Please school me on air compressor motors
 

I've been using a Sears oil-less, 33 gal. air compressors, for the past 8 years. I used it mostly for breaking loose nuts and bolts, and occasional small painting jobs. However, I just picked up a "project," two stage, 60 gal. IR 2340L5, that is missing a pressure switch, missing a 5 hp motor, and I was told that the pump runs hot (I was told by the seller, who was told by the person that gave him the unit). The tag on the tanks says that the pump is rated at ~15 SCFM @ 175 psi max, 1575 rpm, 2-stage. I'm planning to use this air compressor for body work, painting, and sandblasting jobs.

I'm looking for a used 5 hp, 220V, 60Hz, 7/8" shaft, and 1 phase motor to get this thing running again, so that I can see what's really going on with the pump. I've seen a few motors that almost fit what I'm looking for, Baldors and Leesons comes to mind. Most of these motors have a 1750 rpm range. My questions are:

1) Can these higher 1750 RPM motors be used on an IR 2340 pump that is rated at 1575 RPM?

2) Do I need to stick with 5 hp motors or are there benefits with going to a higher (or lower) hp rating motor?

3) What other brand I should also consider in buying a used but reliable motor ?

4) What other factors I should be looking at in a used motor?

5) (non-motor question) How can I hook the 33 gal. and the 60 gal. together to increase my air capacity?

Thanks in advance for all you help.

Pulley ratio sets the speed. Do the math and pick a correct pair. You can use a 3600rpm motor too. They are typ smaller for a given hp since the rotor diameter is smaller (= cheaper usually)

Less hp may not start (even w/ a working unloader valve.) More hp is no issue (or advantage) other than larger current inrush. At high enough hp you may need a soft starter to keep from tripping reasonably sized breakers. Best to stick to 5hp.

Figure out what frame you need (too tired for me to do it now) then search ebay. Should be pretty simple.

Yes you can hook tanks together.

Marathon and GE come to mind as other good brands. Most anything you can google and appears to be made in the states will be fine.

Thanks Stephen. I called IR to ask about the NEMA frame size of the motor for this compressor and the rep told me that he wasn't sure, but he thinks it's a 182. Looking at the dimension of attached picture, 2F and 2E motor dimensions certainly fits the mounting holes.

However, there is a 2340IR compressor on Ebay and the seller told me that the motor has the following specs: HP 5, RPM 3450, V 230, FLA 22.5, FR 56, HZ 60, PH 1, CODE H,INS B, MAX AMB 40 C,DUTY CONT, SF 1.15 SFA BRG BALL. This suggests that the motor is a 56 frame. I don't know how that could be. A 56 frame has a 2F dimension of 3", which is too small for any mounting holes in the picture.

Am I reading the motor specs right? Could the 56 frame motor mounts on the 2340 compressor via an adapter?

Could the motor be on a bracket? The holes would match the bracket, and the bracket would have the holes closer together for the motor...

drill some holes for the feet if you must use a 56 frame on the compressor. 182 frame tends to be a frame spec for bigger stuff than 56. the 182 tends to have a letter or two after it. I have found that replacing a motor with same spec tends to have the best overall results.

I have an IR Model 2340-E 5HP, 60 gal air compressor.

Measurements of the holes seem to be the same as what you show. The slots are 9.5" end to end and 4.5" on center. The holes are 5" on center front to back and 6" on center side to side (the dimension you show as 5.5" from the front of the holes).

Here is the info from the side of my motor:

Attachment 34456