# CAT 10020 Troubleshooting



## jkevin (Nov 19, 2020)

I have a California Air Tools 10020 model, 2 hp, 10 gallon compressor, purchased in September 2013. It won't start, only makes a humming noise. I have replaced the capacitor, but that did not fix the problem. I have contacted California Air Tools, but they just tell me to take it to the "air compressor service center". As far as I know, they don't have a service center in my area. They did say the service center could bypass the pressure switch to see if that was the problem, but did not say how they do that. Other than that, they just said I probably need to replace the motor, to the tune of about $350.

Any ideas on how I should proceed from here?


----------



## stevon (Mar 5, 2019)

jkevin,

Is there a way to manually spin the motor? is it burned up? mechanical blockage? seized bearing?

Stephen



jkevin said:


> I have a California Air Tools 10020 model, 2 hp, 10 gallon compressor, purchased in September 2013. It won't start, only makes a humming noise. I have replaced the capacitor, but that did not fix the problem. I have contacted California Air Tools, but they just tell me to take it to the "air compressor service center". As far as I know, they don't have a service center in my area. They did say the service center could bypass the pressure switch to see if that was the problem, but did not say how they do that. Other than that, they just said I probably need to replace the motor, to the tune of about $350.
> 
> Any ideas on how I should proceed from here?


----------



## stevon (Mar 5, 2019)

jkevin,

How many amps are you pulling when turned on?

Stephen


----------



## jkevin (Nov 19, 2020)

Hi Stephen

Good questions. I did remove a fan cover and I can manually turn the fan, and hear the pistons move. So, appears there is no blockage or seized bearings.

I have not measured amps, I'm not sure how to do that, but I do have a multimeter. Not sure where to stick the probes.....electricity surprises me at times I least expect it to, so I'm cautious with it.

Thanks,
Kevin


----------



## stevon (Mar 5, 2019)

jkevin,

That is strange if the windings were shorted thermal overload or house circuit breaker would trip. A/C current is measured with a "clamp-on" ammeter. They are cheap :
6 Function Mini Clamp Meter 
the windings don't sound open as a hum is heard. There should be two capacitors a "run" and a "starter" capacitor. Does the motor get hot?

Stephen



jkevin said:


> Hi Stephen
> 
> Good questions. I did remove a fan cover and I can manually turn the fan, and hear the pistons move. So, appears there is no blockage or seized bearings.
> 
> ...


----------



## stevon (Mar 5, 2019)

jkevin, 

Here is a link to the manual if you don't already have one:



https://www.californiaairtools.com/app/download/7116083815/California+Air+Tools++10020+Air+Compressor+Manual+10-11R1.pdf



Stephen


----------



## stevon (Mar 5, 2019)

jkevin, 

I looked at the manual and only a run capacitor is shown. Looks like there is no start switch and start capacitor as in most compressors

Stephen


----------



## jkevin (Nov 19, 2020)

Only one capacitor that I can see, and I just replaced it, hoping it was the problem. It's not. I haven't noticed the motor getting hot, but I probably wouldn't, as it sits under a workbench. I have the manual - had to fix an air leak on it once, so I've gone thru it in detail. Also watched the California Air Tools troubleshooting videos.

There is a lever on the pressure switch to start the compressor.



stevon said:


> jkevin,
> 
> That is strange if the windings were shorted thermal overload or house circuit breaker would trip. A/C current is measured with a "clamp-on" ammeter. They are cheap :
> 6 Function Mini Clamp Meter
> ...


----------



## jkevin (Nov 19, 2020)

About the new capacitor - I see zero indication of polarity on it, so I assumed polarity was not a factor. I'll switch the wires and see if that changes anything.


----------



## jkevin (Nov 19, 2020)

jkevin said:


> About the new capacitor - I see zero indication of polarity on it, so I assumed polarity was not a factor. I'll switch the wires and see if that changes anything.


Nope - switched the wires on the capacitor, no change. Still doesn't start.


----------



## iowagold (Jan 22, 2020)

jkevin said:


> Nope - switched the wires on the capacitor, no change. Still doesn't start.


a cap tester is nice
use a meter to check the winding's.
post a pix of the motor tag for us.


