# shop compressor kicks on and off rapidly



## robbt (Jul 1, 2011)

I have just installed a used Champion shop compressor. It came with a new motor and new Siemens relay starter. When the compressor reaches the shut off pressure of 170psi, it then kicks on and off several times rapidly before kicking off completly. The pic below (if I did this right) shows how it is wired. Yes it came from someone else on this forum, but is exactly how it is wired. I thank Stubbie for the pic. I do not know if it is the wiring or the pressure switch or something else causing feedback, but I would thik this is not normal and would cause premature failure of the relay and the motor being kicked on 4-5 time rapidly before turning off completly. If I turn the switch off manually, rather then the pressure switch turning off automatic, it turn off quickly.


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## DexterII (Jul 14, 2010)

First, with the power off, I would carefully inspect all of the wires, to make sure that they are secure, including inside the magnetic starter and pressure switch. After that, I would remove the cover from the pressure switch, cycle the compressor, and see if the pressure switch snaps open when it reaches the cut-off pressure, or if it chatters; if it chatters, replace it.


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## robbt (Jul 1, 2011)

Slow on the resonce. Been collecting parts. Seams the problem was with the pressure switch. It was a Barksdale piston type switch. It was not switching off completely in one motion, but slowly switching off leaving a small gap that can arch across the connections causing the studdering of the relay. Been replaced. works correctly not. thanks.


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## DexterII (Jul 14, 2010)

Good; thank you for letting us know. Champion is a good brand, and should serve you well.


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