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  • MIG welding close to computers???

    Hey Guys,

    I have a question regarding MIG welding close to CNC machines (computers) or cars (with computers), 4-wheelers (with computers), or even home computers in the shop.

    I currently TIG weld close to my CNC machine and home computer but neither are powered up when I weld. I have not seen any negative effect to either for more than several years. My TIG uses a High Freq start.

    I have recently acquired a new MIG welder. Do problems with computers/welding occur because the welding machine is too close to computers or does the problem occur because the MIG gun is physically too close to computers?

    Harold
    For those having fought for it, Freedom has a flavor the protected will never know.
    Freedom is only one generation away from extinction.

  • #2
    As discussed on weldingweb... MIG welders will not be a problem per se. Some equipment is sensitive to vltage spikes and voltage dips that can be caused by large transformers powering up. Some equipment is sensitive to noise on the power line. Filters are available for noise and UPSes (or adequate wiring) will combat voltage dips.

    The arc itself can induce noise in nearby unshielded electronic equipment. That might be a problem when welding near network cables, mouse cords, etc.

    In all cases, it's good practice to make sure you have a good work ground near the torch. It is possible to have the welding current flow from MIG to torch and back to ground via a very long and unanticipated route.

    Dan
    At the end of the project, there is a profound difference between spare parts and extra parts.

    Location: SF East Bay.

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    • #3
      Thanks Dan for your information. Much appreciated!
      Harold
      For those having fought for it, Freedom has a flavor the protected will never know.
      Freedom is only one generation away from extinction.

      Comment


      • #4
        Conventional mig welding is safe in my experience when following good grounding practices as outlined by Dan above.

        I'm not sure of the possible hazards associated with the more advanced process aluminum wire fed welders that use pulse on pulse technology since I have no experience with them. Perhaps others here can enlighten us on those possible issues, if any.
        Last edited by Willy; 03-24-2019, 12:47 PM.
        Home, down in the valley behind the Red Angus
        Bad Decisions Make Good Stories​

        Location: British Columbia

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        • #5
          A side note... My VFD specifically prohibits using a welder on the same circuit as the the VFD is using. It does not say why. I suspect it's to avoid voltage fluctuations as well as to avoid overheating the wire from exceeding the duty cycle.
          At the end of the project, there is a profound difference between spare parts and extra parts.

          Location: SF East Bay.

          Comment


          • #6
            Any welding involves a very wide spectrum of radio interference. That is inherent in the arc.

            Computers are shielded such that the noise generated inside them cannot get out. Generally, shielding against noise getting out will also be good against noise getting IN, but that is not a guarantee for a number of technical reasons.

            Bottom line is that I would not expect the welding to "damage" a nearby computer, as long as you are not welding on the computer, and do not have welding cables draped over it or over its wiring..

            I would NOT want to say that welding might not result in scrambled data etc if the computer is on and working when you are welding, it may foul up whatever is being done on the computer when the welding is going on.

            The best idea is not to be doing anything with the computer when welding is done, and preferably to turn it off, so that any interference cannot cause "unanticipated things" to happen.

            As is always good practice, the welding ground cable should run as much as possible along with the stinger cable. Making a large "loop" between them causes more "broadcasting" of the radio noise from the arc, by acting as a better "antenna".
            1601

            Keep eye on ball.
            Hashim Khan

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            • #7
              Hi Guys,

              I learn new things each time you guys post a response. Willy mentioned pulse technology. My new welder is a Miller Invision MPa Plus System and it has Pulse Profile. I guess that's why I was asking about the potential for computer harm. I do NOT have any computers (including CNC) running while I am welding. I place the welding machine as far away from my CNC Mill as possible. My 4-Wheeler and 6X6 ATV are moved outside. I even pull my cars outside when welding.

              I was once told that radio frequency is emitted but I thought frequency emissions came from the welding machine. So now I've learned that arcs from the MIG gun can also emit radio frequencies. Does that hold true for TIG torches?

              Harold
              For those having fought for it, Freedom has a flavor the protected will never know.
              Freedom is only one generation away from extinction.

              Comment


              • #8
                The first wireless was done with spark transmitters that put out on all imaginable frequencies!!
                Sparks make huge noise and are one of the biggest no-nos in electrical engineering.

                Pete
                1973 SB 10K .
                BenchMaster mill.

                Comment


                • #9
                  Originally posted by hwingo View Post
                  .....

                  I was once told that radio frequency is emitted but I thought frequency emissions came from the welding machine. So now I've learned that arcs from the MIG gun can also emit radio frequencies. Does that hold true for TIG torches?

                  Harold
                  Tig, Mig, stick, fluxcore, they all produce a wide range "noise" signal. It's the nature of any welding arc, or, really any arc or spark at all. Welding has such a high power arc that it is particularly noisy

                  A length of wire, such as the mouse cable, or a wire between the computer and a video monitor, will resonate at some frequency depending on how long it is, and will pick that frequency up and provide a fairly large voltage on an input to the compute Essentially, wires act like radio antennas. A noise voltage can foul up data being moved around inside the computer, IF it gets in.

