# Craftsman compressor starting and stopping



## Tjb393 (Sep 24, 2019)

New to the forum here and hoping to get some help. Just got a good deal on a used craftsman air compressor model 919-16560 and it turns on for a few seconds then shuts off for about 10-15 seconds then turns on and continuously does this pattern. Now if I turn the motor on with the switch and after it shuts off, I turn the switch off, after about 10-15 seconds I hear a click around the motor and can then flip the switch and it will turn back on for a few seconds otherwise if I dont hear that click, it wont turn back on. Anyone have any idea what it could be? Thanks for any advice!


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## stevon (Mar 5, 2019)

Tjb393,

Sounds like it could be the thermal overload switch. Does the motor imediately run Hot? Is it drawing too many amps? a clamp on ameter would tell you that. Amps drawn running should be within listed FLA on the motor tag. When first running a compressor (before the air ressure builds up) motor should use less currnet than FLA. Mine uses 10 amps at empty (no pressure in the tank) and 15 amps @165PSI. If it is the thermal protection constantly tripping see: https://www.groschopp.com/resources/troubleshooting-guide/ 

Stephen


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## stevon (Mar 5, 2019)

*Capacitor*

Tjb393,

Sounds like the run capacitor could also be a problem. A clamp on ameter will help diagnose the issue. they are cheap at Harbor freight. https://www.harborfreight.com/digital-clamp-meter-96308.html 

Stephen



stevon said:


> Tjb393,
> 
> Sounds like it could be the thermal overload switch. Does the motor imediately run Hot? Is it drawing too many amps? a clamp on ameter would tell you that. Amps drawn running should be within listed FLA on the motor tag. When first running a compressor (before the air ressure builds up) motor should use less currnet than FLA. Mine uses 10 amps at empty (no pressure in the tank) and 15 amps @165PSI.
> 
> Stephen


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## Tjb393 (Sep 24, 2019)

Thanks for the response, I'll pick up one of those meters and check it out to try to see what's going on with it.


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## Tjb393 (Sep 24, 2019)

Finally got a chance to test it and for the 2-3 seconds that it runs before it shuts off, its reading around 85 amps and according to the tag on the motor, it has a max of 14. Any idea what my next move might be?



stevon said:


> Tjb393,
> 
> Sounds like it could be the thermal overload switch. Does the motor imediately run Hot? Is it drawing too many amps? a clamp on ameter would tell you that. Amps drawn running should be within listed FLA on the motor tag. When first running a compressor (before the air ressure builds up) motor should use less currnet than FLA. Mine uses 10 amps at empty (no pressure in the tank) and 15 amps @165PSI. If it is the thermal protection constantly tripping see: https://www.groschopp.com/resources/troubleshooting-guide/
> 
> Stephen


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## stevon (Mar 5, 2019)

Tjb39,

If you have the time and ambition you can try to figure this out. If not I have a cheap smith+Jones 3hp (actually 2 HP overated) Harbor Freight motor you can have for the shipping cost to send it to you. You may have a bad run or start capacitor, start clutch or a toasted winding. Discharge the capacitors for safety (screwdriver across the terminals) and test them. while the caps are disconnected test windings to ground and each other. See the process at:
https://www.hunker.com/13414244/how-to-test-ac-motors 

Stephen




Tjb393 said:


> Finally got a chance to test it and for the 2-3 seconds that it runs before it shuts off, its reading around 85 amps and according to the tag on the motor, it has a max of 14. Any idea what my next move might be?


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