Announcement

Collapse
No announcement yet.

Trailblazer 250G AC welding output issue

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

  • Trailblazer 250G AC welding output issue

    Hey guys, I've been finally using my TB lately and discovered an issue involving AC weld output. DC works well but decided to Switch over to AC at about 115 amps And all I got was a rather large arc but it won't stay lit. The only way to keep it lit is to bury the rod like you want to pierce through the workpiece. I tried every range setting and dial position and it just won't stay lit like it should. I just pulled the panels and checked for anything obvious and also sanded the brushes and slip rings since it was apart which probably didn't need to be done but did it anyway. I fired up and no change. I talked with a guy at miller and he told me to check output voltages and told me to adjust the engine rpm so I have 61hz at the AC receptacles and check AC voltage at the receptacles and weld outputs as well as D.C. Output. My frequency was 57-58hz to start. Adjusted the rpm so I got 61.6-61.7hz and my outputs are as follows 126-127vac at receptacles, AC weld output 67vac, and 108vdc. With current outputs there was some change but only at high amperage 175-200ish and higher can I actually get a decent arc and keep it lit but the rod will get cherry red and I even had one melt off at the stinger. Cables, ground clamp and stinger are all new and I even strung out the cables full length to see if that made any difference but it did not. I have a 50' ground and a 25' stinger lead. I'm gonna call the guy at miller again but just wanted to see if anyone can help me here too. The serial number is KA777403.
    Last edited by Dberset; 09-07-2017, 06:28 PM.

  • #2
    I'd be looking really hard at the contacts on the AC/DC selector switch. That's about the only thing different between AC and DC. AC takes most of the other parts out of the circuit.

    Comment


    • #3
      I was thinking about the switch too. I'll figure out a way to get in there to clean it.

      Comment


      • #4
        The selector switch looks good. No corrosion no arcing plenty of tension to make a good connection.
        i tried a little more welding on AC and I'm able to get an arc started and travel with it but only if I leave the rod buried in the puddle and before too long the rod gets so hot the it actually bends. And when you pull away and flip up your hood the rod is glowing orange. Not sure but I'm thinking I have enough amperage and not enough voltage because I can only get it to do any kind of welding in the high range and the dial about 60-70% which is180-200 amps which is way too much amperage to get the job done . I just need information on what else I can do to track down the problem.

        Comment


        • #5
          Originally posted by Dberset View Post
          The selector switch looks good. No corrosion no arcing plenty of tension to make a good connection.
          i tried a little more welding on AC and I'm able to get an arc started and travel with it but only if I leave the rod buried in the puddle and before too long the rod gets so hot the it actually bends. And when you pull away and flip up your hood the rod is glowing orange. Not sure but I'm thinking I have enough amperage and not enough voltage because I can only get it to do any kind of welding in the high range and the dial about 60-70% which is180-200 amps which is way too much amperage to get the job done . I just need information on what else I can do to track down the problem.
          Is that both DC and AC or only on AC?

          Comment


          • #6
            What electrodes are you using to weld in AC? Not all electrodes like AC. If you are not already using it try some 6011 or 7018AC.

            Comment


            • #7
              Originally posted by Aeronca41 View Post

              Is that both DC and AC or only on AC?
              Only AC. DC works fine.

              Comment


              • #8
                Originally posted by Meltedmetal View Post
                What electrodes are you using to weld in AC? Not all electrodes like AC. If you are not already using it try some 6011 or 7018AC.
                I'm using Hobart 3/32 7018 AC/DC

                Comment


                • #9
                  Looking at the diagrams, you must have a bad connection on some internal wire/cable if the amps range switch is good. There is nothing else used only on AC. Look for connections that appear to have been heated up.

                  Comment


                  • #10
                    Originally posted by Dberset View Post
                    I'm using Hobart 3/32 7018 AC/DC
                    Try some 6011 if possible.

                    Comment


                    • #11
                      I'm with MM, try a different rod first. The 7018 I've been using lately says it will work DCEN, DCEP and AC. I say bull butter. Ya, it sort of works on DCEN and AC, but not well. Only enough to make you snap your hood up, cuss a few times and throw a half used rod in the scrap bin.

                      Comment


                      • #12
                        Well I tried a different rod. Hobart 7018ac. No different. You have to crank the dial in high gear to only be able to push the rod straight down into the metal in order to maintain an arc. If you lift and try to travel horizontal you're either gonna lose the arc or stick the rod. Funny thing is that the 7018ac welds perfectly on DC.
                        not sure where to go next. One thing I did too was took the brush holder out to check them when I first started to diagnose this. Everything was clean and the brushes were well over the 5/16 minimum so I put it back together. Just took them out again and the wear pattern isn't even like it was but it's impossible to get them back to where they were originally. Could this be an issue? The problem still existed before I checked them the first time.

                        Comment


                        • #13
                          You have a bad connection in the AC current path inside the welder somewhere. It has to be either the polarity switch or one of the wires connecting to it. There is nothing else in the circuit that isn't also used for DC. My bet is on the switch. Someone had a similar problem with a Bobcat on another thread this week.

                          Comment


                          • #14
                            Try a 6011. It is not at all surprising that 7018AC runs good on DC. There are a lot of things that you could mean when you say "lift" the rod. 7018 needs a good, right arc, almost like dragging the rod right down on the metal and not lifted much if any at all. I don't know enough about circuitry to be of any help, but sounds like Wayne has it narrowed down to just a few things for you. It's hard to diagnose a person's technique and skill via forum post.

                            Comment


                            • #15
                              Check that every connection is clean switches ,lugs eyelet connectors on the rectfier diode on the rectifier ?
                              All the diodes working ?
                              little bit of corrosion at a connection could make a big differance .

                              Comment

                              Working...
                              X