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Phase converter for a shear

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  • #16
    Portable the first thing i would check is the size of the transformer feeding your place. My friend at mason mi with a grain setup on single phase needed a 100 kva transformer to run the leg and the dryer at the same using VFD's also i would double the size not 1 1/2 times been there done that


    • #17
      Dipsomaniac, Are you saying that because you think its going to take more power than what I have available.

      I have a 200 amp service in the shop, I have 24 flourecent light fixtures that pull approximately 1.2 amps each. = 28.8 amps.
      Lets minus telephone, fax, computer, cordless chargers. and say that draws another 6 amps. = approximately 35 amps total.

      That leaves me approximately 165 amps provided the compressor doesnt pop on or we have a welder on when we fire up the shear. ( Which is a good probability since we have several welders in the shop.)

      I'm still researching this to avoid any problems so I appreciate every ones input.


      • #18
        Originally posted by Portable Welder View Post
        Are you saying that because you think its going to take more power than what I have available.
        I know it will take more than 100amps to start a 30Hp phase converter. Also, Milkerman is absolutely correct about the supply transformer. You don't even know if the power company can supply you 200 amps currently, so how would I?


        • #19
          Dispomaniac, I assume that they are supplying me with 200 amps already because I have a 200 amp service.

          So I would think I can pull 200 amps.

          Or am I missing something.

          In one of my earlier posts I may have stated a lower amp# because I never dreamed that a motor of that size would even come close to maxing me out power wise.


          • #20
            Portable in my post i talked about the in coming transformer size as may not being big enough. Its the current spike that you are going to put on it for a split second that may cause a problem. Thats when the lights dim down and you put extra stress on the start capacitors. Checking on the american rotary site they recommend for a shear a 40 hp converter. That why you need to check with your power suppler if there transformer is big enough. My friend at mason did and consumers eng was concerned about the voltage spike down line till he told them he was going to use a 40 hp abb vfd thats when they said they would upgrade to a 100 kva transformer at no cost to him. Ok this is my take on your problem find out from the shear manufactor if a vfd is the better option. if you need a small second drive to adjust the shear that is still a better option. I checked the price of a 40 hp abb drive from galco electronics of madison heights it was $3900.00 then you have the ability to ramp up the drive to get the shear running and not spike your power supply also it has all the protection builded into. The 40 hp is the correct size to use for you applaction on single phase power in the manuel it tells where the single phase wires are hooked up also you want to use a vfd motor cable to run from the drive to the motor. This option your not going to have starting problems, in this area of michigan in the ag field i know of no one going with rotary phase converters. Also a lot of electicans do not know the advantages of vfd compared to phase converters. Our major electrical contactor to the ag field north of lansing is very familiar with vfd drives and ther applaction as they have installed 100s. May be i just muddy up the waters but as you said you have to check out all options


            • #21
              My shop and house are at the same location, I have what they call a dual meter can stand so I have a 200 amp service for the house and a 200 amp service for the shop.

              They both run off the same transformer.

              The manufacturer said the shear pulls 60 full load amps at 230 volt 3 phase and the future press brake pulls 77 Full Load amps. They both have 20 HP motors.


              • #22
                In the back of my service truck, I have a 1500 amp 450VAC service that hasn't powered squat yet.

                The National Electric Code requires 2.5 times the three-phase load current to allow for the single phase starting current and a margin of safety.

                My Phoenix phase 30hp rotary converter has a max three-phase load rating of 113amps which is 45HP for starting and surge. Now 113amps times 2.5 gives me a single phase maximum current for starting and surge of 282.5 amps.

                Something to think about...

                I explain it like this. When you power up one of these units, your house and shop lights are barely burning, the rotary converter isn't able to get to full speed and you are wondering why that 200 amp breaker isn't tripping you will understand.
                Last edited by Dipsomaniac; 03-05-2013, 10:23 AM.


                • #23
                  Milkerman, I think your right, I talked to the manufacturer and he said I could use a 35Hp rotary phase converter ( However he was a little wishy washy on the phone ), I then called my electrician that I use to work with at Fedex, I use to hire him to put VFD's on the conveyors that I installed when we needed speed control ability so he not your average electrician.
                  When I mentioned a VFD he said that would be my best choice because I would have true 3 phase with that ( Meaning all legs would be equal power and equal amperage.

                  He recommended I look at Yaskawa which led me to Hitachi and I talked to a guy there that had every answer on the tip of his tongue and he said a 40HP is what I needed and the cost is $ 1,976.00.

                  He said that it would have to be wired on a 100 amp breaker and that it needs to be wired into the machine controls.

                  The unfortunate thing is that it sounds like if and when I get a press brake I will need one for that verses being able to use multiple machines off a rotary.



                  • #24
                    Portable you can't go wrong with a vfd they are like welders one can not have too many. When you get your brake buying a vfd will be easy same way any other 3 phase power tools. The concerns i still have is the size of your transformer on the pole being in michigan with some farms on consumers energy or detroit edison a lot of transfomers are not big enough, this could still lead to problems have your electican check this out sounds like you have a good one. I had to smile when [ every answer on the tip of tongue ] a true salesman. What models of hatachi did he quote you i looked up on the galco websit and they had 2 models sj700 ,L700 series both 40 hp 230 v input but in there manuels they both say 3 phase input only no single phase. You have a major buying decison so take your time to gather all the information that you can. For me ABB is the way to go i have had yaskawa,allen bradley,and altvar they have all died. One thing you won't miss will be the rotary phase converter. If you want to talk about my experience with vfd pm me i don't have all the answers but what i have been using works