I just replaced my pressure switch (120/150) due to the compressor not shutting off at 155+. Just installed exact replacement (non-adjustable devilbiss) and the pressure keeps going up – No shut off. Any thoughts?, says Andrew.
Hello Andrew. In order for the compressor motor to keep running past the cut out pressure setting on the pressure switch, the pressure switch cannot be tripping to off at the cut out pressure to stop power flow to the compressor motor.
Assuming that your new Devilbiss compressor pressure switch has not failed, a sample of one Devilbiss pressure switch shown above, and assuming that the tank pressure is actually reaching the cut out pressure setting of the switch (a setting that may be off 45 PSI or so depending on the quality of the switch and the quality of the gauge displaying the pressure) the only other thing that comes to mind is that it is wired incorrectly.
Since the wiring of a compressor pressure switch is fairly straightforward, and even easier if, as I expect, you mirrored what was the wiring on the original switch when you replaced it, then it must be that the pressure switch itself is not working.
You say it’s got the same pressure settings as the old. I wonder if that’s so?
Is the pressure in the compressor tank building to the point where the pressure relief valve is opening? Please provide a bit more info. Thanks.
Andrew, I had the same problem with a new switch but I let run and when it hit 160 psi it did shut down, at 160 psi. (anonymous commenter)