Air Compressor Throwing Breaker

[Kev7274]

I got a Craftsman Air Compressor (model 919-16523) that has started throwing the breaker. It had been working fine for years and it just started doing this.

It will try to start up and then the breaker trips.Sometimes it takes a second,but it will start up.Turn it off and it trips again.I'm not sure as to what I need to check first. I don't want to start throwing parts at it.

I put the compressor onto another circuit that I know is good,and it does the same thing.So,the breaker isn't the problem.

Any suggestions will be appreciated.Thanks

 

[sam.coll]

capacitor start/capicitor run motor?

 

[b_bueno]

With no power (breaker off) does it turn by hand?
Oil level/ condition of oil (metallic particles)?
Try running the motor with out the drive belt.

 

[Kev7274]

With no power (breaker off) does it turn by hand?
Oil level/ condition of oil (metallic particles)?
Try running the motor with out the drive belt.

With power off,I can turn it by hand without any resistance.
Compressor is a sealed unit.

I have found out that it may be the pressure switch?

 

[The Cobbler]

I have the same or nearly the same model of compressor that I bought at a clearance center that was never used. it was a floor model and from what I could tell it had never been put into service. the price was right which is why I bought it( mainly for the tank)
anyway, it did the same from new.when there was no pressure in the tank it would start fine, when it was full of air and wanted to cycle it would blow the breaker. read this thread, particularly my post #15 http://www.garagejournal.com/forum/s...d.php?t=196633
a cold start or unloader assist valve will probably help your problems

 

[Kev7274]

I have the same or nearly the same model of compressor that I bought at a clearance center that was never used. it was a floor model and from what I could tell it had never been put into service. the price was right which is why I bought it( mainly for the tank)
anyway, it did the same from new.when there was no pressure in the tank it would start fine, when it was full of air and wanted to cycle it would blow the breaker. read this thread, particularly my post #15 http://www.garagejournal.com/forum/s...d.php?t=196633
a cold start or unloader assist valve will probably help your problems

Page not found

 

[The Cobbler]

try this. sorry

http://www.garagejournal.com/forum/showthread.php?t=196633

 

[wild cowboy]

Many compressors that I have owned that kept throwing breakers in colder weather have been solved by draining the current oil and replacing with a full synthetic 5W-30 or 0W-30 such as Pennzoil Platinum, Mobil 1, Castrol Edge, Valvoline SynPower etc.

In the last 5 years, a lot of major compressor manufacturers have changed their recommendation to this type of oil.

 

[justme-]

9 times out of 10 with an induction motor when it does that it's a capacitor ime.
Easy change - but beware caps carry a hell of a charge - short them with a screwdriver before touching the terminals.
Also check the steady state switch to make sure it's not damaged and the contacts are not too badly worn/burned.

 

[boobag]

verify that the pressure release valve is working. when the switch cycles off, the pressure release valve opens, to release the air from the main pressure line that goes from pump to tank. this allows the pump to spin against no pressure the next time it goes to start up.

 

[Kev7274]

Many compressors that I have owned that kept throwing breakers in colder weather have been solved by draining the current oil and replacing with a full synthetic 5W-30 or 0W-30 such as Pennzoil Platinum, Mobil 1, Castrol Edge, Valvoline SynPower etc.

In the last 5 years, a lot of major compressor manufacturers have changed their recommendation to this type of oil.

Compressor is a sealed unit.

 

[Kev7274]

try this. sorry

http://www.garagejournal.com/forum/showthread.php?t=196633

My pressure switch already has the unloader valve built into it.Thanks for the link.

 

[Scimmia]

You keep saying "sealed unit", do you mean it's oilless? If it's oiled and sealed, I would get rid of it.

 

[nahuebsch82]

I got a Craftsman Air Compressor (model 919-16523) that has started throwing the breaker. It had been working fine for years and it just started doing this.

It will try to start up and then the breaker trips.Sometimes it takes a second,but it will start up.Turn it off and it trips again.I'm not sure as to what I need to check first. I don't want to start throwing parts at it.

I put the compressor onto another circuit that I know is good,and it does the same thing.So,the breaker isn't the problem.

Any suggestions will be appreciated.Thanks

By any chance are you using an extension cord to it? I had the same problem, removed the extension cord=problem fixed! If so, I'd try this first before anything invasive

 

[The Cobbler]

My pressure switch already has the unloader valve built into it.Thanks for the link.

this is another valve that allows the pump to get up to full spin before it's under pressure. it bleeds off some air until about 15psi is reached then it closes. what it does is allow the motor to get to full rpm before there is pressure on the pump.