                  As mentioned by 10KPete, the first radio was indeed spark gap. They tuned the output crudely by filtering out most of the noise other than the frequency they wanted to transmit on. The first demonstrations of radio by Heinrich Hertz actually transmitted enough energy to make a spark at a distance between the ends of a wire bent into a circle, so it is possible to get significant voltage. https://en.wikipedia.org/wiki/Heinrich_Hertz

                  Welding is the raw noise, at fairly high power.

                  I would say, as an "educated W.A.G.", that if no welding cable is closer to the computer or computer wiring than about 1.5 m, or 5 feet, you are OK. There is no real need to move cars farther away than that, although aside from the inconvenience, there is no harm in it, if you want to exercise an "abundance of caution".

                  But computers in cars are able to operate near spark plug wires, etc, and are generally resistant to being derailed by noise. Home computers are required not to EMIT electrical noise, and the filters, etc work decently for incoming noise as well as outgoing noise.
                  Last edited by J Tiers; 03-26-2019, 02:02 AM.
                  1601

                  Keep eye on ball.
                  Hashim Khan

                  Comment


                  • #10
                    Reminds me of when I first got into CNC servicing, looking after a couple of wheel boring machines that were designed around a PDP11 data processing computer, they used magnetic core memory where you could see the individual memory bits!!

                    Every time a mechanic would weld close by, the memory was wiped, reload was laborious via paper tape.
                    Max.

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                    • #11
                      Modern cnc plasma cutters use a fairly standard PC motherboard for the control computer. Reasonable case shielding, and a good electrical ground keep the high Freq out of the control. A good noise block is some ferite blocks on all cables entering the cnc cabinet. Probably a good idea to not weld on your CNC machines while powered up. Small machines shhould probably be completely disconnected so that their ground wires don't servbe as backups if the welder ground is less than ideal.

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                      • #12
                        I don't know if I wasn't just lucky, but when I was learning to make molds I sometimes welded up bad cuts in aluminum plates right on the table of my little Taig mill. A few times it was powered up when I did it so I wouldn't lose position before I learned how to pick up a part again later.

                        What I have heard is a common issue is high frequency TIG.
                        *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

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                        • #13
                          Wow Bob! Perhaps you were fortunate in various ways. Perhaps you had your electrical connections (ground, etc.) properly done. Based on my very limited experience, I would have been afraid to weld on a part fixed to my CNC mill.
                          I am the first to admit my knowledge is pathetically lacking when discussing electricity; pathways of electron travel, and electrical potentials, etc. These are simply "words" that I've seen used over time and I have scant understanding of the real meaning and significance of such phrases.
                          Years ago, I purchased a large Miller TIG welder. They didn't have solid state at that time. I knew nothing about welding (sadly as now). I needed a means of holding a piece in place when attempting to TIG weld. The only vise I had was mounted on my drill press. Placing the part in the vise, I began welding. In short, I smoked the electrical chord on my drill press (which was plugged in). Luckily, no known damage was done to the motor but I definitely ruined the electrical chord to the drill press. In passing, The TIG had a High Freq start.
                          Years later, I was stationed in Schweinfurt, Deutschland where I took a course in Ham Radio (KD5DNA). I learned that any length of wire could serve as an antenna causing one to possibly "smoke" a piece of electronic equipment if resonated adequately. So, later on I wondered if that was the reason I burned up my Drill Press's electrical chord. I did continue to weld on my drill press but I unplugged the drill. No problems from that point on. Still, there was a random length of wire simply hanging loose so I suppose that the hanging wire could be resonated as well.

                          Harold
                          For those having fought for it, Freedom has a flavor the protected will never know.
                          Freedom is only one generation away from extinction.

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                          • #14
                            Originally posted by hwingo View Post
                            Placing the part in the vise, I began welding. In short, I smoked the electrical chord on my drill press (which was plugged in). Luckily, no known damage was done to the motor but I definitely ruined the electrical chord to the drill press.
                            Harold
                            The most common scenario that would explain the smoked cord is that you failed to connect the work ground (clamp from welder) to the vise. If you instead left it connected to something that was earth grounded (likely the table or cart) you would have a path for the current to flow through. Welder to clamp to table to earth ground to cord to drill press frame to vise to electrode and back to the welder.

                            I've seen some old welders set up with the work ground and electric power ground connected together. Not sure if that is OK by code or not. I suspect it isn't.

                            If you connect the work ground close to the place where you are welding, the majority of the current should flow through that even if there is a secondary ground somewhere.

                            Dan
                            At the end of the project, there is a profound difference between spare parts and extra parts.

                            Location: SF East Bay.

                            Comment


                            • #15
                              Elaborating just a tad....

                              Every reputable welding device I know of has the welding circuit, the stinger wire and the ground wire, totally isolated from the chassis of the welder, or any other ground.

                              The reason is to avoid problems such as the drill press story above. I have to assume that Dan is correct, and that the ground was connected somewhere else, not to the drill press or vise or direct to work. That would have allowed the welding current to go down the cord, which would indeed have probably toasted it with any normal welding current.

                              Connecting the welder ground to the drill press would have isolated the welding circuit to the path from stinger to work, to vise, to drill press chassis, to welder ground cable. There would not have been any circuit through the power cord.

                              Connecting ground cable directly to the work would be the best, that eliminates current anywhere except from stinger to work to welder ground cable, which is what you want.
                              Last edited by J Tiers; 03-30-2019, 07:33 PM.
                              1601

                              Keep eye on ball.
                              Hashim Khan

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