Air compressor electrical advice needed

Basically my 15 year old Campbell Hausfeld air compressor crashed today. It was running just fine, it changed it's normal sound while running, and then started blowing my 20A garage circuit breaker. It's a 120V 15.0A 60HZ 1PH motor. It has the "oil less" type compressor made as part of the motor.

I replaced my old wall circuit breaker and it still does the same. I took the pump and the motor apart for inspection and nothing appears broken or burnt, and it all turns over freely. But it only runs for about tweny seconds before it blows the 20A circuit breaker. I really do not want to put a new $223.00 motor/compressor, plus freight into this old compressor.

Any ideas that I can check out? Thanks

Check your blow by valve, some times they mess up and start building head pressure and that will cause you to start tripping you circiut breaker. You might have to replace that blow by valve.
Oh ya and they will start sounding differant when that happens. You guys correct me if you know something else I could be missing.
Kurt

John,
Please clarify, are you saying that when you start the compressor with no pressure in the tank it only runs ~ 20 seconds before tripping out the breaker, or is the tank already at shutoff pressure when you turn it on?

And---what else do you have on that 20 amp brkr?????could just be one too many lights

Usally there is pressue in the tank it does not have to be much though.
See as soon as it build pressure above the piston it's not letting enough air out of the cylinder and builds head pressure, it's like the timming being off and the valves don't open in you motor and this makes it hard to crank, thus blowing the circuit breaker or tripping it. I had the same problem a couple years back and thought I needed to replace the motor but it was just the valve that lets the pressure off the head. That by pass valve is probably gummed up and needs replaced.
Kurt

I just talked to a buddy that works on them and he said that also might be trying to run on one leg of the 220. He also said to check the cut off switch on the compressor it's self, that could also be bad.
kurt

Quote:

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Originally Posted by John Palmer

Basically my 15 year old Campbell Hausfeld air compressor crashed today. It was running just fine, it changed it's normal sound while running, and then started blowing my 20A garage circuit breaker. Thanks

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To me it sounds like the compressor could be dragging, seizing. A change in sound indicates mechanical problems. The idea of a pressure problem as mentioned, could be proved or eliminated if you try running it without a load, if it runs without popping the breaker then that pressure valve sure could be a problem..

Wow! Thanks for all of the help guys.

Vara4-Kurt Yes, it has a small plastic air hose running from "tank pressure" to an air plunger that kicks on/off (?) the air pressure regulator electrical switch. But it looks more like a maximum pressure safety switch to me. I looked at it, and it is clean and has a small spring inside that looks like in a tire valve core.

RSpears - Rodger Yes, it blows the circuit within 20 seconds of when the compressor starts even with the tank line disconnected from the compressor head, ie: as in "no load".

Jerry, Possible but it's been working just fine for the past twenty years with the same things running off of the same line. I even run my MIller 130XP 110 volt mig welder on this circuit with no problems (I'm carefull to not have more than one heavy load on at a time, ie: only one tool, the table saw, welder or air compressor at a time). I did replace the circuit breaker which had to be more than twenty years old. The new one does the same thing.

Vara4-Kurt Yes, it has a low "on" at about 40# psi and a high pressure "turn off" at about 100# psi setting. I will have to do some more research about the pressure relief valve. It makes sense to me. Also, it a 110 volt system, not a 220 system.

Angrystroker I agree, that's why I pulled it all apart today to look it over. It's really a simple "oil less" system, just a rod and a bearing attached to the motor with a short crankshaft. It still blows the cicuit without any load on the compressor.

You really take your shop compressor for granted until it's broken. I'd like to know for sure what the exact fault is, before I start ordering parts because money is really tight right now.

About the only other "proof" you could do is to separate the motor from the pump and see if the motor runs ok; if so, you can be sure it's the pump, otherwise, it's the motor. Either way, you might be bucks up to just replace it; I'd go for an oil lubed one, even if they do require an occasional oil change and belts, and not nearly so noisy.

Well if that valve still looks good and it's only a 110 motor, I am thinking the motor is going out and needs replaced.
Harbor frieght usally has some great deals I would check with them, if it ends up you need a motor.
Kurt