Freebie

I was given this air compressor for free today. Its currently at work as I got to figure out how to get it home.
I need to change the 3 phase electric motor to a 2 phase. But other than that, I should be pushing some serious air soon.

 

Shouldn't be hard to change 3 phase to 3 phase

 

yea, i fixed my type-o.

 

There, I fixed it more better

 

You most likely are going to have to buy a 220 motor in the same hp and frame size as the one on the compressor. I saw a similar compressor sell for 350.00 Saturday at the swap meet. The guy also had a monster of a pedestal grinder that was three phase that he couldn't get a bite on.

 

What...is 2 phase?

 

2 phase. If I'm thinking right (which is possible i'm not), isn't a house (110/220) considered 2 phase?

 

why dont you just buy a rotory phase converter, plug it in, and use it?

example:http://www.americanrotary.com/phase-converters.html

 

You want single phase for residential wiring.

2 phase is either something to do with the moon, or was it " two phases of eve" ?

 

two phased people annoy me!

 

Sweet! I've learned something new today.
So let me rephrase, I will switch the 3 phase motor to a single phase motor. Then I will be pushing air.

 

You ain't done learning yet.. Those motors are pricey, they need to be capacitor start type to be able to restart under a load.

I got a good motor for one of mine from a rusted out Sears compressor that was given to me. 3 or 4 hp. I had to mess with drive pulley diameter, because the "new" motor was slightly less power. Before I went 1/4" smaller on the drive pulley, it would trip the motors overheat switch while continous blasting.

 

Trying to match a single phase motor to drive that properly is a chore and $$$. Cheaper and logical has been said already. Get a rotary phase converter.

 

this might be the way to go

 

Don't say two phase, it's a really old term and people who don't know better will giggle at you. Get a rotary phase converter, they're cheap and easy to install, and your compressor will work better.

 

I'd phase out the motor and put a Briggs and Stratton on it. Or a V8 60, whichever makes more power....

 

I think you are on something 33 & 1/3.
I HAVE PHASED ALL THEM OUT.
THE BOWTIE.

 

What is the HP of the three phase motor?

 

I bought a 6hp 220 single phase motor at tractor supply in January for $160

 

While it is technically correct, 220 volt power is a 2 phase 110 volt power from the breaker to the outlet. If you plugged up an oscilloscope to a 220 plug, your phase A and B would be 120 degrees out of phase with each other. A 3 phase outlet has phase A, B, and C all present with C following B by 120 degrees and B following A by 120 degrees. most home shops only have 2 phases to the breaker box, hence 220 volt 2 phase is whatcha got.

Easiest way to say it is just 220 volt. And if it's already set for 3 phase, then get a phase convertor. It opens up your power options for larger tools (lathes and such).

 

I will be looking into a phase convertor. Thanks everyone for the info.

 

Just plug the thing in, it will either go like the clapers, or go slow ! It`s only air, it`s free, we breath it !

 

It's free until you want to compress it, then it gets kinda pricey.

Someone mentioned starting under a load. With an unloader valve, it would have very little load to start under. When we built "Frankenpressor," we used a pressure switch with an unloader valve in it.

 

Where do you find these "cheap" phase converters?

 

They are 180 degrees apart, not 120. Phase separation is equal.

I usually just google and run through the searches until I find what I want. Here's an example:

http://for-sale.yakaz.com/used-phase-converters-for-sale

 

Thats what I did. peace of cake. If you don't have elect skills get help.

 

You could get a big compressor for a couple hundo and use that tank as assistance for volume, or make a soapbox derby belly tank racer.

 

If you get a new motor,make sure that it is rated at the same rpm. Most of the old compressors run at lower rpm than the made in China buy at box store compressors. Lower rpm is better. Less heat and moisture in the air. And a lot quieter. Low rpm motors are more expensive in the 5hp and up ratings.
I have an old Westinghouse compressor that I used in my racecar trailer. It is a single cylinder unit but made good pressure for a single stage compressor. 180 psi. I was amazed. Any idea of the vintage of your machine?
On the phase converter option,do not use a static phase converter. All that they do is try to get the motor turning and then it is back to single phase. I used one of those many years ago and it wouldn't start my Bridgeport unless I started and ran my surface grinder at the same time as a "idler motor". You will need a rotary phase converter. Lots of folks make their own from a 3phase motor that are often very cheap or free.
My suggestion is to buy a good rotary phase convertor and then you can then buy other 3 phase equipment that generally goes cheap because folks generally steer away from 3 phase powered equipment. Most all of my equipment is now 3 phase. I have even remotored some of my single phase tools to 3 phase so that I have speed control using a VFD. I have a rotary and a VFD. The rotary would be best for the compressor use and anything else that wouldn't need speed control.

 

Here's a trick, Pick up a used 3phase motor of equal or larger size ( I would go larger) and the same voltage. Pony it up to a 110 or 220 volt motor with sheaves and a belt. Run the large motor Leeds to a phase panel. From there you can feed the air compressor. The motor being driven by the smaller pony motor is now a generator producing 3 phase. You do need to spin the larger 3 phase motor at the correct nameplate rpm.

 

I do not know the visage as of yet. I haven't had the chance to really dig into it.
Thanks everyone for all the insight.