anyone here built a rotary phase converter??

B

bomccorkle

I recently acquired a Dayton speedair compressor for a steal. The only catch is that its a 3 phase machine and being as I'm in a residential area there is no 3 phase service. I had thought of switching to a single phase motor that comparable but my local electric motor shop is telling me the three phase will be more reliable and overall run better.

My question is has anyone built their own convertor?? I have found several plans and such but this place here is it when I have questions...

Thanks

Bo
 
well yes but it really doesnt make sense to do that for one machine because you need a 3 phase motor larger than the motor you are driving to generate the 3rd leg.......so unless you have a big 3 phase motor just lying around then you would need to buy one so why not just buy a single phase motor for the machine and make it easy on yourself. how big is the compressor you have? i have a 7hp 1ph motor sitting here doing nothing. it came off a compressor and is practically brand new.
 
I have been working at scrounging a motor but no luck as of yet. The motor is a 5hp continuous.
 
By the time you do all that you can just get a 5hp 1ph. They are not expensive. Not sure what you would need for a ph converter. Either a 7.5 or 10hp motor. Its just gonna cost you more to go that route
 
Jim C;36159 said:
well yes but it really doesnt make sense to do that for one machine because you need a 3 phase motor larger than the motor you are driving to generate the 3rd leg.......so unless you have a big 3 phase motor just lying around then you would need to buy one so why not just buy a single phase motor for the machine and make it easy on yourself. how big is the compressor you have? i have a 7hp 1ph motor sitting here doing nothing. it came off a compressor and is practically brand new.
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A rotary phase convertor is not satisfactory for use with hi current starting loads. A vfd is very expensive for your application, prolly twice as much as a new single phase motor. To run a 220/240v single phase convertor you will need to use 2of them as 5hp current is way more than a vfd will handle.
I recently bought a5hp single phase motor from a guy on craigslist. $125 and he loaded it into the back of my truck. The prolly weighs over 100 pounds. Is nearly new.
Shop around and you will find one.

I bought my 3hp phase convertor @ http://www.factorymation.com/Products/acdrives/?gclid=COzjhKqilr4CFa1FMgodXi8A9Q

There some invertors from China that claim they will run 5hp3ph on220 single pH, but I don't want to be a Guinea pig,lol
 
Yes. I'd bet the 3 phase on the co.pressor is every bit of 100# , I am a tool and die maker and have a couple friends who do commercial a/c so I am hoping to turn up some leads there, I'd think if I can run tandem 10's or a 20hp rotary I should be able to kick the compressor over, then again if I can find a motor for the idler cheap enough. They build Waterjet cutters here and I'm hoping maybe one of the old hydraulic pump motors piled out back may be a source but it would be massive overkill, I think the smallest out there is a 40hp and they go up to about 125hp. Hopefully something will turn up. If not it seems a single phase may be in my future. I had also thought it may be nice to have a converter in case a lathe or mill needed adopting as well....
 
bomccorkle;36168 said:
Yes. I'd bet the 3 phase on the co.pressor is every bit of 100# , I am a tool and die maker and have a couple friends who do commercial a/c so I am hoping to turn up some leads there, I'd think if I can run tandem 10's or a 20hp rotary I should be able to kick the compressor over, then again if I can find a motor for the idler cheap enough. They build Waterjet cutters here and I'm hoping maybe one of the old hydraulic pump motors piled out back may be a source but it would be massive overkill, I think the smallest out there is a 40hp and they go up to about 125hp. Hopefully something will turn up. If not it seems a single phase may be in my future. I had also thought it may be nice to have a converter in case a lathe or mill needed adopting as well....
Click to expand...

Friend runs his mill on a convertor, he grabs the impact wrench to turn the convertor,lol.
 
The best price I have found for a new 5hp Leeson 1ph compressor motor $320:

http://www.ptjindustrial.com/ProductDetails.asp?ProductCode=131537

I haven't bought yet, so I can't comment on that vendor. I wish I could find one local as cheap as SOF did. For the hassle of a phase converter, I wouldn't bother unless you can find a motor for scrap value. My dad runs one in his home shop for a mill and lathe without any problems. He uses an old washing machine motor to get it spinning. I think you need 1.5 or 2 times the HP for the motor you're running, I can't remember.
 
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