I bought an old Industrial Air Machine air compressor from a guy this weekend. It came out of a military warehouse and is a 5 hp 80 gallon 2 stage. It weighs over 400 pounds. Anyway I bought it with the idea of switching the motor out for a 5hp single phase. I bought the compressor for 80 bucks so I figure 300 for a motor still isn't bad. What I want to know is the motor it has now is using a seperate magnetic starter and a label on the side says this unit must use a magnetic starter, if I convert to a single phase motor will I still need the magntic starter and if so can I make the 3 phase magnetic starter work, or will I need a new 1 phase magnetic starter as well? Also does anybody know where i can get parts or a manual for this brand? I can't find any info on google.

 

if your converting because of no 3 phase, then google phase converters, theres lots of diagrams for them.

 

I already posted this but some how its gone. What does it mean when an electric motor is drip proof or open drip?

Here is a link to a newer version of the compressor, but mine is very similar ust different motor.

http://aircompressorsdirect.com/cata...products_id=33

 

Yep, just use two of the poles (T1 and T3) on the 3 phase starter contactor rather than using all three of the poles, assuming you are using a single phase 220 volt motor. Be sure to put your line conductors ( hots) on L1 and L3 contacts on top of the starter. ..

For a five hp, a mag starter with the in line heaters( thermal overloads) on the load side of the contactor is a good idea too. Just be sure the heaters are sized for your F.L.A. draw on your new motor.

 

You will need a REAL 5HP motor to run that compressor, not just some mis-rated 5HP "compressor duty" motor. User Fixnair can probably help you some.

 

Change the replaceable coil in the starter for the voltage you'll be running as well the correct heaters for motor protection.
.....=o&o>.....

 

A 5 HP three phase starter is not near big enough to run a 5 HP single phase motor. I would get a contactor rated for the appropriate amperage and a fused disconnect with timed delay fuses. The Air conditioning people use a lot of single phase contactors for residential air conditioners. Check with them. Wire your pressure switch to operate the contactor in response to air pressure.

You should also be aware that a 5 HP single phase motor requires a great deal of power to start the compressor, more than most households are wired for and you will probably need to run # 8 AWG wire. Pretty big stuff! Starting amperage will probably in the neighborhood of 75 amps.

Good luck

 

A new 5HP motor will run $500+ also.

A rotary converter could be used to run the compressor also. Looks like a 10HP rotary converter would be needed. Check out this site:
http://www.andersonconverters.com/ $589 for a 10HP unit tho.

 

If you do not have the power available to run that much horsepower you could remove the 5 HP motor and install a 3 HP single phase motor. You would also have to reduce the motor pulley size. Contact the Mfgr. for correct speed and pressure curves. If they are not available you could approximate the pulley size by reducing its diameter by the same ratio you reduced the HP, or 40%.

 

Some compressors require a certain RPM for proper oiling. They usually have a range for proper operation tho.

 

If not already equipped, an auto unloader will help with the startup current.....

 

This is the motor I was looking at getting. If I get this and a new magnetic starter rated for 1 pahse 5 hp then what amperage breaker and size wire will I need. I just had my shop wired and I have a 200amp subpanel. This is not run off my house but a seperate direct line from the power pole. This is very similar to the 3 phase motor that is currently on the compressor.

Leeson Reversible Electric Motor — 5 HP, 1740 RPM

Single phase, open drip-proof motor has a 1 1/8 inch diameter x 2 3/4 inch shaft. Turns at 1740 RPM counter-clockwise viewed from shaft end; electrically reversible. Heavy duty motor draws 21 Amps on 230 Volt current. Capacitor-start, capacitor-run. 184T frame style.

 

A 30 amp breaker should hold it if it draws 21 amps..... as above, make sure you get the correct starter....

 

So I am a little confused, what exactly is the function of the magnetic starter? If the motor draws 21 amps and the motor draws like 4 times as much at startup wouldn't I need something crazy like 80 amp breaker and wire to handle 80 amps?

 

More reading here:

https://www.ford-trucks.com/forums/s....php?&t=411818