 

[Kev7274]

I haven't had time to mess with it anymore until today.....I picked up a check valve today just to see if that was it,$5 didn't seem to bad, if it worked,It didn't. It looked pretty rough,so it was probably a good thing.

I hooked up the tube on top of the motor that connects to top of the check valve and left the tube that goes from the side of the check valve to the switch and.....it started right away.


I connected that tube back to the switch and it started doing the same thing,won't start and blows the breaker.

I disconnected that tube again just to be sure, and it started up.

Could the unloader valve on the pressure switch be bad?

 

[The Cobbler]

drain the tank completely. hook everything up and see if the motor starts and doesn't throw the breaker.

 

[redmondjp]

I haven't had time to mess with it anymore until today.....I picked up a check valve today just to see if that was it,$5 didn't seem to bad, if it worked,It didn't. It looked pretty rough,so it was probably a good thing.

I hooked up the tube on top of the motor that connects to top of the check valve and left the tube that goes from the side of the check valve to the switch and.....it started right away.


I connected that tube back to the switch and it started doing the same thing,won't start and blows the breaker.

I disconnected that tube again just to be sure, and it started up.

Could the unloader valve on the pressure switch be bad?

So, what you are saying is - with the small tube between the check valve and the pressure switch disconnected, it starts.

With small tube connected, it doesn't.

If this is the case, then you need to see why the unloader valve in your pressure switch is not working - are you by any chance plugging the compressor in with the manual control on the pressure switch in the 'ON' position? With the manual control in the 'OFF' position, the unloader valve should open and release pressure.

With the manual control in the 'ON' position, the unloader valve will only operate once the compressor has reached its pressure limit setpoint. If you unplug the compressor before this is reached and then try to plug it in again, the compressor will do as you are stating as it's trying to start against pressure.

 

[Kev7274]

Yes.

So, what you are saying is - with the small tube between the check valve and the pressure switch disconnected, it starts.
With small tube connected, it doesn't.

 

[Kev7274]

I don't think that is was on when I plugged it in,but I'm not 100 percent sure.
I'll check it later.Can it be this simple.

If this is the case, then you need to see why the unloader valve in your pressure switch is not working - are you by any chance plugging the compressor in with the manual control on the pressure switch in the 'ON' position? With the manual control in the 'OFF' position, the unloader valve should open and release pressure.

With the manual control in the 'ON' position, the unloader valve will only operate once the compressor has reached its pressure limit setpoint. If you unplug the compressor before this is reached and then try to plug it in again, the compressor will do as you are stating as it's trying to start against pressure.

 

[Kev7274]

OK,manual control was in the "off" position,still does the same thing.

I also completely drained the tank,no luck.

 

[redmondjp]

OK,manual control was in the "off" position,still does the same thing.

I also completely drained the tank,no luck.

This doesn't sound good. If you drained the tank, assuming that your check valve into the tank is functioning properly, then that should have unloaded the output of the compressor.

I'd check to see if your check valve is sticking.

 

[Kev7274]

I'd check to see if your check valve is sticking.

The check valve is new,could it still be sticking?

 

[redmondjp]

The check valve is new,could it still be sticking?

Anything is possible. Have you tried what worked earlier - disconnecting the small line from the check valve to the pressure switch to see if it will start up?

 

[Kev7274]

Anything is possible. Have you tried what worked earlier - disconnecting the small line from the check valve to the pressure switch to see if it will start up?

Yes,just did it and it started right up.

I talked to a guy at sears parts direct and he thinks that the unloader valve on the pressure switch is bad. Since that part is $50 from them,I am wondering if there is a cross reference number that may be cheaper.

I see a couple for good prices,but those unloader valves are longer and pointing in the wrong direction. The part on it now that came with it is...
AC-0385-1.

 

[454ragtop]

Any chance the check valve is installed backwards?
Jim

 

[Kev7274]

Any chance the check valve is installed backwards?
Jim

Nope.I installed the new one exactly the same way as the old one. Anyway to test the check valve off the compressor?

 

[redmondjp]

So this is really odd. I am not understanding how any of this can be. If the tank was fully drained and the check valve is working properly, there should not have been any pressure in the discharge pipe between the pump and the valve. Removing that small pipe shouldn't have then made any difference at all.

