I ride the air compressor SHORT BUS

[stsguy]

Air compressors maintenance and repair start to finish
Hello, I found an old laydown compressor. I've been wanting a slow rpm unit that will last for years. My issue is I have a knowledge void on compressors maintenance and repair. Here is what I have it runs on 220 or 110, I do not know what oils to use when to oil electric motor or how often. I need to learn how to make sure the cut-off switch is working and any other knowledge I should have to keep this in good working order you for y help Joe

 

[MacMcMacmac]

I'd replace that pressure switch. It looks unreliable. That motor is a lot older than the compressor. I'd oil it whenever I remembered to, which is probably more often than it has been. Any compressor oil will work find in your machine. Do not use engine oil as it plays hell with the valves. Have an electrician install a proper disconnect switch and appropriate fuses and breakers to protect your home. Install a good 1/4" drain valve on the tank and use it. That is a Schultz pump, made in Brazil. Make sure the 1/4" copper line in the fourth picture is plumbed into something that blows down the pressure at shut off, usually a needle valve on the pressure switch, or a centrifugal valve built on the end of the crankshaft. Replace that air filter pronto. I'd fab up a belt guard for it as well, if there are any little ones living in your home.

 

[stsguy]

WOW Buddy Great info the pressure switch was the 1st thing I was to tackle after wiring
I found the motor is pre 52 but the best info was the manf of the pump thanks so much Now I have a starting place to search from

 

[stsguy]

I'd replace that pressure switch. It looks unreliable. That motor is a lot older than the compressor. I'd oil it whenever I remembered to, which is probably more often than it has been. Any compressor oil will work find in your machine. Do not use engine oil as it plays hell with the valves. Have an electrician install a proper disconnect switch and appropriate fuses and breakers to protect your home. Install a good 1/4" drain valve on the tank and use it. That is a Schultz pump, made in Brazil. Make sure the 1/4" copper line in the fourth picture is plumbed into something that blows down the pressure at shut off, usually a needle valve on the pressure switch, or a centrifugal valve built on the end of the crankshaft. Replace that air filter pronto. I'd fab up a belt guard for it as well, if there are any little ones living in your home.

By the way what type of pump is it. Single stage dual? or any other terms that may help sir/

 

[May Pop]

Dual stage. Large cylinder feeds into smaller cylinder to compress the air a second time =2 stage. The 2 cylinders are piped together with a tube that usaully has fins on it to cool the air as it passes.
Nice compressor!

 

[R1Rider]

run it 220v, will save you money and use a synthetic oil, change it every 20 hours or so.

 

[stsguy]

Dual stage. Large cylinder feeds into smaller cylinder to compress the air a second time =2 stage. The 2 cylinders are piped together with a tube that usaully has fins on it to cool the air as it passes.
Nice compressor!

worst case. later in life if the compressor needs to be overhauled. Is this doable? And or cost-effective ?

 

[May Pop]

If parts are available.

 

[The Cobbler]

run it 220v, will save you money .....

incorrect. 240 is not any cheaper to run than 120, electrically wise

 

[BFBOB]

incorrect. 240 is not any cheaper to run than 120, electrically wise

Incorrect. 240 requires smaller, cheaper wire than 120.

 

[The Cobbler]

incorrect. 240 is not any cheaper to run than 120, electrically wise

Incorrect. 240 requires smaller, cheaper wire than 120.

I said, "electrically" not material wise...

 

[tatra]

Any idea of the condition of the reservoir ?

 

[jscott14]

That motor is only 2 hp (even though it looks huge). That can't be enough for a big 2-stage compressor like that. Perhaps it has a tiny sheave on the motor so that it's not drawing too many amps, but I would bet that one of two things are happening:

1. The motor is overloaded (an ammeter would tell you if this is happening)
2. You're getting nowhere close to the potential CFM of the pump.

I'd try to find a used single phase 5hp motor and get a proper pulley on it. Hopefully it'll be a good pump for you. It's a reed valve pump, so that's not as desirable as a disc valve, but it should still deliver decent CFM with the proper motor. Good luck!

 

[seber]

I ran a 25 hp compressor on a 5 hp motor at lower speed for many years. The reason was not to be cheap but because that way it was so quiet you could stand next to it and have a normal conversation while running. Slow compressors are friendly. It also meant no high heat troubles and very extended maintenance intervals.

 

[stsguy]

Any idea of the condition of the reservoir ?

Im about to open the inspection plate to clean out the small amount of sludge build up

 

[stsguy]

That motor is only 2 hp (even though it looks huge). That can't be enough for a big 2-stage compressor like that. Perhaps it has a tiny sheave on the motor so that it's not drawing too many amps, but I would bet that one of two things are happening:

1. The motor is overloaded (an ammeter would tell you if this is happening)
2. You're getting nowhere close to the potential CFM of the pump.

