Ingersoll Rand Compressor Overload

[boilermanc]

Hi all! I have an older Ingersoll Rand upright that is giving me fits. I started a thread earlier and we ran through a good many ideas but wanted start fresh with where we are now, what we can rule out and add some pictures. Hopefully someone can push this across the finish line.

It has a new pressure switch.

I had the motor bench tested today. Turns out its good to go. Nothing wrong with it. Another 20 years the man says.

So brought it home and hooked it up again. Ran it without the compressor and it runs and runs and runs. No issues.

Connected it to compressor. Starts up hard and pushes to 30lbs in the tank and then shuts off. The overload button on the motor trips at this point.

I disconnected the compressor at point A in the diagram and ran it again. At this point the compressor runs hard and fast and just keeps going. So not building any compression it runs fine.

I included a couple of pics. The second might be helpful in someone's explanation.

thanks!

https://sphotos-b.**.fbcdn.net/hphotos-snc6/246438_10151184268114242_1649923360_n.jpg

https://sphotos-b.**.fbcdn.net/hphotos-ash4/408641_10151184271259242_1153149993_n.jpg

 

[ForceFed70]

Only thing I can think of is that the pump may be binding up under load/pressure.

 

[Charles (in GA)]

Next step would be to hook up the line from the pump head to the tank, which you have disconnected. Then open the tank to atmosphere via the outlet ball valve, and see if it runs. It should run just as free as if you had the line disconnected at the head. If it does not, then the line from the head to the tank, or the tank inlet check valve, has an obstruction or the check valve is stuck closed. The check valve is B in your bottom pic.

The purpose of this check valve is to prevent pressure from the tank from backing up into the compressor, the small L fitting and line on the side relieves air from the tube and head of the compressor to allow the pump to start without any load. This line probably goes to the pressure switch, and is vented to atmosphere when the pressure switch is satisfied at the shut off pressure (135 psi or whatever it is set at)

Another thought, since you say it will bring the tank up to 30 psi and then overload, do you get air back out of the tank when you disconnect the tube at the tank? If you do, the check valve is bad.

Charles

 

[larry_g]

Have you confirmed the pressure guage? I also 2x what charles suggests.

lg
no neat sig line

 

[boilermanc]

Thanks Charles, I hooked it all back up, opened the valve and let it run. It ran for about the same time as it took to build up to 30lbs and then shut off, but the valve was open so no pressure built up in the tank.

thanks!

 

[Kevin C]

I would put an amp meter on the motor to see how much current it is drawing under load. The pulley on that motor looks huge.... What does the pump RPM work out to?

 

[Charles (in GA)]

Somethings plugging that snakey tube from the head to the tank, or that check valve in the tank inlet is stuck, and I'll bet its the check valve. The check valve may be allowing some air past it, but not enough and the compressor is overloading.

You can get new check valves rather easily, Unscrew the one from the tank, its pipe thread so its tight. Knowing the pipe size, the large copper tube size and that it has an 1/8 pipe thread on the side elbow outlet (or is that 1/4?) will get you the right valve.

Make sure air flows freely thru the large copper tube, blow thru it with your mouth, should be wide open.

http://www.surpluscenter.com/sort.asp?catname=air&keyword=AVC1

These are 1/2, 3/4 and 1" pipe thread. You would need to add a male flare to male pipe fitting onto it to equal what you have now, and swap over the small elbow, and a little tweaking on the large copper tube.

Charles

 

[boilermanc]

Thanks Charles, I think I will give that a shot. Trying to get the out is a b... There is no easy way to get a wrench on it. I'll get a little more serious on it when I have some time tomorrow.

thanks!

 

[boilermanc]

Well, having to take out the check valve caused me to have to buy a new tool... hate that! lol... I am now the proud owner of a set of crowfoot wrenches. Worked like a champ. Had it off in a minutes. I am sure the will be useful for other things so not a bad thing at all!

In any case, I added a couple of pics of the valve. Probably doesn't mean anything for the forum. Think I will try to take it to Grainger and see if they can match it and just replace it. Not sure how you would test this.

Charles, i need to blow through that tube and let you know if the it is clear.

Little by little. Really want to get this thing working!

https://sphotos-a.**.fbcdn.net/hphotos-ash4/487633_10151186545264242_667027783_n.jpg


https://sphotos-a.**.fbcdn.net/hphotos-prn1/155280_10151186545299242_2141033781_n.jpg

 

[boilermanc]

Well, second verse same as the first... I got the new check valve today and hooked it up. It didn't have the right flare to match to the pipe that comes out of the pump and into the tank so it has a small leak but I could run it just the same. It didn't fill the tank very much but it ran for about the same time, maybe 1 minute and then shuts off. So if it's not the check valve what's next? How do you test the pump? Are there people who test/rebuild them?

