Compressor not shutting off at 115 psi

[jalmos]

Thanks for the info. How do we configure the relief valve. The pressure will not go over 100psi and it continues to run.

Should there be a ground connect. Now we have it connect to our DSC with two small wires.

Thanks so much

jalmos

[EricH]

Configuring the relief valve: screw the large part at the end out or in (I forget which is the raising direction) until you get to the correct pressure (125 PSI). Make sure you keep an eye on the gauges. Once the large part is in the right place, jam the nut next to it into it.

[Daniel_LaFleur]

Originally Posted by jalmos

Thanks for the info. How do we configure the relief valve. The pressure will not go over 100psi and it continues to run.

Should there be a ground connect. Now we have it connect to our DSC with two small wires.

Thanks so much

jalmos

The relief valve has no wires attached. It is a brass poppit valve that looks kinda like a brass plug with a hole in it. To adjust it you need to turn the "cap" portion.

The pressure switch has 2 wires that run to it. It is preset to 115 PSI and will not activate (shut off your compressor) until the pressure gets to 115PSI (which your system is not doing).

It sounds to me like you may have a leak in your system that is preventing it from getting to 115PSI. When you shut off the compressor does the pressure immediately fall to zero? If so you have a large leak.

[Andrew Bates]

Ah, so the pressure never gets high enough to trigger the pressure switch. This means you likely have a leak in your system or the blow off valve is venting prematurely. If you turn your robot off how fast does the pressure drop?

[jalmos]

WE will give all of the things a try. Thanks for your help

Jalmos

[roystur44]

We had the same problem last night. At 130 we disabled and checked the wiring, fiddle with the screw then we replaced the pressure sensor with another and it worked correctly.

[bandslak]

a couple of days ago I was spraying primer on a few car parts and heard a loud "pop" or "boom" so I immediately stopped and shut off the compressor. A while later i started it up again and noticed the main pressure gauge only went up to about 90 psi instead of the normal 125 or so psi and the compressor did no seem to want to shut off. I manually shut it off and went away for a while. The gauge stayed at about 90 psi and I could not hear any air leaking. I have read a few other forums and am a bit confused as to the possible causes that range from replacing a number of switches (including the pressure switch) to possibly a blown gasket or baffle somewhere that may be preventing the pressure from getting above the 90 psi. Any help would be greatly appreciated. Thanks

[Al Skierkiewicz]

Jalmos,
The pressure switch is not an accurate device and may not shut off the compressor until it reaches 120 psi or slightly more. If you are removing power before the compressor shuts itself off, try letting it run. If it should rise to 130 psi then disable the robot, bleed the system and check your wiring. The switch should connect back to the DSC but must not connect the red wire in the PWM cable if you are using one. As a second check, use an ohmeter or continuity checker and see if the pressure switch changes state at 120 psi +/-5 with the connector pulled out of the dsc. This most often occurs with a wiring error.