The small unloader port on the check valve should connect directly to the upstream (pump side) of the check valve. Any chance that it doesn't?

So, on your pressure switch, you should be able to take the cover off of it and look at the unloader valve. It looks like a small pipe fitting with a small round pintle sticking out of it. When the pressure switch is at its upper limit, a small lever should press against this pintle (as it should when the on/off control is in the 'off' position). As I recall, some of these valves are adjustable (either by threading valve in/out or by bending something).

Here's another option for you - change your check valve out with a "load genie" one - this valve has a tiny orifice on the upstream side that leaks a small amount of air while the pump is running, and after the pump shuts off, the residual air between the pump and the check valve bleeds off through this orifice. So no connection to the pressure switch is needed. A lot of older, portable compressors used these type of unloader valves and they are dead-simple and still available - here is one on Amazon:

http://www.amazon.com/dp/B007GDXWMC/?tag=atomicindus08-20

 

[littletoes]

Interesting....

Is the compressor plugged into an extension cord, and is the "excess" of the cord wound in a coil???

HAVE YOU AMPED YOUR COMPRESSOR???

If the breaker has broke more than 4 times, it could be BAD. Have you tried plugging it into another circuit?

Have you tried "jumping out" your pressure switch, to see what happens?

Is it wired into a "starter", that might be out of adjustment, if the amperage is "adjustable"?

Or...it's the unloader.

 

[Kev7274]

Ill look into that on Amazon.

I actually took off the unloader valve from the pressure switch.I did see the pintel inside,but it would go up and down inside the housing with little force,is that right? The pintle fit inside a little holder that had indentions that correlated with place son the top of the housing that I guess held it in place.It also had a small spring,which didn't seem to have any effect tension wise on the pintle going up and down when i was moving it around.

Here's what the unloader valve looks like.
http://www.ebay.com/itm/Craftsman-69D109740-Furnas-Hubble-Pressure-Switch-Unloader-Valve-Devilbiss-/360747658589?pt=LH_DefaultDomain_0&hash=item53fe3c6d5d

 

[Kev7274]

Interesting....

Is the compressor plugged into an extension cord, and is the "excess" of the cord wound in a coil??? No

HAVE YOU AMPED YOUR COMPRESSOR??? No

If the breaker has broke more than 4 times, it could be BAD. Have you tried plugging it into another circuit? Yes

Have you tried "jumping out" your pressure switch, to see what happens? No,explain

Is it wired into a "starter", that might be out of adjustment, if the amperage is "adjustable"? No

Or...it's the unloader.

Not sure

 

[littletoes]

Amp it, if its "out of range", motor is bad, or something is broke, like the unloader-and its starting under a load.

If its not starting under a load,and your amps are way up, the motor/compressor has something wrong with it, replace it.

Maybe you have a bent or broken crank, or etc. Either way, if its a "sealed" unit, scrap it.

 

[Kev7274]

Just wanted to give you guys an update on this.....Its FIXED

I have been messing with it the last few days and tonight I was leaning against the rear cover to try to see/hear anything out of the ordinary when I started it up, and it started up just like it used to. I let it run until it hit 125psi and it stopped.I released some pressure,and it tried to start back up,but started doing the same thing again,would blow the breaker.

I couldn't figure out what I had done any different than when it started right up,except I was leaning against the rear cover.So,I figure I would lean against again.Well,guess what.....it started right up again.Hmmm. I decided to investigate.

I popped off the rear cover and didn't see anything.I then noticed that the top screw hole that held the top of what looks like the capacitor packs had broken. I decided to remove the bottom screw to see if I could see anything and removed the packs.

On the bottom of that cover that housed the capacitors was another switch that rode a little disk that was attached to the shaft.When the top screw hole broke off,the capacitor pack started to lean away from the shaft,therefore causing that switch to no engage fully against the shaft. This explained why it would start up when I was leaning against the rear cover.

I fixed it so it wouldn't move and ran it for 30 minutes releasing the pressure and letting it start back up.No problems at all.

Sorry for the long explanation,but it this can help somebody else having the same problem,I figured it was worth it.

I'm going to start looking for another Air Compressor just in case something happens to this one and it can't be fixed,but for now it serves my needs.

Thanks for all the help.

 

[pancho400cid]

That's great!

 

[The Cobbler]

great news