Convert air compressor from M1031 to 2-phase / 220V

[akonitony]

Hello, I've done a pretty extensive search on this topic, and have not found any answers yet, so hopefully this thread is well-warranted. I removed the air compressor out of the back of my M1031 and want to use it as a shop air compressor which means it needs to go from the 3-phase / 208V setup to a 2-Phase / 220V sytem. Anyone done this before or know how to do it? I also realize that the 2-phase I'm referring to is actually single phase that has been split to simulate true 2-phase, so no need to waste time explaining that any further.

 

[cornrichard]

You will need a new motor. You could also buy a phase converter but they are more expensive and a bigger PITA than a single phase motor.

 

[ODdave]

There is no shuch thing as "2 phase" Only 1 & 3. Your easiest and far cheapest is to simply buy a new motor.

 

[ODdave]

Also DO NOT TRY WHAT YOU ARE THINKING ABOUT JUMPING CIRCUTS. You wont be making many more posts on here if you start toying with these things without knowing what you are doing.

 

[akonitony]

There is no shuch thing as "2 phase" Only 1 & 3. Your easiest and far cheapest is to simply buy a new motor.

There is such a thing, Dave, but is was "phased out" in the early part of the last century. See link - Two-phase electric power - Wikipedia, the free encyclopedia

Like I said in post #1, I know the 2-phase I am referring to is not true 2-phase, but for the sake of argument, that is what I used to distinguish it from single or 3-phase since it is a lot shorter than typing "split single phase" or two hots and a neutral.

 

[deuceaid]

The rotary ones work better, but You can use the static starters, then again it may not push the load as good because it will have to overcome inertia and start the compressor too. If You have an unloader to dump air from the compressor , it will be easier to start,,,,also dont forget the motor loses up to 1/2 of its power, 1/3 if Your lucky.

Rotary Phase Converter, Static Phase Converter, and CNC Phase Converters - Phase-A-Matic

And they did have 2 phase early in the century, but why when for the same number of wires you can have another 50% of the power


http://www.3phasepower.org/2phasesystems.htm

 

[akonitony]

You will need a new motor. You could also buy a phase converter but they are more expensive and a bigger PITA than a single phase motor.

I was looking into that route, but figured it would be easier to just buy a compressor, so I'm thinking I might be able to make use of this one still. I don't have it in front of me at the moment, and it's too cold to walk out to the shop, but I remember the tag on the motor saying something about it being capable of running on both a high or low wattage, or something like that. Makes me think I can run it on single phase and maybe a start capacitor to get it turning.

 

[M1031CMT]

What type of compressor do you have in your truck? The one in the back of mine was wired up for 110v, but it can also be changed to run on 220v if needed.

 

[akonitony]

Also DO NOT TRY WHAT YOU ARE THINKING ABOUT JUMPING CIRCUTS. You wont be making many more posts on here if you start toying with these things without knowing what you are doing.

Thanks for the warning Dave. I certainly am not an expert in this area, but my roomate in college was a nuclear engineer, so I call him up with any questions regarding electricity that I can't find an answer to, and he usually tells me instantly and explains all the pros and cons as well. Unfortunately in this instance, he is currently out of the country for another few weeks. I did know there is a true 2-phase, so I think I deserve some credit. I've also done all the wiring in my shop on our Florida property, and I've passed all the inspections.

 

[akonitony]

What type of compressor do you have in your truck? The one in the back of mine was wired up for 110v, but it can also be changed to run on 220v if needed.

I think it is the same one you have. It is the M1031 contact maintenance truck with the NP205 transfer case running a 15kW alternator via PTO that powers a single and 3-phase circuit board. The wires going to the air compressor were 3 legs, a ground, and a pair for the pressure switch.

 

[akonitony]

I think I found my answer: Three-phase electric power - Wikipedia, the free encyclopedia

I believe I can use the neutral wire as one of the phases on the compressor motor. I'm going to have a 60-amp breaker (the "nevertrip" brand, of course) for some protection when the sparks start to fly. Watch this, y'all!!!

 

[Keith_J]

Stop. You will do damage, probably lethal damage. You don't understand three phase alternating current.

A surplus motor will be cheaper than a phase converter. And you might be able to sell the existing motor.