----------



## jkevin (Nov 19, 2020)

iowagold said:


> post a pix of the motor tag for us.


----------



## jkevin (Nov 19, 2020)

The old capacitor was 140 mf. The new one that Master Tool Repair sent was 150 mf. I don't know if that will cause a problem or not?


----------



## iowagold (Jan 22, 2020)

mf or uf?
watch the rating! the higher the UF the more current delivery it has!
also watch that it is a start rated cap.
and that it is an AC cap.

low value caps are run, high value caps are start.


inside the motor end cap with the wires connections there will be a weighted assy with a start switch that switches out the start cap when it comes up to speed.

check the contacts on that switch assy.
depending on the frame of the motor there can be 2 switches.
be care full when doing your tear down.
disconnect from power, bleed down the start cap voltage.
and watch when you separate the end cap from the case as every thing is delicate in there!!

click here for a good video of the start switch of a compressor motor


----------



## jkevin (Nov 19, 2020)

iowagold said:


> mf or uf?


Sorry, I am referring to the Greek letter μ, which represents "m" in english. I don't have a Greek alphabet on my keyboard, so I just used mf. To get " μ" in this note, I copied it from Wikipedia.

The CAT 10020 model has been discontinued and replaced by the CAT 10020C. Master Tool Repair has instructed me to use the parts list from the newer 10020C model, as neither CAT or Master Tool Repair carries parts for the 10020. The capacitor on the newer model is 150 μF, which is slightly different than the 140 μF capacitor on my compressor. I'm hoping they are similar enough that the new one will work for me.

Thanks for the info on the pressure switch, that is the next area I was going to check out.


----------



## iowagold (Jan 22, 2020)

jkevin said:


> Sorry, I am referring to the Greek letter μ, which represents "m" in english. I don't have a Greek alphabet on my keyboard, so I just used mf. To get " μ" in this note, I copied it from Wikipedia.
> 
> The CAT 10020 model has been discontinued and replaced by the CAT 10020C. Master Tool Repair has instructed me to use the parts list from the newer 10020C model, as neither CAT or Master Tool Repair carries parts for the 10020. The capacitor on the newer model is 150 μF, which is slightly different than the 140 μF capacitor on my compressor. I'm hoping they are similar enough that the new one will work for me.
> 
> Thanks for the info on the pressure switch, that is the next area I was going to check out.


start winding switch is inside the motor. this is where they issue might be.

pressure switch is on the tank.


----------



## stevon (Mar 5, 2019)

iowagold,

The manual does not show a typical start capacitor circuit only a capacitor inline. I think the windings may be the problem:









Stephen


----------



## iowagold (Jan 22, 2020)

there should be a start switch inside the motor case.


----------



## jkevin (Nov 19, 2020)

Well, after a few months of tinkering I gave up fixing it myself and took it to a power tool repair shop. They called today and said the windings were burned up. It needs a new windings or new motor, which will cost nearly as much as a new compressor.

Some interesting stuff on California Air Tools that I learned in this process. CAT continues to sell compressors in this area, and they are showing up in more and more stores. They do not have a service center in my city of over a million people, because the local repair shops have refused to work under the CAT terms. They get no discount on parts and they have to buy them from Master Tool Repair. Two repair shops said they refuse to deal with Master Tool Repair. They had nothing good to say about them. I hear all this stuff on the internet about these new quiet oil-free compressors as great tools and have long life. But the repair guys I talked to said they found them difficult to work on - one guy called them "throw-away tools" (at this point I agree with him).

At any rate, I'll never buy another CAT compressor. If I could ask another few questions of you guys, appreciate your input.

1) Since I want a quiet portable compressor, should I consider buying an oiled compressor? I need oil-free air.
2) If so, what brand is reliable and easy to work on?
3) Is there a good way to make sure my compressed air is oil-free? Filter on the output?

Thanks


----------



## jkevin (Nov 19, 2020)

OK, I've really changed gears here, moved from a repair to a replacement. I'll start another thread to address this. Thanks for all the help from everyone!


----------

