Announcement

Collapse
No announcement yet.

High Amp Welding Considerations

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • High Amp Welding Considerations

    So it looks like most(?) high amp output AC/DC machines will do a lot higher AC than DC. I.e. a machine may do 500 amps stick on AC but only 350 amps DC. So when making high amp output buy decisions one just assumes they’ll be buying AC versions of electrodes more often? (I.e. 6011, 7018 AC, etc.).

    One thing that struck me off is on a 330a/ab AC SMAW and DC TIG will both top out at 460 Amps. Why will DC TIG provide 460 but DC SMAW tops at 315? I’ll post a spec chart pic when I can get to a PC browser.
    =======================
    Miller 211 AutoSet
    Miller Dynasty 200 DX
    Thermal Dynamics Cutmaster 42

    "The Sleep of Reason Produces Monsters"
    Francisco Goya

  • #2
    =======================
    Miller 211 AutoSet
    Miller Dynasty 200 DX
    Thermal Dynamics Cutmaster 42

    "The Sleep of Reason Produces Monsters"
    Francisco Goya

    Comment


    • #3
      I wouldn't worry about it too much. I can't ever remember needing more than maybe 150A on DC. I might have cranked it up to 175 or 200 ... maybe ... once? How big of an electrode do you want to burn?

      With AC tig on aluminum, you might want a lot more, but again -- that's AC.

      I have a 330A/BP, and I, too, have wondered about the apparent inconsistency that it can weld 460A in DC tig but much less in DC stick ... I just assumed that it was an error in the owner's manual, or that they assumed no one would ever want more than say 315A in DC stick welding. Unless you're running 1/4" 7018, you shouldn't need it. (Can you gouge with AC current? I've only done it on DC machines...)
      Last edited by Helios; 08-25-2020, 07:04 AM.

      Comment


      • #4
        Without being an electrical guy like some on here, I’d bet it has something to do with power loss through the rectifier when the current is made from AC to DC.

        Comment


        • #5
          I queried Miller support. Wonder if they just laugh and delete.
          =======================
          Miller 211 AutoSet
          Miller Dynasty 200 DX
          Thermal Dynamics Cutmaster 42

          "The Sleep of Reason Produces Monsters"
          Francisco Goya

          Comment


          • #6
            It depends on the welder design and the V-I (voltage vs amperage) curve shown in the manual. Stick welding has a higher arc voltage than tig welding. The output stabilizer plays a different role in DC than AC (sometimes no role in AC, depending on the design), which is why the curves are different. For SMAW start at 20V at 0 amp and climb 4V per 100amps. Where that line hits the V-I curve is your max current. For Tig, start at 10V instead. The AC V-I curve is more vertical at the higher amperages than the DC curve.

            Comment


            • #7
              I was afraid math was going to have something to do with it. Even worse is the math is calculus! LOL
              =======================
              Miller 211 AutoSet
              Miller Dynasty 200 DX
              Thermal Dynamics Cutmaster 42

              "The Sleep of Reason Produces Monsters"
              Francisco Goya

              Comment


              • #8
                Calcul-what?

                Comment


                • #9
                  Originally posted by ryanjones2150 View Post
                  Calcul-what?
                  Well, you're posting so you must not have gotten washed/blown away today!

                  Comment


                  • #10
                    I’m ready for some rest. Hope to be able to go home in the morning.

                    Comment

                    Working...
                    X