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3 phase to single phase

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  • #31
    Originally posted by Sberry View Post
    Now, as for principle, sure you can find cheap machine and spend "few hundred" ...

    ... converting a CP200 is fine,,, if,,,, you are electrical engineer with free parts and its a hobby,,,, ...
    I don't want all that ****t, I wanna plug in the wall, pull trigger. Use a cord I already got, one that works for every other machine as do the outlets,
    Dont want to turn 2 machines on 2 rundon't, dont want the ndon't, dont want it to idle long runs, take up space that cost me 500 to build.
    So it's clear you haven't read any details deep enough to have a clue what you're talking about. Take a few minutes to read, then add up the cost of two $7 transformers, 12' of 10awg wire, six ring-lugs, a $30 range cord and two hours of shop time. Mebbie three, if you've got the capacity to pressure wash it out, and perform the type of routine maintenance that they SHOULD have (but frequently did not get) when working in an industrial environment.

    A large contingency of folks who've performed the CP-200 conversion adamantly admitted to having much less technical confidence than they expected necessary, but the reality is, that they found it to be much more simple and obvious than expected. A person that feels themselves incapable of doing this conversion, particularly after it's been presented in a step-by-step format, is probably not capable of properly operating the volume control on a television remote, much less changing the batteries.


    • #32
      thanks Dave

      Hey Dave I truly appreciate the time you have put into making this conversion available. I like Especially the simplicity of the instructions. I am no electrician, I am a welder and you brought the difficulty level way down. I'm still pretty low budget and this a great help to me. I now have an industrial grade welder with feeder that fits my power for 250$. God bless!


      • #33
        Thanks from me too, dave

        Dave, I sent you a PM thanking you for the conversion info, but I would like to take this opportunity to thank you publicly. It was the conversion you posted that I used and it works great. The whole point was exactly what you said. I wanted an industrial quality welder with a feeder on top to use at home on single phase power. How does this look Millermatic 252 60% duty cycle at 200A, 40% duty cycle at 250A $2764.00 msrp. CP200 using Dave's conversion 100% duty cycle at 200A 60% duty cycle at 260A cost $200-$300 conversion less than $100. Do the math people for me this is a hobby welder, as far as a warrenty goes, if this welder made it 40 years I don't think it's ready to give up the ghost yet. Dave, I thought you said in one of your build articles that the output was cut until you converted the output side drom delta to Y, I didn't mean to mislead anyone. The conversion rocks. As Dave said people who have done the conversion may be willing to let you try their welder. I am in the Northern sububurbs of Minneapolis StPaul Mn. send me a PM if you are serious about trying the conversion.


        • #34
          So it's clear you haven't read any details deep enough to have a clue what you're talking about
          In most of the sense you will get no argument from me that I don't know anything about the conversion. Bus since we got to source a unit,, for whatever that cost (for most people it wont be free), ad some stuff, wash it out, hope it all works, stuff the conversion, buy some stuff all to get a machine I bet a guy could buy used for 500 that runs by plugging it in.

          I am not arguing that it cant be done, if its a hobby or you have a burning desire thats understandable. If you "cant stand to discard perfectly good equipment" (providing you have one to discard) and obviously its not "perfect" or we could dimply plug it in then I woulagreee4, this project is for you, also for you should it crap usomethingng obsolete or over my head, this job would be for you too as would it be if I wanted to drive around half my state adding another 100 in fuel and alwaysys time to see "someone that has done it" agree same deal, its for that person.

          I also understand some people are near compulsive,, just cant stand to see some antique go to scrapscap, going to "save" it from something no matter how much effort it takes. As for consumption, agree, not a deal but you figure someone that has no machine, never welded or does minimal needs this beast, figure they need an industrial or "real welder", this crowd is poster children for the 200A compact class, they got their pictures up on the wall when they invent it.

