Air compressor motor question..3hp work?

[Murphy4570]

Hey, I have a big ancient 120 gallon dual piston Curtis compressor, and it has a 7.5hp 3 phase motor on it. I want to put a 1 phase motor on it, for ease of wiring it up.

There's a used 3hp motor on my local craigslist, would that suffice you think? or is that too big of a horsepower loss to work properly?

Here's a photo of the compressor in question.

 

[bsaint]

You'd have to run it slower. But find out the minimum speed of the pump. Then get the right size pulley. You prob have to use an amp clamp to find out what your max pressure can be. If its already at its slowest, you may have to lower the max pressure of the unit.

 

[Steevo]

Every compressor pump has a minimum and maximum HP/RPM requirement that the manufacturer establishes, and the CFM/PSI you can expect at each speed.
Get the pump model and serial number information, and look it up.

You should be able to find a specifications document that looks something like this:

 

[Murphy4570]

I do have some photos of the pump, actually.

This is on the frame of the thing.

 

[930dreamer]

I think a 5hp motor would be a closer match.