with a real good electrical contact spray. Unless there’s something I don’t know about, that should fire you up
I appreciate all the help folks...I agree that when I find the issue its going to be a face palm...Firemark the part with all the spade terminals unclips and has the contacts on the other side. I bought 1000 to 5000 grit paper to clean them and did so with 2000 grit gently for a few passes. I thought that would be enough, I can do it again but it had not even the smallest effect. I did not want to go overboard and take off the surface.

I am going to try a new start cap when it comes and go from there. I'll take a few pics of it this week as I am working on it and see if you guys see something I am missing.

IMG_20190925_182401 (1).jpg
 

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Looking forward to seeing you figure this out, I get to learn from it.
Your doing quite well so far, you haven't "let the smoke out"!:bigthumb:
 
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Discussion Starter #18 (Edited)
Looking forward to seeing you figure this out, I get to learn from it.
Your doing quite well so far, you haven't "let the smoke out"!:bigthumb:
I worked on it , yesterday...I got nothing.... the points make good contact for the start capacitor . New start capacitor did nothing. I am going to put it away for awhile (I have so little time available) I redid everything that was suggested and it is still the same.

I had to get some maintenance done on the tractor this weekend and spend time switching tool boxes. I switched to my backup compressor so I don't really need this one and as much as it pains me to not fix it...If I don't put it all back together and get the parts out of my way, I'll end up throwing in the metal bin just to get rid of it...
 

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Damn...
I saw the new post from you and thought for sure we were going to be getting the forensic report.
I hear you limited time, it seems like some things never get done.
 
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