# Devilbiss pro air 2 Tripping Breaker



## ChadT (Jul 6, 2019)

Hi there, so I've been troubleshooting my father's Air compressor. It starts up and then after 30 seconds trips the breaker. First thing I checked was the start and run capacitors and they both tested fine non-energized. The compressor is 120V and FLA is 7 amps. I took an amp reading at startup and it was drawing 39 amps. Just want some advice on what to check next or if more information is needed. Thanks in advance.


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## StevenHill (Feb 21, 2018)

Is this starting it up with no air in the tank or back pressure? I would check out the centrifugal switch on the motor to start with if capacitors are ok and the unit turns freely enough


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## stevon (Mar 5, 2019)

ChadT,

A little more history/info might help, the motor brand, model number HP rating. How long has this compressor been at it's current location and used on the same wiring? Using a long undersize extension cord? How close are you to running this circuit at the recommended 80% or less rule? Is there any wiring damage, burned plug, cable or socket issues? Is this a dedicated circuit (not shared). Does the compressor turn by hand easily at zero pressure at the tank? Any recent changes like a new belt? or tightening slack recently. 39 startup amps wouldn't really concern me, if that doesn't trip the breaker instantly, running amps under full load would be of interest.

Stephen


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## stevon (Mar 5, 2019)

*centrifugal switch*

StevenHill, 

Maybe it is the centrifugal switch. If it was stuck open the motor wouldn't start under load and if it was stuck closed the start winding/starting cap could burn out and the motor also wouldn't start under load if the circuit breaker didn't trip. A volt meter on the start capacitor while the motor is starting should give you a clue. Generally you should hear the clutch snap or disengage after a few milliseconds

You might try the old bloodhound technique. Smell around for a burnt smell around the motor , any contacts and even the circuit breaker. 
Stephen



StevenHill said:


> Is this starting it up with no air in the tank or back pressure? I would check out the centrifugal switch on the motor to start with if capacitors are ok and the unit turns freely enough


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