The pressure switch on my 60-gallon Porter Cable air compressor has started misbehaving. A couple of times, it has failed to turn off and the relief valve has popped off. Obviously, this will not do.
Any suggestions for troubleshooting/fixing? It's almost as if the contacts are sticking together, although I suppose it could be something to do with the spring. I don't know how these work exactly although I think I have a general idea.
Real replacements are $60-ish and random Chinese crap are $25, but if I can fix this I'd rather do that. The switch is a D22260 and it's probably about 18 years old.
I had a old craftsman compressor and the contacts would arc and fuse together, doing exactly what yours did. I would unplug it, then bump the contacts with a screwdriver to get them apart if they were still fused.
Folded up a strip of 220 sandpaper so there is grit on both sides and pulled it through the contacts several times while holding them closed. Mine had a pair of contacts on the top and bottom on both the hot and neutral sides (I think the idea was to reduce the load on each contact pair). Be sure to sand all of the contacts if it has that setup.
After I did this on mine, it would work for several months, then start arcing again. After a couple of years, i just replaced the pressure switch, which solved the problem until I sold the compressor.
I have worked on a couple of well pumps that had replaceable contacts; a great system if yours has them.
Good luck.
PS - I'm sure you already do this, but I have a tendency to forget to drain the tank on my compressor. The tools really seem to like the drier air they get when I remember.
In reply to CJ :
Thanks. Given the fact that it's in a detached garage so I don't know it's stuck on, I think I'll just skip to the "replace the switch" step.
Remove the switch and the relief valve and live dangerously. For a short while anyway.
FYI, I found an Ingersoll Rand troubleshooting video about this, and the statement there was that the contacts were plated to avoid them welding themselves together. The plating wears off, they start sticking and the solution is a new switch. Or contacts if your manufacturer was farsighted enough.
Mechanical contactors of all kinds have a limited lifespan due to arcing. Some have contact points made of special alloys to resist welding, but continuity failure when closed will still prevail eventually. All seem to attract ants for some bizarre reason science does not understand (google it for a TIL). Refinishing the contacts is a short-term workaround I have employed. Yours is a replacement scenario if you're looking for long-term.
