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Phase converters?

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  • Phase converters?

    Has anyone here ever built there own rotary phase converter? Me and a buddy are looking at a good use Bridgeport mill but it is 3 phase and 3 phase is not available where we are at. So I was told that a phase converter could easily be built out of an out 3 phase motor and some other parts and was wondering if anyone here has ever done it or know where I could find a good how to on making one.


    Thanks

  • #2
    I haven't build one but a few years back I looked into a used 13x40 3 phase lathe. If I remember correctly they were Hp specific. I couldn't just get a big one and cover a number of posibilities.

    Comment


    • #3
      Originally posted by TrxR View Post
      Has anyone here ever built there own rotary phase converter? Me and a buddy are looking at a good use Bridgeport mill but it is 3 phase and 3 phase is not available where we are at. So I was told that a phase converter could easily be built out of an out 3 phase motor and some other parts and was wondering if anyone here has ever done it or know where I could find a good how to on making one.


      Thanks
      I built my first about eight years ago. I used a time delay relay with start cap. so it would self start. Here is one link http://www.metalwebnews.com/howto/ph...converter.html

      There are even kits available and all you supply is the 3 phase motor and complete the wiring. Info is readily available, just GOOGLE "PHASE CONVERTER" and you will find more info.

      I bought a PHASE PERFECT when I got my cnc mill. I was concerned about the phase to phase voltage with all the electronics. With a standard mill I would go with a rotary phase converter. Some guys go with a VFD (variable freq. drive) but it is up to you. Good luck

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      • #4
        Another link: http://www.laserfx.com/Backstage.Las...seConvert.html

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        • #5
          TrxR,

          I run 2 mills and each one is on it's own 3ph converter. The small converters I bought right from ebay and each is capable of running a 5hp. I think I paid about $69 each from a place in AZ. I looked at getting a bigger one to run all the 3ph stuff but it was a bunch cheaper to just get individual ones. That way you are not wasting any additional power if any of your other equipment is idle.
          Good luck
          Andy

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          • #6
            One thing to remember about phase converters, static converters are about 85% efficient & rotary converters are 98 or 99% efficient.

            Comment


            • #7
              but remember the best of 3phase wye connected motors are only about 90% effecient, and best of single phase motors are only about 80% the power factor goes to crap with a rotory converter. static converters are more effecient at end result. i used to be an industrial electrician, now im a electrical enginner at a electric utility, we had a customer that was runnin a 100hp rotory converter to run his wood workin shop and using about 80hp on the converter and his power bill ran $3000-4000 a month and with the new 3phase wye service his bill is $1500-2500 on the average now theres not a whole lot that goes into building one, especially if you have some of the parts. you may want to still contact your utility and see if there planning on bringin 3ph closer to ya in the future and how much it would be to have a service dropped if your in an area like ours were building so much line right now its crazy.

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              • #8
                Thanks for the info Jake. A 3 phase drop out here is totally out of the question
                Now I read somewhere else that a rotary was the better setup especially for something like a mill that changes directions regularly. Is that wrong?

                Thanks

                Comment


                • #9
                  Another option is a VFD (Variable Frequency Drive) for only 1 machine it may be your best choice, if your going to buy more 3 machines a rotary converter may be better, and a static converter would be your least desirable choice.


                  Here is a site to ask questions on VFD's & RPC's....




                  http://www.practicalmachinist.com/vb...splay.php?f=11

                  Comment


                  • #10
                    I built a rotary converter for my mill & it works great...
                    I boujht a VFD for one of my lathes, & I like it much better.
                    Here's a link to a source for a VFD.
                    http://www.factorymation.com/s.nl;js...&category=-101

                    Comment


                    • #11
                      Originally posted by jake View Post
                      static converters are more effecient at end result. .
                      That confused me.

                      I have a few years under my belt in industrial electrical work, too, and I've always thought that a rotary converter was more efficient, as it delivers a waveshape closer to 3-phase due to the generator effect of the idle motor.

                      I'd appreciate it if you would elucidate me on the engineering, as I have apparently been misguided for a long time!

                      Hank

                      Comment


                      • #12
                        I ran a phase converter in my shop for 9 years, I ran a big grinder off of it and a 2500 LB. drill press.

                        I built the converter from a 3 phase Y-wound motor. I paid $35.00 for the used motor and a little for the wiring and it worked great for a cheap price.

                        In my current shop I have a static phase converter which I am running a small drill.

                        Static converters run one machine while the Y- wound rotary converters will run multiple machines.

                        If your looking for cheap you can send me your fax# and Ill draw you a diagram as to how to do it.

                        The most user friendly is a static converter

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                        • #13
                          http://metalwebnews.com/howto/phase-...converter.html

                          http://www.homemetalshopclub.org/pro...nv/phconv.html

                          both useful links

                          Comment


                          • #14
                            I'll third the VFD , I have one on my Rockwell vertical mill . A VFD will also give you variable speed which is really nice , sure beat's changing belts . You need to get one that is specific to the horsepower of your electric motor[search ebay].

                            Comment

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