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Thunderbolt & Thunderbolt XL transformers

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  • Thunderbolt & Thunderbolt XL transformers

    Does the Thunderbolt 225AC\150DC with top mounted shunt crank current adjustment use aluminum or copper in the primary\secondary transformer windings and the inductor choke?
    Same question for the Thunderbolt XL ,later model, with front mounted shut crank.

    Understand aluminum has 50% more resistance than copper, which means the transformer would generate more heat with AL with equal current on secondary for both AL & Cu.

  • #2
    Here

    http://apps.geindustrial.com/publibr...pper%7Cgeneric

    is a pretty well done paper on comparison of the two in electrical applications. Yes, aluminum has much higher specific resistance, but it's cost is so much lower that it is advantageous to simply use larger Al wire than you would Cu for a particular application, thus keeping the "installed system" resistance the same. So, no, you would not generate more heat in a well-designed system. I don't know what kind of wire is used in those machines, so can't help you there.

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    • #3
      My older Thunderbolt AC/DC is copper wound...Bob
      Bob Wright

      Spool Gun conversion. How To Do It. Below.
      http://www.millerwelds.com/resources...php?albumid=48

      Comment


      • #4
        aametalmaster
        Does the vintage Thunderbolt with Cu transformer wiring have the top shut crank and front mounted.
        How is it identified?

        After studying the online Miller operational manuals appears the XL version was introduced in ~1998 with four position selector switch and side mounted variable shut crank.

        Prefer the front mounted lead connectors over the switch because the full output current must flow through this switch.
        Also, the vertical scale is easier to read rather than the lower mounted circular scale.
        Suppose rain water could leak into the cabinet interior?

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        • #5
          I am sure rain can get into mine. Mine had the top crank and jack plugs for the cables. Its a late 80's model. This is the manual for mine....Bob
          https://www.millerwelds.com/files/ow.../O316B_MIL.pdf
          Last edited by aametalmaster; 12-08-2017, 09:00 PM.
          Bob Wright

          Spool Gun conversion. How To Do It. Below.
          http://www.millerwelds.com/resources...php?albumid=48

          Comment


          • #6
            Reviewed all the Miller thunderbolt online operating manuals from 1982 to present, except the new inverter based 160 & 210 that have replaced the transformer based thunderbolt line and are no longer manufactured.
            1982 to 1998 , net weight for the 225 AC 150 DC is 114#.
            2000 to present weight is 104#, 10# weight reduction.

            Also 1982 to 1993 had an option for a power factor correction(PFC) capacitor = 4#, not a light weight.
            Capacitor is connected between the two input power leads and an extra transformer coil.
            PFC capacitor reduces input current by ~5 amp AC at 100% rated output current ,compared to the power source without PFC feature.

            The extra weight could be Cu transformer winding and rectified output choke winding.
            Last edited by Almond farmer; 12-09-2017, 07:04 AM. Reason: Changed from 5VAC to 5 amp AC

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            • #7
              ...Understand aluminum has 50% more resistance than copper, which means the transformer would generate more heat with AL with equal current on secondary for both AL & Cu.
              Where did you get that number?

              Obviously a machine with the different material would be engineered for the different material and not just had it substituted in. It would contain a greater volume of aluminum than a comparable copper machine.

              FWIW, aluminum has more resistance per volume but less resistance per mass.

              Comment


              • #8
                Got the thermal conduction and electrical resistivity from "Matweb".... 50% is approximate.
                The physics of thermal conduction and resistivity are similar.

                The thunderbolt 225 draws 45.5 amps AC while the later model XL draws 47.5 amp AC according to the performance ratings in the Miller manuals.

                The LIncoln 225 AC 125 DC uses Cu in the primary and Al in the secondary, while the vintage 180 uses Cu in both and no cooling fan.
                Using the buzz box with no fan only reduces the duty cycle.

                Comment


                • #9
                  ... 50% is approximate...
                  Okay, but 50% is an odd approximation of about 61%, especially when asking a technical question.

                  Regardless, your question seems to imply the same amount (mass or cross-section) is used. But the machine is completely reengineered for the different material.

                  Comment


                  • #10
                    The machine was probably reengineered to reduce cost.
                    Prefer the older design over the new XL design.

                    Al was used for residential house wiring until some fires occured because of extra resistance from corroded aluminum oxide at connections.
                    The national electrical code eliminated aluminum material house wiring.
                    Difficult find or make an aluminum extension cord. Welding leads are all Cu.
                    Found a commercial DC welder choke made from soft copper tubing on a straight ferrite round core.

                    Comment


                    • #11
                      Originally posted by Almond farmer View Post
                      The machine was probably reengineered to reduce cost.
                      Prefer the older design over the new XL design.

                      Al was used for residential house wiring until some fires occured because of extra resistance from corroded aluminum oxide at connections.
                      The national electrical code eliminated aluminum material house wiring.
                      Difficult find or make an aluminum extension cord. Welding leads are all Cu.
                      Found a commercial DC welder choke made from soft copper tubing on a straight ferrite round core.
                      Lower cost is not a bad reason in and of itself. Some might think it's a good reason. Lighter machine is preferable to some as well.