          Finished residential building space is probably near 100 bucks a foot by the time its all said and done plus taxes and upkeep, save 400 on a welder and add another 400 in real estate to house the thing. Probably for every 1 guy that has done this there are 4 others with machine they had "intended to", that never got going, that got talked in to it because it was "so easy" and "all you got to do is" sits in the corner and they still got no machine. If they took sane 6 or 70plunkeduncked it down on they thety would have been making sparks a long time ago.

          Not everyone is stupid because they dont scout the state to find some antique to "rescue". Every once in a while this is probably practical,,, more so for some than others, but I would just about bet the other 85% or so is dome by compulsive junk collectors, barns already full of similar projects stacket on top odf each other.

          Again, different matter if its an interest thing, a hobby, I understand that but most of the time its an excercize in finding a harder way of doing something.
          Last edited by Sberry; 11-17-2012, 05:06 PM.


          • #35
            Mr Berry I appreciate your expertise on the subject but you comments are irrelevant to my initial question. Mr Kemp was just answering my question to the letter for which I am thankful.


            • #36
              a little more help Dave

              Dave could you give me a little more direction on the capacitors. I want to buy the exact ones I need. I found some on eBay which I think are right but not for positive. Thanks again!


              • #37
                55-65uf @ 325vac or HIGHER, MOTOR RUN capacitors (not MOTOR START).

                Originally posted by fencemaker View Post
                Dave could you give me a little more direction on the capacitors. I want to buy the exact ones I need. I found some on eBay which I think are right but not for positive. Thanks again!
                You'll need two capacitors, or sufficient quantity of capacitors to make up two banks of 55-65uf, at 325v or greater. Capacitor type must be the MOTOR RUN category, not motor-start.


                Catalog # 22-1321 is perfect value. They're round, so not as easy to mount as square ones, but creativity will prevail. Seven bucks a piece.

                Bleeder resistors: 15K total, at least 5w... and connect them DIRECTLY across the capacitor terminals, so that the capacitors will always discharge when the machine is shut down.


                These work perfectly. Three bucks.

                Use 10awg stranded, good quality crimp lugs, and watch the diagram closely.

                Make sure YOUR machine matches the diagram in the instructions... get a FACTORY diagram for YOUR unit- If it does not match my diagram, shoot me an Email direct, with a copy of the diagram, and I'll help you sort it out.

                Here's what a few others have posted on their conversions:


                • #38
                  got it

                  Thanks for the help! That made it simple!


                  • #39
                    3 phase to single phase

                    This is what I did ! Get on ebay get a generac 3 phase generator I got a 12 lead unit with a 350 Chevy engine it runs on propane or n/g with the 12 leads you get any voltage u want. I got my unit from a updating grocery store unit had 200 hours got it for $3000. Keep in mined this is a big unit 230 volts 100 amps 3 phase and your done


                    • #40
                      fencemaker,,, see,,, some wonder why I stir the pot, you never know what interesting ideas come up. It hadnt occured to me to run a small block chevy to run a 200A welder.


                      • #41

                        Originally posted by Sberry View Post
                        fencemaker,,, see,,, some wonder why I stir the pot, you never know what interesting ideas come up. It hadnt occured to me to run a small block chevy to run a 200A welder.
                        Boy, ain't that the truth... spend $3k on a generator, plus burn 2.5 gallons of LP-per-hour...The whole idea here, is to take a perfectly good, but otherwise low-demand three-phase industrial grade welder, obtained for $75.00 at auction... take an hour to clean it out, change some wiring connections, slap in $20 in two capacitors, two resistors, and six pieces of wire, plus a $15.00 range cord, and be quietly welding 1/2" plate at 100% duty cycle in a residential neighborhood garage before the nightly news... Sheesh...


                        • #42
                          That or just spend the $3k, on a really nice single phase machine, cause there is lots out there


                          • #43
                            For 3000 you could do a lot! Buy a used bobcat a suitcase feeder and get good fuel economy! On top of that you can still hear a motor run!


                            • #44
                              How many have you converted Dave?


                              • #45
                                I do wonder how many are found for 75$ hough.