 

[PsRumors]

Do you trust the man that tested the motor? Sounds more like an issue with the electric motor heating up

 

[wyliesdiesels]

Have u tried putting a clamp meter on the motor to see what it draws as someone suggested earlier? Is it still tripping the breaker?

 

[boilermanc]

i'll run another clamp meter on there and see what happens. it's the overload switch on the motor that trips.

as for trusting this guy... let me tell you a story! first it was hard as heck to find anyone around my area that services these things. I finally tracked this guy down through the yelllow pages. His "shop" (bat cave) is in the back building of a warehouse. about 14,000 square feet of "mood" lighting. dark, full of piles of motors. huge 1990 console tv on the rack with cnn on. it was the creepiest, coolest place! guys been doing this forever. he was very busy while i was there. 4 customers dropping off and they all know him. huge work table that is setup for quick bench testing. he ran it through its paces. said its just fine. another 20 years. said he would sell me another one but that would be a waste. would say thats pretty honest. so yeah, i would say the motors good.

by the way, he had the largest non-commercial compressor in that shop that i had ever seen. something from the 60's/70's thats still running. said its are REAL 5hp with a 300 gallon tank or something like that. it was awesome. may go back just to take a pic of it.

any other suggestions would be helpful. i may take the top off the pump and see what i see...

 

[Charles (in GA)]

The overload in the motor is a THERMAL overload that trips when the motor gets hot. Its quite possible the motor is fine, but the thermal overload is weak and tripping for no reason, however, it sounds like it is quite consistent about doing it.

Charles

 

[boilermanc]

very consistent and it just doesn't run long enough to get hot. it's a minute or less before it shuts off.

 

[wyliesdiesels]

Ok, so if the overload keeps tripping, then I would DEFINITELY put a clamp on it and see how much its drawing when the overload trips. If the motor is drawing less or equal to what its rated @, then I bet the overload is bad! If the motor is not experiencing over current then I doubt its over heating and you even said its not getting hot. I've seen those go bad once in a while.....

 

[Warrenator]

Might be the centrifugal switch is binding, that is the one that will let the starting winding start the motor, then switch over to the running winding. My old compressor (5 HP Sanborn, 80 gallon 2 stage) did the EXACT SAME THING and was fixed when I cleaned and lubed the little switch assembly. It lives on the end cap of the motor, inside, and has two contact points and some pivot points, you'll know it when you see it.

 

[Angelfire]

Just a thought, and I'm not an expert on compressors by any means, but does this compressor make use of Reeds to manage the air coming out of the cylinders into the tank? If so, I believe these to be a relatively common point of failure on compressors.

 

[boilermanc]

Here is some more feedback...

I set it up tonight without any of the tubes connected. Nothing into the tank and nothing into the pressure switch. Runs like a champ at that point. I let it fun for maybe 10 minutes. It blows air from the compressor outlet with no problem. Neither the motor or the compressor got hot. The compressor was barely warm - could touch it.

I put the amp meter on it at that point and it runs right around 13 amps which I think that is correct.

Then I hooked the pipes back up to pump back into the tank. It ran for a minute and then started to slow down again and finally the motor breaker trips. I noticed that at that point the motor was starting to get warmer. Put the amp meter on it and its pulling as much 33 amps.

Not sure what that means but hopefully that helps!

 

[Charles (in GA)]

Here is some more feedback...

I set it up tonight without any of the tubes connected. Nothing into the tank and nothing into the pressure switch. Runs like a champ at that point. I let it fun for maybe 10 minutes. It blows air from the compressor outlet with no problem. Neither the motor or the compressor got hot. The compressor was barely warm - could touch it.

I put the amp meter on it at that point and it runs right around 13 amps which I think that is correct.

Then I hooked the pipes back up to pump back into the tank. It ran for a minute and then started to slow down again and finally the motor breaker trips. I noticed that at that point the motor was starting to get warmer. Put the amp meter on it and its pulling as much 33 amps.

Not sure what that means but hopefully that helps!

There should not be any significantly load on the pump at this point. Are you absolutely sure the large copper tube is totally unrestricted inside?

I've run out of ideas.

Charles

 

[boilermanc]

Hey Charles, yes, I have taken the hose off the side of the compressor and run it like that. The air blows out of the compressor just fine and thats when you can run it forever. I blew through the pipe and clean as a whistle. I replaced the check valve so air should be flowing into the tank with no issues.

Yeah, I just don't get it. But there has to be something!