                      Actual performance issues seem to be missing from the comparison.

                      Problems with aluminum wiring in residential was from termination methods needing to be different, not from problems difficult to fix. Aluminum wire is still allowed on larger circuits in new residential, and proper devices for existing aluminum wiring on the smaller circuits are easily acquired. You really need to cite sources when you make these claims. That will help you see that they are false before you post it publicly.

                      Extension cords and welding leads need the flexible durability of copper. This has nothing to do with conductivity and, again, some might like having their cords be significantly lighter if they could.
                      Last edited by MAC702; 12-11-2017, 06:40 PM.

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                      • #12
                        I don't know about you guys, buy my old thunderbolt transformers are wound with steady and reliable somethingorother and I like it.

                        Comment


                        • #13
                          Answering my own question.
                          Yes the 1993-1995 Thunderbolt 225 AC & Thunderbolt 225 AC/150 DC has aluminum(AL) primary & secondary transformer windings and aluminum choke windings on the DC unit verified by cover removal.
                          The AL windings are coated with a red colored shellac giving the appearance of copper.

                          mac702
                          do not know where to find residential AL wire.
                          Some counties adopt the national electrical code , some counties have there own electrical code.
                          Some cities adopt the national electrical code, some cities have there own electrical code.
                          Los Angeles city has there own electrical code.

                          These transformer based welding machines have the same corrosion issues,
                          brass lead thermal stud to AL conductor connections with increased electrical resistance from galvanic corrosion.

                          Comment


                          • #14
                            Originally posted by Almond farmer View Post
                            ...The AL windings are coated with a red colored shellac giving the appearance of copper.

                            mac702
                            do not know where to find residential AL wire.
                            Some counties adopt the national electrical code , some counties have there own electrical code.
                            Some cities adopt the national electrical code, some cities have there own electrical code.
                            Los Angeles city has there own electrical code.

                            These transformer based welding machines have the same corrosion issues,
                            brass lead thermal stud to AL conductor connections with increased electrical resistance from galvanic corrosion.
                            That shellac is the insulation. That same red shellac is used on copper windings, too. Are you insinuating a nefarious purpose here?

                            Local codes are not relevant. You specifically called out the NEC and gave a misleading reason for a total residential ban that does not exist. Since you're new here, I'll remind the record that I've been an electrician for two decades.

                            So there are more welding machine failures now? And they've been attributed to aluminum? Sounds like a good time for a source.

                            BTW, the 2017 City of Los Angeles Electrical Code is based on the 2016 California Electrical Code and the 2014 NEC. They don't start from scratch. Feel free to discuss specific amendments, with citations.
                            Last edited by MAC702; 12-13-2017, 11:51 AM.

                            Comment


                            • #15

                              I know the red colored coating is shellac and used as an insulator on transformer windings and electric motor field windings.
                              however , looking from a distance it might appear that your aluminum transformer windings are copper,since the red colored shellac is almost the same color a corroded copper conductor.

                              when subjected to vibration the hard shellac, can wear off and decrease the number of affective core windings.
                              This condition happens to motors, still rotate at specified speed, but rated torque is reduced.
                              The large welder transformer vibrates from eddy currents.

                              Is most if not all overhead and underground feed lines to houses, apartments, condos from utility company (residential not commercial) 8000 series AL?

                              if aluminum wiring is still used in residual it must be a minimum 8 gage strained from the best able to determine and 8000 series even for a 15 amp circuit.

                              The point is residual in the 60's and early seventies when aluminum solid wire was used and copper wire price was quite high the issues were with the connections, aluminum to copper switches, fixtures, etc., Failures occurred at the connections.

                              aluminum transformer based welders have the same issue at the copper/brass to aluminum connections.

                              The GE paper linked by Aero addresses two basic issues with All to Cu connections.
                              1. Connection loosening
                              2. Corrosion

                              loosening
                              when the Al transfers current with resulting generated heat the Al flat strap and square cross section want to expand , but limited by the thermal expansion of the brass stud. So the Al is plastically permanently deformed past yield. Then when the Al cools with current removed the Al has some degree of spring back but the thickness has decreased. Each time the cycle is repeated the Al gets thinner.
                              experienced a loose connection on the Thunderbolt AC negative terminal.
                              however the brass stud has a thermal expansion coefficient = ~ 11.3 micro in /in, if yellow brass
                              while 1100 AL has a thermal expansion coefficient = ~13.1 micro in in, which is better than if the stud was steel at ~6.5 micro in in.

                              On corrosion , the paper states that bare All should not be mated to bare brass or Cu because of galvanic action.
                              It states the AL and Cu should be tin coated
                              when wiring custom motor cycles and farm tractors have always used tinned stranded copper wire, tinned copper lugs, tin copper buses bars.
                              thunderbolt connections are between bare Al & bare Cu causing a corrosion issue

                              ​​​​​​​really do not yet have a solution.
                              Last edited by Almond farmer; 12-14-2017, 12:14 AM.

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