I'd try to find a used single phase 5hp motor and get a proper pulley on it. Hopefully it'll be a good pump for you. It's a reed valve pump, so that's not as desirable as a disc valve, but it should still deliver decent CFM with the proper motor. Good luck!

replied below

 

[stsguy]

So I was able to get it going. The lead wires were the biggest issue. I shrink-wrapped them as deep as I could rewire the whole thing wall to switch to the motor. One brush had the copper wire out of the brush. I reinstalled and she runs great... {kind of} Pumps air like a beast. I have it shut offset at 120 for now on at 60psi Tank is clean dry no rust. the motor looks great except for the lead wires Arm is very clean no wear on the copper really It was a backup used little in a county body shop ..

So I called an electric MOTOR co.
A super nice man (DID NOT BLOW ME OFF) helped me on the phone. He told me to shrink wrap the wires as deep as I could. since it's possible the if they messed with the motor at its age the trouble may keep growing.. the deeper you get. Like Plumbing on a post ww2 house, this was months ago as I got sidetracked,. But, I did ask about the price of a new motor. 2 hp sp 1750rpm. He said If memory serves ... 250.00 and I ask to rebuild? Poss. 350 to 400.. Maybe less but.....So I ask how long will a new motor last? "2 yrs 3 maybe" and the rebuild? "50 yrs" .... FIFTY YEARS?< I do not see any reason NOT to rebuild. If they could upgrade the bearings to sealed even better.

Now im ready to finish I had left a message for him but he called during a maiden flight so i could not answer Ill call him 2morrow

I stopped writing this to finish the oil change on the pump and decide to open the side and clean out the oil res. Man, this thing looks good. There was a 1/4 inch of sludge but no metal I cleaned this out with a carb cleaner wiped it all out and let it dry and new oil

My only issue.
Intermittently the motor sounds funny ( laboring) when it cycles back on.. when it does I shut her down and restart. I think it's a loss of power via old internal; wiring ..

IDENTITY,,, I looked at

Schulz MSV series, Ranger and Champion all I was told possible made in Brazil but still found no match.

I like the slow rpm. it why I search for so long for a unit like this. But I want to know the rpm specs psi specs etc. The old 2hp motor is not laboring when working right Hell it will not even get warm but it would be nice to know what it was supposed to have powering it.,


Thank you all for your help any more is a blessing .and I'm thankful.
SHE WILL BE REBORN TO A FULL SERV> COMPRESSOR
Joe

 

[stsguy]

That motor is only 2 hp (even though it looks huge). That can't be enough for a big 2-stage compressor like that. Perhaps it has a tiny sheave on the motor so that it's not drawing too many amps, but I would bet that one of two things are happening:

1. The motor is overloaded (an ammeter would tell you if this is happening)
2. You're getting nowhere close to the potential CFM of the pump.

I'd try to find a used single phase 5hp motor and get a proper pulley on it. Hopefully it'll be a good pump for you. It's a reed valve pump, so that's not as desirable as a disc valve, but it should still deliver decent CFM with the proper motor. Good luck!

12 to 13 amps on 220

 

[stsguy]

Looks like 5c14 stamped on rod

 

[MacMcMacmac]

Hmm. I would have expected needle bearings all around on a Schulz. I may be wrong about this one, or it predates the use of needle bearings in their design. It still looks like a good machine.

Is there anything on that square area on the lower right corner of the crankcase? It almost looks like a painted over tag on one photo. I am getting a faint Worthington vibe from this. Very faint.

 

[The Tool Tyrant]

No crankshaft bearing on the inboard (opposite sheave) end? I would have to assume there are 2 sets of bearings at the sheave end? I would like to see a photo of the sheave end of the case.

Mac...are you aware of any other pumps without inboard crankshaft bearings?

 

[MacMcMacmac]

This overhung crankshaft design is practically an IR Type 30 calling card. There must be a few million of them built like this. They would usually also have an unloader flyweight system mounted offset to stay centered to the unloader valve.

 

[The Tool Tyrant]

Very interesting to say the least. I'd love to know what IR saw as an advantage to this design. I assume crankshaft endplay is adjusted with crank seal cover shims?

 

[MacMcMacmac]

No. The bearings are held in the proper orientation by a piece of pipe separating them, then the bearing closest to the flywheel keeps the crank from floating backwards with the snap ring on its outer circumference, The endplay is eliminated when the cap with the oil seal in it is bolted into place, preventing the bearing from moving forward. Any change in position of the crank after an overhaul could easily be accommodated by the rod small ends moving sideways a little on the wristpin.

It's a very simple, crude even, design that takes very little machining or material to make. Three machined surfaces for the bearings, a taper, a thread and a Woodruff key, compared to forging a whole multi-throw crank and grinding multiple journals. The big ends ride on a polished hardened steel ring that can be replaced when worn. These are about the easiest compressors on earth to overhaul. It's a very "service friendly" design and the parts are, or used to be, cheap enough that you sometimes got connecting rods as part of the overhaul kit.

 

[The Tool Tyrant]

Thanks so much for the explanation Mac! Very interesting concept indeed and I can see how it would be "service friendly"...just don't misplace the bearing spacer!