 

[goneflyin2002]

Looks like you have a serious air restriction in the compressor head, or the motor really isn't any good. I'd check what Warrenator suggested first.
Do you have a possiblility of borrowing another motor to substitute test?
Does the compressor feel a bit tight after it shuts down?

Don

 

[wyliesdiesels]

How many HP is this motor? 33a would put it just over a 5hp.

 

[boilermanc]

I will clean the centugral thingy. That sounds like a good next step. I may take the head off the compressor and just see if anything is constricting in there. I dont notice any weird noise and it blows pretty good out that side port but you never know.

It says its a 5hp on the side but I know how those ratings work so it's not a true 5hp.

 

[wyliesdiesels]

28a, according to my 2011 uglys book, is FLC for a 5hp. So it sounds like your motor might be pulling a little much. Sorry if u already answered this but have u checked voltage @ the motor while it's running? Also, I think someone earlier mentioned that the compressor drive wheel looks a little big. Have u checked the pulleys to make sure they are the right size?

 

[Greatbear]

Are you running this setup on 120 volts? If so, check to see if the motor is wired for 240 volt operation. This can cause the premature stalling and overload device tripping. Even when run on half the voltage, the motor will draw an inordinate amount of current once it reaches the "breakdown torque" level. This will happen at around 1/4-1/3 of the motor HP rating, since power is quartered when the voltage is halved. If the motor is 1HP, you will stall it at 1/4-1/3HP level, the motor will no longer hold synchronous RPM. Once you reach that point, the current draw rises dramatically, even more if the motor totally stalls. Since a compressor pump presents a slowly increasing load on a motor as the pressure rises, it will begin to enter the "stall zone" gradually instead of suddenly stopping. Either way, you will run the motor with an increasing current draw.

 

[boilermanc]

Hi Greatbear, the unit is rated at 230v 15amp. I have it setup on a dual 30amp breaker and wired to a dryer outlet. I wired a new dryer plug to the pressure switch. I think that should be good on the power side?

 

[boilermanc]

The setup of the compressor is the same that its been for probably 25 years, at least when I got it. It ran at the garage when I got it. What I have "updated" is the pressure switch, check valve, and a new drain plug. I rewired the pressure switch when I put it on. Other than that its still the stock compressor. Oh, I changed the oil too...

 

[wyliesdiesels]

Sorry for the obvious but did it build pressure when it ran @ the seller's house?

 

[maddog1949]

what size wire and how far from the panel is the compressor? check wires at breaker to see if they are loose. my compressor would trip the motor overload, the old owner had ran to small of wire for the compressor.

 

[boilermanc]

Hey Wyliesdiesels, yes, it ran fine there, and then I touched it... lol...

I'll have to check the wires again. I know I had been through all of that and everything there seemed to check out.

 

[wyliesdiesels]

Ok have u checked the voltage @ the motor terminals while it's running?

 

[Greatbear]

Power sounds good to me. You might want to check the voltage at the motor terminals while the unit is running to see if it is dropping excessively, just in case.

 

[PeterT]

Interesting post & replies, but I have to chime in and say Ingersoll Rand Compressor ain't what they use to be.

 

[wyliesdiesels]

Yes, they may be but how does that help figure out the problem?

 

[pattenp]

I've gone through all the posts on both threads and I see you mention 3 wire, 2 wire and am starting to question the wiring. I do not see where you have put a voltage meter on the hots at the pressure switch and reported that the actual supply voltage is 240V.

 

[wyliesdiesels]

I've gone through all the posts on both threads and I see you mention 3 wire, 2 wire and am starting to question the wiring. I do not see where you have put a voltage meter on the hots at the pressure switch and reported that the actual supply voltage is 240V.

I think I suggested this @ least twice. The 33a FLC he's seeing does seem a bit high for the size of motor!

 

[pattenp]

I think I suggested this @ least twice. The 33a FLC he's seeing does seem a bit high for the size of motor!

Yes I saw that you had. I don't know enough about 240V motors if it's possible with the wiring up the outlet that he has only got 120V and the motor will run until it gets any load on it. He said the motor run amps was 15 but was stating 40+ at times. So I was wondering if it was running on 120V which may account for the high amps and causing the thermal overload to trip.

He said it ran fine before he got it and the only thing he's done to change that is wire it up.

 

[wyliesdiesels]

The last load check was 33a. And his motor is supposedly 5hp. My 2011 Ugly's book lists 28a FLC for a 5hp motor!

 

[pattenp]

The last load check was 33a. And his motor is supposedly 5hp. My 2011 Ugly's book lists 28a FLC for a 5hp motor!

In his other thread he says the motor plate says 230V 15A, so there's noway it's a true 5hp.