Compressor diagnosis/help wanted

[bigred292]

Recently bought used compressor. Ingersoll Rand Model B, around 40-50 gallon horizontal. Year on tank gives a date of 1963. Compressor in very good shape for its age.
Bought it off CL for $75. Had to replace a broken elbow at drain and splice a new plug on. Fired it up tonight for first time. Checked oil in pump-OK. Ran real nice but it took a long time to build air up. Took about 15 min to get to 125. I know that's too long- here's the questions.
How do you tell if it needs to be rebuilt? No sounds of leaks- am doing a test tonight to see if it holds.
The other question is the motor- it's not the original, it's a 1 hp Craftsman.
Is it me or is that motor much too small?
What size would this one normally have?

 

[930dreamer]

Can you post some pictures?

 

[bigred292]

Sorry, wifes out tonight and has camera. it's about 40 inches high and is kind of green .

 

[kartracer55]

any model numbers on it anywhere?

 

[930dreamer]

How about this?

Ingersoll-Rand model "B" 1.0 HP air compressor (2-cylinder, single-stage air compressor, 4.0 CFM @ 100 PSI)

1 HP electric motor and drive pulley

 

[ibedayank]

50 gallon tanks normaly come with a 5hp or bigger motor and the compressor part would weigh over 75 pounds and not be small... twin vbelt or surpintine belt drive

 

[930dreamer]

Sorry, wifes out tonight and has camera. it's about 40 inches high and is kind of green .

That's a big pump @ 40". To big for a 1hp motor. Post some pics when you can.

 

[z28snksknr]

40 gallons = 5.34 ft^3. At 125 psi, you full your tank has 3.108 lbs of air inside.

If your compressor supplies 4 CFM @100psi, that's ~ 1.87 lb/min of air getting pumped. Now, that flow rate varies with pressure so it will be higher at lower pressures and lower at higher pressures, but you can see how it shouldn't take 15 min to fill your tank.

Your compressor is either not able to pull enough air to fill the cylinder to compress (check inlet piping for clogs - probably not likely) or it is not able to compress that volume of air properly or at the rate it should be (either internally -worn rings, mechanical damage to the piston, stuck or leaking valves, etc. or externally - belt is slipping, motor is running at lower RPM than it's designed for - aka original pulleys reused on the new compressor = different speed than intended for the compressor).

I would rule out the inlet and external potential causes first, then go by a new compressor or rebuild the one you have.

 

[bigred292]

Here's some pix of the compressor- put the 4 ft level next to it to show scale

 

[hydramatic]

check if the motor can also run on 240..if your on 120 with a 1 horse, 15 min is about all your gonna get..mine is similiar, except it`s an upright,,takes about 15 mins from dead 0 psi..

 

[z28snksknr]

You can also test your compressor's flow rate by filling a known volume with air (like a grocery bag- measure how much water it takes to fill it first to get it's volume) and see how long it takes for the compressor to **** the air from the bag. If you start the timer when the tank is @ 100 psi, you should get ~ 4 ft^3/min.

So if your grocery bag is 1 ft^3 (7.48 gallons), it should take about 15 seconds to **** all the air out of it through the inlet of your compressor when your tank is at 100 psi. It's a simple way to see if your compressor is meeting it's specs.

 

[z28snksknr]

check if the motor can also run on 240..if your on 120 with a 1 horse, 15 min is about all your gonna get..mine is similiar, except it`s an upright,,takes about 15 mins from dead 0 psi..

Changing the voltage does not affect the RPM of the motor, only the amperage needed to sustain that RPM.

 

[bigred292]

930Dreamer- mine kinda looks like the pix you posted earlier of pump and motor- did IR make a 1 hp compressor or is my replacement motor smaller than what it calls for?
Thanks for your help.

 

[930dreamer]

930Dreamer- mine kinda looks like the pix you posted earlier of pump and motor- did IR make a 1 hp compressor or is my replacement motor smaller than what it calls for?
Thanks for your help.

I'm not sure of the correct hp for the Model B. 1hp might be the correct one.

 

[kams1973]

pull the heads off the pump and check the valves. I've seen them foul with carbon deposits among other things.

 

[tokillamurderer]

Here's some pix of the compressor- put the 4 ft level next to it to show scale

I have a compressor that I got from Craigslist that looks just like this, except with a vertical tank. I can't seem to find any information on it, except that it says Model B on the pump data plate, serial number 22056, and the tank is dated 1960. It has a Dayton motor on it (not sure of the HP at the moment). Does anyone know how to determine the specs of this compressor, or where I can find more information on it? I'd like to know the CFM rating, tank size, what oil to use, etc.

Also, I was trying to figure out how to wire the motor for 220V, as it was 110V when I got it. I had it running great on 110V. I removed the motor and let my dad figure out where the wires should go for a 220V application (the diagram on the motor was worn off). He figured it out and gave it back to me. I installed a new power cord to the pressure regulator, and ran the wires from the regulator to the spots he marked on the motor. I haven't yet been able to get it running. Nothing happens when I plug it in. Does anyone else know anything about wiring these?

Thanks!

 

[C96]

According to this calculator:

If you’re timing the compressor from 0 psi to 125 psi it would take approximately:

50 gal tank @ 4.0 CFM = roughly 14.24 min.

40 gal tank @ 4.0 CFM = roughly 11.40 min.

Sounds like your in the ballpark.