That motor is switched with a 3 pole contactor which is controlled by single phase power. Meaning you would need a 2-pole contactor if powering off split phase 240 VAC. Otherwise, you will burn out the pressure switch.

Yes, 208 volt 3-phase power has 3 'hots", called legs. Each leg to neutral is 120 volts, 120 degrees out of phase to the other which gives 208 volts leg to leg. This is how the generator supports 120 volt loads.


Here is a 5 Hp compressor duty motor for $186:https://www.surpluscenter.com/item.asp?item=10-2530&catname=electric

That will do you just fine. Should be good for up to 15 SFCM at 100 PSI. You will have to reduce pulley size by a factor of 2 as this is a 3450 RPM while that compressor uses a 1750 RPM unit.

 

[akonitony]

Thanks Keith. I was thinking I might be able to get away with using the autotransformer that is wired into the circuit board, but I'll take your suggestion and buy the 5 HP motor for $186 and put the other one up for sale. As far as learning about 3-phase AC, I think this page does a pretty good job of explaining it: High-leg delta - Wikipedia, the free encyclopedia

 

[M1031CMT]

I don't have a good pic, but here is the one in my truck. We changed the generator (originally had a very old generator/welder combo unit that was hacked up), but the compressor is original. Like I said before, mine was already wired for 110v, but on the wiring box on the compressor there is a diagram explaining how to wire it for 220v.

You must have a different motor on the compressor due to your PTO powered generator.

 

[ODdave]

I guess I should have clarified, THERE IS NO AVALIBLE 2phase CURRENT, But it your motor, your garage and your LIFE at stake. If you think you can wire a 3 phase motor to run off single phase have at it. I cant stop you from thinning the gene pool.

 

[KsM715]

Dave, some people only learn one way, the hard way.

akonitony, Electricity is not some thing you can just experiment with and if it doesnt work, expext to just take it a part and re-do it. You start tying wires together flip the breaker your taking an awfully big chance. Especially if you have a "never-trip" brand breaker. Thats how fires start and people die. A house 1 mile down the road from me burned down a few years ago and the home owner died. I did some service work in his machine shop in town. Saw some scary "owner built" wiring in it, rumor had it he did his own home wiring also. He survived the initial start but ran back inside to get something, never came back out.

Spend a couple hundred bucks and get a motor that will work with your single phase shop system.

 

[akonitony]

Dave, some people only learn one way, the hard way.

akonitony, Electricity is not some thing you can just experiment with and if it doesnt work, expext to just take it a part and re-do it. You start tying wires together flip the breaker your taking an awfully big chance. Especially if you have a "never-trip" brand breaker. Thats how fires start and people die. A house 1 mile down the road from me burned down a few years ago and the home owner died. I did some service work in his machine shop in town. Saw some scary "owner built" wiring in it, rumor had it he did his own home wiring also. He survived the initial start but ran back inside to get something, never came back out.

Spend a couple hundred bucks and get a motor that will work with your single phase shop system.

Appreciate the advice. Like I said, I've passed all the inspections each time. I was being facetious by saying I was going to try some sort of weird wiring and saying "watch this y'all". I know they fill the box up with smoke at the factory, and if you let the smoke out, it won't work anymore...

 

[akonitony]

I guess I should have clarified, THERE IS NO AVALIBLE 2phase CURRENT, But it your motor, your garage and your LIFE at stake. If you think you can wire a 3 phase motor to run off single phase have at it. I cant stop you from thinning the gene pool.

I see, so THAT'S what you meant when you typed "There is no shuch thing as 2 phase. Only 1 & 3". Thanks for clarifying that with us.

 

[ODdave]

Keep in mind Craigslist is a great place to find the apropriate motor for your needs, Usualy cheep too

 

[akonitony]

I don't have a good pic, but here is the one in my truck. We changed the generator (originally had a very old generator/welder combo unit that was hacked up), but the compressor is original. Like I said before, mine was already wired for 110v, but on the wiring box on the compressor there is a diagram explaining how to wire it for 220v.

You must have a different motor on the compressor due to your PTO powered generator.

Yep, mine does not have a capacitor on the top of the motor like your's does. Thanks for the pic.