So Im looking to pick up a used air compressor from a guy I know. Its a Craftsman 6HP (2hp running), 33 gal model. The issue is that the motor has been rewired to run on 220v. I dont have a 220v outlet and I dont really want to have one wired in. Does anyone know how intensive it would be to wire the motor back to run on 120? I have no intention of doing this myslef and burning the house down when I fire (literally) it up. Anywhere locally that might be able to do this? $$$?

10/4/2005 12:51:50 AM

how's it wired? 2 commons (120 each, likely green in color), a neutral (white probably), and a ground (black)? you *should* be able to just eliminate one of the commons with a 120 cord/plug. this is not knowing what type of motor, exactly how it's wired, etc... but that would be the most likely solution.

10/4/2005 1:03:56 AM

btw, are you sure it was rewired? most craftsmen compressors that size require/come with 240v power...

10/4/2005 1:05:32 AM

Southern Electric Motor Company
(919) 688-7879


602 N Mangum St
Durham, NC 27701


They rebuild electric motors and also do rewinds so I'm sure they can change the wiring for you or even just tell you how to do it.

Get the info on the motor itself and either google it or call the manufacturer, they will help you. I used to change motor wirings frequently from 240 single phase to 240 3 phase. Anytime I had a burnt winding I sent it to the company listed above. If it's possible to change it from 240 (230 220) to 120 (115 110) it will be as simple as switching a couple of leads around. Otherwise you'd be better to buy a new motor with the same NEMA frame, HP and RPM's as the current motor. All of this can be found on the nameplate of the motor.

10/4/2005 5:59:31 AM

The instructions that come with the compressor explain how to do it, I believe. It's an option on a lot of Craftsman/DeVilbiss compressors.

Go to Sears' website and look for the instruction set online. Betcha it will be in there.

10/4/2005 8:08:16 AM

also its not hard to add a 220v outlet if you ever wanted to

10/4/2005 8:24:07 AM

you can't run a 3 phase motor on 2 phase power. id wire up an outlet

unless what zx says is true. it would be handy if it was that adaptable.

[Edited on October 4, 2005 at 9:16 AM. Reason : adfadf]

10/4/2005 9:16:00 AM

not all 220 motors are 3 phase. Most under seven horsepower are single phase.

10/4/2005 9:49:48 AM

^^^it's alot harder than rewiring or switching the motor, even in the best case scenario. not to mention the possibilities of the panel not being anywhere close, no available slots, main line not being able to safely support additional load, etc.

10/4/2005 10:14:58 AM

^^^Thats the thing, To wire a 220 outlet I need to go from the box outside, under the crawlspace, through a wall, and then some. It just seemed easier to rewire the motor. A few guys I have talked to have confirmed that , as was said, Craftsman motors generally allow you to rewire them for 220v usage. Its definately not 3 phase. being listed at 6hp max, and only 2HP running. I guess I'm just rying to weight the pros/cons or getting it rewired vs. having the outlet installed.

10/4/2005 11:28:04 AM

rewiring or replacing the motor will be cheaper by a long shot. from your explanation, having an outlet installed would be at least 250-300 bucks easy. likely 75-100 in just materials if you did it yourself.

10/4/2005 11:34:48 AM

dual voltage single phase motors are extremly easy to rewire. if you take off the plate that the cord goes into, there whould be a diagram on the backside. hook up your new 120v cord to the correct wires in the motor and thats it. just look on the tag on the outside of the motor, if it says something like 110/220, 115/230, or 120/240 under the voltage column, you are good to go. if you dont feel comfortable doing it yourself, i could do it for you in a few minutes if you run it by my house when you pick it up, just shoot me a pm.

also check the amperage on the tag, if it is over 10 amps on 120, which it probably will be, it needs to be on a dedicated circuit

[Edited on October 4, 2005 at 12:44 PM. Reason : blah]

10/4/2005 12:42:32 PM